TY  - JOUR
PY  - 2008//
TI  - Effects of varying stop-signal probability on ERPs in the stop-signal task: do they reflect variations in inhibitory processing or simply novelty effects?
JO  - Biological psychology
A1  - Dimoska, Aneta
A1  - Johnstone, Stuart J.
SP  - 324
EP  - 336
VL  - 77
IS  - 3
N2  - The aim of the present study was to determine whether ERP modulations associated with varying the probability of the stop-signal in the stop-signal task reflect variations in inhibitory processing, or whether they simply reflect general arousal associated with novel stimuli. This was achieved by examining the effects of probability on a control"ignore-signal"stimulus in addition to the stop-signal. ERP findings revealed large fronto-central N1 and P3 components that were larger in amplitude for stop-signals than ignore-signals, and when stimuli were rare (30%) compared to frequent (70%). However, probability effects were not greater for stop-signals compared to ignore-signals, discounting an interpretation exclusively in line with inhibitory processing. A principal components analysis (PCA) revealed a slow-wave ERP component that partially accounted for these probability effects. Together, the present findings indicate that ERP differences between rare and frequent stop-signals did not primarily reflect varying inhibitory requirements, but rather may be confounded by novelty effects.<p />  <p>Language: en</p>
LA  - en
SN  - 0301-0511
UR  - http://dx.doi.org/10.1016/j.biopsycho.2007.11.005
ID  - ref1
ER  -