scholarly journals Using the Change Manager Model for the Hippocampal System to Predict Connectivity and Neurophysiological Parameters in the Perirhinal Cortex

2016 ◽  
Vol 2016 ◽  
pp. 1-13
Author(s):  
L. Andrew Coward ◽  
Tamas D. Gedeon
Keyword(s):  
Receptive Field ◽  
Memory Retrieval ◽  
Focal Point ◽  
Receptive Fields ◽  
Perirhinal Cortex ◽  
Prior Learning ◽  
Episodic Memories ◽  
Cortical Receptive Fields ◽  
The Brain

Theoretical arguments demonstrate that practical considerations, including the needs to limit physiological resources and to learn without interference with prior learning, severely constrain the anatomical architecture of the brain. These arguments identify the hippocampal system as the change manager for the cortex, with the role of selecting the most appropriate locations for cortical receptive field changes at each point in time and driving those changes. This role results in the hippocampal system recording the identities of groups of cortical receptive fields that changed at the same time. These types of records can also be used to reactivate the receptive fields active during individual unique past events, providing mechanisms for episodic memory retrieval. Our theoretical arguments identify the perirhinal cortex as one important focal point both for driving changes and for recording and retrieving episodic memories. The retrieval of episodic memories must not drive unnecessary receptive field changes, and this consideration places strong constraints on neuron properties and connectivity within and between the perirhinal cortex and regular cortex. Hence the model predicts a number of such properties and connectivity. Experimental test of these falsifiable predictions would clarify how change is managed in the cortex and how episodic memories are retrieved.

Two-dimensional receptive-field organization in striate cortical neurons of the cat

1994 ◽  
Vol 11 (4) ◽  
pp. 703-720 ◽  
Author(s):  
Ming Sun ◽  
A. B. Bonds
Keyword(s):  
Receptive Field ◽  
Cortical Neurons ◽  
Ocular Dominance ◽  
Receptive Fields ◽  
Field Size ◽  
Two Dimensional ◽  
Cortical Layers ◽  
Field Organization ◽  
Receptive Field Organization ◽  
Cortical Receptive Fields

AbstractThe two-dimensional organization of receptive fields (RFs) of 44 cells in the cat visual cortex and four cells from the cat LGN was measured by stimulation with either dots or bars of light. The light bars were presented in different positions and orientations centered on the RFs. The RFs found were arbitrarily divided into four general types: Punctate, resembling DOG filters (11%); those resembling Gabor filters (9%); elongate (36%); and multipeaked-type (44%). Elongate RFs, usually found in simple cells, could show more than one excitatory band or bifurcation of excitatory regions. Although regions inhibitory to a given stimulus transition (e.g. ON) often coincided with regions excitatory to the opposite transition (e.g. OFF), this was by no means the rule. Measurements were highly repeatable and stable over periods of at least 1 h. A comparison between measurements made with dots and with bars showed reasonable matches in about 40% of the cases. In general, bar-based measurements revealed larger RFs with more structure, especially with respect to inhibitory regions. Inactivation of lower cortical layers (V-VI) by local GABA injection was found to reduce sharpness of detail and to increase both receptive-field size and noise in upper layer cells, suggesting vertically organized RF mechanisms. Across the population, some cells bore close resemblance to theoretically proposed filters, while others had a complexity that was clearly not generalizable, to the extent that they seemed more suited to detection of specific structures. We would speculate that the broadly varying forms of cat cortical receptive fields result from developmental processes akin to those that form ocular-dominance columns, but on a smaller scale.

