Academic literature on the topic 'Attention. Motor ability'

This chapter deals with two separate areas of learning: attention and sequential organization. Difficulties in either area can occur in isolation or in combination with other forms of specific learning difficulty. The ability to ignore distractions and to focus on one activity at a time is a skill that children usually develop gradually as they grow. It is quite normal for toddlers and pre-school-aged children to be easily distractible, but the ability to channel attention selectively usually increases progressively once children start school. Some children experience significant difficulties in learning to attend. As a result, they are easily distractible and do not persist for long with tasks. If this is a significant problem, it is referred to by the umbrella term ‘attention-deficit/hyperactivity disorder’ (ADHD). This means attention-deficit with or without hyperactivity. Such children may be overactive and impulsive, although this is not always the case. It is this overactivity that has given rise to the term hyperactivity (‘hyper’ is Greek for ‘over’). All children with attention-deficit/hyperactivity disorder experience difficulty with concentration. There are two forms of the condition: one where overactivity and impulsivity are present and the other where these coexisting problems are absent. The two forms of attention-deficit/hyperactivity disorder may be clarified by describing two children, each with one of the forms of the disorder. George is his mother’s third child. She describes him as completely different from the other two. As a baby he slept very little and cried constantly. As a toddler he was always on the go, ‘as if driven by a motor’. Now, aged nine years, his teacher describes him as ‘disorganized, disruptive, and fidgety’. His mother reports that he hardly ever sits still at home. He will not sit through a favourite TV programme or a meal. He is still so disorganized that if she did not help him to dress in the morning, he would not be in time for school. He is also very impulsive. He does not seem to think before he acts. He takes terrible risks and often says the first thing that comes in to his head.

The authors are developing a hybrid walking rehabilitation system to realize the early recovery of walking ability, which includes both active movement training using walking rehabilitation machines and neurorehabilitation using mental imaginary of walking. In this study, the authors compared the activation of the motor area during real walking (RW), virtual walking (VW), and walking observation (WO) using fNIRS (functional Near-InfraRed Spectroscopy). VW was a first-person perspective imagery in which the subjects were shown moving scenes and imagined that they were actually walking in the scenes. WO was a third-person perspective imagery in which the subjects were instructed to imagine that they were walking at the same pace as the person in the video being shown to the subjects. Based on four subjects, results showed that the oxygenated hemoglobin (oxy-Hb) in the motor area during both the VW and WO were on average higher than during the RW. This might be because it was not necessary to pay attention to the movements of the legs and feet during normal walking, whereas movement planning was required when the subjects imagined that they were walking similar to another person. There was no significant difference between the oxy-Hb during the VW and the WO. The importance of the stimulus diversity in the mental imagery of walking was suggested.

The cognitive ability to process kinesic stimuli is nonverbal. Sensorimotor concepts are predictive and operate primarily outside of language. Human beings are able to perform a precise gesture without knowing how to account for it verbally. In literature, verbal artists work with the connections afforded in their language between sensorimotor and verbal concepts. In turn, the act of reading their texts taps into readers’ kinesic intelligence and their ability to connect a verbal concept of movement to a sensorial and motor concept. When writers play with such connections, kinesic humor in literature is liable to be experienced. In such instances, shifts in rhythm, tonicity, and kinesthetic intensity are paramount within readers’ perceptual simulations. While perceptual simulations are the prime trigger of an experience of humor, they generally remain pre-reflective. They can, however, become a focus of reflective attention. The introduction to Kinesic Humor provides a theory for this claim, and substantiates it with preliminary literary examples.

