scholarly journals A sinusoidal transform of the visual field in cortical area V2

2020 ◽  
Author(s):  
Madineh Sedigh-Sarvestani ◽  
Kuo-Sheng Lee ◽  
Rachel Satterfield ◽  
Nicole Shultz ◽  
David Fitzpatrick
Keyword(s):  
Large Scale ◽  
Tree Shrew ◽  
Cortical Surface ◽  
Cortical Circuits ◽  
Retinal Surface ◽  
Stimulus Response ◽  
Retinotopic Maps ◽  
Area V2 ◽  
Conventional Mapping ◽  
Visual Cortical

The retinotopic maps of many visual cortical areas are thought to follow the fundamental principles that have been described for primary visual cortex (V1) where nearby points on the retina map to nearby points on the surface of V1, and orthogonal axes of the retinal surface are represented along orthogonal axes of the cortical surface. Here we demonstrate a striking departure from this conventional mapping in the secondary visual area (V2) of the tree shrew. Although local retinotopy is preserved, orthogonal axes of the retina are represented along the same axis of the cortical surface, an unexpected geometry explained by an orderly sinusoidal transform of the retinal surface. This sinusoidal topography is ideally suited for achieving uniform coverage in an elongated area like V2, is predicted by mathematical models designed to achieve wiring minimization, and provides a novel explanation for stripe-like patterns of intra-cortical connections and stimulus response properties in V2. Our findings suggest that cortical circuits flexibly implement solutions to sensory surface representation, with dramatic consequences for the large-scale layout of topographic maps.

scholarly journals Feedforward and feedback frequency-dependent interactions in a large-scale laminar network of the primate cortex

2016 ◽  
Vol 2 (11) ◽  
pp. e1601335 ◽  
Author(s):  
Jorge F. Mejias ◽  
John D. Murray ◽  
Henry Kennedy ◽  
Xiao-Jing Wang
Keyword(s):  
Large Scale ◽  
Complex Dynamics ◽  
Predictive Coding ◽  
Causality Analysis ◽  
Frequency Dependent ◽  
Brain Functions ◽  
Wide Range ◽  
Cortical Laminar ◽  
Feedback Frequency ◽  
Visual Cortical

Interactions between top-down and bottom-up processes in the cerebral cortex hold the key to understanding attentional processes, predictive coding, executive control, and a gamut of other brain functions. However, the underlying circuit mechanism remains poorly understood and represents a major challenge in neuroscience. We approached this problem using a large-scale computational model of the primate cortex constrained by new directed and weighted connectivity data. In our model, the interplay between feedforward and feedback signaling depends on the cortical laminar structure and involves complex dynamics across multiple (intralaminar, interlaminar, interareal, and whole cortex) scales. The model was tested by reproducing, as well as providing insights into, a wide range of neurophysiological findings about frequency-dependent interactions between visual cortical areas, including the observation that feedforward pathways are associated with enhanced gamma (30 to 70 Hz) oscillations, whereas feedback projections selectively modulate alpha/low-beta (8 to 15 Hz) oscillations. Furthermore, the model reproduces a functional hierarchy based on frequency-dependent Granger causality analysis of interareal signaling, as reported in recent monkey and human experiments, and suggests a mechanism for the observed context-dependent hierarchy dynamics. Together, this work highlights the necessity of multiscale approaches and provides a modeling platform for studies of large-scale brain circuit dynamics and functions.

scholarly journals Large-scale Dynamics of Perceptual Decision Information across Human Cortex

2020 ◽  
Author(s):  
Niklas Wilming ◽  
Peter R Murphy ◽  
Florent Meyniel ◽  
Tobias H Donner
Keyword(s):  
Large Scale ◽  
Time Course ◽  
Action Plan ◽  
Frequency Channel ◽  
Human Cortex ◽  
Cortical Hierarchy ◽  
Specific Frequency ◽  
Sensory Evidence ◽  
Visual Cortical ◽  
Endogenous Component

AbstractPerceptual decisions entail the accumulation of sensory evidence for a particular choice towards an action plan. An influential framework holds that sensory cortical areas encode the instantaneous sensory evidence and downstream, action-related regions accumulate this evidence. The large-scale distribution of this computation across the cerebral cortex has remained largely elusive. We developed a regionally-specific magnetoencephalography decoding approach to exhaustively map the dynamics of stimulus- and choice-specific signals across the human cortical surface during a visual decision. Comparison with the evidence accumulation dynamics inferred from behavior enabled us to disentangle stimulus-dependent and endogenous components of choice-predictive activity across the visual cortical hierarchy. The endogenous component was present in primary visual cortex, expressed in a low (< 20 Hz) frequency-band, and its time course tracked, with delay, the build-up of choice-predictive activity in (pre-)motor regions. Our results are consistent with choice-specific cortical feedback signaling in a specific frequency channel during decision formation.

