Intentional Encoding in Elderly Adults: An Event-Related Potential Study

Elderly people face difficulties in encoding as part of aging. A better understanding of the encoding process and deficits helps to develop and design more effective memory strategies in the future. The current study aimed to examine intentional encoding processes in older adults using the event-related potential (ERP) technique. Fifteen healthy elderly subjects completed the experiment. A study and recognition subsequent memory effect (SME) paradigm was implemented. Subjects memorized Chinese characters using their own strategies while having their electroencephalograms recorded. At recognition phase, percentage of correct judgments was 70.7 ± 8.6 and the d-prime for recognition performance was 1.1 ± 0.5. SMEs were marginally significant from 240 to 360 ms and significant from 360 to 700 ms post-stimulus with a superior scalp distribution. SME in late positive complex (LPC) was not significant. Behavioral and ERP evidence suggested that healthy elderly adults attempted to encode in a semantic-like manner. In addition, they appeared to have decreased the ability to elaborately process newly formed memory representations and perform cognitive binding of concepts.