Academic literature on the topic 'Parahippocampal Cortex'
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Journal articles on the topic "Parahippocampal Cortex"
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Loprinzi, PD. "The effects of physical exercise on parahippocampal function." Physiology International 106, no. 2 (June 2019): 114–27. http://dx.doi.org/10.1556/2060.106.2019.10.
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Objective The objective of this study was to examine the effects of physical exercise on parahippocampal function. Methods Studies were identified using electronic databases, including PubMed, PsychInfo, Sports Discus, and Google Scholar. In total, 28 articles met the inclusionary criteria. Among these, 20 were among humans and 8 in animal models. Among the 20 human studies that examined some aspects of the parahippocampal gyrus, 5 evaluated the entorhinal cortex and 1 evaluated the perirhinal cortex. Among the 20 human studies, 3 evaluated neural activity (or BOLD-signal changes), 14 evaluated brain volume (gray or white matter), 2 examined fractional anisotropy, 1 examined glucose metabolism, and 1 examined functional connectivity between the parahippocampal gyrus and a proximal brain tissue. Among the 8 animal studies, 4 evaluated the entorhinal cortex, with the other 4 examining the perirhinal cortex. Results The results demonstrated that, among both animal and human models, exercise had widespread effects on parahippocampal function. These effects, included, for example, increased neural excitability in the parahippocampal gyrus, increased gray/white matter, reduced volume of lesions, enhanced regional glucose metabolism, increased cerebral blood flow, augmented markers of synaptic plasticity, and increased functional connectivity with other proximal brain structures. Conclusion Exercise appears to have extensive effects on parahippocampal function.
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Doeller, Christian F., and Raphael Kaplan. "Parahippocampal Cortex: Translating Vision into Space." Current Biology 21, no. 15 (August 2011): R589—R591. http://dx.doi.org/10.1016/j.cub.2011.06.023.
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Mormann, Florian, Simon Kornblith, Moran Cerf, Matias J. Ison, Alexander Kraskov, Michelle Tran, Simeon Knieling, Rodrigo Quian Quiroga, Christof Koch, and Itzhak Fried. "Scene-selective coding by single neurons in the human parahippocampal cortex." Proceedings of the National Academy of Sciences 114, no. 5 (January 17, 2017): 1153–58. http://dx.doi.org/10.1073/pnas.1608159113.
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Imaging, electrophysiological, and lesion studies have shown a relationship between the parahippocampal cortex (PHC) and the processing of spatial scenes. Our present knowledge of PHC, however, is restricted to the macroscopic properties and dynamics of bulk tissue; the behavior and selectivity of single parahippocampal neurons remains largely unknown. In this study, we analyzed responses from 630 parahippocampal neurons in 24 neurosurgical patients during visual stimulus presentation. We found a spatially clustered subpopulation of scene-selective units with an associated event-related field potential. These units form a population code that is more distributed for scenes than for other stimulus categories, and less sparse than elsewhere in the medial temporal lobe. Our electrophysiological findings provide insight into how individual units give rise to the population response observed with functional imaging in the parahippocampal place area.
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Cheung, Olivia S., and Seoyoung Lee. "Roles of parahippocampal cortex and retrosplenial cortex in scene integration." Journal of Vision 20, no. 11 (October 20, 2020): 532. http://dx.doi.org/10.1167/jov.20.11.532.
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SATO, Nobuya. "The primate parahippocampal cortex and scene recognition." Japanese Journal of Animal Psychology 50, no. 1 (2000): 161–70. http://dx.doi.org/10.2502/janip.50.161.
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Huang, Chu-Chung, Edmund T. Rolls, Chih-Chin Heather Hsu, Jianfeng Feng, and Ching-Po Lin. "Extensive Cortical Connectivity of the Human Hippocampal Memory System: Beyond the “What” and “Where” Dual Stream Model." Cerebral Cortex 31, no. 10 (May 19, 2021): 4652–69. http://dx.doi.org/10.1093/cercor/bhab113.
