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1
Flanagan, J. Randall, Gerben Rotman, Andreas F. Reichelt, and Roland S. Johansson. "The role of observers' gaze behaviour when watching object manipulation tasks: predicting and evaluating the consequences of action." Philosophical Transactions of the Royal Society B: Biological Sciences 368, no. 1628 (October 19, 2013): 20130063. http://dx.doi.org/10.1098/rstb.2013.0063.
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When watching an actor manipulate objects, observers, like the actor, naturally direct their gaze to each object as the hand approaches and typically maintain gaze on the object until the hand departs. Here, we probed the function of observers' eye movements, focusing on two possibilities: (i) that observers' gaze behaviour arises from processes involved in the prediction of the target object of the actor's reaching movement and (ii) that this gaze behaviour supports the evaluation of mechanical events that arise from interactions between the actor's hand and objects. Observers watched an actor reach for and lift one of two presented objects. The observers' task was either to predict the target object or judge its weight. Proactive gaze behaviour, similar to that seen in self-guided action–observation, was seen in the weight judgement task, which requires evaluating mechanical events associated with lifting, but not in the target prediction task. We submit that an important function of gaze behaviour in self-guided action observation is the evaluation of mechanical events associated with interactions between the hand and object. By comparing predicted and actual mechanical events, observers, like actors, can gain knowledge about the world, including information about objects they may subsequently act upon.
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Johnson, Leif, Brian Sullivan, Mary Hayhoe, and Dana Ballard. "Predicting human visuomotor behaviour in a driving task." Philosophical Transactions of the Royal Society B: Biological Sciences 369, no. 1636 (February 19, 2014): 20130044. http://dx.doi.org/10.1098/rstb.2013.0044.
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The sequential deployment of gaze to regions of interest is an integral part of human visual function. Owing to its central importance, decades of research have focused on predicting gaze locations, but there has been relatively little formal attempt to predict the temporal aspects of gaze deployment in natural multi-tasking situations. We approach this problem by decomposing complex visual behaviour into individual task modules that require independent sources of visual information for control, in order to model human gaze deployment on different task-relevant objects. We introduce a softmax barrier model for gaze selection that uses two key elements: a priority parameter that represents task importance per module, and noise estimates that allow modules to represent uncertainty about the state of task-relevant visual information. Comparisons with human gaze data gathered in a virtual driving environment show that the model closely approximates human performance.
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MARUFF, P., R. PURCELL, P. TYLER, C. PANTELIS, and J. CURRIE. "Abnormalities of internally generated saccades in obsessive–compulsive disorder." Psychological Medicine 29, no. 6 (November 1999): 1377–85. http://dx.doi.org/10.1017/s0033291799008843.
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Background. We aimed to utilize tests of saccadic function to investigate whether cognitive abnormalities in obsessive–compulsive disorder (OCD) arise from a dysfunction of inhibitory processes or whether they reflect a more general difficulty in guiding behaviour on the basis of an internal representation of task goal.Methods. Twelve patients with OCD and 12 matched controls performed a visually-guided saccade task, a volitional prosaccade task and an antisaccade task. The latency and gain of saccades was compared between groups for the three saccade tasks. The number of antisaccade errors was also calculated and compared between groups.Results. There was no difference for antisaccade error rates between the groups. The latency of visually guided saccades did not differ between groups, however the latency of both volitional prosaccades and antisaccades was significantly slower in the patients with OCD than in controls. The difference in latency between volitional prosacades and antisaccades, however, was equal between groups.Conclusions. These results suggest that patients with OCD have an abnormality in guiding behaviour on the basis of an internal representation of the task goal, rather than a problem with inhibiting reflexive behaviour.
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Waller, B. M., A. Misch, J. Whitehouse, and E. Herrmann. "Children, but not chimpanzees, have facial correlates of determination." Biology Letters 10, no. 3 (March 2014): 20130974. http://dx.doi.org/10.1098/rsbl.2013.0974.
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Facial expressions have long been proposed to be important agents in forming and maintaining cooperative interactions in social groups. Human beings are inordinately cooperative when compared with their closest-living relatives, the great apes, and hence one might expect species differences in facial expressivity in contexts in which cooperation could be advantageous. Here, human children and chimpanzees were given an identical task designed to induce an element of frustration (it was impossible to solve). In children, but not chimpanzees, facial expressions associated with effort and determination positively correlated with persistence at the task. By contrast, bodily indicators of stress (self-directed behaviour) negatively correlated with task persistence in chimpanzees. Thus, children exhibited more behaviour as they persisted, and chimpanzees exhibited less. The facial expressions produced by children, could, therefore, function to solicit prosocial assistance from others.
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Sun, Xiaoguang, Rémy Houssin, Jean Renaud, and Mickaël Gardoni. "Towards a human factors and ergonomics integration framework in the early product design phase: Function-Task-Behaviour." International Journal of Production Research 56, no. 14 (February 13, 2018): 4941–53. http://dx.doi.org/10.1080/00207543.2018.1437287.
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Ma, Jasmin K., Lucy Le Mare, and Brendon J. Gurd. "Four minutes of in-class high-intensity interval activity improves selective attention in 9- to 11-year olds." Applied Physiology, Nutrition, and Metabolism 40, no. 3 (March 2015): 238–44. http://dx.doi.org/10.1139/apnm-2014-0309.
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The amount of time allocated to physical activity in schools is declining. Time-efficient physical activity solutions that demonstrate their impact on academic achievement-related outcomes are needed to prioritize physical activity within the school curricula. “FUNtervals” are 4-min, high-intensity interval activities that use whole-body actions to complement a storyline. The purpose of this study was to (i) explore whether FUNtervals can improve selective attention, an executive function posited to be essential for learning and academic success; and (ii) examine whether this relationship is predicted by students’ classroom off-task behaviour. Seven grade 3–5 classes (n = 88) were exposed to a single-group, repeated cross-over design where each student’s selective attention was compared between no-activity and FUNtervals days. In week 1, students were familiarized with the d2 test of attention and FUNterval activities, and baseline off-task behaviour was observed. In both weeks 2 and 3 students completed the d2 test of attention following either a FUNterval break or a no-activity break. The order of these breaks was randomized and counterbalanced between weeks. Neither motor nor passive off-task behaviour predicted changes in selective attention following FUNtervals; however, a weak relationship was observed for verbal off-task behaviour and improvements in d2 test performance. More importantly, students made fewer errors during the d2 test following FUNtervals. In supporting the priority of physical activity inclusion within schools, FUNtervals, a time efficient and easily implemented physical activity break, can improve selective attention in 9- to 11-year olds.
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Barkus, Chris, Jacqueline-Marie N. Ferland, Wendy K. Adams, Grant C. Churchill, Philip J. Cowen, David M. Bannerman, Robert D. Rogers, Catharine A. Winstanley, and Trevor Sharp. "The putative lithium-mimetic ebselen reduces impulsivity in rodent models." Journal of Psychopharmacology 32, no. 9 (July 10, 2018): 1018–26. http://dx.doi.org/10.1177/0269881118784876.
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Background: Deficits in impulse control feature in many psychiatric conditions including bipolar disorder, suicidality and addictions. Lithium lowers impulsivity in clinical populations and decreases pathological gambling in experimental medicine studies, but suffers from adverse effects, poor compliance and a low therapeutic index. Aims: Recently we identified that the neuroprotective agent ebselen, which is reportedly safe in humans, inhibited inositol monophosphatase (IMPase), a candidate lithium mechanism. Ebselen also reduced 5-HT receptor (5-HT2A) function which predicts impulsivity lowering properties. Here we investigated the effect of ebselen in rat models of impulsive behaviour. Methods: Ebselen was tested in two models of impulsivity with human analogues: the five-choice serial reaction time task (5-CSRTT) and rodent gambling task (rGT). The main outcome measures were premature responses (5-CSRTT and rGT) and choice behaviour (rGT), which model motor impulsivity and choice impulsivity, respectively. Results: At doses that decreased 5-HT2A receptor function (DOI-induced wet dog shakes), ebselen decreased premature responding in the 5-CSRTT both in the absence and presence of cocaine. The 5-HT2A receptor antagonist MDL 100,907 also reduced premature responding in the 5-CSRTT although not in the presence of cocaine. In the rGT ebselen showed a tendency to reduce premature responding but had no effect on choice behaviour. Conclusions: These findings suggest that ebselen preferentially reduces motor impulsivity over choice impulsivity, and that inhibition of 5-HT2A receptor function is a contributing mechanism. Collectively, these data support the repurposing of ebselen as an anti-impulsive treatment and fast-tracking to clinical trials in patient groups characterised by poor impulse control.
