Common capacity limit for visual short-term memory with and without delay intervals(Summary of Awarded Presentation at the 26th Annual Meeting)

抄録

Recent studies on visual short-term memory have demonstrated that our visual system can retain only a few objects. However, it remains unclear whether this capacity limitation is because we forget the visual representation during a delay interval or because visual representations are formed for only a fraction of the visual objects from the beginning. The present study manipulated the delay interval to test these two possibilities. In the experiment, a sample display of six oriented bars was presented, followed by a 0-s or 1-s blank interval, and then by a test display with a cue. The participants reported the orientation of the sample stimulus at the cued location. The results showed that the measured visual capacity was about 3 items under both the 0-s and 1-s conditions. The measured capacity varied substantially across individuals. However, an individual's capacity under the 1-s condition was highly correlated with that under the 0-s condition. These results suggest that the capacity limit is originated from encoding rather than retention or retrieval processes.