Abstract
Temporal attention can be entrained exogenously to rhythms. Indeed, faster and more accurate responses were previously found when the target appeared in sync with a preceding rhythm in comparison to when it is out of sync. However, the nature of this rhythm-induced attentional effect is not well understood. To better understand how rhythm-induced attention may affect the quality of the perceptual representation, and specifically to test whether it improves the precision of the target's encoding, we employed a continuous measure of perceived orientation and the mixture-modeling analysis. A trial in our study started with a sequence of beeps separated by a fixed inter-beeps interval (400 ms; regular, rhythmic condition) or variable inter-beeps intervals (irregular condition). A target line followed the sequence. The 'critical' interval between the last beep and the target was chosen randomly from 4 possible Inter-Onset Intervals (IOI), of which one was 400 ms. The target was followed by a probe line, and the participants were asked to rotate it to assume the target's orientation. The measure of performance for a given trial was the difference in degrees between the orientation of the target and that reproduced by the observer. The results show a main effect for regularity: the standard deviation (SD) of report errors was significantly smaller when the observers were exposed to regular vs irregular rhythm. Importantly, there was also an interaction between regularity and IOI: when the target appeared 400 ms after the regular rhythm (but not after an irregular rhythm), a smaller SD of report error was found in comparison to other critical intervals (100, 200 and 600 ms). These results suggest that rhythm-induced attention improves the precision of perceptual representation.
Meeting abstract presented at VSS 2017