scholarly journals Developmental prosopagnosics have widespread selectivity reductions across category-selective visual cortex

2018 ◽  
Vol 115 (28) ◽  
pp. E6418-E6427 ◽  
Author(s):  
Guo Jiahui ◽  
Hua Yang ◽  
Bradley Duchaine
Keyword(s):  
Visual Cortex ◽  
Neurodevelopmental Disorder ◽  
Behavioral Deficits ◽  
Identity Recognition ◽  
Facial Identity ◽  
Video Clips ◽  
Cortical Areas ◽  
The Face ◽  
Face Selectivity ◽  
High Level

Developmental prosopagnosia (DP) is a neurodevelopmental disorder characterized by severe deficits with facial identity recognition. It is unclear which cortical areas contribute to face processing deficits in DP, and no previous studies have investigated whether other category-selective areas function normally in DP. To address these issues, we scanned 22 DPs and 27 controls using a dynamic localizer consisting of video clips of faces, scenes, bodies, objects, and scrambled objects. We then analyzed category selectivity, a measure of the tuning of a cortical area to a particular visual category. DPs exhibited reduced face selectivity in all 12 face areas, and the reductions were significant in three posterior and two anterior areas. DPs and controls showed similar responses to faces in other category-selective areas, which suggests the DPs’ behavioral deficits with faces result from problems restricted to the face network. DPs also had pronounced scene-selectivity reductions in four of six scene-selective areas and marginal body-selectivity reductions in two of four body-selective areas. Our results demonstrate that DPs have widespread deficits throughout the face network, and they are inconsistent with a leading account of DP which proposes that posterior face-selective areas are normal in DP. The selectivity reductions in other category-selective areas indicate many DPs have deficits spread across high-level visual cortex.

scholarly journals Effects of individuation and grouping on face representations in the visual cortex

2018 ◽  
Author(s):  
Hyehyeon Kim ◽  
Gayoung Kim ◽  
Sue-Hyun Lee
Keyword(s):  
Information Processing ◽  
Visual Cortex ◽  
Face Perception ◽  
Response Patterns ◽  
Top Down ◽  
Identity Recognition ◽  
Face Area ◽  
The Face ◽  
Early Visual Cortex ◽  
High Level

AbstractTop-down signals can influence our visual perception by providing guidance on information processing. Especially, top-down control between two basic frameworks, “Individuation” and “grouping”, is critical for information processing during face perception. Individuation of faces supports identity recognition while grouping subserves higher category level face perception such as race or gender. However, it still remains elusive how top-down dependent control between individuation and grouping affects cortical representations during face perception. Here we performed an fMRI experiment to investigate whether representations across early and high-level visual areas can be altered by top-down control between individuation and grouping process during face perception. Focusing on neural response patterns across the early visual cortex (EVC) and the face-selective area (the fusiform face area (FFA)), we found that the discriminability of individual faces from the response patterns was strong in the FFA but weak in the EVC during the individuation task whereas the EVC but not the FFA showed significant face discrimination during the grouping tasks. Thus, these findings suggest that the representation of face information across the early and high-level visual cortex is flexible depending on the top-down control of the perceptual framework between individuation and grouping.

scholarly journals Characterization of Feedback Neurons in the High-Level Visual Cortical Areas That Project Directly to the Primary Visual Cortex in the Cat

2021 ◽  
Vol 14 ◽  
Author(s):  
Huijun Pan ◽  
Shen Zhang ◽  
Deng Pan ◽  
Zheng Ye ◽  
Hao Yu ◽  
...  
Keyword(s):  
Information Processing ◽  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Information ◽  
Higher Order ◽  
Top Down ◽  
Cortical Areas ◽  
Area 21A ◽  
High Level ◽  
Visual Cortical