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Abstract The human hippocampus is involved in forming new memories: damage impairs memory. The dual stream model suggests that object “what” representations from ventral stream temporal cortex project to the hippocampus via the perirhinal and then lateral entorhinal cortex, and spatial “where” representations from the dorsal parietal stream via the parahippocampal gyrus and then medial entorhinal cortex. The hippocampus can then associate these inputs to form episodic memories of what happened where. Diffusion tractography was used to reveal the direct connections of hippocampal system areas in humans. This provides evidence that the human hippocampus has extensive direct cortical connections, with connections that bypass the entorhinal cortex to connect with the perirhinal and parahippocampal cortex, with the temporal pole, with the posterior and retrosplenial cingulate cortex, and even with early sensory cortical areas. The connections are less hierarchical and segregated than in the dual stream model. This provides a foundation for a conceptualization for how the hippocampal memory system connects with the cerebral cortex and operates in humans. One implication is that prehippocampal cortical areas such as the parahippocampal TF and TH subregions and perirhinal cortices may implement specialized computations that can benefit from inputs from the dorsal and ventral streams.
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Vincent, Justin L., Itamar Kahn, David C. Van Essen, and Randy L. Buckner. "Functional Connectivity of the Macaque Posterior Parahippocampal Cortex." Journal of Neurophysiology 103, no. 2 (February 2010): 793–800. http://dx.doi.org/10.1152/jn.00546.2009.
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Neuroimaging experiments in humans suggest that regions in parietal cortex and along the posterior midline are functionally connected to the medial temporal lobe and are active during memory retrieval. It is unknown whether macaques have a similar network. We examined functional connectivity in isoflurane-anesthetized macaques to identify a network associated with posterior parahippocampal cortex (PPHC). Functional connectivity was observed between the PPHC and retrosplenial, posterior cingulate, superior temporal gyrus, and inferior parietal cortex. PPHC correlations were distinct from regions in parietal and temporal cortex activated by an oculomotor task. Comparison of macaque and human PPHC correlations revealed similarities that suggest the temporal-parietal region identified in the macaque may share a common lineage with human Brodmann area 39, a region thought to be involved in recollection. These results suggest that macaques and humans may have homologous PPHC-parietal pathways. By specifying the location of the putative macaque homologue in parietal cortex, we provide a target for future physiological exploration of this area's role in mnemonic or alternative processes.
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Meunier, M., W. Hadfield, J. Bachevalier, and E. A. Murray. "Effects of rhinal cortex lesions combined with hippocampectomy on visual recognition memory in rhesus monkeys." Journal of Neurophysiology 75, no. 3 (March 1, 1996): 1190–205. http://dx.doi.org/10.1152/jn.1996.75.3.1190.
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1. We assessed the visual recognition abilities, as measured by delayed nonmatching-to-sample with trial-unique objects, of rhesus monkeys with hippocampectomy (i.e., removal of the hippocampal formation plus parahippocampal gyrus) combined with ablations of the rhinal cortex (i.e., entorhinal cortex plus perirhinal cortex). 2. Relative to unoperated controls, monkeys with combined hippocampectomy and rhinal cortex ablation (H+Rh) were significantly impaired in visual recognition. 3. Comparison of the scores of the monkeys in the present H+Rh group, which sustained near-complete rhinal cortex damage, with the scores of monkeys in an earlier H+Rh group in which the rostral part of the rhinal cortex had been spared indicates that the magnitude of the impairment is greater in the group with the more complete rhinal cortex damage. This finding is consistent with the idea that the rhinal cortex is critical for visual recognition. 4. Comparison of the present results with those from an earlier study on visual recognition that employed lesions limited to the rhinal cortex (Rh group) shows, paradoxically, that adding removal of the hippocampal formation and parahippocampal gyrus to a rhinal cortex lesion significantly reduces the recognition impairment produced by rhinal cortex lesions alone. 5. Our findings do not fit the view that the hippocampal formation, parahippocampal gyrus, and rhinal cortex constitute parts of a single functional system, such that the greater the damage to the entire system, the more severe the impairment. Instead, the results are consistent with the view that there are multiple functional subdivisions within the medial temporal lobe.
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Epstein, Russell, Kim S. Graham, and Paul E. Downing. "Viewpoint-Specific Scene Representations in Human Parahippocampal Cortex." Neuron 37, no. 5 (March 2003): 865–76. http://dx.doi.org/10.1016/s0896-6273(03)00117-x.
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Aminoff, E., N. Gronau, and M. Bar. "The Parahippocampal Cortex Mediates Spatial and Nonspatial Associations." Cerebral Cortex 17, no. 7 (September 21, 2006): 1493–503. http://dx.doi.org/10.1093/cercor/bhl078.