Neurologic diseases may lead to brain dysfunction and consequently to impairment of consciousness, cognitive decline, and emotional disturbances. These conditions may give rise to a wide array of ethical issues. Cerebral dysfunction can be temporary but many conditions are chronic and/or progressive, and the impact of such long-lasting brain dysfunction on decision-making processes is substantial. In this chapter, disturbances of consciousness and the decision-making process, with focus on communication during the various stages of coma, persistent vegetative state, and permanent vegetative state, are discussed. Special attention is paid to the role of proxies, who often have to act as surrogate decision-makers. Further, some aspects of brain death and organ donation are reviewed and the role of the neurologist as a specialist with respect to brain functioning, but also as an advocate acting in the interest of the patient and the patients’ relatives is depicted. Subsequently, consequences of impaired decision-making capacity in dementia and other diseases leading to diminished cognitive functioning are discussed and a short reflection is dedicated to driving ability. Ultimately, ethical issues in connection with decisions on withdrawing and withholding life-sustaining treatment including end-of-life decisions are discussed, both in neurologic diseases with diminished cognitive functioning but also in neurologic disorders, like motor neuron disease, where cognitive functions are preserved.

If an intelligent system is to benefit from prior experiences, then such a system must have the ability to learn. Learning must lead to the gathering of new knowledge of increased complexity and is based on the exploration of the world and social interactions. In this chapter authors describe building representations in motivated learning, a process that is close to learning by natural systems and yields better learning results in artificial systems than reinforcement learning. An embodied agent's mission is to survive in an unfavorable environment. The agent must have needs whose fulfillment is a measure of its success – survival. Meeting these needs require physical and mental efforts, and the development of useful skills is associated with the development of intelligence. The agent's environment must provide conditions in which individuals will be subjected to pressure from an environment in which better solutions, greater skills, and broader knowledge count. The agent treats unmet needs as signals to act. The strength of these signals depends on the degree of unmet needs so that the agent can differentiate between them and compared them. Various need signals provide motivation for action and control the learning process. In complex environments, there are rules that regulate the relationships between objects. By discovering these rules, the machine gains knowledge about the environment. Knowledge is represented by building connections between neurons in semantic memory. New concepts, objects, needs, or motor skills are represented by adding new memory cells and by associating them with other concepts, actions, and needs. Whether or not a new object or idea is created in semantic memory depends on the mechanism of novelty detection. The more time an agent spends on working or playing with an object, the better it learns the object's physical properties and how to use it. The intended use of objects determines characteristic features needed to classify them. Initially, semantic memory does not store any concepts, does not know places, does not recognize any objects, and does not support any activities or motivations. New concepts or representations of objects emerge from observation and manipulation of objects. A virtual agent's semantic memory obtains symbolic representations of objects and their location or movement in the observed scene. The focus of perceptual attention may result from detection of novelty, change, movement, signal intensity, or meaning in the context of needs. Attention should be focused long enough for the working memory to evaluate how much observed object or considered plan is useful. The focus of attention must also be accompanied by the possibility of switching attention. The attention switching responds to various types of signals, from sensory stimuli through planning and monitoring of performed activities to associative activation of memory. It results from constant rivalry between these signals for attention.

Schizophrenia symptoms fall into two categories: positive and negative symp­toms. Positive symptoms are behaviours or experiences outside the normal range of human activities. Hearing voices is a good example. Negative symp­toms are behaviours that are removed from the normal range. A reduced ex­perience of pleasure is a good example. Positive symptoms are prominent during the ‘active’ phase of the illness, when an affected individual is most disturbed and disruptive. The active phase is the phase that will more often lead to the individual’s referral for care. This is often because the affected individual will be doing or saying things that upset or disturb people around them, or at least get their attention and draw concern. For example, an individual with delusions might complain to her spouse that she is being followed by aliens and demandthat he help her find a way to stop them. Negative symptoms are most visible during the ‘prodromal’ and ‘residual’ phases of the illness. The prodromal phase comes before the first active phase (so actually occurs before a diagnosis of schizophrenia is ever made), and a residual phase follows each active phase.This class of symptoms most often includes delusions and auditory, visual, or other sensory hallucinations. Positive symptoms can be divided into percep­tual (i.e., affecting perception, or the ability to become aware of some stimulus through the senses), cognitive (i.e., impacting ways of thinking), emotional, or motor (physical) signs. Because these symptoms are so easy to recognize, even to the untrained eye, they make up a large part of the layperson’s general view of schizophrenia.Auditory hallucinations are the most common perceptual problems seen in schizophrenia. Many times, these hallucinations take the form of a voice, some­times making a running commentary on the individual’s thoughts or behaviours. Sometimes they take the form of several voices, each talking with the other. Some individuals with schizophrenia have visual, olfactory (i.e., affecting the sense of smell), or gustatory (i.e., affecting taste) hallucinations, but these are rare. Somatic hallucinations may also occur, in which the altered perception centres at or on the body’s organs.