Previous studies indicate that top-down influence plays a critical role in visual information processing and perceptual detection. However, the substrate that carries top-down influence remains poorly understood. Using a combined technique of retrograde neuronal tracing and immunofluorescent double labeling, we characterized the distribution and cell type of feedback neurons in cat’s high-level visual cortical areas that send direct connections to the primary visual cortex (V1: area 17). Our results showed: (1) the high-level visual cortex of area 21a at the ventral stream and PMLS area at the dorsal stream have a similar proportion of feedback neurons back projecting to the V1 area, (2) the distribution of feedback neurons in the higher-order visual area 21a and PMLS was significantly denser than in the intermediate visual cortex of area 19 and 18, (3) feedback neurons in all observed high-level visual cortex were found in layer II–III, IV, V, and VI, with a higher proportion in layer II–III, V, and VI than in layer IV, and (4) most feedback neurons were CaMKII-positive excitatory neurons, and few of them were identified as inhibitory GABAergic neurons. These results may argue against the segregation of ventral and dorsal streams during visual information processing, and support “reverse hierarchy theory” or interactive model proposing that recurrent connections between V1 and higher-order visual areas constitute the functional circuits that mediate visual perception. Also, the corticocortical feedback neurons from high-level visual cortical areas to the V1 area are mostly excitatory in nature.

Dissociable Neural Patterns of Facial Identity across Changes in Viewpoint

2010 ◽  
Vol 22 (7) ◽  
pp. 1570-1582 ◽  
Author(s):  
Vaidehi S. Natu ◽  
Fang Jiang ◽  
Abhijit Narvekar ◽  
Shaiyan Keshvari ◽  
Volker Blanz ◽  
...  
Keyword(s):  
Activity Patterns ◽  
Human Perception ◽  
Neural Response ◽  
Behavioral Experiment ◽  
Neural Activation ◽  
Response Patterns ◽  
Activation Patterns ◽  
Facial Identity ◽  
The Face ◽  
High Level

We examined the neural response patterns for facial identity independent of viewpoint and for viewpoint independent of identity. Neural activation patterns for identity and viewpoint were collected in an fMRI experiment. Faces appeared in identity-constant blocks, with variable viewpoint, and in viewpoint-constant blocks, with variable identity. Pattern-based classifiers were used to discriminate neural response patterns for all possible pairs of identities and viewpoints. To increase the likelihood of detecting distinct neural activation patterns for identity, we tested maximally dissimilar “face”–“antiface” pairs and normal face pairs. Neural response patterns for four of six identity pairs, including the “face”–“antiface” pairs, were discriminated at levels above chance. A behavioral experiment showed accord between perceptual and neural discrimination, indicating that the classifier tapped a high-level visual identity code. Neural activity patterns across a broad span of ventral temporal (VT) cortex, including fusiform gyrus and lateral occipital areas (LOC), were required for identity discrimination. For viewpoint, five of six viewpoint pairs were discriminated neurally. Viewpoint discrimination was most accurate with a broad span of VT cortex, but the neural and perceptual discrimination patterns differed. Less accurate discrimination of viewpoint, more consistent with human perception, was found in right posterior superior temporal sulcus, suggesting redundant viewpoint codes optimized for different functions. This study provides the first evidence that it is possible to dissociate neural activation patterns for identity and viewpoint independently.

scholarly journals Improvement of Identity Recognition with Occlusion Detection-Based Feature Selection

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 167
Author(s):  
Jaeyoon Jang ◽  
Ho-Sub Yoon ◽  
Jaehong Kim
Keyword(s):  
Feature Vector ◽  
Recognition Performance ◽  
Recognition System ◽  
Identity Recognition ◽  
Facial Identity ◽  
Prevalent Disease ◽  
Significant Area ◽  
The Face ◽  
Additional Costs ◽  
The Stability

