Decoding the Performance of a Memory Task Using Single-trial Intracranial EEG

Hyung-Tak Lee, Soyeon Jun, June Sic Kim, Chun Kee Chung, Han-Jeong Hwang

Abstract: Most of previous studies related to decoding memory task have focused on the interpretation of neurophysiological characteristics during the memory task. Some studies have attempted to decode the performance of the memory task using brain activity measured in a retrieval session. The aim of this study is to decode the results of a memory task using intracranial EEG (iEEG) measured before (pre-encoding phase) and during (encoding phase) an encoding session in advance of a retrieval session. iEEG data were measured from two epilepsy patients during a memory task, and the power spectral densities of the iEEG data were extracted as decoding features. Event-related spectral perturbation (ERSP) in high-beta band (24 – 30 Hz) showed the significant difference between correctly and incorrectly memorized items in common along with the unique patterns of each patient. The mean decoding accuracy was 74.0% and 73.2% for pre-encoding phase and encoding phase, respectively, demonstrating the possibility of decoding the results of a memory task before and during an encoding session.