Since the birth of computer science, researchers have secretly thought of themselves as brain-builders. After all, our thoughts are made from billions of little electrical impulses fired by neurons. Why can’t computers be made to think in similar ways to us, using the electrical impulses in their electronic circuits? Why can’t we make intelligent computers that can perform tasks that require intelligence? We could have learning, predicting, walking, talking, seeing, speaking computers. We might also have computers that can diagnose our illnesses, drive our cars, or explore distant planets for us. But how do you make intelligence? Through logic and reasoning? Or through lessons learned in life? How do intelligent minds think about their environments and themselves? Could we ever create a conscious artificial brain? . . . Cheerful music plays in the background. The grainy colour film shows a tall, slightly gaunt American man wearing a dark suit. As he speaks, he holds up something in his right hand. ‘This is Theseus.’ The film switches to a close-up of a little white mouse in a maze, moving forwards, flicking right, left, and forwards again. ‘Theseus is an electrically controlled mouse. He has the ability to solve a certain class of problems by trial and error, and then remember the solution. In other words, he can learn from experience.’ Once again, the work of Claude Shannon was attracting the attention of the public and academics alike. When he demonstrated his amazing machine at the Eighth Cybernetics Conference it created nothing but fascination and admiration from the other scientists. Perhaps to sound a little more serious, he usually called the mouse a ‘finger’ at the scientific conference. ‘You see the finger now exploring the maze, hunting for the goal,’ says Shannon, as he demonstrates the device live at the conference. ‘When it reaches the centre of a square the machine makes a new decision as to the direction to try. If the finger hits a partition, the motors reverse, taking the finger back to the center of the square, where a new direction is chosen.

Diagnosis systems for evaluating driver’s attention level have become very important in the last years and have gained an increasing attention from automotive manufacturers; indeed, traffic crashes represent worldwide one of the main public health problems and many accidents are demonstrated to be due to drivers’ hypovilance. In this work a driving simulator and specific test tools were developed to validate the possibility of monitoring the drivers’ attention level and capability. The driving simulator is equipped with a fixed cockpit and a single front screen. The cockpit reproduces the man-machine interface of a typical medium class car with automatic transmission, i.e. the driver interacts with the simulator by means of the throttle and brake pedals and the steering wheel. The pedals are endowed with passive feedback systems, whereas an electric motor applies an active feedback torque on the steering wheel. From the software point of view, the simulator is managed by four PCs connected by a LAN. Two of them are dedicated to the simulation of vehicle dynamics and for data logging, while the other two run the graphical scenario software. This includes a motorway area connected to an urban area with an autonomous traffic. The vehicle model was built with a block architecture in the Matlab/Simulink environment and is run in real-time by using the xPC Target toolbox. A specific block, consisting of an in-house developed 14 d.o.f. model, was set up to represents vehicle dynamics. The driving simulator is currently employed in experimental campaigns acquiring about 60 signals of driver’s input and vehicle quantities. In order to evaluate the drivers’ attention level, two specific tests were developed, which aim at measuring the drivers’ reaction time and ability in sudden events such as a brake manoeuvre or a sudden lateral skid. In the paper the driving simulator hardware and software are presented. The tests procedures, which were developed to investigate the driver’s attention, are also discussed with reference to some tests.