Full textDissertations / Theses on the topic "Parahippocampal Cortex"
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Knieling, Simeon [Verfasser]. "Effects of intracranial stimulation and the involvement of the human parahippocampal cortex in perception / Simeon Knieling." Bonn : Universitäts- und Landesbibliothek Bonn, 2019. http://d-nb.info/1198933623/34.
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Karanian, Jessica M. "Theneural basis of true memory and false memory for visual features:." Thesis, Boston College, 2017. http://hdl.handle.net/2345/bc-ir:107364.
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Thesis advisor: Scott D. SlotnickEpisodic memory is a constructive process in which a system of sensory and control processes works to transport one’s conscious mind through time–in essence, recreating a previous perceptual experience. For instance, sensory-specific activity that was associated with an original encoding experience is reinstated during retrieval–almost as if the sensory regions are processing the stimulus again, albeit this activation is smaller in spatial extent. This process of sensory-specific reinstatement occurs across all sensory modalities (e.g., Gottfried et al., 2004; Nyberg et al., 2001; Vaidya et al., 2002; Wheeler et al., 2000). That is, retrieval of a visually encoded stimulus (e.g., a picture of a dog) reinstates activity in the visual cortex, while retrieval of an aurally encoded stimulus (e.g., a barking dog) reinstates activity in the auditory cortex. In Chapter 1 and Chapter 2, I demonstrate the specificity of such sensory reinstatement during true memory for visual features and investigate the role of such sensory regions during the construction of false memory for visual features. In addition to sensory processes, our conscious experience of memory also relies on control regions. At the center of this memory control network sits a key memory structure, the hippocampus, as well as other important control regions such as the dorsolateral prefrontal cortex and the parietal cortex. Furthermore, the parahippocampal cortex appears to play a critical role in memory; however, the exact role of this region has been debated (Aminoff, Kverga, & Bar, 2013). In Chapter 3, I investigate the functional role of the parahippocampal cortex during true memory and false memory, and provide evidence that the parahippocampal cortex mediates general contextual processing
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Berman, Daniel. "From Photons to Photos: Mapping Functional and Organizational Properties of Human Visual Cortex with fMRI." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1422972281.
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Brooks, Samantha J., Jonathan Cedernaes, and Helgi B. Schiöth. "Increased prefrontal and parahippocampal activation with reduced dorsolateral prefrontal and insular cortex activation to food images in obesity : a meta-analysis of fMRI studies." Uppsala universitet, Funktionell farmakologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-199757.
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BACKGROUND AND OBJECTIVES: Obesity is emerging as the most significant health concern of the twenty-first century. A wealth of neuroimaging data suggest that weight gain might be related to aberrant brain function, particularly in prefrontal cortical regions modulating mesolimbic addictive responses to food. Nevertheless, food addiction is currently a model hotly debated. Here, we conduct a meta-analysis of neuroimaging data, examining the most common functional differences between normal-weight and obese participants in response to food stimuli. DATA SOURCE: We conducted a search using several journal databases and adhered to the 'Preferred Reporting Items for Systematic Reviews and Meta-analyses' (PRISMA) method. To this aim, 10 studies were found with a total of 126 obese participants, 129 healthy controls, equaling 184 foci (146 increased, 38 decreased activation) using the Activation Likelihood Estimation (ALE) technique. Out of the 10 studies, 7 investigated neural responses to food versus non-food images. RESULTS: In response to food images, obese in comparison to healthy weight subjects had increased activation in the left dorsomedial prefrontal cortex, right parahippocampal gyrus, right precentral gyrus and right anterior cingulate cortex, and reduced activation in the left dorsolateral prefrontal cortex and left insular cortex. CONCLUSIONS: Prefrontal cortex areas linked to cognitive evaluation processes, such as evaluation of rewarding stimuli, as well as explicit memory regions, appear most consistently activated in response to images of food in those who are obese. Conversely, a reduced activation in brain regions associated with cognitive control and interoceptive awareness of sensations in the body might indicate a weakened control system, combined with hypo-sensitivity to satiety and discomfort signals after eating in those who are prone to overeat.
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Couch, Thomas. "Exploring the processes of recollection using eye tracking and parametric fMRI." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/exploring-the-processes-of-recollection-using-eye-tracking-and-parametric-fmri(10ea7549-2b4a-42ef-9031-1218002c41d1).html.
