Abstract
Through consolidation in working memory, the information that is extracted from a visual stimulus can be retained over time and distraction, thus affording a moment to reflect and report on what was in view only an instant ago. What is currently unclear is how long this consolidation process takes, whether it can deal with multiple stimuli in parallel, and whether it can continue after a stimulus has been erased from view by a trailing mask. Here, we report a series of experiments in which we addressed these matters by examining for how long the consolidation of one or more visual stimuli remains vulnerable to interference from a trailing event. Participants had to memorize masked or unmasked visual stimuli (letters or unfamiliar Kanji characters) that were shown simultaneously or sequentially and that could be followed within 100-1000 ms by an additional mask, a speeded detection task, or a speeded or unspeeded visual or auditory discrimination task. The main finding of interest was that the speeded discrimination tasks produced a pronounced retro-active interference effect for memory of the preceding stimuli. This interference effect occurred regardless of whether these stimuli had been masked, and it occurred regardless of the modality of the discrimination task. Most importantly, the magnitude of interference declined as the stimulus onset asynchrony increased from 100-1000 ms, reflecting the gradual formation of a memory trace strong enough to outlive the parity judgment. Taken together, the results suggest that visual working memory consolidation involves a relatively slow process that can deal with multiple stimuli in parallel, that continues after a stimulus has been masked, and that can then still be disrupted by a trailing second task.
Meeting abstract presented at VSS 2013