scholarly journals The role of body partonomics and biological class in the representation of animacy in the ventral visual pathway

2019 ◽  
Vol 19 (10) ◽  
pp. 114
Author(s):  
J.Brendan W Ritchie ◽  
Joyce Bosmans ◽  
Shuo Sun ◽  
Kirsten Verhaegen ◽  
Astrid Zeman ◽  
...  
Keyword(s):  
Visual Pathway ◽  
Ventral Visual Pathway

A functional role of multiple spatial resolution maps in form perception along the ventral visual pathway

2005 ◽  
Vol 65-66 ◽  
pp. 219-228 ◽  
Author(s):  
Yoshiki Kashimori ◽  
Nobuyuki Suzuki ◽  
Kazuhisa Fujita ◽  
Meihong Zheng ◽  
Takeshi Kambara
Keyword(s):  
Spatial Resolution ◽  
Functional Role ◽  
Visual Pathway ◽  
Form Perception ◽  
Ventral Visual Pathway

scholarly journals Evidence from imaging resilience genetics for a protective mechanism against schizophrenia in the ventral visual pathway

2021 ◽  
Author(s):  
Meike Dorothee Hettwer ◽  
Thomas M. Lancaster ◽  
Eva Raspor ◽  
Peter K. Hahn ◽  
Nina Roth Mota ◽  
...  
Keyword(s):  
Visual Processing ◽  
Visual Information ◽  
Visual Pathway ◽  
Protective Mechanism ◽  
Replication Sample ◽  
Discovery Sample ◽  
Ventral Visual Pathway ◽  
Positive Correlations ◽  
Cortical Morphology

Recently, the first genetic variants conferring resilience to schizophrenia have been identified. However, the neurobiological mechanisms underlying their protective effect remain unknown. Current models implicate adaptive neuroplastic changes in the visual system and their pro-cognitive effects in schizophrenia resilience. Here, we test the hypothesis that comparable changes can emerge from schizophrenia resilience genes. To this end, we used structural magnetic resonance imaging to investigate the effects of a schizophrenia polygenic resilience score (PRSResilience) on cortical morphology (discovery sample: n=101; UK Biobank replication sample: n=33,224). We observed positive correlations between PRSResilience and cortical volume in the fusiform gyrus, a central hub within the ventral visual pathway. Our findings indicate that resilience to schizophrenia arises partly from genetically mediated enhancements of visual processing capacities for social and non-social object information. This implies an important role of visual information processing for mitigating schizophrenia risk, which might also be exploitable for early intervention studies.

Topography of Visual Features in the Human Ventral Visual Pathway

2021 ◽  
Author(s):  
Shijia Fan ◽  
Xiaosha Wang ◽  
Xiaoying Wang ◽  
Tao Wei ◽  
Yanchao Bi
Keyword(s):  
Visual Pathway ◽  
Visual Features ◽  
Ventral Visual Pathway

scholarly journals View-tuned and view-invariant face encoding in IT cortex is explained by selected natural image fragments

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yunjun Nam ◽  
Takayuki Sato ◽  
Go Uchida ◽  
Ekaterina Malakhova ◽  
Shimon Ullman ◽  
...  
Keyword(s):  
Face Recognition ◽  
Visual Pathway ◽  
Visual Features ◽  
Natural Image ◽  
Face Representation ◽  
Low Level ◽  
Ventral Visual Pathway ◽  
Neural Substrate ◽  
The Face

AbstractHumans recognize individual faces regardless of variation in the facial view. The view-tuned face neurons in the inferior temporal (IT) cortex are regarded as the neural substrate for view-invariant face recognition. This study approximated visual features encoded by these neurons as combinations of local orientations and colors, originated from natural image fragments. The resultant features reproduced the preference of these neurons to particular facial views. We also found that faces of one identity were separable from the faces of other identities in a space where each axis represented one of these features. These results suggested that view-invariant face representation was established by combining view sensitive visual features. The face representation with these features suggested that, with respect to view-invariant face representation, the seemingly complex and deeply layered ventral visual pathway can be approximated via a shallow network, comprised of layers of low-level processing for local orientations and colors (V1/V2-level) and the layers which detect particular sets of low-level elements derived from natural image fragments (IT-level).

Temporal Dynamics of Shape Processing Differentiate Contributions of Dorsal and Ventral Visual Pathways

2019 ◽  
Vol 31 (6) ◽  
pp. 821-836 ◽  
Author(s):  
Elliot Collins ◽  
Erez Freud ◽  
Jana M. Kainerstorfer ◽  
Jiaming Cao ◽  
Marlene Behrmann
Keyword(s):  
Visual Information ◽  
Temporal Dynamics ◽  
Object Perception ◽  
Visual Pathway ◽  
Shape Sensitivity ◽  
Shape Information ◽  
Dorsal Pathway ◽  
Ventral Visual Pathway ◽  
Shape Processing ◽  
Ventral Pathway

