Spatiotemporal illusions in manual interception for auditory and visual stimuli


Successfully catching a ball requires high temporal and spatial precision. Studies on perceptual illusions show that spatial judgments can be influenced by task-irrelevant temporal information (tau effect; Benussi, 1913, Helson & King, 1931) and vice versa: when judging the duration of intervals between successfully flashing lights, participants typically perceive the spatially most distant lights to have the longest temporal interval (kappa effect; Abe, 1935; Cohen et al., 1953). The current study tested whether (i) these perceptual illusions impact interception performance (e.g., catching a ball), and (ii) whether the size of the effects differs between modalities due to different sensitivities to temporal and spatial information (cf. Recanzone, 2009). Participants either observed a white, intermittently presented circle on a touchscreen (visual block) or listened to an 800 Hz pure tone presented through two loudspeakers (auditory block). The stimulus was presented on four locations sequentially moving from left to right with constant temporal and spatial intervals between presentations. Participants predicted the fifth location and time of presentation by tapping on the screen. The size of the spatial or temporal intervals was manipulated between trials and effects on the temporal vs. spatial response were tested via linear mixed models. Auditory results revealed that participants' spatial response depended on the temporal intervals (p<.001) indicating a tau effect: with longer duration participants touched the screen further from the initial location. No other significant effects were found. These findings seem to indicate that spatiotemporal interrelations depend on task modality.