Poster A61, Saturday, March 24, 1:30–3:30 pm, Exhibit Hall C
Theta oscillations during active and passive decision making for navigation
Elizabeth Chrastil1,2, Mathias Goncalves1, Kylie Moore3, Chantal Stern1, Erika Nyhus3; 1Boston University, 2University of California, Santa Barbara, 3Bowdoin College
“Active” navigation seems to yield better spatial knowledge than “passive” navigation, but it is unclear how active decision making influences learning and memory. We previously found that actively making decisions about where and how to explore a novel environment facilitated learning the path structure of a maze. Here, we tested the relationship between decision making and spatial memory by examining the role of theta oscillations during navigation. Theta rhythm is theorized to play a role in setting the dynamics for encoding and retrieval and is known to contribute to spatial coding in both animals and humans. Theta oscillations in prefrontal cortex could indicate integration of new information into memory and communication with the hippocampus. We tested individuals on a maze-learning task in which participants made discrete decisions about where to explore at each choice point in the maze. Half of the participants were free to make decisions at each choice point, and the other half passively explored by selecting a marked choice (matched to active exploration) at each intersection. They were then tested on their knowledge of the maze by traveling from object A to object B within the maze corridors. Exploration and test in this novel environment occurred while undergoing electroencephalography (EEG). Preliminary results show an advantage for active decision making during learning and indicate that the active group had greater theta power during choice points in exploration, particularly in prefrontal cortex. These results suggest that hippocampal-prefrontal interactions are vital for learning and memory during active decision making.
Topic Area: LONG-TERM MEMORY: Episodic