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Recollection, the process by which an item provokes the retrieval of associated information stored in the brain, is a key component of recognition memory. It is explored in this thesis through the use of a paradigm designed to allow the neural correlates of amount recalled to be identified through parametric fMRI analysis. A series of experiments were carried out during the development and optimisation of this paradigm in order to ensure that the various demands of this analysis were met. Subsequently this paradigm was applied during an fMRI experiment which provided data from both the encoding and retrieval stages of recollection.Whilst the development work was chiefly concerned with producing a suitable task design for the parametric fMRI analysis, these experiments provided some interesting results in their own right. The task design, which required participants to associate multiple item types within a story context, showed that there are significant differences in the frequency with which different stimuli are recollected. Participants were found to be particularly poor at recollecting faces whilst words were also shown to be recollected less frequently than either object or animal picture stimuli. A possible explanation for these differences may be related to the picture superiority effect although eye-tracking data collected from these experiments demonstrates large differences in viewing behaviour between different target stimulus types which is not correlated with later recall success. The amount of time participants spend engaging with the highly contextual scene item does predict later recall success.The fMRI analysis (Chapter 5) carried out during the encoding and retrieval stages of recollection found a variety of regions exhibiting a positive linear relationship with recollection at both these stages. This result provides support for the cortical reinstatement hypothesis of recollection despite the fact that the hippocampus only showed parametric modulation of activity during retrieval. It is proposed that parahippocampal activity during encoding and retrieval supports the recollection of contextual information whilst the same pattern of activity in parietal regions related to recollection may reflect the reinstatement of the global image of the story created during the encoding task.
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Berman, Daniel. "Representations of Spatial Frequency, Depth, and Higher-level Image Content in Human Visual Cortex." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1542184547546769.
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Périco, Cintia de Azevedo Marques. "Ressonância magnética estrutural em pacientes com transtorno afetivo com características psicóticas avaliados no primeiro contato com serviço de saúde mental." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/5/5142/tde-11032008-150019/.
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Os transtornos afetivos são altamente prevalentes dentre os transtornos mentais, principalmente Transtorno Afetivo Bipolar (TAB) e Depressão Maior Unipolar (DMU), apresentando altas taxas de morbi-mortalidade. Estudos prévios de Ressonância Magnética (RM) têm identificado anormalidades estruturais cerebrais em indivíduos com TAB e DMU quando comparados a controles normais. Entretanto, nenhum destes estudos foi realizado a partir da comparação direta entre pacientes com DMU e TAB de início recente, nem comparou separadamente tais grupos com amostras representativas de controles assintomáticos provenientes de mesma região geográfica. No presente estudo, definimos a priori que regiões do circuito córtico-límbico-talâmico-estriatal estariam alteradas quando comparados indivíduos com TAB, DMU e controles normais diretamente entre si, em amostra de pacientes com quadros graves de sintomatologia psicótica e pareada com controles normais selecionados na mesma área geográfica dos pacientes. Foram selecionados 46 pacientes (20 com DMU e 26 com TAB) que tiveram contato pela primeira vez com serviço de saúde mental após início de sintomas psicóticos e 62 controles normais. Tanto pacientes quanto controles foram submetidos à RM em aparelho de 1,5 Tesla. Os diagnósticos foram baseados no DSM-IV e confirmados após 1 ano da realização da RM. As imagens foram analisadas pelo método automatizado de processamento denominado morfometria baseada no voxel (voxel-based morphometry). A comparação entre os grupos mostrou redução significativa de substância cinzenta regional em pacientes com DMU comparados aos controles (p<0,05, corrigido para comparações múltiplas) em duas regiões cerebrais selecionadas a priori: córtex pré-frontal dorsolateral (CPFDL) bilateralmente e giro parahipocampal posterior esquerdo. Na comparação direta entre pacientes com DMU e TAB encontramos uma redução de substância cinzenta de CPFDL direito em pacientes com DMU, como tendência a significância estatística (p<0,10, corrigido para comparações múltiplas). Nossos achados