Visual information represented in different levels of functional hierarchy in monkey inferior temporal cortex revealed by machine learning

2010 ◽  
Vol 68 ◽  
pp. e381
Author(s):  
Go Uchida ◽  
Takayuki Sato ◽  
Jun Kitazono ◽  
Masato Okada ◽  
Manabu Tanifuji
Keyword(s):  
Machine Learning ◽  
Visual Information ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Functional Hierarchy ◽  
Different Levels

scholarly journals Dynamic Population Coding of Category Information in Inferior Temporal and Prefrontal Cortex

2008 ◽  
Vol 100 (3) ◽  
pp. 1407-1419 ◽  
Author(s):  
Ethan M. Meyers ◽  
David J. Freedman ◽  
Gabriel Kreiman ◽  
Earl K. Miller ◽  
Tomaso Poggio
Keyword(s):  
Prefrontal Cortex ◽  
Visual Information ◽  
Activity Patterns ◽  
Temporal Cortex ◽  
Relevant Information ◽  
Population Coding ◽  
Inferior Temporal Cortex ◽  
Category Information ◽  
Almost All ◽  
Dynamic Population

Most electrophysiology studies analyze the activity of each neuron separately. While such studies have given much insight into properties of the visual system, they have also potentially overlooked important aspects of information coded in changing patterns of activity that are distributed over larger populations of neurons. In this work, we apply a population decoding method to better estimate what information is available in neuronal ensembles and how this information is coded in dynamic patterns of neural activity in data recorded from inferior temporal cortex (ITC) and prefrontal cortex (PFC) as macaque monkeys engaged in a delayed match-to-category task. Analyses of activity patterns in ITC and PFC revealed that both areas contain “abstract” category information (i.e., category information that is not directly correlated with properties of the stimuli); however, in general, PFC has more task-relevant information, and ITC has more detailed visual information. Analyses examining how information coded in these areas show that almost all category information is available in a small fraction of the neurons in the population. Most remarkably, our results also show that category information is coded by a nonstationary pattern of activity that changes over the course of a trial with individual neurons containing information on much shorter time scales than the population as a whole.

scholarly journals The Effect of Spatial Frequency on the Visual Category Representation in the Macaque Inferior Temporal Cortex

2021 ◽  
Author(s):  
Esmaeil Farhang ◽  
Ramin Toosi ◽  
Behnam Karami ◽  
Roxana Koushki ◽  
Ehsan Rezayat ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Visual Processing ◽  
Visual Information ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Category Representation ◽  
Neural Basis ◽  
Shape Information ◽  
Category Information ◽  
The Impact

ABSTRACTTo expand our knowledge about the object recognition, it is critical to understand the role of spatial frequency (SF) in an object representation that occurs in the inferior temporal (IT) cortex at the final stage of processing the visual information across the ventral visual pathway. Object categories are being recognized hierarchically in at least three levels of abstraction: superordinate (e.g., animal), mid-level (e.g., human face), and subordinate (e.g., face identity). Psychophysical studies have shown rapid access to mid-level category information and low SF (LSF) contents. Although the hierarchical representation of categories has been shown to exist inside the IT cortex, the impact of SF on the multi-level category processing is poorly understood. To gain a deeper understanding of the neural basis of the interaction between SF and category representations at multiple levels, we examined the neural responses within the IT cortex of macaque monkeys viewing several SF-filtered objects. Each stimulus could be either intact or bandpass filtered into either the LSF (coarse shape information) or high SF (HSF) (fine shape information) bands. We found that in both High- and Low-SF contents, the advantage of mid-level representation has not been violated. This evidence suggests that mid-level category boundary maps are strongly represented in the IT cortex and remain unaffected with respect to any changes in the frequency content of stimuli. Our observations indicate the necessity of the HSF content for the superordinate category representation inside the IT cortex. In addition, our findings reveal that the representation of global category information is more dependent on the HSF than the LSF content. Furthermore, the lack of subordinate representation in both LSF and HSF filtered stimuli compared to the intact stimuli provide strong evidence that all SF contents are necessary for fine category visual processing.

