The present study was devoted to the investigation of relationships between the attentional lapses and cerebral activity, manifested in the event-related potentials of the brain. The study was performed in 30 university students aged 19-26 years (M±SD=20.9±1.3 years) (19 females and 11 males). We used a new task, which was based on decision making involving feature binding in the auditory domain and response selection. During the task four auditory tones were presented. Each tone was a sinusoidal signal of either 500 Hz ("low") or 2000 Hz ("high"), either a pure tone ("pure") or the same tone with broadband noise admixed to the signal ("noised"). Participants were asked to press on of the two buttons in case of (1) "low pure" or (2) "high noised" signals and another button in case of (3) "high pure" or (4) "low noised" signals. The instruction only informed the participants that they had to press one of the two the buttons according to the rule, but it did not tell them that they had to react as fast as possible, and it did not tell them to make a random choice if they were unsure. Behavioral outcome of each trial could be one of the following: a correct response, an error, and a response omission. Event-related potentials (ERPs) averaged in relation to the stimulus onset were obtained for all the three abovementioned outcomes. Both behavioral manifestations of inattention – errors and omissions – produced the same pattern of changes in the ERPs, namely an increase in P2 amplitude. No difference was noted for earlier component N1. Despite the significant attentional load produced by the task, there was no pronounced late positive component (such ad P3) in the ERPs. The response rules set in our attentional task were quite simple, and the participants had no problems in understanding them, they also had no problems in recognizing the stimuli. Thus behavioral lapses – errors and omissions – could not be attributed to the participants' failure to understand the task instruction, or to the failures in the stimuli discrimination. This means that the real difficulty of the task lies in the process of decision making, which impacted on the P2 amplitude. Hypothetically, reallocation of the attentional resources to some inner activity such as "mind-wandering" may be the cause of these difficulties in the process of decision making in the absence of any additional distracting tasks.
The study was implemented in the framework of The Basic Research Program of the National Research University Higher School of Economics in 2013.