Poster C93, Sunday, March 26, 5:00 – 7:00 pm, Pacific Concourse
An electocorticography (ECoG) study of memory formation in children
Qin Yin1, Lingfei Tang1, Mo Malik1, Andrea Shafer1, David Chen1, Eishi Asano1,2, Noa Ofen1; 1Wayne State University, 2Children's Hospital of Michigan
Evidence from non-invasive neuroimaging methods has shown that episodic memory formation in children is supported by activity in the medial temporal lobes (MTL) and lateral prefrontal cortex (PFC), with the latter having a protracted functional development compared to the former. Intracranial EEG, also referred as ECoG, provides novel and exciting opportunities to investigate the temporo-spatial dynamics of neural activities for memory formation. Recent ECoG studies have shown increased power in theta (4-7 Hz) and gamma (30-150 Hz) bands. Here, we tested 12 epilepsy participants (aged 6-17) who underwent extraoperative ECoG as part of clinical management. Participants studied pictures of indoor and outdoor scenes, and were informed that their memory of the scenes would be tested in a following recognition test. Data were recorded using a 192-channel digital system with platinum grid and strip electrodes. We examined changes in theta power for subsequently remembered vs. forgotten scenes in surface electrodes placed on MTL and lateral PFC. Event-related spectral changes were determined through wavelet time-frequency decomposition for 2500 ms pre- to 1000 ms post-response onset. Preliminary analysis showed that successful memory formation was associated with an early decrease followed by later increase in theta in both MTL and lateral PFC. Interestingly, the increased theta power occurred to the posterior MTL before the response and to the anterior MTL afterward. Additional analyses will examine the temporo-spatial dynamics in gamma band frequency as well as cross frequency coupling. Our findings will yield a deeper understanding of the electrophysiological mechanisms underlying memory development.
Topic Area: LONG-TERM MEMORY: Development & aging