Poster #: 2
Topic: Attention and distraction
Thursday, Sep 10, 2015
Dissociating the impact of unexpected salient sounds: increase in arousal versus attentional capture
Lyon Neuroscience Research Center INSERM U1028, Bron, France
Studies investigating behavioral distraction have found inconsistent results with significant cost (see Escera et al. 2000; Escera et al. 2003 for reviews), or benefit (see Parmentier 2014 for a review) in reaction times to targets when preceded by a so-called distracting sound. These results suggest that distracting sounds would not only trigger a detrimental attentional capture but could also produce a facilitation effect.
We investigated the impact of unexpected salient sounds on the processing of a target sound, by manipulating the delay between the two sounds. We could evidence that distracting sounds trigger several phenomena that produce opposite effects on the reaction time to a subsequent target: a cost by an attentional capture mechanism, and a benefit due to an increase in arousal.
Moreover, the analysis of the event-related potentials revealed that (1) increasing task load in top-down attention reduces early processing of the distracting sound (N100 and early frontal P3), but not bottom-up attentional capture mechanisms indexed by the late P3 response, (2) the bottom-up attentional capture by distracting sounds on target processing results in a delayed latency of the N100 sensory response to target sounds mirroring increased reaction times. Further analysis showed that the early frontal P3 amplitude is related to the arousal content of the distracting sounds and may index the arousal increase triggered by these sounds.
Therefore, this work provides evidence for different mechanisms triggered by unexpected salient sounds both at the behavioral and electrophysiological levels.