Poster D89, Monday, March 27, 8:00 – 10:00 am, Pacific Concourse
THETA OSCILLATORY ACTIVITY IN SENSORY CORTEX IS ASSOCIATED WITH REACTIVATION AND ACCURACY AT SUBSEQUENT TEST
John Walker1, Kathy Low1, Neal Cohen1, Gabriele Gratton1, Monica Fabiani1; 1University of Illinois at Urbana-Champaign
Multiple theories have suggested that one possible form of communication between the hippocampus and cortical memory stores is through synchronizing oscillatory activity between the hippocampus and the cortex. We sought to demonstrate this oscillatory power increase in cortical memory stores during retrieval of information. We utilized a paradigm in which participants studied faces and scenes and were re-presented with the scenes prior to the test trials to elicit retrieval and reactivation of the associated face. The data were from two previous studies, Walker et al. (2014, 2015), that have shown that the superior temporal sulcus (STS), a known part of the face processing network, is reactivated to the presence of the scenes in college-aged and older adults, respectively. Here we show that oscillatory power in the theta band (4-8 Hz) and in the band just above theta (8-10 Hz) in the STS is associated with later memory performance across all participants. Furthermore, we show that power in the 8-10 Hz band in the STS, immediately prior to the reactivation, is associated with the magnitude of that reactivation in college-aged adults. These findings provide evidence that oscillatory activity is associated with memory retrieval and reactivation in the cortex and is a possible source through which information from the cortex can be retrieved. We also show that there is a different pattern in aging in that older adults show lower oscillatory power in the theta band in the STS and also do not show a link between oscillatory power and reactivation.
Topic Area: LONG-TERM MEMORY: Episodic