Context dependence of receptive field remapping in superior colliculus

2011 ◽  
Vol 106 (4) ◽  
pp. 1862-1874 ◽  
Author(s):  
Jan Churan ◽  
Daniel Guitton ◽  
Christopher C. Pack
Keyword(s):  
Receptive Field ◽  
Superior Colliculus ◽  
Visual Stimulation ◽  
Receptive Fields ◽  
Spatial Location ◽  
Macaque Monkey ◽  
Visual Signals ◽  
Perceptual Stability ◽  
Visual Background ◽  
The Brain

Our perception of the positions of objects in our surroundings is surprisingly unaffected by movements of the eyes, head, and body. This suggests that the brain has a mechanism for maintaining perceptual stability, based either on the spatial relationships among visible objects or internal copies of its own motor commands. Strong evidence for the latter mechanism comes from the remapping of visual receptive fields that occurs around the time of a saccade. Remapping occurs when a single neuron responds to visual stimuli placed presaccadically in the spatial location that will be occupied by its receptive field after the completion of a saccade. Although evidence for remapping has been found in many brain areas, relatively little is known about how it interacts with sensory context. This interaction is important for understanding perceptual stability more generally, as the brain may rely on extraretinal signals or visual signals to different degrees in different contexts. Here, we have studied the interaction between visual stimulation and remapping by recording from single neurons in the superior colliculus of the macaque monkey, using several different visual stimulus conditions. We find that remapping responses are highly sensitive to low-level visual signals, with the overall luminance of the visual background exerting a particularly powerful influence. Specifically, although remapping was fairly common in complete darkness, such responses were usually decreased or abolished in the presence of modest background illumination. Thus the brain might make use of a strategy that emphasizes visual landmarks over extraretinal signals whenever the former are available.

Computational Predictions on the Receptive Fields and Organization of V2 for Shape Processing

2009 ◽  
Vol 21 (3) ◽  
pp. 762-785 ◽  
Author(s):  
Yiu Fai Sit ◽  
Risto Miikkulainen
Keyword(s):  
Receptive Field ◽  
Visual Processing ◽  
Receptive Fields ◽  
Self Organization ◽  
General Shape ◽  
Orientation Component ◽  
Shape Processing ◽  
Primary Orientation ◽  
Computational Predictions

It has been more than 40 years since the first studies of the secondary visual cortex (V2) were published. However, no concrete hypothesis on how the receptive field of V2 neurons supports general shape processing has been proposed to date. Using a computational model that follows the principle of self-organization, we advance two hypotheses in this letter: (1) typical V2 orientation-selective receptive field contains a primary orientation and a secondary orientation component, forming a corner, a junction, or a cross; and (2) V2 columns with the same primary orientation form contiguous domains, divided into subdomains that prefer different secondary orientations. The first hypothesis is consistent with existing experimental evidence, and both hypotheses can be tested with current techniques in animals. In this manner, computational modeling can be used to provide verifiable predictions that eventually allow us to understand the role of V2 in visual processing.

Cortical Synchronization and Perceptual Framing

1997 ◽  
Vol 9 (1) ◽  
pp. 117-132 ◽  
Author(s):  
Stephen Grossberg ◽  
Alexander Grunewald
Keyword(s):  
Object Representation ◽  
Receptive Fields ◽  
Shape From Shading ◽  
Visual Object ◽  
Nonlinear Feedback ◽  
Object A ◽  
Stimulus Length ◽  
Cortical Receptive Fields ◽  
The Brain ◽  
Different Parts

How does the brain group together different parts of an object into a coherent visual object representation? Different parts of an object may be processed by the brain at different rates and may thus become desynchronized. Perceptual framing is a process that resynchronizes cortical activities corresponding to the same retinal object. A neural network model is presented that is able to rapidly resynchronize desynchronized neural activities. The model provides a link between perceptual and brain data. Model properties quantitatively simulate perceptual framing data, including psychophysical data about temporal order judgments and the reduction of threshold contrast as a function of stimulus length. Such a model has earlier been used to explain data about illusory contour formation, texture segregation, shape-from-shading, 3-D vision, and cortical receptive fields. The model hereby shows how many data may be understood as manifestations of a cortical grouping process that can rapidly resynchronize image parts that belong together in visual object representations. The model exhibits better synchronization in the presence of noise than without noise, a type of stochastic resonance, and synchronizes robustly when cells that represent different stimulus orientations compete. These properties arise when fast long-range cooperation and slow short-range competition interact via nonlinear feedback interactions with cells that obey shunting equations.