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Pascual-Leone, Alvaro. "Transcranial magnetic stimulation: studying the brain--behaviour relationship by induction of ‘virtual lesions’." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 354, no. 1387 (July 29, 1999): 1229–38. http://dx.doi.org/10.1098/rstb.1999.0476.
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Transcranial magnetic stimulation (TMS) provides a non-invasive method of induction of a focal current in the brain and transient modulation of the function of the targeted cortex. Despite limited understanding about focality and mechanisms of action, TMS provides a unique opportunity of studying brain-behaviour relations in normal humans. TMS can enhance the results of other neuroimaging techniques by establishing the causal link between brain activity and task performance, and by exploring functional brain connectivity.
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Filippi, Roberto, Andrea Ceccolini, Eva Periche-Tomas, and Peter Bright. "Developmental trajectories of metacognitive processing and executive function from childhood to older age." Quarterly Journal of Experimental Psychology 73, no. 11 (June 13, 2020): 1757–73. http://dx.doi.org/10.1177/1747021820931096.
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The modern understanding of the term metacognition encompasses two levels of processing: a lower level awareness or knowledge of one’s own thoughts and a higher level regulation or control of our thinking. Metacognition, therefore, bears conceptual similarity with executive function: both are concerned with top-down monitoring and control of cognition in the service of ongoing goal-directed behaviour. Previous studies have shown a possible executive function advantage in multilingual speakers but also a possible disadvantage in metacognitive processing. To progress theory on metacognitive processing and the relationship with executive function and linguistic experience across the lifespan, we conducted a study testing 330 healthy individuals in four age groups from 7 to 80 years old. All participants performed a metacognition task and two measures of executive function, which included the Simon task and the Tower of London task. Half the participants were multilingual speakers since birth. We built developmental trajectories of metacognitive and executive function across the lifespan. The best metacognitive efficiency was observed in mid-adulthood, whereas the best executive function processing reached its peak in young adulthood. A steep cognitive decline was observed in older age, while metacognitive efficiency was preserved. Exploratory factor analysis indicated that metacognition and executive function are served by different factors across all ages. Contrary to previous findings in the bilingual literature, a multilinguistic experience conferred neither any significant advantage nor disadvantage in both executive function and metacognitive processing across the lifespan.
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Lambert, Megan L., Martina Schiestl, Raoul Schwing, Alex H. Taylor, Gyula K. Gajdon, Katie E. Slocombe, and Amanda M. Seed. "Function and flexibility of object exploration in kea and New Caledonian crows." Royal Society Open Science 4, no. 9 (September 2017): 170652. http://dx.doi.org/10.1098/rsos.170652.
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A range of non-human animals frequently manipulate and explore objects in their environment, which may enable them to learn about physical properties and potentially form more abstract concepts of properties such as weight and rigidity. Whether animals can apply the information learned during their exploration to solve novel problems, however, and whether they actually change their exploratory behaviour to seek functional information about objects have not been fully explored. We allowed kea ( Nestor notabilis ) and New Caledonian crows ( Corvus moneduloides ) to explore sets of novel objects both before and after encountering a task in which some of the objects could function as tools. Following this, subjects were given test trials in which they could choose among the objects they had explored to solve a tool-use task. Several individuals from both species performed above chance on these test trials, and only did so after exploring the objects, compared with a control experiment with no prior exploration phase. These results suggest that selection of functional tools may be guided by information acquired during exploration. Neither kea nor crows changed the duration or quality of their exploration after learning that the objects had a functional relevance, suggesting that birds do not adjust their behaviour to explicitly seek this information.
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Welker, Keith M., and Justin M. Carré. "Individual Differences in Testosterone Predict Persistence in Men." European Journal of Personality 29, no. 1 (January 2015): 83–89. http://dx.doi.org/10.1002/per.1958.
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Persistence is an important predictor of future successes. The present research addresses the relationship between testosterone and persistence in men. One hundred eighteen men were randomly assigned to win or lose a competitive number tracing task against a confederate or complete the task alone in a non–competitive control condition. Saliva samples were collected prior to and after the competition or control conditions. Participants were then given a maximum time of 30 min to spend attempting to solve unsolvable puzzles, with the option to quit at any time. In contrast to our prediction, changes in testosterone concentrations in response to the competitive interaction did not predict persistence behaviour. However, individual differences in testosterone concentrations (pre–competition/non–competition) were positively correlated with persistence. These findings are the first to examine associations between neuroendocrine function and persistence behaviour in people and suggest that testosterone should also be considered when predicting persistence–related outcomes. Copyright © 2014 European Association of Personality Psychology
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Perez, Vicente, Andres Garcia, and Jesus Gomez. "Facilitation of equivalence – equivalence responding: generalization of relational responses." International Journal of Psychological Research 4, no. 2 (December 30, 2011): 20–29. http://dx.doi.org/10.21500/20112084.774.
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Equivalence-equivalence responding (Eq-Eq) has become a behaviour analytic model of analogical reasoning. In previous works it was demonstrated that the exposition to a non-arbitrary relational task (facilitation procedure) improves performance in Eq-Eq tasks. In the present work we attempted to analyze the role of task components: arbitrary or non-arbitrary relational responses, role as sample or comparisons, and relating relations. In the first experiment, we devised four facilitation procedures combining two dimensions: simple or compound sample or comparisons and arbitrary or non-arbitrary relations among compound stimuli. In the second experiment two facilitation procedures including compound stimuli were tested. In one condition arbitrary relations worked as sample, and non-arbitrary relations as comparison. In the other condition its function was reversed. All procedures were effective to improve Eq-Eq to different extents, being arbitrary relational responses the key element. These results show generalization between non-arbitrary and arbitrary responses, and add further support to Eq-Eq responding as operant behaviour.
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Kandasamy, Kirthevasan, Gautam Dasarathy, Junier Oliva, Jeff Schneider, and Barnabás Póczos. "Multi-fidelity Gaussian Process Bandit Optimisation." Journal of Artificial Intelligence Research 66 (September 15, 2019): 151–96. http://dx.doi.org/10.1613/jair.1.11288.
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In many scientific and engineering applications, we are tasked with the maximisation of an expensive to evaluate black box function f. Traditional settings for this problem assume just the availability of this single function. However, in many cases, cheap approximations to f may be obtainable. For example, the expensive real world behaviour of a robot can be approximated by a cheap computer simulation. We can use these approximations to eliminate low function value regions cheaply and use the expensive evaluations of f in a small but promising region and speedily identify the optimum. We formalise this task as a multi-fidelity bandit problem where the target function and its approximations are sampled from a Gaussian process. We develop MF-GP-UCB, a novel method based on upper confidence bound techniques. In our theoretical analysis we demonstrate that it exhibits precisely the above behaviour and achieves better bounds on the regret than strategies which ignore multi-fidelity information. Empirically, MF-GP-UCB outperforms such naive strategies and other multi-fidelity methods on several synthetic and real experiments.
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Hvoslef-Eide, Martha, Simon R. O. Nilsson, Jonathan M. Hailwood, Trevor W. Robbins, Lisa M. Saksida, Adam C. Mar, and Timothy J. Bussey. "Effects of anterior cingulate cortex lesions on a continuous performance task for mice." Brain and Neuroscience Advances 2 (January 1, 2018): 239821281877296. http://dx.doi.org/10.1177/2398212818772962.
