Emotional valence impacts lexical activation and inhibition differently in aging: an emotional Hayling task investigation

摘要

Background: Aging is characterized by cognitive changes such as a potential inhibition deficit. However, growing evidence shows that positive valence stimuli enhance performances in older adults to a greater degree than in younger adults. The aim of the present study was to investigate the effect of the emotional valence of words on lexical activation and inhibition in aging by using a new Emotional Hayling Task. Methods: Thirty-eight younger adults (mean age = 20.11 years) and 38 older adults (mean age = 66.47 years) performed a computerized Emotional Hayling task. Participants had to choose the correct (initiation part) or incorrect (inhibition part) final words of highly predictable incomplete sentences. Final words had a negative or positive emotional valence and were paired for reaction time comparison with neutral words. Results: Response times were faster in younger adults than in older adults in both the initiation and the inhibition parts. In addition, response times indicated that older adults initiated more slowly negative than neutral words while no differences emerged in inhibition. No differences were obtained between negative and neutral words in younger adults. Response times showed faster initiation and inhibition for positive than for neutral words in both age groups. Conclusion: These data are consistent with previous findings suggesting a disengagement from the processing of negative versus neutral words in older adults when compared with younger adults. A possible explanation is that activation of negative words in the mental lexicon is weaker in older than in younger adults. Conversely, the positive valence of words seems to enhance both activation and inhibition processes in both young and older adults. These findings suggest that positive stimuli can improve performance.