Learning and transfer of feature-based attentional modulation

Attending to a visual stimulus feature, such as color or motion, enhances the processing of that feature in the visual cortex. Moreover, the processing of the attended object's other, unattended, features is also enhanced. Here, we used functional magnetic resonance imaging to show that attentional modulation in the auditory system may also exhibit such feature- and object-specific effects. Specifically, we found that attending to auditory motion increases activity in nonprimary motion-sensitive areas of the auditory cortical “where” pathway. Moreover, activity in these motion-sensitive areas was also increased when attention was directed to a moving rather than a stationary sound object, even when motion was not the attended feature. An analysis of effective connectivity revealed that the motion-specific attentional modulation was brought about by an increase in connectivity between the primary auditory cortex and nonprimary motion-sensitive areas, which, in turn, may have been mediated by the paracingulate cortex in the frontal lobe. The current results indicate that auditory attention can select both objects and features. The finding of feature-based attentional modulation implies that attending to one feature of a sound object does not necessarily entail an exhaustive processing of the object's unattended features.

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Body shape as a visual feature: evidence from spatially-global attentional modulation in human visual cortex

10.1101/2021.11.17.469004 ◽

2021 ◽

Author(s):

Sushrut Thorat ◽

Marius V. Peelen

Keyword(s):

Visual Cortex ◽

Visual Processing ◽

The Body ◽

Attentional Modulation ◽

Low Level ◽

Object Categories ◽

Feature Based ◽

Vertically Aligned ◽

High Level ◽

Task Irrelevant

Feature-based attention supports the selection of goal-relevant stimuli by enhancing the visual processing of attended features. A defining property of feature-based attention is that it modulates visual processing beyond the focus of spatial attention. Previous work has reported such spatially-global effects for low-level features such as color and orientation, as well as for faces. Here, using fMRI, we provide evidence for spatially-global attentional modulation for human bodies. Participants were cued to search for one of six object categories in two vertically-aligned images. Two additional, horizontally-aligned, images were simultaneously presented but were never task-relevant across three experimental sessions. Analyses time-locked to the objects presented in these task-irrelevant images revealed that responses evoked by body silhouettes were modulated by the participants' top-down attentional set, becoming more body-selective when participants searched for bodies in the task-relevant images. These effects were observed both in univariate analyses of the body-selective cortex and in multivariate analyses of the object-selective visual cortex. Additional analyses showed that this modulation reflected response gain rather than a bias induced by the cues, and that it reflected enhancement of body responses rather than suppression of non-body responses. Finally, the features of early layers of a convolutional neural network trained for object recognition could not be used to accurately categorize body silhouettes, indicating that the fMRI results were unlikely to reflect selection based on low-level features. These findings provide the first evidence for spatially-global feature-based attention for human bodies, linking this modulation to body representations in high-level visual cortex.

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