Extrinsic and intrinsic factors influencing the positive memory bias in aging ; Facteurs extrinsèques et intrinsèques qui influencent le biais de positivité mnésique dans le vieillissement

Emotional experiences are more likely to be remembered than more neutral, mundane ones. In young adults, negative information may be particularly memorable. Yet, an interesting change seems to happen in aging: As adults grow older, they may start remembering positive information more often than negative information. This positive memory bias in aging is commonly reported and is often explained in terms of changing time perspectives and motivation across the lifespan (i.e., Socioemotional Selectivity Theory). However, few studies have considered the basic interactions between memory and emotion that could influence this positivity bias. In this thesis, I examine whether certain factors partially independent of aging (i.e., semantic relatedness and distinctiveness, Study 1; mood, Studies 2-4), might influence the presence and magnitude of the positivity bias in memory. In Study 1, I explore the cognitive mechanisms required to produce the positivity bias and apply what is learned in this paper to investigate, in Studies 2-4, whether differences in mood could explain why the positivity bias occurs. In all studies, memory is measured using immediate free recall of positive, negative, and neutral pictures. In Study 1, I manipulate item interrelatedness (i.e., the extent of relatedness among pictures of a same category) and relative distinctiveness (i.e., the processing of a picture category at the same time as or in isolation from the others) to show that older adults’ emotional memory can be entirely explained by these two factors. The distinctive processing of positive pictures relative to other pictures is necessary for producing a positivity bias in older adults, which completely disappears when the distinctive processing of positive pictures is removed. Therefore, in subsequent studies I encourage the distinctive processing of items to increase the likelihood of observing a positivity bias and its possible interaction with mood. In Study 2, I test whether differences in mood predict differences in emotional ...