mostram que anormalidades volumétricas de CPFDL e região temporal medial estão presentes em pacientes com DMU em primeiro episódio psicótico, mas não em pacientes com TAB com gravidade de sintomas semelhante.Affective disorders are highly prevalent mental disorders, mainly Major Depressive Disorder (MDD) and Bipolar Disorder (BD), with high morbidity and mortality rates. Previous morphometric magnetic resonance imaging (MRI) studies have identified brain volumetric abnormalities in samples of subjects suffering from MDD or BD. However, none of these have conducted direct brain volume comparisons between patients with recent-onset MDD and BD, nor contrasted them separately against representative groups of asymptomatic controls recruited from exactly the same environment. In the present study, we defined a priori that brain regions involved in cortico-limbic-thalamic-striatal circuits would present volume abnormalities when comparing subjects with MDD and BD with psychotic features, in their first contact with the health care system in Brazil, and a control sample of next-door asymptomatic neighbors. Forty-six patients (20 MDD and 26 BD) and 62 controls were examined with MRI, using an equipment of 1.5 Tesla. Diagnoses were based on DSM-IV, and confirmed one year after scanning. Image processing was conducted using voxel-based morphometry methods. Between-group comparisons showed significant regional gray matter deficits in MDD subjects relative to controls (p<0.05, corrected for multiple comparisons), involving two brain regions where abnormalities in mood disorder patients had been predicted a priori: the dorsolateral prefrontal cortex (DLPFC) bilaterally and the left posterior parahippocampal gyrus. In the direct comparison between MDD and BD patients, the right-sided finding of decreased DLPFC gray matter in the former group retained trend levels of significance (p<0.10 corrected). Our findings indicate that significant structural abnormalities of the DLPFC and medial temporal region are present in patients with MDD in their first episode with psychotic features, but not in BD subjects with symptoms of similar severity.
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Shaw, Lynda Joan. "Emotional processing of natural visual images in brief exposures and compound stimuli : fMRI and behavioural studies." Thesis, Brunel University, 2009. http://bura.brunel.ac.uk/handle/2438/3203.
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Can the brain register the emotional valence of brief exposures of complex natural stimuli under conditions of forward and backward masking, and under conditions of attentional competition between foveal and peripheral stimuli? To address this question, three experiments were conducted. The first, a behavioural experiment, measured subjective valence of response (pleasant vs unpleasant) to test the perception of the valence of natural images in brief, masked exposures in a forward and backward masking paradigm. Images were chosen from the International Affective Picture System (IAPS) series. After correction for response bias, responses to the majority of target stimuli were concordant with the IAPS ratings at better than chance, even when the presence of the target was undetected. Using functional magnetic resonance imaging (fMRI), the effects of IAPS valence and stimulus category were objectively measured on nine regions of interest (ROIs) using the same strict temporal restrictions in a similar masking design. Evidence of affective processing close to or below conscious threshold was apparent in some of the ROIs. To further this line of enquiry, a second fMRI experiment mapping the same ROIs and using the same stimuli were presented in a foveal (‘attended’) peripheral (‘to-be-ignored’) paradigm (small image superimposed in the centre of a large image of the same category, but opposite valence) to investigate spatial parameters and limitations of attention. Results are interpreted as showing both valence and category specific effects of ‘to-be-ignored’ images in the periphery. These results are discussed in light of theories of the limitations of attentional capacity and the speed in which we process natural images, providing new evidence of the breadth of variety in the types of affective visual stimuli we are able to process close to the threshold of conscious perception.
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Chand, Ganesh. "Oscillatory Network Dynamics in Perceptual Decision-Making." 2015. http://scholarworks.gsu.edu/phy_astr_diss/79.
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Synchronized oscillations of ensembles of neurons in the brain underlie human cognition and behaviors. Neuronal network oscillations can be described by the physics of coupled dynamical systems. This dissertation examines the dynamic network activities in two distinct neurocognitive networks, the salience network (SN) and the ventral temporal cortex-dorsolateral prefrontal cortex (VTC-DLPFC) network, during perceptual decision-making (PDM).
