Guest Presenter: Dr. Xiaoli Zhang (Post-doctoral researcher in the Attention and Cognition Lab with Dr. Sarah Shomstein at George Washington University)

Talk Title: How does spatial certainty influence task-irrelevant object processing

Abstract: Our environments consist of objects that occupy spatial locations, so it is not surprising that both objects and space are represented in the brain. The degree to which these representations influence perception remains an open question. For example, behavioral evidence suggests that object representations constrain attention only when the location of the upcoming target is uncertain (Drummond & Shomstein, 2010), predicting that the contribution of object representation is minimized when spatial location is attended (high spatial certainty). Here, we obtain fMRI data to directly investigate whether and how spatial certainty influences object representations in the brain. Preliminary data show stronger decoding accuracy of object identities in early visual cortex when spatial certainty for the task target is lower compared to when it’s higher. This indicates a potential mechanism between space and object representations, counter to the predictions based on the ‘binding’ theories of attention.