An Electrophysiological Predictor of Imminent Action Error in Humans

Abstract:
Abstract: 'Absentminded' slips of action can occur as routine actions are triggered inappropriately by a familiar context. The Sustained Attention to Response Test (SART), a computerised go no-go task, has previously been shown to be sensitive to the increased frequency of such attentional lapses in patients with traumatic brain injuries and in healthy volunteers.Here encephalographic (EEG) recordings were made as 25 healthy volunteers completed 2500 trials of the SART. Previous research has consistently pointed to the P300 component within event related potentials (ERP) as a marker of attentional processing. We examined the magnitude of P300 on all go trials that received correct button push responses. Prior to an error of commission the P300 was significantly reduced compared with trials that preceded correctly withheld responses. The trials of this comparison are identical in terms of stimulus, response and the probability of a subsequent trial being a no-go trial (1/8). The observed difference can therefore be interpreted as a marker of attentional lapse in which 'task-triggered' action errors are more likely. In line with this conclusion, there was a significant relationship between the maintenance of P300 magnitude over the task as a whole and individual propensity to error.