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

Abstract

Background: 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. Objectives: The current study aimed to examine intentional encoding processes in older adults using the event-related potential (ERP) technique. Methods: 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. Results: 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. Conclusions: 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.