The effect of emotion on working memory: Valence model versus motivational model

The main aim of this thesis is to investigate the effects of emotion on working memory (WM). It is seen that emotions used in previous research differed on both dimensions of valence and motivation. Especially, anger which is a negative but approach-related emotion, was not previously investigated. Hence, it is unclear whether the effects of emotion on WM are valence-based or motivation-based. Two studies were conducted in which participants were induced one of four emotions to create approach-positive, avoidance-negative, approach-negative, and control conditions. In the first study, after mood induction participants performed Self-Ordered Pointing Tasks. Results of the first study showed that the effect of emotion on WM was not significant. However, a similar trend in the data was observed in happiness and anger conditions in terms of WM performance, and this trend was different from that in the fear condition. This pattern is consistent with the motivational model since both anger and happiness are approach-related emotions, despite carrying different valences. In the second study, after the mood induction participants completed 2-Back tasks which allowed us to measure reaction times (RT) and obtain unbiased measures of accuracy as the Signal Detection Theory suggests. The data revealed that only RTs in the avoidance-related emotion condition were faster for both verbal and visuospatial tasks compared to those in approach-related conditions without compromising accuracy. Main effect of emotion on WM accuracy wasn't significant. Together the two studies showed that the motivational dimension of emotion was more effective on WM than the valence dimension. Key words: Emotion, working memory, valence, motivation, self-ordered pointing task, N-Back task.