Olfactory or auditory stimulation and their hedonic values differentially modulate visual working memory

Working memory (WM) designates the retention of objects or events in conscious awareness when these are not present in the environment. Many studies have focused on the interference properties of distracter stimuli in working memory, but these studies have mainly examined the influence of the intensity of these stimuli. Little is known about the memory modulation of hedonic content of distracter stimuli as they also may affect WM performance or attentional tasks. In this paper, we have studied the performance of a visual WM task where subjects recollect from five to eight visually presented objects while they are simultaneously exposed to additional - albeit weak- auditory or olfactory distracter stimulus. We found that WM performance decreases as the number of Items to remember increases, but this performance was unaltered by any of the distracter stimuli. However, when performance was correlated to the subject's perceived hedonic values, distracter stimuli classified as negative exhibit higher error rates than positive, neutral or control stimuli. We demonstrate that some hedonic content of otherwise neutral stimuli can strongly modulate memory processes.