scholarly journals Critical Role of Plasma Corticosteroid-Binding-Globulin During Stress to Promote Glucocorticoid Delivery to the Brain: Impact on Memory Retrieval

Endocrinology ◽  
2012 ◽  
Vol 153 (10) ◽  
pp. 4766-4774 ◽  
Author(s):  
Amandine M. Minni ◽  
Rodolphe Dorey ◽  
Christophe Piérard ◽  
Gaëlle Dominguez ◽  
Jean-Christophe Helbling ◽  
...  
Keyword(s):  
Memory Retrieval ◽  
Critical Role ◽  
Corticosteroid Binding Globulin ◽  
The Brain

scholarly journals The Anatomy of Object Processing: The Role of Anteromedial Temporal Cortex

2005 ◽  
Vol 58 (3-4b) ◽  
pp. 361-377 ◽  
Author(s):  
Peter Bright ◽  
Helen E. Moss ◽  
Emmanuel A. Stamatakis ◽  
Lorraine K. Tyler
Keyword(s):  
Cognitive Neuroscience ◽  
Conceptual Knowledge ◽  
Nonhuman Primates ◽  
Temporal Cortex ◽  
Perirhinal Cortex ◽  
Object Processing ◽  
Fine Grained ◽  
Temporal Structures ◽  
The Brain

How objects are represented and processed in the brain remains a key issue in cognitive neuroscience. We have developed a conceptual structure account in which category-specific semantic deficits emerge due to differences in the structure and content of concepts rather than from explicit divisions of conceptual knowledge in separate stores. The primary claim is that concepts associated with particular categories (e.g., animals, tools) differ in the number and type of properties and the extent to which these properties are correlated with each other. In this review, we describe recent neuropsychological and neuroimaging studies in which we have extended our theoretical account by incorporating recent claims about the neuroanatomical basis of feature integration and differentiation that arise from research into hierarchical object processing streams in nonhuman primates and humans. A clear picture has emerged in which the human perirhinal cortex and neighbouring anteromedial temporal structures appear to provide the neural infrastructure for making fine-grained discriminations among objects, suggesting that damage within the perirhinal cortex may underlie the emergence of category-specific semantic deficits in brain-damaged patients.

scholarly journals Human primary visual cortex shows larger population receptive fields for binocular disparity-defined stimuli

2021 ◽  
Author(s):  
Ivan Alvarez ◽  
Samuel A. Hurley ◽  
Andrew J. Parker ◽  
Holly Bridge
Keyword(s):  
Receptive Field ◽  
Binocular Disparity ◽  
Receptive Fields ◽  
Stereoscopic Vision ◽  
Neural Representation ◽  
Receptive Field Properties ◽  
Visual Areas ◽  
Electrophysiological Studies ◽  
Specific Stimulation

AbstractThe visual perception of 3D depth is underpinned by the brain’s ability to combine signals from the left and right eyes to produce a neural representation of binocular disparity for perception and behaviour. Electrophysiological studies of binocular disparity over the past 2 decades have investigated the computational role of neurons in area V1 for binocular combination, while more recent neuroimaging investigations have focused on identifying specific roles for different extrastriate visual areas in depth perception. Here we investigate the population receptive field properties of neural responses to binocular information in striate and extrastriate cortical visual areas using ultra-high field fMRI. We measured BOLD fMRI responses while participants viewed retinotopic mapping stimuli defined by different visual properties: contrast, luminance, motion, correlated and anti-correlated stereoscopic disparity. By fitting each condition with a population receptive field model, we compared quantitatively the size of the population receptive field for disparity-specific stimulation. We found larger population receptive fields for disparity compared with contrast and luminance in area V1, the first stage of binocular combination, which likely reflects the binocular integration zone, an interpretation supported by modelling of the binocular energy model. A similar pattern was found in region LOC, where it may reflect the role of disparity as a cue for 3D shape. These findings provide insight into the binocular receptive field properties underlying processing for human stereoscopic vision.

