[The properties of visual short-term memory on change detection task].

Visual short-term memory (VSTM) has been investigated with a change detection task. Recent studies suggested that there might be some representations in VSTM even when a change was not detected. However, this is discrepant with the previous studies that estimated the representation by change detection. In this study, we investigated the properties of the representation to be retained between two stimuli in a change detection task combined with the probe method so as to explore what causes the discrepancy. The interval between the test and the comparison stimuli and the timing of a positional cue at the location of change were manipulated. The results of three experiments suggested that, before the comparison stimulus presentation, the representations in VSTM were retained more than representations estimated by a normal change detection task, that they decayed with time, and that their availability decreased when the representations of the comparison stimulus were formed. From these results, we discussed a model of VSTM with attention.