2021

Petrizzo, I., Pellegrino, M., Navicelli, I., Anobile, G., Doricchi, F. & Arrighi, R.

Task-dependent interaction between stimulus numerosity and duration.

43rd European Conference on Visual Perception (ECVP) 2021 Online. (2021)

poster

The ATOM Theory suggests that space, time and numerosity might be encoded by a common neural mechanism to pro- mote the interplay between perception and action (Walsh, 2003). In line with that, Xian et al. (2007) demonstrated via a discrimination task that larger or more numerous sti- muli are judged to last longer than smaller/less numerous sti- muli of the same physical duration. However, Yates et al. (2012) reported that the interaction between stimuli dur- ation and size is intrinsically task dependent: the duration of larger stimuli was over-estimated in comparative judg- ments (which stimulus lasts longer?) but the opposite occurred during equality judgments (are the stimuli matched for duration?). Here we investigated whether a task depend- ent interaction also occurs for estimates of the duration of stimuli with different numerosities. Participants judged the duration of a variable test stimulus (duration: 400 -1600 ms; numerosity: 12 or 48; tested in separate sessions) against the duration of a reference (duration: 800 ms; numerosity: 24) in a discrimination and a same/different task. Numerosity strongly affected perceived duration in the dis- crimination task, with more numerous stimuli being per- ceived as lasting longer, but no significant interaction was found for the same/different task. On top of this, duration estimates for stimuli of different numerosity turned out in being rather identical also in a duration reproduction task. Taken together our results suggest that the interactions between magnitudes might not be the automatic outcome of a shared perceptual mechanism, but the result of a percep- tual/cognitive strategy employed in the behavioral task.