scholarly journals Human Primary Visual Cortex Shows Larger Population Receptive Fields for Binocular Disparity-Defined Stimuli

2021 ◽  
Author(s):  
Ivan Alvarez ◽  
Samuel Hurley ◽  
Andrew John Parker ◽  
Holly Bridge
Keyword(s):  
Receptive Field ◽  
Binocular Disparity ◽  
Receptive Fields ◽  
Stereoscopic Vision ◽  
Neural Representation ◽  
Neural Population ◽  
Receptive Field Properties ◽  
Visual Areas ◽  
Electrophysiological Studies

Abstract The visual perception of 3D depth is underpinned by the brain's ability to combine signals from the left and right eyes to produce a neural representation of binocular disparity for perception and behavior. Electrophysiological studies of binocular disparity over the past two decades have investigated the computational role of neurons in area V1 for binocular combination, while more recent neuroimaging investigations have focused on identifying specific roles for different extrastriate visual areas in depth perception. Here we investigate the neural population receptive field properties of responses to binocular information in striate and extrastriate cortical visual areas using ultra-high field fMRI. We measured BOLD fMRI responses while participants viewed retinotopic-mapping stimuli defined by different visual properties: contrast, luminance, motion, correlated and anti-correlated stereoscopic disparity. By fitting each condition with a population receptive field model, we were able to compare quantitatively the size of the population receptive field for disparity-defined vs not disparity-defined stimulation conditions. We found larger population receptive fields for disparity compared to the contrast and luminance stimuli in area V1, the first stage of binocular combination, which likely reflects the binocular integration zone, an interpretation supported by modelling of the binocular energy model. A similar pattern was found in region LOC, where it may reflect the role of disparity as a cue for 3D shape. These findings provide insight into the binocular receptive field properties underlying processing for human stereoscopic vision.

scholarly journals Enhanced aversive memory retrieval by chemogenetic activation of locus coeruleus norepinephrine neurons

2019 ◽  
Author(s):  
Ryoji Fukabori ◽  
Yoshio Iguchi ◽  
Shigeki Kato ◽  
Kazumi Takahashi ◽  
Satoshi Eifuku ◽  
...  
Keyword(s):  
Locus Coeruleus ◽  
Memory Retrieval ◽  
Adrenergic Receptors ◽  
Retrieval Process ◽  
Memory Store ◽  
Facilitative Role ◽  
Pharmacological Blockade ◽  
The Brain ◽  
Stimulation Of

AbstractThe ability to retrieve memory store in response to the environment is essential for animal behavioral adaptation. Norepinephrine (NE)-containing neurons in the brain play a key role in the modulation of synaptic plasticity underlying various processes of memory formation. However, the role of the central NE system in memory retrieval remains unclear. In this study, we developed a neural chemogenetic activation strategy using insect olfactory Ionotropic Receptors (IRs), and used it for selective stimulation of NE neurons in the locus coeruleus (LC) in transgenic mice. Ligand-induced activation of LC NE neurons resulted in enhancement of the retrieval process of conditioned taste aversion, which was mediated through at least partly adrenergic receptors in the amygdala. Pharmacological blockade of LC activity confirmed the facilitative role of these neurons in memory retrieval. Our findings indicate that the LC-amygdalar pathway is required and sufficient for enhancing the recall of taste associative memory.

Cutting out the middleman: Separating attributional biases from memory deficits

2019 ◽  
Vol 42 ◽  
Author(s):  
Wei-Chun Wang
Keyword(s):  
Implicit Memory ◽  
Memory Retrieval ◽  
Memory Deficits ◽  
Integrative Model ◽  
Prior Work ◽  
Memory Traces ◽  
Attributional Biases ◽  
Cutting Out ◽  
The Brain

Abstract Bastin and colleagues present an integrative model of how recollection- and familiarity-based memories are represented in the brain. While they emphasize the role of attribution mechanisms in shaping memory retrieval, prior work examining implicit memory suggests that memory deficits may be better understood by separating attributional biases from the underlying memory traces.

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