Differential EEG Characteristics during Working Memory Encoding and Re-encoding
This work addresses the unclear neural mechanisms of re-encoding in working memory, which could potentially improve learning efficiency, but it is incremental as it builds on existing encoding-retrieval research.
The study investigated differences in brain activity during working memory encoding and re-encoding, finding that alpha power decreased with learning progress and there were significant differences in phase-locking values and phase-amplitude coupling between brain states.
Many studies have discussed the difference in brain activity related to encoding and retrieval of working memory (WM) tasks. However, it remains unclear if there is a change in brain activation associated with re-encoding. The main objective of this study was to compare different brain states (rest, encoding, and re-encoding) during the WM task. We recorded brain activity from thirty-seven participants using an electroencephalogram and calculated power spectral density (PSD) and phase-locking value (PLV) for different frequencies. In addition, the difference in phase-amplitude coupling (PAC) between encoding and re-encoding was investigated. Our results showed that alpha PSD decreased as the learning progressed, and theta PLV, beta PLV, and gamma PLV showed differences between brain regions. Also, there was a statistically significant difference in PAC. These findings suggest the possibility of improving the efficiency of learning during re-encoding by understanding the differences in neural correlation related to learning.