For an individual standing or walking on a moving or non-moving surface, perturbations can result in postural instability and sudden loss of balance. When unexpected perturbations occur, specific mechanisms involving the sensory, cognitive, and motor systems activate in order to regain postural control. For example, specific muscle synergies can result in compensatory limb movements (e.g. stepping or reaching towards a fixed object) that are prevalent mechanical responses to sudden loss of balance and play a crucial role in preventing falls. These movements require the interaction of multiple sensory systems including the visual, somatosensory, and vestibular systems. If sensory information is unavailable or incomplete, there may be a greater reliance on cognitive processes such as memory and attention in order to execute a balance-recovering mechanical response; however, if cognitive processes are tasked, compensatory responses may be negatively affected. The ability to recover from sudden loss of balance is critical in preventing falls on both non-moving and moving surfaces. This review includes a discussion of the biomechanical, perceptual, and cognitive factors responsible for the control of balance recovery on moving surfaces.

Postural control has been defined as “regulating the body’s position in space for the dual purposes of stability and orientation.” How the body achieves postural control depends, in part, on the environment. A person navigating a non-moving surface (e.g. hallway, stairway, or step ladder) will process information and will employ different strategies to maintain postural control than someone who is standing or walking on a moving surface (e.g., forklifts, personal transportation systems, escalators, and moving walkways). In both environments, sensory, cognitive, and motor control systems contribute to postural control. The musculoskeletal system uses muscle activation and joint positioning to control the body’s alignment and muscle tone. The biomechanics of postural control rely on information that the musculoskeletal system receives from sensory systems including the vestibular system, which is generally implicated in behaviors requiring balance control, as well as the somatosensory and visual systems. Furthermore, sensory information from these and other systems can be enhanced by cognitive processes, such as attention. The ability to maintain postural control while standing or walking is critical in preventing falls on both non-moving and moving surfaces. This review focuses on moving surfaces and includes a discussion of the biomechanical, perceptual, and cognitive factors responsible for postural control.

Abstract In the last 10 years, Metal Additive Manufacturing (AM) has matured substantially [1,2]. The evolution of metal powder-bed AM now, facilitates production-quality parts to be manufactured. Additive manufacturing has specially attracted attention for its ability to manufacture parts with complex shapes that are cost-ineffective or impossible to manufacture with traditional technologies. For Oil and Gas industry, this ability to manufacture complex shapes offers unprecedented opportunity to redesign and optimize wide ranging components from cutting heads, heat exchangers [3], pumping and filtration equipment to drill motors, inline static-mixers and flanges. as well as advantages over traditional manufacturing techniques. The present work shows how optimization and simulation tools are valuable in rapid development of more efficient and light-weighted components that take advantage of the 3D printing process. Additive Manufacturing, while promising offers its own challenges related to process parameter optimization and part distortions. So, testing new paradigm-shifting design becomes time consuming and expensive trial and error process. Computational methods for optimization and physics simulation reduce the risk of testing new designs concepts and make the transition to new products efficient and inexpensive. Conventional design and design-optimization techniques typically do not apply for AM part design. The flexibility of AM in generating complex shapes implies a lesser number of components and implicit savings in assembly. Also, the possibility of latticed structures allows for reduced components through consolidation. The ability to incorporate these structures broadens the design criteria to achieve previously unforeseen possibilities. After arriving at the part design, the "print design" needs to be addressed. The AM process involves large thermal transients, phase change and non-linear material properties potentially leading to distortions and residual stresses in the finished component. Process simulation is valuable in estimating stresses generated in components, distortion, and adequacy of the support design. The presentation illustrates the simulation methodologies in design, multi-physics and process optimization for a drill-head geometry.