The key nodes of the SN include the right anterior insula (rAI), left anterior insula (lAI), and dorsal anterior cingulate cortex (dACC) in the brain. When and how a sensory signal enters and organizes within the SN before reaching the central executive network including the prefrontal cortex has been a mystery. Second, prior studies also report that perception of visual objects (face and house) involves a network of the VTC—the fusiform face area (FFA) and para-hippocampal place area (PPA)—and the DLPFC. How sensory information enters and organizes within the VTC-DLPFC network is not well understood, in milliseconds time-scale of human’s perception and decision-making. We used clear and noisy face/house image categorization tasks and scalp electroencephalography (EEG) recordings to study the dynamics of these networks. We demonstrated that beta (13–30 Hz) oscillation bound the SN, became most active around 100 ms after the stimulus onset, the rAI acted as a main outflow hub within the SN, and the SN activities were negatively correlated with the difficult tasks. We also uncovered that the VTC-DLPFC network activities were mediated by beta (13-30 Hz) and gamma (30-100 Hz) oscillations. Beta activities were enhanced in the time frame 125-250 ms after stimulus onset, the VTC acted as main outflow hub, and network activities were negatively correlated with the difficult tasks. In contrast, gamma activities were elevated in the time frame 0-125 ms, the DLPFC acted as a main outflow hub, and network activities—specifically the FFA-PPA pair—were positively correlated with the difficult tasks. These findings significantly enhance our understanding of how sensory information enters and organizes within the SN and the VTC-DLPFC network, respectively in PDM.
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Chebat, Daniel-Robert. "Un oeil sur la langue : aspects neuro-cognitifs du processus de la navigation chez l'aveugle-né." Thèse, 2010. http://hdl.handle.net/1866/4421.
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La vision est un élément très important pour la navigation en général. Grâce à des mécanismes compensatoires les aveugles de naissance ne sont pas handicapés dans leurs compétences spatio-cognitives, ni dans la formation de nouvelles cartes spatiales. Malgré l’essor des études sur la plasticité du cerveau et la navigation chez les aveugles, les substrats neuronaux compensatoires pour la préservation de cette fonction demeurent incompris.
Nous avons démontré récemment (article 1) en utilisant une technique d’analyse volumétrique (Voxel-Based Morphometry) que les aveugles de naissance (AN) montrent une diminution de la partie postérieure de l’hippocampe droit, structure cérébrale importante dans la formation de cartes spatiales. Comment les AN forment-ils des cartes cognitives de leur environnement avec un hippocampe postérieur droit qui est significativement réduit ? Pour répondre à cette question nous avons choisi d’exploiter un appareil de substitution sensorielle qui pourrait potentiellement servir à la navigation chez les AN. Cet appareil d’affichage lingual (Tongue display unit -TDU-) retransmet l’information graphique issue d’une caméra sur la langue. Avant de demander à nos sujets de naviguer à l’aide du TDU, il était nécessaire de nous assurer qu’ils pouvaient « voir » des objets dans l’environnement grâce au TDU. Nous avons donc tout d’abord évalué l’acuité « visuo »-tactile (article 2) des sujets AN pour les comparer aux performances des voyants ayant les yeux bandées et munis du TDU. Ensuite les sujets ont appris à négocier un chemin à travers un parcours parsemé d’obstacles
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(article 3). Leur tâche consistait à pointer vers (détection), et contourner (négociation) un passage autour des obstacles. Nous avons démontré que les sujets aveugles de naissance non seulement arrivaient à accomplir cette tâche, mais encore avaient une performance meilleure que celle des voyants aux yeux bandés, et ce, malgré l’atrophie structurelle de l’hippocampe postérieur droit, et un système visuel atrophié (Ptito et al., 2008). Pour déterminer quels sont les corrélats neuronaux de la navigation, nous avons créé des routes virtuelles envoyées sur la langue par le biais du TDU que les sujets devaient reconnaitre alors qu’ils étaient dans un scanneur IRMf (article 4). Nous démontrons grâce à ces techniques que les aveugles utilisent un autre réseau cortical impliqué dans la mémoire topographique que les voyants quand ils suivent des routes virtuelles sur la langue. Nous avons mis l’emphase sur des réseaux neuronaux connectant les cortex pariétaux et frontaux au lobe occipital puisque ces réseaux sont renforcés chez les aveugles de naissance. Ces résultats démontrent aussi que la langue peut être utilisée comme une porte d’entrée vers le cerveau en y acheminant des informations sur l’environnement visuel du sujet, lui permettant ainsi d’élaborer des stratégies d’évitement d’obstacles et de se mouvoir adéquatement.Vision is a very important tool for navigation in general. Due to compensatory mechanisms people who are blind from birth are not handicapped in spatio-cognitive abilities, nor in the formation of novel spatial maps. Despite the growing volume of studies on brain plasticity and navigation in the blind, the compensatory neural substrates or the preservation of this function remain unclear. We have recently demonstrated (article 1) by using volumetric analysis techniques (Voxel-Based Morphometry) that early blind individuals (EB) show a reduction of the