Spontaneous attentional performance lapses during the auditory condensation task: an ERP study
The causal mechanisms of spontaneous attentional performance lapses in alert non-clinical individuals during purposeful responses to complex stimuli remain largely unknown. In order to address this question, the auditory condensation task was used, which involves both stimulus feature binding and response selection. This task is known to create high attentional load and is well suited to reveal subtle variations in the level of attention. Four auditory stimuli differing in two independent features were presented randomly with equal probability. Each stimulus required pressing one or the other of two buttons; constant stimulus-to-response mapping was based exclusively on feature conjunction. Participants made errors on 10.2 ± 0.7 % and response omissions on 5.4 ± 0.5 % of trials. In the ERP pattern, the N1 and P2 peaks were well pronounced, while later N2 and P3 peaks were rather small in amplitude. The P2 amplitude was greater on trials with errors compared to correct responses, possibly reflecting reduction in the stimulus processing. Spontaneous attentional performance lapses may be tentatively explained by inadequate distribution of attentional resources due to competition with other mental processes such as mind-wandering. This competition is likely to occasionally subdue early preattentional stages of stimulus processing and thus cause behavioral errors.