Individual differences in positive affect moderate age-related declines in episodic long-term memory

Abstract

Previous studies have attributed declining episodic memory in increased adult age to less efficient contextual markers that are typically associated with ventromedial prefrontal cortex function (e.g., Allen et al., 2005). However, this previous research found the link only for negative affect. Ashby, Isen, and Turken (1999) predicted that individual differences in positive affect should also have an impact on cognitive performance. The present study therefore extended our earlier work on negative affect to positive affect and showed that individual differences in NEO Extraversion scores (a proxy for affective intensity) moderated age differences in episodic memory. Older adults with lower extraversion scores performed more poorly on a test of long-term memory (the Rey Auditory Verbal Learning Task—RAVLT) than did older adults with high extroversion scores. Yet no such effect was found on a test of short-term memory (RAVLT Trial 1). Furthermore, restricting analyses to those high in extraversion (i.e., high affective intensity) eliminate age effects on long-term memory. We propose that adult age is often characterised by a decline in affective intensity (sometimes resulting in weaker positive affective states), which might lead to encoding of fewer/weaker contextual markers at study, which then impairs later recall from long-term memory.

Keywords:

• Ageing
• Episodic memory
• Individual differences
• Positive affect