posterior end of the hippocampus on the right side. This cerebral structure is important for the formation of cognitive maps. How do EB form maps of their environment with a significantly reduced posterior right hippocampus? To answer this question we chose to exploit a sensory substitution device that could potentially serve navigation in EB. This tongue display unit (TDU) is capable of transmitting pictorial imagery in the form of electricity on the tongue. Before asking our participants to navigate using the TDU, it was necessary to ascertain that they could really « see » objects in the environment using the TDU. We thus evaluated the « visuo »-tactile acuity (article 2) of EB compared to sighted blindfolded participants using the TDU. Participants later learned to negotiate a path through an obstacle course (article 3). Their task consisted of pointing to (detection), and avoiding (negotiation) obstacles while advancing through the hallway. We demonstrated that despite a reduced right posterior hippocampus, and an iii atrophied visual system (Ptito et al., 2008) EB not only were able to accomplish this task, but had a better performance than the blindfolded sighted controls. To determine what the neural correlates of navigation in EB are, we devised an fMRI compatible virtual route task conveyed through the tongue (article 4). Participants had to learn to navigate the routes and recognize them. We showed that EB use another cortical network involved in cognitive mapping than the sighted when recognizing routes on the tongue. We have emphasized neural networks connecting parietal and frontal cortices since they are re-enforced in EB. These results show that the tongue can be used as a portal to the brain by transferring pictorial information from the visual environment of participants, allowing the elaboration of strategies to avoid obstacles and move around in their environment.
Books on the topic "Parahippocampal Cortex"
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Sulphide Silver Pattern and Cytoarchitectonics of Parahippocampal Areas in the Rat: Special Reference to the Subdivision of Area Entorhinalis and its Demarcation from the Pyriform Cortex. Springer, 2012.
Find full textBook chapters on the topic "Parahippocampal Cortex"
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Poeta, Devon L., and Rebecca D. Burwell. "Parahippocampal Cortex (PHC)." In Encyclopedia of Animal Cognition and Behavior, 1–5. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-47829-6_1272-1.
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Li, Mi, Shengfu Lu, Jiaojiao Li, and Ning Zhong. "The Role of the Parahippocampal Cortex in Memory Encoding and Retrieval: An fMRI Study." In Brain Informatics, 377–86. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-15314-3_36.
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Rolls, Edmund T. "The cingulate cortex." In Brain Computations, 447–63. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780198871101.003.0012.
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The cingulate cortex is involved in action-outcome learning. The concept is that posterior cingulate cortex action-related information received from the parietal cortex is brought together in the cingulate cortex with the anterior cingulate cortex reward outcome-related information received from the orbitofrontal cortex, and via the midcingulate cortex the result of action-outcome learning can influence premotor areas. In addition, the posterior cingulate cortex has major connectivity with the parahippocampal cortex, which in turn projects spatial information to the entorhinal cortex and thereby into the hippocampal episodic memory system. The posterior cingulate cortex thus provides a route for spatial including visuo-spatial information to reach the hippocampus, where it can be combined with object and reward-related information to form episodic memories.
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Passingham, Richard E. "Medial Prefrontal Cortex." In Understanding the Prefrontal Cortex, 71–117. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780198844570.003.0003.
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In primates, the medial prefrontal cortex (PF) supports sequences of self-generated actions that are performed spontaneously and without external cues to instruct the action that is appropriate. Instead, the actions are performed on the basis of memories of previous events and their outcomes. Inputs from the parahippocampal and hippocampal cortex provide information about the scene or context; and inputs from the amygdala and orbital prefrontal cortex specify the outcomes. In ancestral anthropoids the hippocampal system for navigation was co-opted to support the retrieval of sequences of actions performed with the hand and arm, as in foraging. Outputs to the medial premotor areas influence the choice of actions, either for exploiting current resources or for exploring so as to find new ones. In anthropoids, visual and auditory inputs also convey the actions of conspecifics and predators so that the animal can predict what others are going to do.
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Graterón, L., A. M. Insausti, F. García-Bragado, M. M. Arroyo-Jiménez, P. Marcos, A. Martínez-Marcos, X. Blaizot, E. Artacho-Pérula, and R. Insausti. "Postnatal development of the human entorhinal cortex." In The Parahippocampal RegionOrganization and Role in Cognitive Function, 20–31. Oxford University Press, 2002. http://dx.doi.org/10.1093/acprof:oso/9780198509172.003.0002.