Body Patches in Inferior Temporal Cortex Encode Categories with Different Temporal Dynamics

2019 ◽  
Vol 31 (11) ◽  
pp. 1699-1709 ◽  
Author(s):  
Satwant Kumar ◽  
Rufin Vogels
Keyword(s):  
Temporal Dynamics ◽  
Qualitative Difference ◽  
Temporal Cortex ◽  
The Body ◽  
Inferior Temporal Cortex ◽  
Support Vector ◽  
Hierarchical Processing ◽  
Object Categories ◽  
Anterior Body ◽  
Different Levels

An unresolved question in cognitive neuroscience is how representations of object categories at different levels (basic and superordinate) develop during the course of the neural response within an area. To address this, we decoded categories of different levels from the spiking responses of populations of neurons recorded in two fMRI-defined body patches in the macaque STS. Recordings of the two patches were made in the same animals with the same stimuli. Support vector machine classifiers were trained at brief response epochs and tested at the same or different epochs, thus assessing whether category representations change during the course of the response. In agreement with hierarchical processing within the body patch network, the posterior body patch mid STS body (MSB) showed an earlier onset of categorization compared with the anterior body patch anterior STS body (ASB), irrespective of the categorization level. Decoding of the superordinate body versus nonbody categories was less dynamic in MSB than in ASB, with ASB showing a biphasic temporal pattern. Decoding of the ordinate-level category human versus monkey bodies showed similar temporal patterns in both patches. The decoding onset of superordinate categorizations involving bodies was as early as for basic-level categorization, suggesting that previously reported differences between the onset of basic and superordinate categorizations may depend on the area. The qualitative difference between areas in their dynamics of category representation may hinder the interpretation of decoding dynamics based on EEG or MEG, methods that may mix signals of different areas.

scholarly journals Neural microgenesis of personally familiar face recognition

2015 ◽  
Vol 112 (35) ◽  
pp. E4835-E4844 ◽  
Author(s):  
Meike Ramon ◽  
Luca Vizioli ◽  
Joan Liu-Shuang ◽  
Bruno Rossion
Keyword(s):  
Face Recognition ◽  
Visual Information ◽  
Medial Temporal Lobe ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Sufficient Information ◽  
Neural Basis ◽  
Familiar Face ◽  
Spatial Frequencies ◽  
The Face

Despite a wealth of information provided by neuroimaging research, the neural basis of familiar face recognition in humans remains largely unknown. Here, we isolated the discriminative neural responses to unfamiliar and familiar faces by slowly increasing visual information (i.e., high-spatial frequencies) to progressively reveal faces of unfamiliar or personally familiar individuals. Activation in ventral occipitotemporal face-preferential regions increased with visual information, independently of long-term face familiarity. In contrast, medial temporal lobe structures (perirhinal cortex, amygdala, hippocampus) and anterior inferior temporal cortex responded abruptly when sufficient information for familiar face recognition was accumulated. These observations suggest that following detailed analysis of individual faces in core posterior areas of the face-processing network, familiar face recognition emerges categorically in medial temporal and anterior regions of the extended cortical face network.

Qualitative and quantitative features of axons projecting from caudal to rostral inferior temporal cortex of squirrel monkeys

1995 ◽  
Vol 12 (4) ◽  
pp. 701-722 ◽  
Author(s):  
G.E. Steele ◽  
R.E. Weller
Keyword(s):  
Visual Information ◽  
Temporal Cortex ◽  
Squirrel Monkeys ◽  
Inferior Temporal Cortex ◽  
Type I ◽  
Type Ii ◽  
Areal Extent ◽  
Type Iii ◽  
Terminal Arbor ◽  
Mean Width