Image-based facial identity recognition has become a technology that is now used in many applications. This is because it is possible to use only a camera without the need for any other device. Besides, due to the advantage of contactless technology, it is one of the most popular certifications. However, a common recognition system is not possible if some of the face information is lost due to the user’s posture or the wearing of masks, as caused by the recent prevalent disease. In some platforms, although performance is improved through incremental updates, it is still inconvenient and inaccurate. In this paper, we propose a method to respond more actively to these situations. First, we determine whether an obscurity occurs and improve the stability by calculating the feature vector using only a significant area when the obscurity occurs. By recycling the existing recognition model, without incurring little additional costs, the results of reducing the recognition performance drop in certain situations were confirmed. Using this technique, we confirmed a performance improvement of about 1~3% in a situation where some information is lost. Although the performance is not dramatically improved, it has the big advantage that it can improve recognition performance by utilizing existing systems.

scholarly journals Visual category-driven differences in memory

2021 ◽  
Author(s):  
Adam Steel ◽  
Edward Silson
Keyword(s):  
Visual Cortex ◽  
Human Memory ◽  
Memory Systems ◽  
Neural Mechanisms ◽  
Neural Responses ◽  
Cortical Areas ◽  
Visual Areas ◽  
High Level ◽  
Human Categorization ◽  
The Brain

Categorizing classes of stimuli in the real-world is thought to underlie features of general intelligence, including our ability to infer identities of new objects, environments, and people never encountered before. Our understanding of human categorization, and the neural mechanisms that underlie this ability, was initially described in the context of visual perception. It is now broadly accepted that a network of high-level visual areas on the ventral and lateral surfaces of the brain exhibit some level of ‘domain (or category)-selective’ activity: preferential neural responses to visual stimuli of one category more than another (e.g., larger responses to faces compared to scenes or manipulable objects). Inspired by this robust and intuitive organization, recent studies have begun investigating the extent to which human memory systems also exhibit a category-selective organization. Surprisingly, this work has revealed strong evidence for the existence of category-selective areas in swaths of cortex previously considered to be domain-general. These results suggest that category-selectivity is a general organizing principle not only of visual cortex, but also for higher-level cortical areas involved in memory. In this chapter we review the evidence for the manifestation of visual category preferences in memory systems, and how this relates to the well-established category-selectivity exhibited within visual cortex.

scholarly journals Spatiotemporal dynamics of similarity-based neural representations of facial identity

2016 ◽  
Vol 114 (2) ◽  
pp. 388-393 ◽  
Author(s):  
Mark D. Vida ◽  
Adrian Nestor ◽  
David C. Plaut ◽  
Marlene Behrmann
Keyword(s):  
Occipital Cortex ◽  
Stimulus Onset ◽  
High Temporal Resolution ◽  
Object Identity ◽  
Complex Objects ◽  
Facial Identity ◽  
The Face ◽  
Identity Based ◽  
Types Of Information ◽  
High Level

Humans’ remarkable ability to quickly and accurately discriminate among thousands of highly similar complex objects demands rapid and precise neural computations. To elucidate the process by which this is achieved, we used magnetoencephalography to measure spatiotemporal patterns of neural activity with high temporal resolution during visual discrimination among a large and carefully controlled set of faces. We also compared these neural data to lower level “image-based” and higher level “identity-based” model-based representations of our stimuli and to behavioral similarity judgments of our stimuli. Between ∼50 and 400 ms after stimulus onset, face-selective sources in right lateral occipital cortex and right fusiform gyrus and sources in a control region (left V1) yielded successful classification of facial identity. In all regions, early responses were more similar to the image-based representation than to the identity-based representation. In the face-selective regions only, responses were more similar to the identity-based representation at several time points after 200 ms. Behavioral responses were more similar to the identity-based representation than to the image-based representation, and their structure was predicted by responses in the face-selective regions. These results provide a temporally precise description of the transformation from low- to high-level representations of facial identity in human face-selective cortex and demonstrate that face-selective cortical regions represent multiple distinct types of information about face identity at different times over the first 500 ms after stimulus onset. These results have important implications for understanding the rapid emergence of fine-grained, high-level representations of object identity, a computation essential to human visual expertise.

Сирия (аш-Шам) в системе османских владений (XVI – начало XX в.)