scholarly journals Representational drift in the mouse visual cortex

2020 ◽  
Author(s):  
Daniel Deitch ◽  
Alon Rubin ◽  
Yaniv Ziv
Keyword(s):  
Large Scale ◽  
Activity Patterns ◽  
Population Level ◽  
Population Activity ◽  
Cortical Areas ◽  
Electrophysiological Recordings ◽  
The Face ◽  
Visual Cortical ◽  
Mouse Visual Cortex ◽  
Over Time

AbstractNeuronal representations in the hippocampus and related structures gradually change over time despite no changes in the environment or behavior. The extent to which such ‘representational drift’ occurs in sensory cortical areas and whether the hierarchy of information flow across areas affects neural-code stability have remained elusive. Here, we address these questions by analyzing large-scale optical and electrophysiological recordings from six visual cortical areas in behaving mice that were repeatedly presented with the same natural movies. We found representational drift over timescales spanning minutes to days across multiple visual areas. The drift was driven mostly by changes in individual cells’ activity rates, while their tuning changed to a lesser extent. Despite these changes, the structure of relationships between the population activity patterns remained stable and stereotypic, allowing robust maintenance of information over time. Such population-level organization may underlie stable visual perception in the face of continuous changes in neuronal responses.

scholarly journals Corticocortical connection patterns reveal two distinct visual cortical areas bordering dorsal V2 in marmoset monkey

2015 ◽  
Vol 32 ◽  
Author(s):  
JANELLE JEFFS ◽  
FREDERICK FEDERER ◽  
ALESSANDRA ANGELUCCI
Keyword(s):  
Visual Area ◽  
New World Primates ◽  
Lower Field ◽  
Visual Stream ◽  
Field Representation ◽  
Lower Quadrant ◽  
The Third ◽  
Dorsal Aspect ◽  
Area V2 ◽  
Visual Cortical

AbstractThe organization of the cortex located immediately anterior to the second visual area (V2), i.e., the third tier visual cortex, remains controversial, especially in New World primates. In particular, there is lack of consensus regarding the exact location and extent of the lower visual quadrant representation of the third visual area V3 (or ventrolateral posterior –VLP – of a different nomenclature). Microelectrode and connectional mapping studies have revealed the existence of an upper visual quadrant representation abutting dorsal V2 anteriorly, and bordered medially and laterally by representations of the lower visual quadrant. It remains unclear whether these lower field regions are both part of a single area V3, which is split into two patches by an interposed region of upper field representation, or whether they are the lower field representations of two different areas, the dorsomedial area (DM) and area V3/VLP, respectively. To address this question, we quantitatively analyzed the patterns of corticocortical afferent connections labeled by tracer injections targeted to these two lower field regions in the dorsal aspect of the third tier cortex. We found different inter-areal connectivity patterns arising from these two regions, strongly suggesting that they belong to two different visual areas. In particular, our results indicate that the dorsal aspect of the third tier cortex consists of two distinct areas: a full area DM, representing the lower quadrant medially, and the upper quadrant laterally, and the lower quadrant representation of V3/VLP, located laterally to upper field DM. DM is predominantly connected with areas of the dorsal visual stream, and V3/VLP with areas of the ventral stream. These results prompt further functional investigations of the third tier cortex, as previous studies of this cortical territory may have pooled response properties of two very different areas into a single area V3.

scholarly journals Regulation of spike timing in visual cortical circuits

2008 ◽  
Vol 9 (2) ◽  
pp. 97-107 ◽  
Author(s):  
Paul Tiesinga ◽  
Jean-Marc Fellous ◽  
Terrence J. Sejnowski
Keyword(s):  
Spike Timing ◽  
Cortical Circuits ◽  
Visual Cortical

scholarly journals Hierarchical reasoning by neural circuits in the frontal cortex

Science ◽  
2019 ◽  
Vol 364 (6441) ◽  
pp. eaav8911 ◽  
Author(s):  
Morteza Sarafyazd ◽  
Mehrdad Jazayeri
Keyword(s):  
Frontal Cortex ◽  
Neural Circuits ◽  
Anterior Cingulate ◽  
Cortical Circuits ◽  
Neural Basis ◽  
Stimulus Response ◽  
Response Contingency ◽  
Dorsomedial Frontal Cortex ◽  
Reasoning Strategy ◽  
Additional Perturbation