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Background: Important tools in the study of prefrontal cortical -dependent executive functions are cross-species behavioural tasks with translational validity. A widely used test of executive function and attention in humans is the continuous performance task. Optimal performance in variations of this task is associated with activity along the medial wall of the prefrontal cortex, including the anterior cingulate cortex, for its essential components such as response control, target detection and processing of false alarm errors. Methods: We assess the validity of a recently developed rodent touchscreen continuous performance task that is analogous to typical human continuous performance task procedures. Here, we evaluate the performance of mice with quinolinic acid -induced lesions centred on the anterior cingulate cortex in the rodent touchscreen continuous performance task following a range of task parameter manipulations designed to challenge attention and impulse control. Results: Lesioned mice showed a disinhibited response profile expressed as a decreased response criterion and increased false alarm rates. Anterior cingulate cortex lesions also resulted in a milder increase in inter-trial interval responses and hit rate. Lesions did not affect discriminative sensitivity d′. The disinhibited behaviour of anterior cingulate cortex -lesioned animals was stable and not affected by the manipulation of variable task parameter manipulations designed to increase task difficulty. The results are in general agreement with human studies implicating the anterior cingulate cortex in the processing of inappropriate responses. Conclusion: We conclude that the rodent touchscreen continuous performance task may be useful for studying prefrontal cortex function in mice and has the capability of providing meaningful links between animal and human cognitive tasks.
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Boyer, Michelle, Stephanie Rees, Joanne Quinn, Karen Grattan-Miscio, Meghan McCallum, and Matti J. Saari. "Caffeine as a Performance-Enhancing Drug in Rats: Sex, Dose, Housing, and Task Considerations." Perceptual and Motor Skills 97, no. 1 (August 2003): 259–70. http://dx.doi.org/10.2466/pms.2003.97.1.259.
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Past animal studies of the performance-enhancing properties of stimulant drugs, such as caffeine, may have suffered from a number of procedural and ethical problems. For example, the housing condition of the animals was often not taken into consideration. As well, endurance tests, such as the forced swim task, sometimes involved ethically (and procedurally) questionable interference with natural swimming behaviour. Some of the manipulations, such as attaching a weight to the swimming animal's tail to increase the difficulty of the task and using mortality as a dependent variable, seem grotesque, even unnecessary. In this experiment, the performance-enhancing effects of caffeine in a modified forced swim task and a dominance task were evaluated using male and female rats as subjects ( N = 60), housed in either enriched or isolated environments. Analysis indicated that rats respond to caffeine as an interactive function of sex, housing, dose, and task characteristics. It was concluded that performance-enhancing properties of stimulant drugs may be the result of a complex interplay of variables, making simple generalizations questionable.
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Behrend, Douglas A., Karl Rosengren, and Marion Perlmutter. "A New Look at Children's Private Speech: The Effects of Age, Task Difficulty, and Parent Presence." International Journal of Behavioral Development 12, no. 3 (September 1989): 305–20. http://dx.doi.org/10.1177/016502548901200302.
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The present study re-evaluated several hypotheses concerning the selfregulatory nature of children's private speech. It was hypothesised that if children's private speech is self-regulatory, it should differ systematically as a function of child's age, task difficulty, and the presence of another in a task situation, and it should be positively related to task performance. Twenty-four children at each of three age levels (2, 31/2, and 5 years) were videotaped while working alone and with a parent on different sets of 3 puzzles that varied in difficulty. Children's speech was recorded and coded as private or social. The proportion of total speech coded as private increased slightly with age and was curvilinearly related to puzzle difficulty, with the most private speech observed on moderately difficult puzzles. In addition, private speech was positively related to task performance, especially on medium and difficult tasks. These results are consistent with the view that private speech is self-regulatory. Parental presence had no effect on the percentage of private speech. These results suggest that parents' behaviour during joint problem-solving probably should not be taken to be strictly regulatory.
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Buchanan, John J., and Young U. Ryu. "The Interaction of Tactile Information and Movement Amplitude in a Multijoint Bimanual Circle-Tracing Task: Phase Transitions and Loss of Stability." Quarterly Journal of Experimental Psychology Section A 58, no. 5 (July 2005): 769–87. http://dx.doi.org/10.1080/02724980443000313.
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Adaptive behaviour in bimanual coordination was examined with the use of a bimanual circle-tracing task. Circle diameter and tactile information were manipulated to form four tracing conditions: tracing a pair of 3-cm diameter circles with the tips of the index fingers (3F) or hand-held styli (3S) and tracing a pair of 10-cm diameter circles with the tips of the index fingers (10F) or hand-held styli (10S). Movement frequency was increased in all conditions. In the 3F, 3S, and 10S tracing conditions, an abrupt transition from asymmetric to symmetric coordination was the main adaptive response, while in the 10F tracing condition, phase wandering was the main adaptive response. Enhancement of fluctuations in relative phase, a signature of loss of stability, occurred before the transition from asymmetric to symmetric coordination. Movement frequency and movement amplitude interact as control parameters in this task. The results are discussed with reference to tactile surface contact and joint motion as sources of sensory information that can be used to stabilize bimanual coordination patterns. The presence or absence of tactile information is directly linked to the specific form of adaptive behaviour (phase transition or phase wandering) that emerges as a function of required movement amplitude and required pacing frequency.
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Vakulenko, S., and M. Zimin. "An Analytically Tractable Model of Large Network." International Journal of Nanotechnology and Molecular Computation 2, no. 1 (January 2010): 1–12. http://dx.doi.org/10.4018/jnmc.2010010101.
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This paper considers specially organized networks of large size. They can serve as models of computer communication systems, economical systems, neural and genetic networks. The topology of this network is simple and the analysis of the network behaviour is an analytically tractable task, while computer simulations are difficult. The authors show that such networks generate any structurally stable attractors in particular chaotic and periodic. They can simulate all Turing machines, that is, perform any computations. In noisy cases, the reliability of such network is exponentially high as a function of network size and has a maximum for an optimal network size.
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Pedro, B. M., L. S. Pilowsky, D. C. Costa, D. R. Hemsley, P. J. Ell, N. P. L. G. Verhoeff, R. W. Kerwin, and N. S. Gray. "Stereotypy, schizophrenia and dopamine D2 receptor binding in the basal ganglia." Psychological Medicine 24, no. 2 (May 1994): 423–29. http://dx.doi.org/10.1017/s0033291700027392.
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SynopsisAnimal models suggest a relationship between disturbed striatal dopaminergic function and stereotyped behaviour. Several studies show increased stereotypy in schizophrenic patients compared to normal controls. We investigated the performance of 12 antipsychotic-drug-free schizophrenic patients, and 15 healthy control subjects on a neuropsychological measure of stereotypy – the two-choice guessing task – and correlated this with in vivo striatal dopamine D2 receptor binding, as measured by 123I-iodobenzamide single photon emission tomography. Patients and controls did not differ with respect to the measures of stereotypy derived from the task. However, there was a significant correlation between one of these measures (RR Information) and the degree of striatal D2 receptor binding asymmetry in the patient group only. In view of research connecting striatal and frontal lesions with stereotypy in animals and cognitive inflexibility in humans, these data could suggest a similar disturbance underlying the phenomenon in schizophrenia.
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van Oorschot, Frederike. "‘Making Public Theology Operational’: Public Theology and the Church." International Journal of Public Theology 13, no. 2 (July 1, 2019): 203–26. http://dx.doi.org/10.1163/15697320-12341572.
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AbstractThis article examines how public theologians aim to bring their theology into the practice of the church. In the first part it analyses the references to the church in the work of contemporary public theologians from the United States and Germany and suggests four different categories for the relations explored (explicit function, implicit function, public church, church as public). In the second part, it discusses three systematic aspects of these relations. First, following Kuyper, it defines the term ‘church’ more accurately. Second, it offers insights into liturgical research in order to help to sharpen the places where and means by which the implicit shaping of individual ethical behaviour in the church takes place, as exemplified in the work of Dirk Smit. Third, it discusses the task of pastors as mediators between church and theology.