2019 ◽  
Author(s):  
D.R. Zhantiev
Keyword(s):  
Ottoman Empire ◽  
19Th Century ◽  
Social Mechanisms ◽  
Checks And Balances ◽  
Local Elites ◽  
The Balkans ◽  
The Face ◽  
High Level ◽  
The 19Th Century

Аннотация В статье рассматривается роль и место Сирии (включая Ливан и Палестину) в системе османских владений на протяжении нескольких веков от османского завоевания до периода правления султана Абдул-Хамида II. В течение четырех столетий османского владычества территория исторической Сирии (Билад аш-Шам) была одним из важнейших компонентов османской системы и играла роль связующего звена между Анатолией, Египтом, Ираком и Хиджазом. Необходимость ежегодной организации хаджа с символами султанской власти и покровительства над святынями Мекки и Медины определяла особую стратегическую важность сирийских провинций Османской империи. Несмотря на ряд серьезных угроз во время общего кризиса османской государственности (конец XVI начало XIX вв.), имперскому центру удалось сохранить контроль над Сирией путем создания сдержек и противовесов между местными элитами. В XIX в. и особенно в период правления Абдул- Хамида II (18761909 гг.), сохранение Сирии под османским контролем стало вопросом существования Османской империи, которая перед лицом растущего европейского давления и интервенции потеряла большую часть своих владений на Балканах и в Северной Африке. Задача укрепления связей между имперским центром и периферией в сирийских вилайетах в последней четверти XIX в. была в целом успешно решена. К началу XX в. Сирия была одним из наиболее политически спокойных и прочно связанных со Стамбулом регионов Османской империи. Этому в значительной степени способствовали довольно высокий уровень общественной безопасности, развитие внешней торговли, рост образования и постепенная интеграция местных элит (как мусульман, так и христиан) в османские государственные и социальные механизмы. Положение Сирии в системе османских владений показало, что процесс ослабления и территориальной дезинтеграции Османской империи в эпоху реформ не был линейным и наряду с потерей владений и влияния на Балканах, в азиатской части империи в течение XIX и начала XX вв. происходил параллельный процесс имперской консолидации.Abstract The article examines the role and place of Greater Syria (including Lebanon and Palestine) in the system of Ottoman possessions over several centuries from the Ottoman conquest to the period of the reign of Abdul Hamid II. For four centuries of Ottoman domination, the territory of historical Syria (Bilad al-Sham) was one of the most important components in the Ottoman system and played the role of a link between Anatolia, Egypt, Iraq and Hijaz. The need to ensure the Hajj with symbols of Sultan power and patronage over the shrines of Mecca and Medina each year determined the special strategic importance of the Syrian provinces of the Ottoman Empire. Despite a number of serious threats during the general crisis of the Ottoman state system (late 16th early 19th centuries), the imperial center managed to maintain control over Syria by creating checks and balances between local elites. In the 19th century. And especially during the reign of Abdul Hamid II (18761909), keeping Syria under Ottoman control became a matter of existence for the Ottoman Empire, which, in the face of increasing European pressure and intervention, lost most of its possessions in the Balkans and North Africa. The task of strengthening ties between the imperial center and the periphery in Syrian vilayets in the last quarter of the 19th century was generally successfully resolved. By the beginning of the 20th century, Syria was one of the most politically calm and firmly connected with Istanbul regions of the Ottoman Empire. This was greatly facilitated by a fairly high level of public safety, the development of foreign trade, the growth of education and the gradual integration of local elites (both Muslims and Christians) into Ottoman state and social mechanisms. Syrias position in the system of Ottoman possessions clearly showed that the process of weakening and territorial disintegration of the Ottoman Empire during the era of reform was not linear, and along with the loss of possessions and influence in the Balkans, in the Asian part of the empire during the 19th and early 20th centuries there was a parallel process of imperial consolidation.