Humans process information hierarchically. In the presence of hierarchies, sources of failures are ambiguous. Humans resolve this ambiguity by assessing their confidence after one or more attempts. To understand the neural basis of this reasoning strategy, we recorded from dorsomedial frontal cortex (DMFC) and anterior cingulate cortex (ACC) of monkeys in a task in which negative outcomes were caused either by misjudging the stimulus or by a covert switch between two stimulus-response contingency rules. We found that both areas harbored a representation of evidence supporting a rule switch. Additional perturbation experiments revealed that ACC functioned downstream of DMFC and was directly and specifically involved in inferring covert rule switches. These results‏ reveal the computational principles of hierarchical reasoning, as implemented by cortical circuits.

scholarly journals Fractured tonotopy of functional neural clusters in mouse auditory cortex

2016 ◽  
Author(s):  
Isabel Delgado Ruz ◽  
Simon R. Schultz
Keyword(s):  
Auditory Cortex ◽  
Large Scale ◽  
High Signal ◽  
Cortical Circuits ◽  
The Subject ◽  
Response Profiles ◽  
Salt And Pepper ◽  
Degree Of Order ◽  
Signal Correlation

AbstractThe degree of order versus randomness in mammalian cortical circuits has been the subject of much discussion. Previous reports showed that at a large scale there is smooth tonotopy in mouse auditory cortex, while at the single neuron level the representation is the traditional “salt and pepper” configuration attributed to rodent cortex. Here we show that at the micro columnar scale we find a large variety of response profiles, but neurons tend to share similar preference in terms of frequency, bandwidth and latency. However, this smooth representation was fractured and large differences were possible between neighbouring neurons. Despite the tendency of most groups of neurons to operate redundantly, high information gains were achieved between cells that had a high signal correlation. Connectivity between neurons was highly non-random, in agreement with a previous in-vitro report from layer five. Our results suggest the existence of functional clusters, connecting neighbouring mini-columns. This supports the idea of a “salt and pepper” configuration at the level of functional clusters of neurons rather than single units.

scholarly journals All hands on deck: Large-scale (re)sculpting of cortical circuits in post-resection children

2020 ◽  
Author(s):  
Anne Margarette S. Maallo ◽  
Michael C. Granovetter ◽  
Erez Freud ◽  
Sabine Kastner ◽  
Mark A. Pinsk ◽  
...  
Keyword(s):  
Large Scale ◽  
Brain Regions ◽  
Cortical Circuits ◽  
Pharmacoresistant Epilepsy ◽  
Cortical Volume ◽  
Normal Behavior ◽  
Hands On ◽  
The Mean ◽  
Time Courses ◽  
Positive Correlations

AbstractDespite the relative successes in the surgical treatment of pharmacoresistant epilepsy, there is rather little research on the neural (re)organization that potentially subserves behavioral compensation. Here, we examined the post-surgical functional connectivity (FC) in children and adolescents who have undergone unilateral cortical resection and, yet, display remarkably normal behavior. Conventionally, FC has been investigated in terms of the mean correlation of the BOLD time courses extracted from different brain regions. Here, we demonstrated the value of segregating the voxel-wise relationships into mutually exclusive populations that were either positively or negatively correlated. While, relative to controls, the positive correlations were largely normal, negative correlations among networks were increased. Together, our results point to reorganization in the contralesional hemisphere, possibly suggesting competition for cortical territory due to the demand for representation of function. Conceivably, the ubiquitous negative correlations enable the differentiation of function in the reduced cortical volume following a unilateral resection.

scholarly journals Visual Cortex Engagement in Retinitis Pigmentosa

2021 ◽  
Vol 22 (17) ◽  
pp. 9412
Author(s):  
Gianluca Pietra ◽  
Tiziana Bonifacino ◽  
Davide Talamonti ◽  
Giambattista Bonanno ◽  
Alessandro Sale ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Retinitis Pigmentosa ◽  
Intracortical Inhibition ◽  
Visual Sensitivity ◽  
Cortical Circuits ◽  
Inherited Disorders ◽  
Progressive Degeneration ◽  
Visual Inputs ◽  
Retinal Photoreceptors ◽  
Visual Cortical

Retinitis pigmentosa (RP) is a family of inherited disorders caused by the progressive degeneration of retinal photoreceptors. There is no cure for RP, but recent research advances have provided promising results from many clinical trials. All these therapeutic strategies are focused on preserving existing photoreceptors or substituting light-responsive elements. Vision recovery, however, strongly relies on the anatomical and functional integrity of the visual system beyond photoreceptors. Although the retinal structure and optic pathway are substantially preserved at least in early stages of RP, studies describing the visual cortex status are missing. Using a well-established mouse model of RP, we analyzed the response of visual cortical circuits to the progressive degeneration of photoreceptors. We demonstrated that the visual cortex goes through a transient and previously undescribed alteration in the local excitation/inhibition balance, with a net shift towards increased intracortical inhibition leading to improved filtering and decoding of corrupted visual inputs. These results suggest a compensatory action of the visual cortex that increases the range of residual visual sensitivity in RP.

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