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Marcone, Sonia, Jean-François Gagnon, Sarah Lecomte, Hélène Imbeault, Frédérique Limoges, Ronald B. Postuma, Josie-Anne Bertrand, Sven Joubert, and Isabelle Rouleau. "Clinical Utility of the Envelope Task in Mild Cognitive Impairment and Dementia." Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques 44, no. 1 (September 26, 2016): 9–16. http://dx.doi.org/10.1017/cjn.2016.298.
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AbstractObjective: Prospective memory (PM) is a cognitive function defined as the ability to perform an intention at an appropriate moment in the future. In the aging population, PM is essential for maintaining independent daily living. Introduced as a simple and quick way to assess PM in clinical settings, the envelope task has to date received very limited empirical and practical interest. Methods: The present study investigated the task’s clinical utility in detecting PM impairment in a sample composed of 49 healthy older adults (OA), 41 patients with Alzheimer’s disease, and 64 individuals with amnestic and nonamnestic mild cognitive impairment (MCI) of heterogeneous etiology: 17 of idiopathic nature, 20 presenting an idiopathic rapid-eye movement sleep behaviour disorder, and 27 patients diagnosed with idiopathic Parkinson’s disease. Results: The envelope task was highly sensitive and specific in discriminating Alzheimer’s disease patients from OA. Although it was specific in distinguishing MCI individuals from OA, its sensitivity was modest, especially in patients presenting a nonamnestic MCI subtype. Conclusions: Given its high specificity and simple low-cost administration procedure, the envelope task is a promising instrument for clinicians who seek to rapidly assess PM impairment in their daily practice.
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Janoschek, F., F. Mancini, J. Harting, and F. Toschi. "Rotational behaviour of red blood cells in suspension: a mesoscale simulation study." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 369, no. 1944 (June 13, 2011): 2337–44. http://dx.doi.org/10.1098/rsta.2011.0086.
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The nature of blood as a suspension of red blood cells makes computational haemodynamics a demanding task. Our coarse-grained blood model, which builds on a lattice Boltzmann method for soft particle suspensions, enables the study of the collective behaviour of the order of 10 6 cells in suspension. After demonstrating the viscosity measurement in Kolmogorov flow, we focus on the statistical analysis of the cell orientation and rotation in Couette flow. We quantify the average inclination with respect to the flow and the nematic order as a function of shear rate and haematocrit. We further record the distribution of rotation periods around the vorticity direction and find a pronounced peak in the vicinity of the theoretical value for free model cells, even though cell–cell interactions manifest themselves in a substantial width of the distribution.
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Raichle, Marcus E. "The restless brain: how intrinsic activity organizes brain function." Philosophical Transactions of the Royal Society B: Biological Sciences 370, no. 1668 (May 19, 2015): 20140172. http://dx.doi.org/10.1098/rstb.2014.0172.
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Traditionally studies of brain function have focused on task-evoked responses. By their very nature such experiments tacitly encourage a reflexive view of brain function. While such an approach has been remarkably productive at all levels of neuroscience, it ignores the alternative possibility that brain functions are mainly intrinsic and ongoing, involving information processing for interpreting, responding to and predicting environmental demands. I suggest that the latter view best captures the essence of brain function, a position that accords well with the allocation of the brain's energy resources, its limited access to sensory information and a dynamic, intrinsic functional organization. The nature of this intrinsic activity, which exhibits a surprising level of organization with dimensions of both space and time, is revealed in the ongoing activity of the brain and its metabolism. As we look to the future, understanding the nature of this intrinsic activity will require integrating knowledge from cognitive and systems neuroscience with cellular and molecular neuroscience where ion channels, receptors, components of signal transduction and metabolic pathways are all in a constant state of flux. The reward for doing so will be a much better understanding of human behaviour in health and disease.
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Meyssonnier, Jacques, and Armelle Philip. "A model for the tangent viscous behaviour of anisotropic polar ice." Annals of Glaciology 23 (1996): 253–61. http://dx.doi.org/10.1017/s0260305500013513.
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During the deformation of polar ice, a fabric develops which results in a macroscopically anisotropic behaviour. Since the plastic anisotropy of the ice single crystal is very high, the effect of a strong (single maximum) fabric on the macroscopic flow law cannot be neglected when simulating the flow of an ice sheet. As this is already a difficult task when using the familiar isotropic power law for ice, the fabric evolution and related macroscopic mechanical behaviour model, to be implemented in such a simulation, must be realistic yet simple enough to achieve results within a reasonable level of complexity, at least as a first step. To this aim, we propose to model polar ice as a transversely isotropic medium; while simplifying the problem, this captures the essential features of the in-situ observed fabrics. The macroscopic mechanical behaviour of the ice polycrystal is obtained by using an orientation distribution function (ODF) for the c axes of the grains, which characterizes the fabric, and a self-consistent scheme, considering each single crystal as transversely isotropic. The evolution of the ODF is described by a conservation equation. In the first stage, this model was run in the simple cases of uniaxial compression and tension along the orthotropy symmetry axis.
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Meyssonnier, Jacques, and Armelle Philip. "A model for the tangent viscous behaviour of anisotropic polar ice." Annals of Glaciology 23 (1996): 253–61. http://dx.doi.org/10.3189/s0260305500013513.
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During the deformation of polar ice, a fabric develops which results in a macroscopically anisotropic behaviour. Since the plastic anisotropy of the ice single crystal is very high, the effect of a strong (single maximum) fabric on the macroscopic flow law cannot be neglected when simulating the flow of an ice sheet. As this is already a difficult task when using the familiar isotropic power law for ice, the fabric evolution and related macroscopic mechanical behaviour model, to be implemented in such a simulation, must be realistic yet simple enough to achieve results within a reasonable level of complexity, at least as a first step.To this aim, we propose to model polar ice as a transversely isotropic medium; while simplifying the problem, this captures the essential features of the in-situ observed fabrics. The macroscopic mechanical behaviour of the ice polycrystal is obtained by using an orientation distribution function (ODF) for the c axes of the grains, which characterizes the fabric, and a self-consistent scheme, considering each single crystal as transversely isotropic. The evolution of the ODF is described by a conservation equation. In the first stage, this model was run in the simple cases of uniaxial compression and tension along the orthotropy symmetry axis.
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Schwibbe, Michael, and Silke Singer. "RIGHT OR LEFT, HAND OR MOUTH: GENERA-SPECIFIC PREFERENCES IN MARMOSETS AND TAMARINS." Behaviour 136, no. 1 (1999): 119–45. http://dx.doi.org/10.1163/156853999500703.
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Hand use was compared in 45 individuals of three genera of the Callitrichinae (Callithrix, Saguinus, Leontopithecus) which differ concerning their postural and manipulative behaviour. The Postural Origins theory of MacNeilage et al. (1987) predicts left-hand preference for visually guided reaching, especially when performed from a vertical clinging posture (as mainly seen in Callithrix) and right-hand preference for manipulative acts (as shown by Leontopithecus). Five tasks were carried out, differing in sensory modality (visual/tactile), postural requirements (vertical/quadrupedal) and task demands (accessibility to food-items). Data on successful left and right-hand reaching and mouth pick-ups were collected using all occurrences sampling. Statistical analysis comprised calculation of binominal z-score, application of unbalanced repeated measures models with structured covariance matrices and analysis of covariance. All individuals displayed hand preferences not influenced by task design. The genera differed in the hand preferred: Leontopithecus showed a greater proportion of right-hand preferences, whereas Callithrix tended to prefer the left hand. Saguinus was intermediate between these two genera. The results point out that genus-specific foraging strategies determine population-level hand preferences rather than task-specific demands. The differences in foraging strategy and hand preference among the three genera correspond to the Postural Origins theory (MacNeilage et al., 1987). When feeding on freely accessible, non-mobile food items, most individuals showed a clear preference in picking-up with the mouth or with one hand. Callithrix took objects predominantly with the mouth, Leontopithecus preferred the hand and Saguinus favoured neither mouth nor hand. Mouth-hand preferences can also be linked to genera differences on hand function in foraging behaviour.
