Temporal changes in ERP amplitudes during sustained performance of the Attention Network Test

This study aimed to use Event-Related Potential (ERP) data to investigate how multiple attentional networks might contribute to vigilance decrement, based on Petersen and Posner's (2012) model of networks for executive control, alerting, and spatial orienting. The networks may differ in their sensitivity to effects of time on task. Based on the theory of attentional networks and previous findings, it was hypothesized that temporal decrements would be found in executive control and alerting networks. 102 participants (53 females) performed a version of the Attention Network Test (ANT) that was modified to require a prolonged period of continuous performance of approximately 70 min during electroencephalogram (EEG) recording. ERP amplitudes were measured in task conditions associated with executive control, alerting, and spatial orienting networks were measured across three consecutive task stages. N100 and P300 amplitudes were used to assess early selective attention and later target discrimination, respectively. Results largely replicated previous findings on ERP responses to the ANT. Amplitudes of the N100 wave and P300 declined over time in multiple conditions, consistent with increasing vulnerability to vigilance decrement. Evidence from cue × stage interactions suggested a temporal decrement in alerting processes, indicated by N100 amplitude, but behavioral data did not show any impairment specific to alerting. By contrast, there was a correspondence between a modest decline in frontal P300 amplitude seen in a no cue condition and slowing of response in this condition. A full explanation for vigilance decrement in terms of attention networks remains elusive. However, the current data suggest that parietal N100 and frontal P300 index two distinct processes that may contribute to loss of alertness and vigilance, depending on task demands.