Response bias shift for positive words in older adults in a surprise recognition memory task: an incidental encoding study

Abstract

Introduction: Although the advantages of positive words on memory enhancement have been documented, the specific effects of the two prominent emotional dimensions (valence and arousal) under incidental encoding require further investigation. The objective is to study memory accuracy and response bias for positive/negative and highly/medium arousing words in a surprise old/new recognition memory paradigm under incidental encoding.

Materials and Method: 113 volunteers (60 young, 53 older) participated. Emotional words were presented on a computer screen and participants were instructed to count vowels in the incidental encoding phase. After a 30-minute retention interval, participants' memory was assessed with a surprise old/new recognition memory task.

Results: A 2x3x2 mixed analysis of variance was conducted. Memory accuracy (using d' scores) and response bias (using criterion scores) were the dependent variables in Signal Detection Theory. Older adults had a significant bias (p < 0.05) responding "yes" to positive words, indicating that they had seen these words beforehand; their memory accuracy did not differ in terms of valence.

Conclusion: Older participants emphasize positive words more than negative words. When considering incidental encoding, this age-related change suggests that older participants regulate their emotion in favor of maintaining their well-being. Our study indicates the importance of disentangling age-related factors from the memory performance metrics.