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Pieruccini-Faria, Frederico, Yanina Sarquis-Adamson, and Manuel Montero-Odasso. "Mild Cognitive Impairment Affects Obstacle Negotiation in Older Adults: Results from “Gait and Brain Study”." Gerontology 65, no. 2 (October 12, 2018): 164–73. http://dx.doi.org/10.1159/000492931.
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Background: Older adults with Mild Cognitive Impairment (MCI) are at higher risk of falls and injuries, but the underlying mechanism is poorly understood. Inappropriate anticipatory postural adjustments to overcome balance perturbations are affected by cognitive decline. However, it is unknown whether anticipatory gait control to avoid an obstacle is affected in MCI. Objective: Using the dual-task paradigm, we aim to assess whether gait control is affected during obstacle negotiation challenges in older adults with MCI. Methods: Seventy-nine participants (mean age = 72.0 ± 2.7 years; women = 30.3%) from the “Gait and Brain Study” were included in this study (controls = 27; MCI = 52). In order to assess the anticipatory control behaviour for obstacle negotiation, a 6-m electronic walkway embedded with sensors recorded foot prints to measure gait speed and step length variability, during early (3 steps before the late phase) and late (3 steps before the obstacle) pre-crossing phases of an ad hoc obstacle, set at 15% of participant’s height. Participants walked under single- and dual-task gait (counting backwards by 1’s from 100 while walking) conditions. Three-way mixed repeated-measures analysis of variance models examined differences in gait performance between groups when transitioning between pre-crossing phases towards an obstacle during single- and dual-task conditions. Analyses were adjusted for age, sex, years of education, lower limb function, fear of falling, medical status, depressive symptoms, baseline gait speed and executive function. Results: A significant three-way interaction among groups, pre-crossing phases and task showed that participants with MCI attenuated the gait deceleration (p = 0.02) and performed fewer step length adjustments (p = 0.03) when approaching the obstacle compared with controls while dual-tasking. These interactions were attenuated when executive function performance was added as a covariate in the adjusted statistical model. Conclusion: Older adults with MCI attenuate the anticipatory gait adjustments needed to avoid an obstacle when dual-tasking. Deficits in higher-order cognitive processing may limit obstacle negotiation capabilities in MCI populations, being a potential falls risk factor.
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Allen, Timothy A., Amanda R. Rueter, Samantha V. Abram, James S. Brown, Colin G. Deyoung, and René Mõttus. "Personality and Neural Correlates of Mentalizing Ability." European Journal of Personality 31, no. 6 (November 2017): 599–613. http://dx.doi.org/10.1002/per.2133.
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Theory of mind, or mentalizing, defined as the ability to reason about another's mental states, is a crucial psychological function that is disrupted in some forms of psychopathology, but little is known about how individual differences in this ability relate to personality or brain function. One previous study linked mentalizing ability to individual differences in the personality trait Agreeableness. Agreeableness encompasses two major subdimensions: Compassion reflects tendencies toward empathy, prosocial behaviour, and interpersonal concern, whereas Politeness captures tendencies to suppress aggressive and exploitative impulses. We hypothesized that Compassion but not Politeness would be associated with better mentalizing ability. This hypothesis was confirmed in Study 1 ( N = 329) using a theory of mind task that required reasoning about the beliefs of fictional characters. Post hoc analyses indicated that the honesty facet of Agreeableness was negatively associated with mentalizing. In Study 2 ( N = 217), we examined whether individual differences in mentalizing and related traits were associated with patterns of resting–state functional connectivity in the brain. Performance on the theory of mind task was significantly associated with patterns of connectivity between the dorsal medial and core subsystems of the default network, consistent with evidence implicating these regions in mentalization. Copyright © 2017 European Association of Personality Psychology
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Dolan, M., and C. Lennox. "Cool and hot executive function in conduct-disordered adolescents with and without co-morbid attention deficit hyperactivity disorder: relationships with externalizing behaviours." Psychological Medicine 43, no. 11 (January 30, 2013): 2427–36. http://dx.doi.org/10.1017/s0033291712003078.
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BackgroundAn understanding of the exact nature of executive function (EF) deficits in conduct disorder (CD) remains elusive because of issues of co-morbidity with attention deficit hyperactivity disorder (ADHD).MethodSeventy-two adolescents with CD, 35 with CD + ADHD and 20 healthy controls (HCs) were assessed on a computerized battery of putative ‘cool’ and ‘hot’ EFs. Participants also completed the Child Behaviour Checklist (CBCL).ResultsIn the cool EF tasks such as planning, the CD + ADHD group in particular showed most notable impairments compared to HCs. This pattern was less evident for set shifting and behavioural inhibition but there were significant correlations between errors scores on these tasks and indices of externalizing behaviours on the CBCL across the sample. For hot EF tasks, all clinical groups performed worse than HCs on delay of gratification and poor performance was correlated with externalizing scores. Although there were no notable group differences on the punishment-based card-playing task, there were significant correlations between ultimate payout and externalizing behaviour across groups.ConclusionsOverall, our findings highlight the fact that there may be more common than distinguishing neuropsychological underpinnings to these co-morbid disorders and that a dimensional symptom-based approach may be the way forward.
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Garavan, Hugh, Jacqueline N. Kaufman, and Robert Hester. "Acute effects of cocaine on the neurobiology of cognitive control." Philosophical Transactions of the Royal Society B: Biological Sciences 363, no. 1507 (July 24, 2008): 3267–76. http://dx.doi.org/10.1098/rstb.2008.0106.
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Compromised ability to exert control over drug urges and drug-seeking behaviour is a characteristic of addiction. One specific cognitive control function, impulse control, has been shown to be a risk factor for the development of substance problems and has been linked in animal models to increased drug administration and relapse. We present evidence of a direct effect of cocaine on the neurobiology underlying impulse control. In a laboratory test of motor response inhibition, an intravenous cocaine administration improved task performance in 13 cocaine users. This improvement was accompanied by increased activation in right dorsolateral and inferior frontal cortex, regions considered critical for this cognitive function. Similarly, for both inhibitory control and action monitoring processes, cocaine normalized activation levels in lateral and medial prefrontal regions previously reported to be hypoactive in users relative to drug-naive controls. The acute amelioration of neurocognitive dysfunction may reflect a chronic dysregulation of those brain regions and the cognitive processes they subserve. Furthermore, the effects of cocaine on midline function suggest a dopaminergically mediated intersection between cocaine's acute reinforcing effects and its effects on cognitive control.
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Lahat, Ayelet, Michaela Gummerum, Lorna Mackay, and Yaniv Hanoch. "Cognitive processing of moral and social judgements: A comparison of offenders, students, and control participants." Quarterly Journal of Experimental Psychology 68, no. 2 (February 2015): 350–62. http://dx.doi.org/10.1080/17470218.2014.944918.
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Examining cognitive processes related to offenders’ moral and social judgements is important in order to better understand their criminal behaviour. In the present study, 30 offenders, 30 students, and 24 control participants were administered the moral-conventional judgements computer task, which requires responding under strict time constraints. Participants read scenarios and were asked to judge whether the act was acceptable or unacceptable when rules were either assumed or removed. Additionally, participants completed an executive function (EF) task in order to examine the relation between EF and moral and social judgements. The findings revealed that, as expected, controls and students had faster reaction times (RTs) and a higher percentage of normative judgements than offenders. Additionally, offenders had a low percentage of normative judgements, particularly in the conventional rule removed condition. Finally, RTs of moral and conventional judgements in most conditions were related to EF among students but not controls or offenders. We conclude that offenders, as compared to controls and students, may rely more on rule-oriented responding and may rely less on EF when making moral and social judgements.
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Urwin, Rosalind, and Claire Ballinger. "The Effectiveness of Sensory Integration Therapy to Improve Functional Behaviour in Adults with Learning Disabilities: Five Single-Case Experimental Designs." British Journal of Occupational Therapy 68, no. 2 (February 2005): 56–66. http://dx.doi.org/10.1177/030802260506800202.
