Incidentally Learned Emotional Valence Affects Spatial Working Memory

Little is known on how emotion information is processed in the working memory system, especially in the visuo-spatial domain. The aim of the present research was to investigate the effect of incidentally learned emotional stimuli on short-term memory for object-location. In the two experiments presented we sought to ascertain the role of valence in spatial working memory by keeping the level of pictures’ arousal constant, and by modulating the level of pictures’ valence. Participants (N=18 in Experiment A; N=21 in Experiment B) were submitted to a modified version of the object relocation task: eight black rectangles appeared (1s) simultaneously on the screen of a computer; this was immediately followed by the sequential presentation of 8 pictures selected from the International Affective Picture System (1s for each picture; ISI: 250 ms) superimposed onto each rectangle. Rectangle position was tagged with pictures with comparable arousal levels, negative and neutral in Experiment A, and positive and neutral in Experiment B. In both cases valence is a within-subject factor. Immediately after presentation, participants had to relocate the black rectangles in the original position as accurately as possible. The statistical analyses (paired t- tests) carried out on displacement errors revealed a significant effect of valence: lower displacement errors for negative-related objects compared to neutral ones (t(17) = −2.89; p < 0.05) in Experiment A, and lower displacement errors for objects associated to positive pictures than those associated to neutral ones (t(20) = 2.28; p < 0.05) in Experiment B. Overall, findings show that when arousal is kept constant (at a low level) the position of negative-related objects (Experiment A) or positive- related object (Experiment B) are better relocated than neutral ones in an immediate visuo-spatial working memory test, thus indicating that valence significantly affects visuo-spatial performance.