AbstractOn the basis of cortical and subcortical connections and architectonics, inferior temporal (IT) cortex of squirrel monkeys consists of a caudal region, ITC, with dorsal (ITCd) and ventral (ITCv) subdivisions; a rostral region, ITR; and possibly a third region intermediate to ITC and ITR, IT1 (Weller & Steele, 1992; Steele & Weller, 1993). The present study qualitatively and quantitatively examined the terminal arborizations of 26 axons in ITR and IT1 labeled by injections of biocytin or, in one case, horseradish peroxidase, in ITCv. The majority of axons gave rise to a single terminal arbor, with a small number branching into two overlapping or nearby arbors. Presumptive terminal specializations consisted of rounded, bead-like swellings, most often located en passant. All axons terminated in layer 4 of cortex, and most had additional terminations in layers 3 and 5. The total extent of each axon's terminal arbor was 125–750 μm dorsoventrally (mean = 360.6 μm) and 150–725 μm anteroposteriorly (mean = 328.1 μm; all values uncorrected for shrinkage). In most axons, especially those with larger terminal fields, boutons were not uniformly distributed, but formed 2–4 clumps (mean = 2.2), with a mean width of 149 μm, separated by narrower regions of fewer boutons. Based on a cluster analysis of characteristics of the 26 axons, axons projecting from caudal (ITCv) to rostral (ITR or IT1) IT cortex of squirrel monkeys comprised three groups that we called Type I, Type II, and Type III. Type I axons, the smallest in areal extent of terminal arbor, terminated predominantly in dorsal ITR. Type III axons, largest in areal extent, and Type II axons, intermediate in areal extent, terminated in ventral ITR and throughout IT1. The three classes of axons may correspond to different types of visual information entering rostral IT cortex. The clumping of boutons suggests that individual axons terminate in limited patches within their terminal fields.

scholarly journals Action-specific feature processing in the human visual cortex

2018 ◽  
Author(s):  
Simona Monaco ◽  
Ying Chen ◽  
Nicholas Menghi ◽  
J Douglas Crawford
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Information ◽  
Temporal Cortex ◽  
Action Planning ◽  
Inferior Temporal Cortex ◽  
Visual Object ◽  
Cortical Processing ◽  
Visual Stream ◽  
Dorsal Visual Stream

AbstractSensorimotor integration involves feedforward and reentrant processing of sensory input. Grasp-related motor activity precedes and is thought to influence visual object processing. Yet, while the importance of reentrant feedback is well established in perception, the top-down modulations for action and the neural circuits involved in this process have received less attention. Do action-specific intentions influence the processing of visual information in the human cortex? Using a cue-separation fMRI paradigm, we found that action-specific instruction (manual alignment vs. grasp) influences the cortical processing of object orientation several seconds after the object had been viewed. This influence occurred as early as in the primary visual cortex and extended to ventral and dorsal visual stream areas. Importantly, this modulation was unrelated to non-specific action planning. Further, the primary visual cortex showed stronger functional connectivity with frontal-parietal areas and the inferior temporal cortex during the delay following orientation processing for align than grasping movements, strengthening the idea of reentrant feedback from dorsal visual stream areas involved in action. To our knowledge, this is the first demonstration that intended manual actions have such an early, pervasive, and differential influence on the cortical processing of vision.

scholarly journals Neuronal oscillatory activities in separate frequencies encode hierarchically distinct visual features

2020 ◽  
Author(s):  
Hiroto Date ◽  
Keisuke Kawasaki ◽  
Isao Hasegawa ◽  
Takayuki Okatani
Keyword(s):  
Visual Information ◽  
Temporal Cortex ◽  
Gamma Band ◽  
Neuronal Firing ◽  
Inferior Temporal Cortex ◽  
Visual Features ◽  
Specific Time ◽  
Feedback Processing ◽  
Frequency Bands ◽  
Time Frequency

AbstractAlthough most previous studies in cognitive neuroscience have focused on the change of the neuronal firing rate under various conditions, there has been increasing evidence that indicates the importance of neuronal oscillatory activities in cognition. In the visual cortex, specific time-frequency bands are thought to have selectivity to visual stimuli. Furthermore, several recent studies have shown that several time-frequency bands are related to frequency-specific feedforward or feedback processing in inter-areal communication. However, few studies have investigated detailed visual selectivity of each time-frequency band, especially in the primate inferior temporal cortex (ITC). In this work, we analyze frequency-specific electrocorticography (ECoG) activities in the primate ITC by training encoding models that predict frequency-specific amplitude from hierarchical visual features extracted from a deep convolutional neural network (CNNs). We find that ECoG activities in two specific time-frequency bands, theta (around 5 Hz) and gamma (around 20-25 Hz) bands, are better predicted from CNN features than the other bands. Furthermore, theta- and gamma-band activities are better predicted from higher and lower layers in CNNs, respectively. Our visualization analysis using CNN-based encoding models qualitatively show that theta- and gamma-band encoding models have selectivity to higher- and lower-level visual features, respectively. Our results suggest that neuronal oscillatory activities in theta and gamma bands carry distinct information in the hierarchy of visual features, and that distinct levels of visual information are multiplexed in frequency-specific brain signals.