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This paper describes a research project using a single-case experimental design (A-B-A), which aimed to explore the impact of sensory integration therapy (SIT) on level of engagement and maladaptive behaviour (measured through timed scores) and function (using Goal Attainment Scaling, GAS) for five learning disabled adults with tactile sensory modulation disorder. Each phase lasted 4 weeks and consisted of 24 measurements in total. Individually tailored SIT was given twice weekly for 4 weeks during the intervention phase (B), immediately prior to each individual's participation in his or her prescribed horticulture task. The changes between phases in engagement, maladaptive behaviours and function scores, measured as the difference between baselines and intervention, were analysed visually and statistically for each participant. The intervention produced significant improvements in engagement for participant four, with a highly significant deterioration in scores for all five participants on withdrawal of SIT. All the participants' maladaptive behaviour decreased significantly on the introduction of SIT. Although there was no significant change to GAS scores for four participants, participant four's score improved significantly with SIT. The withdrawal of SIT resulted in a highly significant deterioration in GAS scores for participants one, two, four and five. This study may be the first to suggest that SIT is effective in improving functional performance in adults with a learning disability with a tactile sensory modulation disorder.
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Kapardi, Mallampalli, and Kavitha Anandan. "Functional Connectivity Assessment for Episodic Memory by Decoding Theta Wave." International Journal of Cognitive Informatics and Natural Intelligence 12, no. 2 (April 2018): 17–31. http://dx.doi.org/10.4018/ijcini.2018040102.
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Autobiographical events help us to analyse our own thoughts and behaviour over a period of time. Analysing the retrieval of memory helps in better understanding of the disorders. This article aims at analysing the functional connectivity of young adults during a multiphase memory retrieval process. Subjects have been made to recall events in different phases of their life. EEG signals have been recorded while the subjects are performing their tasks. Inter-hemispherical coherence has been estimated from the processed EEG signals As theta band posed higher power compared to all other bands, it was considered for further analysis. A mathematical function was formed for the processed theta wave, to determine the coherence between various electrodes. The function generated a theta wave for every task and each wave was significant in its own way. The connectivity matrix was found to identify the active electrodes during retrieval of events. The results were validated by computing coherence separately for the same electrodes and for the same events.
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CORCHADO, JUAN M., B. LEES, and J. AIKEN. "HYBRID INSTANCE-BASED SYSTEM FOR PREDICTING OCEAN TEMPERATURES." International Journal of Computational Intelligence and Applications 01, no. 01 (March 2001): 35–52. http://dx.doi.org/10.1142/s1469026801000020.
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An instance-based problem solving model is presented in which the aim is to forecast, in real time, the physical parameter values of a complex and dynamic environment: the ocean. The situations in which the rules that determine a system are unknown, the prediction of the parameter values that determine the characteristic behaviour of the system can be a problematic task. In such a situation it has been found that an instance-based reasoning system can provide a more effective means of performing such predictions than other connectionist or symbolic techniques. The instance-based reasoning system incorporates a radial basis function artificial neural network for the instance adaptation. The results obtained from experiments, in which the system operated in real time in the oceanographic environment, are presented.
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Schneider, Werner X., Wolfgang Einhäuser, and Gernot Horstmann. "Attentional selection in visual perception, memory and action: a quest for cross-domain integration." Philosophical Transactions of the Royal Society B: Biological Sciences 368, no. 1628 (October 19, 2013): 20130053. http://dx.doi.org/10.1098/rstb.2013.0053.
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For decades, the cognitive and neural sciences have benefitted greatly from a separation of mind and brain into distinct functional domains. The tremendous success of this approach notwithstanding, it is self-evident that such a view is incomplete. Goal-directed behaviour of an organism requires the joint functioning of perception, memory and sensorimotor control. A prime candidate for achieving integration across these functional domains are attentional processes. Consequently, this Theme Issue brings together studies of attentional selection from many fields, both experimental and theoretical, that are united in their quest to find overreaching integrative principles of attention between perception, memory and action. In all domains, attention is understood as combination of competition and priority control (‘bias’), with the task as a decisive driving factor to ensure coherent goal-directed behaviour and cognition. Using vision as the predominant model system for attentional selection, many studies of this Theme Issue focus special emphasis on eye movements as a selection process that is both a fundamental action and serves a key function in perception. The Theme Issue spans a wide range of methods, from measuring human behaviour in the real word to recordings of single neurons in the non-human primate brain. We firmly believe that combining such a breadth in approaches is necessary not only for attentional selection, but also to take the next decisive step in all of the cognitive and neural sciences: to understand cognition and behaviour beyond isolated domains.
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Cammarata, L., A. Fichera, and A. Pagano. "Designing an optimal controller for rectangular natural circulation loops." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 217, no. 3 (August 1, 2003): 171–80. http://dx.doi.org/10.1243/095440803322328845.
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Controlling the dynamics of natural circulation loops represents a major task for the widespread use of this kind of system in safe industrial applications. This paper aims to design an innovative model-based optimal controller for the suppression of unstable oscillations and flow reversals, which affect the dynamical behaviour of a closed-loop thermosyphon at high heating rate. The key idea is to define a multivariable control law aiming to minimize an objective function taking into account both the stability of the system and the cost of control. The design of the proposed controller has been based on a model approximating to the first three modes of the dynamics of rectangular circulation loops with imposed heat fluxes at the boundaries. The capability of the proposed controller in suppressing undesired dynamics has been experimentally demonstrated.
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Pérez-Higueras, Noé, Alberto Jardón, Ángel Rodríguez, and Carlos Balaguer. "3D Exploration and Navigation with Optimal-RRT Planners for Ground Robots in Indoor Incidents." Sensors 20, no. 1 (December 30, 2019): 220. http://dx.doi.org/10.3390/s20010220.
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Navigation and exploration in 3D environments is still a challenging task for autonomous robots that move on the ground. Robots for Search and Rescue missions must deal with unstructured and very complex scenarios. This paper presents a path planning system for navigation and exploration of ground robots in such situations. We use (unordered) point clouds as the main sensory input without building any explicit representation of the environment from them. These 3D points are employed as space samples by an Optimal-RRTplanner (RRT * ) to compute safe and efficient paths. The use of an objective function for path construction and the natural exploratory behaviour of the RRT * planner make it appropriate for the tasks. The approach is evaluated in different simulations showing the viability of autonomous navigation and exploration in complex 3D scenarios.
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Robertson, Judy, Stuart Gray, Toye Martin, and Josephine Booth. "The relationship between Executive Functions and Computational Thinking." International Journal of Computer Science Education in Schools 3, no. 4 (May 5, 2020): 35–49. http://dx.doi.org/10.21585/ijcses.v3i4.76.
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We argue that understanding the cognitive foundations of computational thinking will assist educators to improve children’s learning in computing. We explain the conceptual relationship between executive functions and aspects of computational thinking. We present exploratory empirical data from 23 eleven year old learners which investigates the correlation between assessments of programming and debugging in the visual language Scratch and scores from the BRIEF 2 assessment of executive functions. The initial data shows moderate to large correlations between assessments of debugging and programming with the BRIEF2 teachers’ rating of executive function as manifested in classroom behaviour. Case studies from the empirical data are used to qualitatively illustrate how executive functions relate to a game making task. We discuss the implications of these findings for educators, and present suggestions for future work.
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Shien Wee, Ryan Wei, and Andrew MacAskill. "Hippocampal Circuits for the Hunger-Dependent Control of Feeding Behaviour." Journal of the Endocrine Society 5, Supplement_1 (May 1, 2021): A540. http://dx.doi.org/10.1210/jendso/bvab048.1100.