scholarly journals Intranasal oxytocin administration ameliorates social behavioral deficits in a POGZWT/Q1038R mouse model of autism spectrum disorder

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Kohei Kitagawa ◽  
Kensuke Matsumura ◽  
Masayuki Baba ◽  
Momoka Kondo ◽  
Tomoya Takemoto ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Social Behavior ◽  
Mouse Model ◽  
Mouse Models ◽  
De Novo ◽  
Neurodevelopmental Disorder ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
De Novo Mutation ◽  
Behavioral Deficits

AbstractAutism spectrum disorder (ASD) is a highly prevalent neurodevelopmental disorder characterized by core symptoms of impaired social behavior and communication. Recent studies have suggested that the oxytocin system, which regulates social behavior in mammals, is potentially involved in ASD. Mouse models of ASD provide a useful system for understanding the associations between an impaired oxytocin system and social behavior deficits. However, limited studies have shown the involvement of the oxytocin system in the behavioral phenotypes in mouse models of ASD. We have previously demonstrated that a mouse model that carries the ASD patient-derived de novo mutation in the pogo transposable element derived with zinc finger domain (POGZWT/Q1038R mice), showed ASD-like social behavioral deficits. Here, we have explored whether oxytocin (OXT) administration improves impaired social behavior in POGZWT/Q1038R mice and found that intranasal oxytocin administration effectively restored the impaired social behavior in POGZWT/Q1038R mice. We also found that the expression level of the oxytocin receptor gene (OXTR) was low in POGZWT/Q1038R mice. However, we did not detect significant changes in the number of OXT-expressing neurons between the paraventricular nucleus of POGZWT/Q1038R mice and that of WT mice. A chromatin immunoprecipitation assay revealed that POGZ binds to the promoter region of OXTR and is involved in the transcriptional regulation of OXTR. In summary, our study demonstrate that the pathogenic mutation in the POGZ, a high-confidence ASD gene, impairs the oxytocin system and social behavior in mice, providing insights into the development of oxytocin-based therapeutics for ASD.

scholarly journals Alzheimer’s Disease Progressively Reduces Visual Functional Network Connectivity

2021 ◽  
pp. 1-14
Author(s):  
Jie Huang ◽  
Paul Beach ◽  
Andrea Bozoki ◽  
David C. Zhu
Keyword(s):  
Visual Cortex ◽  
Lower Order ◽  
Resting State ◽  
Visual Processing ◽  
Network Connectivity ◽  
Higher Order ◽  
Functional Network ◽  
Functional Networks ◽  
The Face ◽  
Processing Network

Background: Postmortem studies of brains with Alzheimer’s disease (AD) not only find amyloid-beta (Aβ) and neurofibrillary tangles (NFT) in the visual cortex, but also reveal temporally sequential changes in AD pathology from higher-order association areas to lower-order areas and then primary visual area (V1) with disease progression. Objective: This study investigated the effect of AD severity on visual functional network. Methods: Eight severe AD (SAD) patients, 11 mild/moderate AD (MAD), and 26 healthy senior (HS) controls undertook a resting-state fMRI (rs-fMRI) and a task fMRI of viewing face photos. A resting-state visual functional connectivity (FC) network and a face-evoked visual-processing network were identified for each group. Results: For the HS, the identified group-mean face-evoked visual-processing network in the ventral pathway started from V1 and ended within the fusiform gyrus. In contrast, the resting-state visual FC network was mainly confined within the visual cortex. AD disrupted these two functional networks in a similar severity dependent manner: the more severe the cognitive impairment, the greater reduction in network connectivity. For the face-evoked visual-processing network, MAD disrupted and reduced activation mainly in the higher-order visual association areas, with SAD further disrupting and reducing activation in the lower-order areas. Conclusion: These findings provide a functional corollary to the canonical view of the temporally sequential advancement of AD pathology through visual cortical areas. The association of the disruption of functional networks, especially the face-evoked visual-processing network, with AD severity suggests a potential predictor or biomarker of AD progression.

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