Although shape perception is primarily considered a function of the ventral visual pathway, previous research has shown that both dorsal and ventral pathways represent shape information. Here, we examine whether the shape-selective electrophysiological signals observed in dorsal cortex are a product of the connectivity to ventral cortex or are independently computed. We conducted multiple EEG studies in which we manipulated the input parameters of the stimuli so as to bias processing to either the dorsal or ventral visual pathway. Participants viewed displays of common objects with shape information parametrically degraded across five levels. We measured shape sensitivity by regressing the amplitude of the evoked signal against the degree of stimulus scrambling. Experiment 1, which included grayscale versions of the stimuli, served as a benchmark establishing the temporal pattern of shape processing during typical object perception. These stimuli evoked broad and sustained patterns of shape sensitivity beginning as early as 50 msec after stimulus onset. In Experiments 2 and 3, we calibrated the stimuli such that visual information was delivered primarily through parvocellular inputs, which mainly project to the ventral pathway, or through koniocellular inputs, which mainly project to the dorsal pathway. In the second and third experiments, shape sensitivity was observed, but in distinct spatio-temporal configurations from each other and from that elicited by grayscale inputs. Of particular interest, in the koniocellular condition, shape selectivity emerged earlier than in the parvocellular condition. These findings support the conclusion of distinct dorsal pathway computations of object shape, independent from the ventral pathway.

Emergence of a compositional neural code for written words: Recycling of a convolutional neural network for reading

2021 ◽  
Vol 118 (46) ◽  
pp. e2104779118
Author(s):  
T. Hannagan ◽  
A. Agrawal ◽  
L. Cohen ◽  
S. Dehaene
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Language Processing ◽  
Visual Pathway ◽  
Neural Code ◽  
Letter Recognition ◽  
Invariant Representation ◽  
Spoken Language Processing ◽  
Visual Word Form Area ◽  
Ventral Visual Pathway

The visual word form area (VWFA) is a region of human inferotemporal cortex that emerges at a fixed location in the occipitotemporal cortex during reading acquisition and systematically responds to written words in literate individuals. According to the neuronal recycling hypothesis, this region arises through the repurposing, for letter recognition, of a subpart of the ventral visual pathway initially involved in face and object recognition. Furthermore, according to the biased connectivity hypothesis, its reproducible localization is due to preexisting connections from this subregion to areas involved in spoken-language processing. Here, we evaluate those hypotheses in an explicit computational model. We trained a deep convolutional neural network of the ventral visual pathway, first to categorize pictures and then to recognize written words invariantly for case, font, and size. We show that the model can account for many properties of the VWFA, particularly when a subset of units possesses a biased connectivity to word output units. The network develops a sparse, invariant representation of written words, based on a restricted set of reading-selective units. Their activation mimics several properties of the VWFA, and their lesioning causes a reading-specific deficit. The model predicts that, in literate brains, written words are encoded by a compositional neural code with neurons tuned either to individual letters and their ordinal position relative to word start or word ending or to pairs of letters (bigrams).

scholarly journals Genetic disruption of the On visual pathway affects cortical orientation selectivity and contrast sensitivity in mice

2014 ◽  
Vol 111 (11) ◽  
pp. 2276-2286 ◽  
Author(s):  
Rashmi Sarnaik ◽  
Hui Chen ◽  
Xiaorong Liu ◽  
Jianhua Cang
Keyword(s):  
Contrast Sensitivity ◽  
Visual Pathway ◽  
Response Variability ◽  
Stimulus Contrast ◽  
Wild Type ◽  
Low Contrast ◽  
Pharmacological Blockade ◽  
Single Unit Recordings ◽  
On And Off Pathways

The retina signals stimulus contrast via parallel On and Off pathways and sends the information to higher visual centers. Here we study the role of the On pathway using mice that have null mutations in the On-specific GRM6 receptor in the retina (Pinto LH, Vitaterna MH, Shimomura K, Siepka SM, Balannik V, McDearmon EL, Omura C, Lumayag S, Invergo BM, Brandon M, Glawe B, Cantrell DR, Donald R, Inayat S, Olvera MA, Vessey KA, Kirstan A, McCall MA, Maddox D, Morgans CW, Young B, Pletcher MT, Mullins RF, Troy JB, Takahashi JS. Vis Neurosci 24: 111–123, 2007; Maddox DM, Vessey KA, Yarbrough GL, Invergo BM, Cantrell DR, Inayat S, Balannik V, Hicks WL, Hawes NL, Byers S, Smith RS, Hurd R, Howell D, Gregg RG, Chang B, Naggert JK, Troy JB, Pinto LH, Nishina PM, McCall MA. J Physiol 586: 4409–4424, 2008). In these “nob” mice, single unit recordings in the primary visual cortex (V1) reveal degraded selectivity for orientations due to an increased response at nonpreferred orientations. Contrast sensitivity in the nob mice is reduced with severe deficits at low contrast, consistent with the phenotype of night blindness in human patients with mutations in Grm6. These cortical deficits can be largely explained by reduced input drive and increased response variability seen in nob V1. Interestingly, increased variability is also observed in the superior colliculus of these mice but does not affect its tuning properties. Further, the increased response variability in the nob mice is traced to the retina, a result phenocopied by acute pharmacological blockade of the On pathway in wild-type retina. Together, our results suggest that the On and Off pathways normally interact to increase response reliability in the retina, which in turn propagates to various central visual targets and affects their functional properties.

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