scholarly journals Visual information routes in the posterior dorsal and ventral face network studied with intracranial neurophysiology, and white matter tract endpoints

2020 ◽  
Author(s):  
M Babo-Rebelo ◽  
A Puce ◽  
D Bullock ◽  
L Hugueville ◽  
F Pestilli ◽  
...  
Keyword(s):  
White Matter ◽  
Face Processing ◽  
Visual Information ◽  
Temporal Cortex ◽  
Field Potential ◽  
Occipital Cortex ◽  
Inferior Temporal Cortex ◽  
Direct Gaze ◽  
Superior Temporal Cortex ◽  
White Matter Tractography

ABSTRACTOccipito-temporal regions within the face network process perceptual and socio-emotional information, but the dynamics and interactions between different nodes within this network remain unknown. Here, we analyzed intracerebral EEG from 11 epileptic patients viewing a stimulus sequence beginning with a neutral face with direct gaze. The gaze could avert or remain direct, while the emotion changed to fearful or happy. N200 field potential peak latencies indicated that face processing begins in inferior occipital cortex and proceeds anteroventrally to fusiform and inferior temporal cortices, in parallel. The superior temporal sulcus responded preferentially to gaze changes with augmented field potential amplitudes for averted versus direct gaze, and large effect sizes relative to other regions of the network. An overlap analysis of posterior white matter tractography endpoints (from 1066 healthy brains) relative to active intracerebral electrodes from the 11 patients showed likely involvement of both dorsal and ventral posterior white matter pathways. The inferior occipital and temporal sulci likely broadcast their information - the former dorsally to intraparietal sulcus, and the latter between fusiform and superior temporal cortex. Overall, our data call for inclusion of inferior temporal cortex in face processing models, and anchor the superior temporal cortex in dynamic gaze processing.

Modality Dependent Cross-Modal Functional Reorganization Following Congenital Visual Deprivation within Occipital Areas: A Meta-Analysis of Tactile and Auditory Studies

2014 ◽  
Vol 27 (3-4) ◽  
pp. 247-262 ◽  
Author(s):  
Emiliano Ricciardi ◽  
Leonardo Tozzi ◽  
Andrea Leo ◽  
Pietro Pietrini
Keyword(s):  
Visual Information ◽  
Meta Analysis ◽  
Sensory Modality ◽  
Temporal Cortex ◽  
Sensory Information ◽  
Occipital Cortex ◽  
Inferior Temporal Cortex ◽  
Functional Studies ◽  
Superior Parietal Cortex ◽  
Blind Individuals

Cross-modal responses in occipital areas appear to be essential for sensory processing in visually deprived subjects. However, it is yet unclear whether this functional recruitment might be dependent on the sensory channel conveying the information. In order to characterize brain areas showing task-independent, but sensory specific, cross-modal responses in blind individuals, we pooled together distinct brain functional studies in a single based meta-analysis according only to the modality conveying experimental stimuli (auditory or tactile). Our approach revealed a specific functional cortical segregation according to the sensory modality conveying the non-visual information, irrespectively from the cognitive features of the tasks. In particular, dorsal and posterior subregions of occipital and superior parietal cortex showed a higher cross-modal recruitment across tactile tasks in blind as compared to sighted individuals. On the other hand, auditory stimuli activated more medial and ventral clusters within early visual areas, the lingual and inferior temporal cortex. These findings suggest a modality-specific functional modification of cross-modal responses within different portions of the occipital cortex of blind individuals. Cross-modal recruitment can thus be specifically influenced by the intrinsic features of sensory information.

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