scholarly journals Neural representations of perceptual and semantic identities of individuals in the anterior ventral inferior temporal cortex of monkeys

2013 ◽  
Vol 56 (1) ◽  
pp. 58-75
Author(s):  
Satoshi Eifuku
Keyword(s):  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Neural Representations

scholarly journals Large-scale hyperparameter search for predicting human brain responses in the Algonauts challenge

2019 ◽  
Author(s):  
Kamila M. Jozwik ◽  
Michael Lee ◽  
Tiago Marques ◽  
Martin Schrimpf ◽  
Pouya Bashivan
Keyword(s):  
Large Scale ◽  
Visual Stimuli ◽  
Temporal Cortex ◽  
Image Features ◽  
Inferior Temporal Cortex ◽  
Network Architectures ◽  
Image Preprocessing ◽  
Neural Representations ◽  
Brain Responses ◽  
Early Visual Cortex

Image features computed by specific convolutional artificial neural networks (ANNs) can be used to make state-of-the-art predictions of primate ventral stream responses to visual stimuli.However, in addition to selecting the specific ANN and layer that is used, the modeler makes other choices in preprocessing the stimulus image and generating brain predictions from ANN features. The effect of these choices on brain predictivity is currently underexplored.Here, we directly evaluated many of these choices by performing a grid search over network architectures, layers, image preprocessing strategies, feature pooling mechanisms, and the use of dimensionality reduction. Our goal was to identify model configurations that produce responses to visual stimuli that are most similar to the human neural representations, as measured by human fMRI and MEG responses. In total, we evaluated more than 140,338 model configurations. We found that specific configurations of CORnet-S best predicted fMRI responses in early visual cortex, and CORnet-R and SqueezeNet models best predicted fMRI responses in inferior temporal cortex. We found specific configurations of VGG-16 and CORnet-S models that best predicted the MEG responses.We also observed that downsizing input images to ~50-75% of the input tensor size lead to better performing models compared to no downsizing (the default choice in most brain models for vision). Taken together, we present evidence that brain predictivity is sensitive not only to which ANN architecture and layer is used, but choices in image preprocessing and feature postprocessing, and these choices should be further explored.

scholarly journals Neural Representations of Personally Familiar and Unfamiliar Faces in the Anterior Inferior Temporal Cortex of Monkeys

PLoS ONE ◽  
2011 ◽  
Vol 6 (4) ◽  
pp. e18913 ◽  
Author(s):  
Satoshi Eifuku ◽  
Wania C. De Souza ◽  
Ryuzaburo Nakata ◽  
Taketoshi Ono ◽  
Ryoi Tamura
Keyword(s):  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Neural Representations ◽  
Unfamiliar Faces

scholarly journals Own-species bias in the representations of monkey and human face categories in the primate temporal lobe

2011 ◽  
Vol 105 (6) ◽  
pp. 2740-2752 ◽  
Author(s):  
R. Sigala ◽  
N. K. Logothetis ◽  
G. Rainer
Keyword(s):  
Human Subjects ◽  
Temporal Cortex ◽  
Three Dimensional ◽  
Inferior Temporal Cortex ◽  
Current Evidence ◽  
Neural Data ◽  
Categorical Representation ◽  
Neural Representations ◽  
Face Categorization ◽  
The Continuum

Face categorization is fundamental for social interactions of primates and is crucial for determining conspecific groups and mate choice. Current evidence suggests that faces are processed by a set of well-defined brain areas. What is the fine structure of this representation, and how is it affected by visual experience? Here, we investigated the neural representations of human and monkey face categories using realistic three-dimensional morphed faces that spanned the continuum between the two species. We found an “own-species” bias in the categorical representation of human and monkey faces in the monkey inferior temporal cortex at the level of single neurons as well as in the population response analyzed using a pattern classifier. For monkey and human subjects, we also found consistent psychophysical evidence indicative of an own-species bias in face perception. For both behavioural and neural data, the species boundary was shifted away from the center of the morph continuum, for each species toward their own face category. This shift may reflect visual expertise for members of one's own species and be a signature of greater brain resources assigned to the processing of privileged categories. Such boundary shifts may thus serve as sensitive and robust indicators of encoding strength for categories of interest.

Neural representations of personally familiar and unfamiliar faces in the anterior inferior temporal cortex of monkeys

2011 ◽  
Vol 71 ◽  
pp. e279-e280
Author(s):  
Satoshi Eifuku ◽  
Wania C. De Souza ◽  
Ryuzaburo Nakata ◽  
Taketoshi Ono ◽  
Ryoi Tamura
Keyword(s):  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Neural Representations ◽  
Unfamiliar Faces

Organization of local horizontal functional interactions between neurons in the inferior temporal cortex of macaque monkeys

2014 ◽  
Vol 111 (12) ◽  
pp. 2589-2602 ◽  
Author(s):  
Hiroshi Tamura ◽  
Yoshiya Mori ◽  
Hidekazu Kaneko
Keyword(s):  
Neuronal Activity ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Visual Object ◽  
Detailed Knowledge ◽  
Visual Response ◽  
Stimulus Preference ◽  
Macaque Monkeys ◽  
Functional Interactions ◽  
Cross Correlation Analysis

Detailed knowledge of neuronal circuitry is necessary for understanding the mechanisms underlying information processing in the brain. We investigated the organization of horizontal functional interactions in the inferior temporal cortex of macaque monkeys, which plays important roles in visual object recognition. Neuronal activity was recorded from the inferior temporal cortex using an array of eight tetrodes, with spatial separation between paired neurons up to 1.4 mm. We evaluated functional interactions on a time scale of milliseconds using cross-correlation analysis of neuronal activity of the paired neurons. Visual response properties of neurons were evaluated using responses to a set of 100 visual stimuli. Adjacent neuron pairs tended to show strong functional interactions compared with more distant neuron pairs, and neurons with similar stimulus preferences tended to show stronger functional interactions than neurons with different stimulus preferences. Thus horizontal functional interactions in the inferior temporal cortex appear to be organized according to both cortical distances and similarity in stimulus preference between neurons. Furthermore, the relationship between strength of functional interactions and similarity in stimulus preference observed in distant neuron pairs was more prominent than in adjacent pairs. The results suggest that functional circuitry is specifically organized, depending on the horizontal distances between neurons. Such specificity endows each circuit with unique functions.

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