Alina Krug¹ (), Lisa Eberhardt¹, Anke Huckauf¹; ¹Ulm University

A number of studies have shown that increasing stimulus eccentricity decreases the perceived duration of short stimuli, yet increases for longer stimuli. This might be due to endogenous shifts of spatial attention towards the peripheral stimulus, that have been shown to prolong perceived duration. Aim of the present study is to investigate whether endogenous attentional shifts affect the perceived duration of peripheral stimuli. In a temporal bisection task, participants categorized the duration of a short peripheral stimulus (20-220 ms) presented at 3° or 9° of eccentricity left or right from fixation as short or long. An eyetracker ensured constant fixation. In Experiment 1, a central arrow cue either reliably indicated the position of the subsequent peripheral stimulus (valid cue) or did not convey information regarding its position (neutral cue). In Experiment 2, the cue either correctly indicated the position of the subsequent stimulus in 75% of the trials (valid cue) or pointed towards the opposite direction (invalid cue). For both experiments, perceived duration decreased for stimuli presented at 9° of eccentricity compared to 3°, replicating previous studies. With regard to cueing, reaction times were significantly shorter for the valid cues compared to the neutral (Experiment 1) and invalid cues (Experiment 2), indicating that the attentional manipulation was successful. However, a significant difference in perceived duration was only found in Experiment 2, where validly cued stimuli were perceived as longer than invalidly cued stimuli. Among others, the results are discussed with regard to the notion that directing attention to a stimulus may not increase perceived duration, but that directing attention away from it may decrease it.