ИСТИНА

Manifestations of attentional lapses in the brain event-related potentials (ERPs) were studied. 28 participants (aged 19-26 years) performed the novel sustained attention task, based on decision making involving feature binding. Four auditory tones were presented, each having two distinct features: "low" or "high" (500 Hz or 2000 Hz sinusoidal signal), "noised" or "pure" (with or without broadband noise admixed). Participants were asked to press one or the other button depending on the conjunction of the two features. The instruction didn’t prompt the participants to respond quickly or to respond in the event of uncertainty. All participants performed the task quite well but they occasionally committed both erroneous responses and response omissions (in 9.6% and 5.4% of trials correspondingly). Event-related potentials were separately measured for the three outcomes (correct responses, errors, and a response omissions). Both manifestations of inattention (errors and omissions) produced the same pattern of changes in the ERPs, namely a statistically significant increase in the P2 amplitude. No difference was noted for the earlier peak N1. Since the participants had no problems in understanding the response rules, and they apparently had no problems in recognizing the stimuli, the behavioral lapses could be hypothetically explained by reallocation of the attentional resources to some covert activity such as mind-wandering, which competed for the resources with the process of sensory information processing and decision making.