scholarly journals Novel objects with causal schemas elicit selective responses in tool- and hand-selective lateral occipito-temporal cortex

2021 ◽  
Author(s):  
Anna Leshinskaya ◽  
Mira Bajaj ◽  
Sharon L. Thompson-Schill
Keyword(s):  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Essential Property ◽  
Neural Responses ◽  
Still Images ◽  
Event Sequences ◽  
Environmental Event ◽  
Parahippocampal Cortex ◽  
Novel Objects ◽  
Human Participants

Tool-selective lateral occipito-temporal cortex (LOTC) responds preferentially to images of tools (hammers, brushes) relative to non-tool objects (clocks, shoes). What drives these responses? Tools have elongated shapes and are more likely to have motor associations, but another essential property is that they exert causal effects on the environment. We tested whether LOTC would respond to novel objects associated with a tool-canonical schema in which their actions cause other events. To do so, we taught male and female human participants about novel objects embedded in animated event sequences, which varied in the temporal order of their events. Causer objects moved prior to the appearance of an environmental event (e.g., stars) while Reactor objects moved after an identical event; objects were matched on shape and motor association. During fMRI, participants viewed still images of these novel objects. We localized tool-selective LOTC and non-tool-selective parahippocampal cortex (PHC) by contrasting neural responses to images of familiar tools and non-tools. We found that LOTC responded more to Causers than Reactors; this effect was absent and weaker in right PHC. We also localized responses to images of hands, which elicit overlapping responses with tools. Across inferior temporal cortex, voxels’ tool and hand selectivity positively predicted a preferential response to Causers, and non-tool selectivity negatively so. We conclude that a causal schema typical of tools is sufficient to drive LOTC, and more generally, that preferential responses to domains across the temporal lobe may reflect the relational event structures typical of those domains.

scholarly journals Feature Diagnosticity Affects Representations of Novel and Familiar Objects

2014 ◽  
Vol 26 (12) ◽  
pp. 2735-2749 ◽  
Author(s):  
Nina S. Hsu ◽  
Margaret L. Schlichting ◽  
Sharon L. Thompson-Schill
Keyword(s):  
Fruits And Vegetables ◽  
Temporal Cortex ◽  
Familiar Object ◽  
Behavioral Effects ◽  
Diagnostic Features ◽  
Novel Objects ◽  
Human Participants ◽  
Ventral Temporal Cortex ◽  
Concept Representations ◽  
The Impact

Many features can describe a concept, but only some features define a concept in that they enable discrimination of items that are instances of a concept from (similar) items that are not. We refer to this property of some features as feature diagnosticity. Previous work has described the behavioral effects of feature diagnosticity, but there has been little work on explaining why and how these effects arise. In this study, we aimed to understand the impact of feature diagnosticity on concept representations across two complementary experiments. In Experiment 1, we manipulated the diagnosticity of one feature, color, for a set of novel objects that human participants learned over the course of 1 week. We report behavioral and neural evidence that diagnostic features are likely to be automatically recruited during remembering. Specifically, individuals activated color-selective regions of ventral temporal cortex (specifically, left fusiform gyrus and left inferior temporal gyrus) when thinking about the novel objects, although color information was never explicitly probed during the task. Moreover, multiple behavioral and neural measures of the effects of feature diagnosticity were correlated across participants. In Experiment 2, we examined relative color association in familiar object categories, which varied in feature diagnosticity (fruits and vegetables, household items). Taken together, these results offer novel insights into the neural mechanisms underlying concept representations by demonstrating that automatic recruitment of diagnostic information gives rise to behavioral effects of feature diagnosticity.

scholarly journals Fast Readout of Object Identity from Macaque Inferior Temporal Cortex

