Retroactive interference in visual short-term memory

This article does not exactly replicate the final version published in the journal "Experimental Psychology". It is not a copy of the original published article and is not suitable for citation.Retroactive interference occurs when new information disrupts the retention of an existing representation, but its effects on visual short-term memory remain poorly understood. The present study examined three factors predicted to influence domain-specific retroactive interference, including the type of distractor, its temporal position and the length of the retention interval. Participants compared target and test objects over a brief interval that either was unfilled or contained a similar or dissimilar distractor occurring 200 ms or 1.5 s after the target offset. Retention was influenced by the temporal position of the distractor and its relationship with the to-be-remembered target. Specifically, retroactive interference was only observed following the presentation of a dissimilar distractor that occurred 1.5 s after the target. These results suggest that novel distractors may be particularly interfering

Time-resolved neuroimaging of visual short term memory consolidation by post-perceptual attention shifts

Post-perceptual cues can enhance visual short term memory encoding even after the offset of the visual stimulus. However, both the mechanisms by which the sensory stimulus characteristics are buffered as well as the mechanisms by which post-perceptual selective attention enhances short term memory encoding remain unclear. We analyzed late post-perceptual event-related potentials (ERPs) in visual change detection tasks (100 ms stimulus duration) by high-resolution ERP analysis to elucidate these mechanisms. The effects of early and late auditory post-cues (300 ms or 850 ms after visual stimulus onset) as well as the effects of a visual interference stimulus were examined in 27 healthy right-handed adults. Focusing attention with post-perceptual cues at both latencies significantly improved memory performance, i.e. sensory stimulus characteristics were available for up to 850 ms after stimulus presentation. Passive watching of the visual stimuli without auditory cue presentation evoked a slow negative wave (N700) over occipito-temporal visual areas. N700 was strongly reduced by a visual interference stimulus which impeded memory maintenance. In contrast, contralateral delay activity (CDA) still developed in this condition after the application of auditory post-cues and was thereby dissociated from N700. CDA and N700 seem to represent two different processes involved in short term memory encoding. While N700 could reflect visual post processing by automatic attention attraction, CDA may reflect the top-down process of searching selectively for the required information through post-perceptual attention. (C) 2015 Elsevier Inc. All rights reserved