Northwestern University

Oct
13
Thu 4:00 PM

Psychology Colloquium- Ed Awh

When: Thursday, October 13, 2016
4:00 PM - 6:00 PM  

Where: Swift Hall, Room 107, 2029 Sheridan Road, Evanston, IL 60208 map it

Audience: Faculty/Staff - Student - Public - Post Docs/Docs - Graduate Students

Contact: Laura Nevins   847.467.5027

Group: Department of Psychology

Category: Academic

Description:

The Northwestern University Psychology Colloquium Series Presents:

Ed Awh

Department of Psychology, Institute for Mind and Biology

University of Chicago

 

Tracking the spatial and temporal dynamics of online spatial representations with rhythmic brain activity

 

Abstract: "A substantial body of evidence suggests that neural activity in the alpha frequency band (8-12 Hz) covaries with the locus of covert spatial attention, such that attention to one visual field yields a sustained decline in alpha power at contralateral electrode sites. In our work, we have exploited this covariation by using an inverted encoding model to reconstruct spatial response profiles (termed channel tuning functions, or CTFs) based on the topography of alpha activity on the human scalp. Thus, in a task that required the storage of locations in working memory, we observed a graded profile of activity across spatial channels that peaked at the stored location during both the encoding and delay periods of the task. These spatial CTFs provide an opportunity to quantify the basic tuning properties of online spatial memories to examine how the precision of neural representations changes with manipulations of the probability of storage or the number of items stored. In addition, I’ll show that the same method can be used to track the locus and timing of covert attention following the presentation of symbolic orienting cues and during active visual search. Moreover, we demonstrate that dynamic changes in the selectivity of spatial CTFs provide a sensitive measure of the latency of covert orienting during visual search. These findings demonstrate the integral role that alpha band activity plays in the online representation of space, and provide a powerful new approach for tracking these representations during online storage and covert orienting."

 

Thursday, October 13, 2016

4:00 pm, Swift Hall 107

Reception to follow

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