Science ◽  
2005 ◽  
Vol 310 (5749) ◽  
pp. 863-866 ◽  
Author(s):  
Chou P. Hung ◽  
Gabriel Kreiman ◽  
Tomaso Poggio ◽  
James J. DiCarlo
Keyword(s):  
Neural Coding ◽  
Temporal Cortex ◽  
Population Level ◽  
Inferior Temporal Cortex ◽  
Object Identity ◽  
Neuronal Populations ◽  
Novel Objects ◽  
Coarse Information ◽  
Short Time

Understanding the brain computations leading to object recognition requires quantitative characterization of the information represented in inferior temporal (IT) cortex. We used a biologically plausible, classifier-based readout technique to investigate the neural coding of selectivity and invariance at the IT population level. The activity of small neuronal populations (∼100 randomly selected cells) over very short time intervals (as small as 12.5 milliseconds) contained unexpectedly accurate and robust information about both object “identity” and “category.” This information generalized over a range of object positions and scales, even for novel objects. Coarse information about position and scale could also be read out from the same population.

scholarly journals Preference for Audiovisual Speech Congruency in Superior Temporal Cortex

2016 ◽  
Vol 28 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Claudia S. Lüttke ◽  
Matthias Ekman ◽  
Marcel A. J. van Gerven ◽  
Floris P. de Lange
Keyword(s):  
Visual Information ◽  
Temporal Cortex ◽  
Primary Auditory Cortex ◽  
Neural Responses ◽  
Neuronal Responses ◽  
Audiovisual Stimulation ◽  
Superior Temporal Cortex ◽  
Mcgurk Illusion ◽  
Audiovisual Stimuli ◽  
Human Participants

Auditory speech perception can be altered by concurrent visual information. The superior temporal cortex is an important combining site for this integration process. This area was previously found to be sensitive to audiovisual congruency. However, the direction of this congruency effect (i.e., stronger or weaker activity for congruent compared to incongruent stimulation) has been more equivocal. Here, we used fMRI to look at the neural responses of human participants during the McGurk illusion—in which auditory /aba/ and visual /aga/ inputs are fused to perceived /ada/—in a large homogenous sample of participants who consistently experienced this illusion. This enabled us to compare the neuronal responses during congruent audiovisual stimulation with incongruent audiovisual stimulation leading to the McGurk illusion while avoiding the possible confounding factor of sensory surprise that can occur when McGurk stimuli are only occasionally perceived. We found larger activity for congruent audiovisual stimuli than for incongruent (McGurk) stimuli in bilateral superior temporal cortex, extending into the primary auditory cortex. This finding suggests that superior temporal cortex prefers when auditory and visual input support the same representation.

Differences in Onset Latency of Macaque Inferotemporal Neural Responses to Primate and Non-Primate Faces

2005 ◽  
Vol 94 (2) ◽  
pp. 1587-1596 ◽  
Author(s):  
Roozbeh Kiani ◽  
Hossein Esteky ◽  
Keiji Tanaka
Keyword(s):  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Complex Object ◽  
Neural Responses ◽  
Onset Latency ◽  
Single Cell Responses ◽  
Response Onset ◽  
Stimulus Features ◽  
Animal Faces ◽  
Human Faces

Neurons in the visual system respond to different visual stimuli with different onset latencies. However, it has remained unknown which stimulus features, aside from stimulus contrast, determine the onset latencies of responses. To examine the possibility that response onset latencies carry information about complex object images, we recorded single-cell responses in the inferior temporal cortex of alert monkeys, while they viewed >1,000 object stimuli. Many cells responded to human and non-primate animal faces with comparable magnitudes but responded significantly more quickly to human faces than to non-primate animal faces. Differences in onset latency may be used to increase the coding capacity or enhance or suppress information about particular object groups by time-dependent modulation.

scholarly journals A precursor of reading: Neural responses to letters strings in the untrained primate inferior temporal cortex predict word recognition behavior

