SHORT-TERM VISUAL STORAGE AND THE POSITION EFFECT IN THE STIMULUS DISPLAY

An attempt was made to demonstrate a short-term visual storage (STVS) using a visual marker. The position effect in STVS was also examined. Stimulus arrays consisting of various numbers of letters were tachistoscopically presented. Two types of letter arrangement, the Circular and the Rectangular, were used. S's task was to report all the letters he could remember (whole report) or to report only one letter indicated by a visual marker which was presented with various ISIs (partial report). In Light Condition, the adaptation field with the same luminance as that of the stimulus array and the marker fields was presented at all the time cxcept when the latter fields were presented. In Dark Condition, the stimulus arrays or the markers were presented against the dark background. The results showed clear evidence of STVS in both conditions. The luminance summation effect assumed in Dark Condition did not cancel out STVS effects. The whole and partial reports produced considerably different position effects. The results of the partial report suggested that the decay of information in STVS proceeds evenly in every position.