Abstract
To assess what kinds of visual information affect perceived time and in what ways, we investigated whether the ease with which a stimulus can be discerned affects its perceived duration. We compared perceived duration between readable and crowded stimuli. Each stimulus was presented on a gray background in the periphery of the right visual hemifield and consisted of a target (one of eight digital letters) surrounded by ten flankers (digital number ‘8’) arranged horizontally, five to the left and five to the right of the target. The target and flankers were either black or white. In a readable stimulus condition, only the outermost flankers had the same color as the target (e.g., white) whereas all other flankers had the opposite color (e.g., black), so that the target letter was easier to read. In a crowded stimulus condition, the target and its nearest neighbors had the same color whereas all other flankers had the opposite color, thus the target was crowded and harder to read. We found that the readable stimuli appeared to last longer than the crowded ones. This illusory duration distortion was more pronounced when the participants additionally performed a letter identification task. The distortion was stronger when the flankers appeared before the target and disappeared after its offset, so that the duration of the flankers could not be used as a cue to judge the target duration. The distortion disappeared when the participants additionally performed a position discrimination task for a clearly visible red dot superimposed on the target letter. Therefore, we concluded that it was the target letter in particular that exhibited illusory duration distortion, such that the duration appeared longer when the letter was easier to read than when it was harder. We discuss the implications of this effect for duration perception and its possible mechanisms.