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Grossberg, Stephen. "How Prefrontal Cortex Works." In Conscious Mind, Resonant Brain, 517–38. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780190070557.003.0014.
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This chapter describes a unified theory of how the prefrontal cortex interacts with multiple brain regions to carry out the higher cognitive, emotional, and decision-making processes that define human intelligence, while also controlling actions to achieve valued goals. This predictive Adaptive Resonance Theory, or pART, model builds upon the foundation in earlier chapters. Prefrontal functions are often called executive functions. Executive functions regulate flexible and adaptive behaviors, notably in novel situations, while suppressing actions that are no longer appropriate, notably reflexive responses to current sensory inputs. Working memory is particularly involved in contextually appropriate behaviors. Prefrontal properties of desirability, availability, credit assignment, category learning, and feature-based attention are explained. These properties arise through interactions of orbitofrontal, ventrolateral prefrontal, and dorsolateral prefrontal cortices with inferotemporal cortex, perirhinal cortex, parahippocampal cortices; ventral bank of the principal sulcus, ventral prearcuate gyrus, frontal eye fields, hippocampus, amygdala, basal ganglia, hypothalamus, and visual cortical areas V1, V2, V3A, V4, MT, MST, LIP, and PPC. Model explanations include how the value of visual objects and events is computed, which objects and events cause desired consequences and which may be ignored as predictively irrelevant, and how to plan and act to realize these consequences, including how to selectively filter expected vs. unexpected events, leading to movements towards, and conscious perception of, expected events. Modeled processes include reinforcement learning and incentive motivational learning; object and spatial working memory dynamics; and category learning, including the learning of object categories, value categories, object-value categories, and sequence categories, or list chunks.
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Fisch, Adam J. "The Diencephalon, Basal Ganglia, & Limbic System." In Neuroanatomy, 341–76. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190259587.003.0011.
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This chapter focuses on learning the anatomy of the diencephalon, basal ganglia, and limbic system. It provides instruction on how to draw the basal ganglia, the thalamus, the hypothalamus, diencephalon, limbic system, hippocampus, Papez circuit, parahippocampal gyrus, intrahippocampal circuitry, olfactory cortex, and basal forebrain. Also addressed is the neurocircuitry of sleep, including the anatomical location of the sleep center, the physiology of the thalamocortical circuits, the pathway for the generation of REM sleep, and the biology of sleep and wakefulness. The chapter concludes with key discoveries in the biology of sleep and wakefulness.
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Bussey, Timothy J., Lisa M. Saksida, and Elisabeth A. Murray. "The role of perirhinal cortex in memory and perception: conjunctive representations for object identification." In The Parahippocampal RegionOrganization and Role in Cognitive Function, 238–54. Oxford University Press, 2002. http://dx.doi.org/10.1093/acprof:oso/9780198509172.003.0012.
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Kagan, Jerome. "The Power of the Context." In Five Constraints on Predicting Behavior. The MIT Press, 2017. http://dx.doi.org/10.7551/mitpress/9780262036528.003.0002.
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This chapter discusses contextual constraints on brain profiles. The laboratories that measure brain activity contain uncommon combinations of physical features and incentives that prime some brain sites and suppress others. Despite these possibilities, neuroscientists continue to speculate about the implications of the brain patterns they record as if the context has a minimal influence on their observations. This position is difficult to defend given the fact that the parahippocampal cortex binds objects and events to the context in which they appear. Adults lying supine and still in the narrow tube of a magnetic scanner in an unfamiliar room are in an unusual psychological and bodily state. The compromised sense of agency, awareness of being evaluated, confinement in a narrow space, and the demand to suppress all movement affect brain and psychological processes.
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Austin, James H. "Early Distinctions between Self and Other, Focal and Global, Are Coded in the Medial Temporal Lobe." In Living Zen Remindfully. The MIT Press, 2016. http://dx.doi.org/10.7551/mitpress/9780262035088.003.0006.
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This chapter reviews 2014 Nobel Prize-winning research on the hippocampus and parahippocampus. It considers place cells and grid cells and emphasizes that early primate studies had identified egocentric and allocentric responses in the hippocampus. It also notes that both direction codes and landmark location codes are represented in the retrosplenial cortex as well as in the entorhinal cortex.