The application of new lubrication technology has a close relationship with the industrial development of automobile, machinery and transportation. Energy saving and environment protection are main two factors to push lubricants upgrades. Lubricant quality and correct application directly influence the use-life of machine, consumption of energy and environment protection. All over the world, especially in Western developed countries people pay more attention to the research and application of new lubricant technology. The lubricant specifications were reviewed and upgraded continuously according to the requirements of machine, fuel economy and emission. China’s sustained development means the ability to satisfy current human’s requirement as well as not to destroy nature resources for next generation. That also means we must balance the fast development of economy, society, resources and environment, we must protect natural resources and environment such as water, ocean, lands and forest which we live on, which can keep our next generation developing. Research and application of new lubricant technology is basic issues to keep China’s economy continuously growing. China’s petroleum consumption increased rapidly during the recent decades. There are two rapid period within 25 years after China’s application of opening and reform policy. The first is from 1978 to 1990, the whole petroleum consumption increased from 913 million to 1.18 billion tons respectively, increasing rate is 2.0% per year. The second was from 1991 to 2003, petroleum consumption increased from 1.18 billion to 2.74 billion tons, increasing rate was up to 6.7% per year. If we compare 2003 with 2001, the net petroleum consumption amount had increased 42million tons, increase rate is 8.7% per year. China now becomes one of biggest petroleum consumption country. The efficiency of China’s petroleum consumption is low. According to world petroleum consumption level (ton per thousand U.S. Dollar, GDP), China consumes four times more petroleum than that of Japan, three times of that of European, two times of that of USA. The wide application of low-grade lubricating oil and the lack of new lubrication technology are the main cause of the low-efficient petroleum usage. In the future decades petroleum shortages will be more and more strict in China, and it will have an important role in the delay of economic development and national safety. It is our lubricants workers duty to develop and apply the new lubrication technology to enhance the use efficiency of petroleum, to prevent our reliable environment and to push the China’s sustainable development. The world total consumption quantity of lubricating oil keeps about 37 to 39 million tons per year. It shares about 1% of total crude refining amount. The lube consumption amount in North American keeps stable about 9.5 million tons which listed No.1 while European and previous Unit Soviet area decreased. Asia is the only increased area, mainly because of the fast economic growth in China and India. China has consumed 4.4million tons lubricating oil in 2003, take about 1.6% of total crude refining amount, shares about 11% of whole world consumption amount, values about 22 billion RMB [1]. The increased rate reaches the highest—10.56% compared to 2002. This was the first time China become the second lubricant consumer in the world, just after USA. In 2004, China’s lubricants consumption will reach over 5 million tons, reaches the top in history, the increased rate will reach 10% comparing with 2003. China’s Automobile industry develops rapidly in the recent years, at the same time fuel efficiency keeps a low level. In 2002 China’s automobile has consumed 2.28 ton fuel per automobile which is 110–120 percent of USA, 200 percent of Japan. There exists a wide market for the application of new lubrication technology. The application of those additives and lube oils such as environment-friend additives, friction modified agents, nano-lube additives, energy-conserving multi-grade lube oils can enhance lubrication efficiency of equipments, decrease fuel consumption and conserve the petroleum resources. In this paper the applications of Cu nano-lube additive are introduced. and 0.1% Cu nano-lube is added into passenger car motor oil 5W30 SJ. The four-ball test equipment, cam-tappet test equipment and MS VI engine test are used to evaluate the performance, the test results shows the application of Cu nano-additive can obviously decrease the friction coefficient and fuel consumption. China should establish its national lube oil evaluation system, this system can greatly push the warranty of the quality of lube oil. The standard and national principle for fuel-conserving should be acted to improve the application of multi-grade lube oil and energy-conserving lube oil and new technology.