2019 ◽  
Vol 19 (10) ◽  
pp. 172b
Author(s):  
Rishi Rajalingham ◽  
Kohitij Kar ◽  
Sachi Sanghavi ◽  
Stanislas Dehaene ◽  
James J DiCarlo
Keyword(s):  
Word Recognition ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Neural Responses

scholarly journals Zero-shot neural decoding of visual categories without prior exemplars

2019 ◽  
Author(s):  
Thomas P. O’Connell ◽  
Marvin M. Chun ◽  
Gabriel Kreiman
Keyword(s):  
Neural Network ◽  
Visual Cortex ◽  
Neural Activity ◽  
Deep Neural Network ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Neural Decoding ◽  
Neural Responses ◽  
Prior Training ◽  
Single Category

AbstractDecoding information from neural responses in visual cortex demonstrates interpolation across repetitions or exemplars. Is it possible to decode novel categories from neural activity without any prior training on activity from those categories? We built zero-shot neural decoders by mapping responses from macaque inferior temporal cortex onto a deep neural network. The resulting models correctly interpreted responses to novel categories, even extrapolating from a single category.

scholarly journals Behavioral demand modulates object category representation in the inferior temporal cortex

2014 ◽  
Vol 112 (10) ◽  
pp. 2628-2637 ◽  
Author(s):  
Nazli Emadi ◽  
Hossein Esteky
Keyword(s):  
Signal To Noise Ratio ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Object Categorization ◽  
Visual Object ◽  
Single Neurons ◽  
Neural Responses ◽  
Category Representation ◽  
Passive Fixation ◽  
Insight Into

Visual object categorization is a critical task in our daily life. Many studies have explored category representation in the inferior temporal (IT) cortex at the level of single neurons and population. However, it is not clear how behavioral demands modulate this category representation. Here, we recorded from the IT single neurons in monkeys performing two different tasks with identical visual stimuli: passive fixation and body/object categorization. We found that category selectivity of the IT neurons was improved in the categorization compared with the passive task where reward was not contingent on image category. The category improvement was the result of larger rate enhancement for the preferred category and smaller response variability for both preferred and nonpreferred categories. These specific modulations in the responses of IT category neurons enhanced signal-to-noise ratio of the neural responses to discriminate better between the preferred and nonpreferred categories. Our results provide new insight into the adaptable category representation in the IT cortex, which depends on behavioral demands.

scholarly journals Imaging object-scene integration in visible and invisible natural scenes

2017 ◽  
Author(s):  
Nathan Faivre ◽  
Julien Dubois ◽  
Naama Schwartz ◽  
Liad Mudrik
Keyword(s):  
Visual Masking ◽  
Brain Activity ◽  
Temporal Cortex ◽  
Task Demands ◽  
Inferior Temporal Cortex ◽  
Natural Scenes ◽  
Lateral Occipital Complex ◽  
Parahippocampal Cortex ◽  
Visual Scenes ◽  
Context Integration

AbstractIntegrating objects with their context is a key step in the interpretation of complex visual scenes. Humans can do this very quickly, yet the brain mechanisms that mediate this ability are not yet understood. Here, we used functional Magnetic Resonance Imaging (fMRI) to measure brain activity while participants viewed visual scenes depicting a person performing an action with an object that was either congruent or incongruent with the scene. Univariate and multivariate analyses revealed different activity for congruent compared to incongruent scenes in the lateral occipital complex, inferior temporal cortex, parahippocampal cortex, and prefrontal cortex, in line with existing models of scene processing. Importantly, and in contrast to previous studies, these activations could not be explained by task-induced conflicts. A secondary goal of this study was to examine whether object-context integration could occur in the absence of awareness, by comparing brain activity elicited by congruent vs. incongruent scenes that were suppressed from awareness using visual masking. We found no evidence for brain activity differentiating between congruent and incongruent invisible scenes. Overall, our results provide novel support for the roles of PHC and PFC in conscious object-context integration which cannot be explained by either low-level differences or task demands. Yet they further suggest that activity in these regions is decreased by visual masking to the point of becoming undetectable with our fMRI protocol.

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