Postersession 1
Poster #: 1
Topic: Attention and distraction
Wednesday, Sep 9, 2015
1st floor

Distraction versus task-set change: investigating the functional role of P3a elicited in oddball paradigms

Márta Volosin1, Sabine Grimm2, & János Horváth1

1Institute of Cognitive Neuroscience and Psychology, RCNS-HAS, Budapest, Hungary
2Institute of Psychology, University of Leipzig, Leipzig, Germany

The unfolding of involuntary attention change (distraction) is mostly investigated in paradigms, in which sequences of stimulus event-pairs are presented. Occasional variations of the first event elicit a series of event-related potentials (ERPs), which are interpreted as reflections of various distraction-related processes. It is widely accepted that the P3a ERP reflects an involuntary attention change. Recent studies, however suggest that P3a indexes processes related to task-set changes. Because in most studies the stimulus event-pairs are separated by a constant interval, P3a might be elicited because this constant separation allows participants to prepare for the task-relevant second event. The goal of the present study was to reveal the functional role of P3a in such paradigms by manipulating the opportunity for temporal preparation. We utilized a continuous stimulation paradigm in which 4-minutes long complex tones were presented. The pitch of these tones alternated between two levels, either rarely or frequently. The tones also contained silent periods of 10 or 100 ms duration (gaps) with the task to press one key for the short and another one for the long gaps while ignoring the glides. In the informative condition, 80% of the glides were followed by a gap in exactly 400 ms, while in the uninformative blocks the presentation of glides and gaps was independent. Although negative ERPs (Nd, and CNV) were elicited by glides in the informative condition suggesting a temporal preparation, a P3a enhancement was not found. These results are compatible with the notion that P3a reflects distraction-related processes.