Age-Related Differences in EEG Oscillatory Subsequent Memory Effects

Cognitive aging is associated with alterations in neural oscillatory activity during the encoding stage of episodic memory, but findings have been mixed. Additionally, peak alpha frequency has been shown to be a marker of cognitive functioning that remains understudied in task-based studies. Thus, the current experiment used the subsequent memory effects paradigm to identify age-related differences in EEG oscillatory activity during memory encoding of pictorial stimuli. Frequency bands were organized based on subjects’ peak alpha frequency rather than the canonical approach. Healthy young and older adults (N=44) studied scenes and objects and completed a surprise memory test. Younger adults had better memory performance for scenes, but performance for objects were age-matched. Findings from time-frequency analyses indicated both positive and negative subsequent memory effects in the theta frequency band and negative beta subsequent memory effect across age groups. A positive subsequent memory effect in theta between 384-944 ms was identified for older adults, only. Together, these findings suggest cognitive aging is associated with alterations within the theta frequency band that effect memory encoding driving deficits in mnemonic binding of stimulus features.