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Abstract Background: Feeding behavior is a complex motivated behavior that requires organisms to integrate features of the environment, such as food availability and value, and internal states, such as hunger, in deliberating over the decision to eat. The hippocampus - a brain region classically thought to support spatial cognition and episodic memory - is increasingly recognised to contribute to such decision-making processes. This function makes the hippocampus a likely candidate in supporting the higher-order decisions that underpin motivated behaviors such as feeding. However, the role of the hippocampus during free-feeding behavior has not been examined. Methods and Results: To address this question, we used in vivo calcium imaging during feeding behavior in mice to monitor the neural activity of the ventral subiculum (vS) - one of the main output structures of the ventral hippocampus. In a free-feeding task, we found that the vS encoded the investigative approach phase of feeding behavior and that activity during this period correlated with the probability of transitioning from food investigation to consumption. Calcium imaging during an operant task confirmed the specific encoding of preparatory behaviour preceding food consumption. Furthermore, the sensitivity of vS to the hunger state could be mapped to vS neurons projecting to the nucleus accumbens (vS-NAc). Ghrelin - a hormone signalling the hunger state - altered synaptic transmission specifically in vS-NAc neurons, and molecular knockdown of the ghrelin receptor was required for the hunger sensitivity of vS-NAc. Consequently, both reducing ghrelin signalling in vS-NAc neurons through molecular knockdown and artificially elevating vS-NAc activity through optogenetics were sufficient to shift the feeding strategy of animals, effectively curtailing overall food consumption. Conclusion: In summary, these results provide evidence for a hippocampal circuit that integrates hunger state signals to regulate the decision to eat.
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Skóra, Mariusz, Stanislaw Weglarczyk, Jan Kusiak, and Maciej Pietrzyk. "Computer Aided Design of Manufacturing of Anchors and Formulation of the Optimization Task for in Use Properties." Key Engineering Materials 554-557 (June 2013): 372–82. http://dx.doi.org/10.4028/www.scientific.net/kem.554-557.372.
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Computer aided design of the manufacturing technology for anchors is presented in the paper. Evaluation of applicability of various materials for anchors, as well as analysis of the influence of process parameters on the in use properties of product, were the objectives of the research. In the material part, bainitic steels were considered as an alternative for the commonly used C-Mn steels. Possibility of elimination of the heat treatment was evaluated. Rheological models for the investigated steels were developed and implemented into the finite element code for simulations of drawing and multi stage forging. Criteria for the selection of the best manufacturing chain composed dimensional accuracy, tool life and product properties. Industrial trials were performed for the selected cycle and the efficiency of this cycle was evaluated. Finally, simulations of the in use behaviour of the anchor-concrete joint were performed. On the basis of the simulations the optimization task using strength of the joint as the objective function was formulated
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Chen, C.-L., and C.-J. Lin. "Motion planning of redundant robot manipulators using constrained optimization: A parallel approach." Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 212, no. 4 (June 1, 1998): 281–92. http://dx.doi.org/10.1243/0959651981539460.
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A redundant manipulator can achieve a principal task and additional tasks by utilizing the degrees of redundancy. In the present paper, the redundancy resolution problem is formulated as a local equality constrained optimization problem. A motion planning solution corresponding to a design objective is then obtained using a new approach, called the perturbation method. In contrast to conventional approaches, the inverse of the Jacobian matrix is not required in the method proposed. Tracking errors can be bounded by a permissible zone, which is a function of normal tracking error and a safety factor. Positioning of the end effector within the permissible zone is satisfactory for the completion of any given step and signals the beginning of the next step. The position angle change of each joint is also bounded in each sampling interval as a function of robot maximum speed. Computer simulations written in the parallel processing language occam and computed on a transputer-based computation network are used to study the behaviour of the method proposed. Results validate the approach.
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Olczak, Agnieszka. "Uczenie się demokracji od dzieciństwa – kaprys czy potrzeba współczesności?" Problemy Wczesnej Edukacji 31, no. 4 (December 31, 2015): 92–100. http://dx.doi.org/10.5604/01.3001.0008.5649.
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In the modern, changing, uncertain world, life is becoming more and more complex and difficult. Only those who are well prepared for it will be able to function in this world. Thus, the article raises the question of whether teaching children democracy, liberation behaviour, participation, but also responsibility, is a fantasy, a fiction, or a whim, which teachers and researchers who seek, and parents who reject authoritarianism are often accused of, or whether it is a necessity of the modern times and an expression of an awareness that it is essential wisely to prepare the younger generation for life in contemporary society. In this paper the author also outlines the role of educational institutions that can and should be aware of this task and search for opportunities for the creation of conditions for the development of children’s democratic competences.
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Dubossarskaya, Z. M. "Reproductive toxicants in the environment and their role in some human diseases (Сlinic)." Reproductive health of woman 2 (April 1, 2021): 37–41. http://dx.doi.org/10.30841/2708-8731.2.2021.232523.
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In recent decades, there has been a fairly active debate on the role of genetic predisposition, average factors, adverse effects of reproductive toxins, infections, special behaviour that includes harmful habits for human diseases and not to implement their reproductive plans. Environmental disasters, the Covid-19 pandemic, the incorporation of the modern human and industrial waste, forest fires, excessive radiation following the national tragedy of Chernobyl has become global, not only the age of dependent diseases, but the disorders of the main functional systems of the female and male organism that result in reproductive function, reduce the quality of life and duration. Unfavourable medium effects, disturb the process of interacting with the genotype of the organism in shaping the phenotype. This information is needed by doctors to develop periconceptology, which is the task of this clinical lecture.
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Lv, Yajie, Li Cai, Zhaohuan Gui, Xia Zeng, Minyi Tan, Nianqing Wan, Lijuan Lai, Shaomin Lu, Weiqing Tan, and Yajun Chen. "Effects of physical activity and sedentary behaviour on cardiometabolic risk factors and cognitive function in children: protocol for a cohort study." BMJ Open 9, no. 10 (October 2019): e030322. http://dx.doi.org/10.1136/bmjopen-2019-030322.
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IntroductionAlthough studies showed that physical activity (PA) and sedentary behaviour (SB) were associated with cardiometabolic risk factors and cognitive function, both independent and combined associations among them are inconsistent. Cardiometabolic risk factors are also associated with cognitive function, but research of children is limited. Additionally, the brain level mechanisms have not been fully established. The proposed study aims to explore the associations and mechanisms of PA and SB on cognitive function and cardiometabolic risk factors in children.Methods and analysisThis is a school-based prospective cohort study. A total of 8324 participants of this study are primary school students aged 7–12 years old who are followed up every 2 years from January 2017 to December 2026. We used a stratified cluster random sampling to select five primary schools in Guangzhou, China. There are three phases at baseline. At phase I, we collect PA, SB and cognitive function by questionnaires and also conduct anthropometric and biochemical measurements in all participants. At phase II, PA, SB and cognitive function are measured respectively by accelerometers and cognitive tasks among participants randomly selected from four subgroups with different SB and PA levels. At phase III, event-related potentials are recorded using electroencephalogram during a cognitive task among participants randomly selected from phase II. We plan to follow-up all participants until they graduate from high school. The process applied at baseline and follow-up are approximately identical.Ethics and disseminationProcedures described in this manuscript have been approved by the Ethical Review Committee for Biomedical Research, School of Public Health, Sun Yat-sen University (L2016-010). All parents or guardians of participants signed the informed consent form voluntarily before participating in the study. The findings of the study will be published in peer-reviewed journals.Trial registration numberNCT03582709
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Talbot, Catherine F., Hani D. Freeman, Lawrence E. Williams, and Sarah F. Brosnan. "Squirrel monkeys' response to inequitable outcomes indicates a behavioural convergence within the primates." Biology Letters 7, no. 5 (April 20, 2011): 680–82. http://dx.doi.org/10.1098/rsbl.2011.0211.
