Unconscious Processing of Unattended Features in Human Visual Cortex

Authors

Tatiana Aloi Emmanouil, CUNY Bernard M Baruch CollegeFollow
Philip Burton, University of Minnesota
Tony Ro, CUNY Graduate CenterFollow

Document Type

Article

Publication Date

3-1-2013

Abstract

Unconscious processing has been convincingly demonstrated for task-relevant feature dimensions. However, it is possible that the visual system is capable of more complex unconscious operations, extracting visual features even when they are unattended and task irrelevant. In the current study, we addressed this question by measuring unconscious priming using a task in which human participants attended to a target object's shape while ignoring its color. We measured both behavioral priming effects and priming-related fMRI activations from primes that were unconsciously presented using metacontrast masking. The results showed faster RTs and decreases in fMRI activation only when the primes were identical to the targets, indicating that primes were processed both in the attended shape and the unattended color dimensions. Reductions in activation were observed in early visual areas, including primary visual cortex, as well as in feature-responsive areas for shape and color. These results indicate that multiple features can be unconsciously encoded and possibly bound using the same visual networks activated by consciously perceived images.

Comments

This article was originally published in Journal of Cognitive Neuroscience, available at https://doi.org/10.1162/jocn_a_00320