This paper describes major breakthroughs in foil thrust bearings achieving a thrust load capacity in excess of 570 kPa (83 psi), supersonic tip speed of 625 m/s (2050 ft/s) and temperature capability of 815 °C (1500 °F). Compliant foil bearings surpass many of the inherently show-stopping and debilitating features of rolling element bearings. Foil Bearings not only provide an environmentally-friendly, oil-free system of support, but are also well suited for high speed and extreme temperature applications such as gas turbines, compressors, turbochargers, cryogenic-turbopumps, turboexpanders, high speed motors and others. Modern foil bearings have demonstrated stable operational capabilities at super-critical speeds due to their tribodamping intrinsicality and ability to operate with any process fluid (gas or liquid). Recent developments have allowed increased operating temperatures, soaring to 815 °C and above, thus, providing a broader operational temperature range from deep cryogenic to extreme high temperatures. Foil journal bearings received more research and development attention in the past, achieving load capacity of 670 kPa (97 psi), reported by Heshmat in 1994. Foil thrust bearings’ load capacity at that time was in the range of 150 kPa to 200 kPa (20–30 psi) and their temperature capability was ambient to 150 °C (300 °F). This paper discusses a recent major breakthrough in the improvement of the load capacity, high speed capability of compliant foil thrust bearings, as well as extending their operating temperature range to 815 °C. Applying the available analytical tools and newly developed coatings, new thrust bearings have been designed with improved bearing geometry and structural compliancy. The advancement in solid lubricant coatings provided excellent tolerance to intermittent high-speed rubs, thus, making the bearings more robust against shock and extreme loadings. These advanced bearings, with outer diameters ranging from 90 mm to 230 mm, demonstrated a load capacity of 570 kPa (82.7 psi) at 200 m/s runner tip speed. This achievement constitutes two-fold improvement over any state-of-the-art hydrodynamic foil thrust bearings ever reported in the literatures and significantly expands the envelope of possible bearing applications. Improving the bearing load capacity at speeds near Mach 1.6 and higher is also discussed, as well as hydrodynamic operation of a foil thrust pad at 815 °C.

The paper illustrates the application of a genetic algorithm as a methodology to choose and improve the motion law governing the movement of a redundant robot. The subject of this research is an innovative system developed to introduce the laser ray technology in the on-line tube cutting. This technique allows a quality improvement in the pipe-cutting sector, thanks to the various goals. Firstly we underline the improvement of the working environment due to the elimination of cutting noise taking off the tool changing and the steel shaving creation. Secondarily there is a drastic reduction of the cutting cycle time and an improvement of the productivity accomplished by the use of brushless drives and linear motors. In the robot design, particular attention was dedicated to the masses distributions allowing a good natural machine dynamics. The ability of the robot to avoid the cutting object, the demand to maintain the laser torch orthogonal to the cutting surfaces, as well the necessity to impose a velocity behaviour as constant as possible during the cutting operation, suggested the introduction of a redundant degree of freedom. This aspect gives a lot of opportunities in the choose of movements because there are thousands motion profiles for the joints whichever satisfying the conditions imposed to the end-effector path. In this context, we have proposed the idea to combine the procedure to solve the inverse kinematics problem with the contemporaneous optimization of the trajectory. Literature offers a series of algorithms to solve well-known inverse kinematics problem of redundant robot. These are based on the inversion of the matrix representing the link between the end-effector co-ordinates and the joints. The presence of redundancy makes this matrix rectangular and requires the use of the pseudo-inverse matrix to solve the problem in several points of the trajectory. The introduction of some weights, one for each joint co-ordinate, allows to obtain a different distribution of the joint movements computing the pseudo-inverse matrix. If we change these weights in a continuous way in time domain, we can supervise the dynamic behaviors of the machine. The new idea we propose here is the use of an adapted multi-objective genetic algorithm to define a several of particular motion laws reducing vibrations and realizing “special harmonies” in the robot motion. The procedure, that will be completely discussed in the full paper, is actually working on a laser pipe cutting machine. This robot awarded the first prize between two thousand competitor at the EMO MILANO 2003 exhibition.