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Although several primates respond negatively to inequity, it is unknown whether this results from homology or convergent processes. Behaviours shared within a taxonomic group are often assumed to be homologous, yet this distinction is important for a better understanding of the function of the behaviour. Previous hypotheses have linked cooperation and inequity responses. Supporting this, all species in which inequity responses have been documented are cooperative. In this study, we tested this hypothesis by investigating the response to inequity in squirrel monkeys, which share a phylogenetic family with capuchin monkeys, but do not cooperate extensively. Subjects exchanged tokens to receive food rewards in conditions in which the level of effort required and reward received varied. Squirrel monkeys did not respond negatively to inequity. However, the monkeys were sensitive to the variation present in the task; male subjects showed a contrast effect and, as in previous studies, subjects were more sensitive to differences in reward in the context of a task than when rewards were given for free. Taken with other results, these results support the hypothesis that a negative response to inequity evolved convergently in primates, probably as a mechanism for evaluating outcomes relative to one's partners in cooperative species.
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Keupp, Stefanie, Rowan Titchener, Thomas Bugnyar, Thomas Mussweiler, and Julia Fischer. "Competition is crucial for social comparison processes in long-tailed macaques." Biology Letters 15, no. 3 (March 2019): 20180784. http://dx.doi.org/10.1098/rsbl.2018.0784.
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Humans modulate their self-evaluations and behaviour as a function of conspecific presence and performance. In this study, we tested for the presence of human-like social comparison effects in long-tailed macaques ( Macaca fascicularis ). The monkeys' task was to extract food from an apparatus by pulling drawers within reach and we measured latency between drawer pulls. Subjects either worked on the task with a partner who could access the apparatus from an adjacent cage, worked in the absence of a conspecific but with food moving towards the partner's side or worked next to a partner who was denied apparatus access. We further manipulated partner performance and competitiveness of the set-up. We found no indication that long-tailed macaques compare their performance to the performance of conspecifics. They were not affected by the mere presence of the partner but they paid close attention to the partner's actions when they were consequential for food availability. If social comparison processes are present in long-tailed macaques, the present study suggests they may only manifest in situations involving direct competition and would thus be different from social comparisons in humans, which manifest also in the absence of direct competition, for example in evaluative contexts.
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Henkel, Stefanie, and Joanna M. Setchell. "Group and kin recognition via olfactory cues in chimpanzees ( Pan troglodytes )." Proceedings of the Royal Society B: Biological Sciences 285, no. 1889 (October 24, 2018): 20181527. http://dx.doi.org/10.1098/rspb.2018.1527.
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Primates were traditionally thought to have a reduced sense of smell. Although there is now evidence that olfaction plays a greater role in primate social life than previously assumed, research on the sense of smell in non-human apes is scarce. Chimpanzees sniff the ground and vegetation on boundary patrols, but the function of this behaviour is unclear. Since chimpanzees are highly territorial and can kill individuals that do not belong to their own community, sniffing might function to gather information about conspecifics, particularly concerning group membership and kinship. To investigate whether chimpanzees recognize group members and kin via olfactory cues, we conducted behavioural bioassays on two groups of chimpanzees at Leipzig Zoo. In a pilot study, we found that chimpanzees responded more strongly to urine than to faeces or body odour. We then presented urine from group members, outgroup individuals and an unscented control in aerated boxes using a simultaneous discrimination task. The first behaviour after a chimpanzee first approached a box was related to olfaction (sniffing, nose within 20 cm, licking) in 83% of cases, highlighting the importance of olfaction as a general investigation mechanism in this species. Chimpanzees sniffed significantly longer at urine stimuli than the control and significantly longer at odours from outgroup individuals than those from group members. Furthermore, the duration of sniffing was positively correlated with relatedness. Our results suggest that chimpanzees use olfactory cues to obtain information about social relationships and fill a gap in our understanding of primate chemical communication.
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Mason, Christine R., Fabio Idrobo, Susan J. Early, Ayome Abibi, Ling Zheng, J. Michael Harrison, and Laurel H. Carney. "CS-Dependent Response Probability in an Auditory Masked-Detection Task: Considerations based on Models of Pavlovian Conditioning." Quarterly Journal of Experimental Psychology Section B 56, no. 2b (May 2003): 193–205. http://dx.doi.org/10.1080/02724990244000052.
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Experimental studies were performed using a Pavlovian-conditioned eyeblink response to measure detection of a variable-sound-level tone (T) in a fixed-sound-level masking noise (N) in rabbits. Results showed an increase in the asymptotic probability of conditioned responses (CRs) to the reinforced TN trials and a decrease in the asymptotic rate of eyeblink responses to the non-reinforced N presentations as a function of the sound level of the T. These observations are consistent with expected behaviour in an auditory masked detection task, but they are not consistent with predictions from a traditional application of the Rescorla-Wagner or Pearce models of associative learning. To implement these models, one typically considers only the actual stimuli and reinforcement on each trial. We found that by considering perceptual interactions and concepts from signal detection theory, these models could predict the CS dependence on the sound level of the T. In these alternative implementations, the animal's response probabilities were used as a guide in making assumptions about the “effective stimuli”.
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Sihvola, Nora, Riitta Korpela, Andreas Henelius, Anu Holm, Minna Huotilainen, Kiti Müller, Tuija Poussa, Kati Pettersson, Anu Turpeinen, and Katri Peuhkuri. "Breakfast high in whey protein or carbohydrates improves coping with workload in healthy subjects." British Journal of Nutrition 110, no. 9 (April 16, 2013): 1712–21. http://dx.doi.org/10.1017/s0007114513000779.
Full textAbstract:
Dietary components may affect brain function and influence behaviour by inducing the synthesis of neurotransmitters. The aim of the present study was to examine the influence of consumption of a whey protein-containing breakfast drink v. a carbohydrate drink v. control on subjective and physiological responses to mental workload in simulated work. In a randomised cross-over design, ten healthy subjects (seven women, median age 26 years, median BMI 23 kg/m2) participated in a single-blinded, placebo-controlled study. The subjects performed demanding work-like tasks after having a breakfast drink high in protein (HP) or high in carbohydrate (HC) or a control drink on separate sessions. Subjective states were assessed using the NASA Task Load Index (NASA-TLX), the Karolinska sleepiness scale (KSS) and the modified Profile of Mood States. Heart rate was recorded during task performance. The ratio of plasma tryptophan (Trp) to the sum of the other large neutral amino acids (LNAA) and salivary cortisol were also analysed. The plasma Trp:LNAA ratio was 30 % higher after the test drinks HP (median 0·13 (μmol/l)/(μmol/l)) and HC (median 0·13 (μmol/l)/(μmol/l)) than after the control drink (median 0·10 (μmol/l)/(μmol/l)). The increase in heart rate was smaller after the HP (median 2·7 beats/min) and HC (median 1·9 beats/min) drinks when compared with the control drink (median 7·2 beats/min) during task performance. Subjective sleepiness was reduced more after the HC drink (median KSS − 1·5) than after the control drink (median KSS − 0·5). There were no significant differences between the breakfast types in the NASA-TLX index, cortisol levels or task performance. We conclude that a breakfast drink high in whey protein or carbohydrates may improve coping with mental tasks in healthy subjects.
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Haryono, Haryono, Agfianto Eko Putra, Jazi Eko Istiyanto, and Agus Harjoko. "Error Detection and Correction System (EDAC) of On Board Data Handling (OBDH) in Real Time Operating System Behaviour." Scientific Research Journal 10, no. 2 (March 14, 2019): 17. http://dx.doi.org/10.24191/srj.v10i2.5412.
Full textAbstract:
The satellite requires the support of a robust sub system. On Board Data Handling (OBDH) is the core function of the satellite subsystem and has to be error free in managing the operation of the satellite. It should withstand the harsh environmental conditions in space that has a lot of hazards caused by radiations. In view of these two conditions, the OBDH design should be able to manage the operation and overcome the hazards of radiation. In order to manage the operation Real Time Operating System (RTOS) was applied. RTOS was able to manage the task efficiently and effectively. In the aerospace domain, RTOS has become popular because of its strength in managing the operating system. Error Detection and Correction System (EDAC) system was applied to make OBDH more robust. This paper discusses the implementation of the EDAC system in tandem with the RTOS behaviour to manage the operation and increase the robustness of the system. The findings show that OBDH can be programmed successfully using RTOS to handle critical and robust operations.