Poster E33, Monday, March 27, 2:30 – 4:30 pm, Pacific Concourse
Behavioral and Electrophysiological Measures of Conflict Monitoring
Peter Egeto1, Tisha J Ornstein1, Eleenor H Abraham1; 1Ryerson University
Conflict monitoring is a process that resolves competition between potential responses, and then choosing the appropriate response. Electroencephalographic (EEG) methods have identified the N2 as the marker for conflict monitoring. However, a behavioral measure has not been established. Few reports have linked reaction time (RT) to the N2, although this association has not yet been elucidated. To identify a behavioral measure, the subtraction method was used to isolate conflict monitoring. Here, the RT from a simple RT task (SRT) was subtracted from a forced-choice RT task (Stop Signal Task; SST); the subtraction parses out common processes while isolating the conflict monitoring unique to the SST. Longer time spent resolving conflicts (larger RT difference) was hypothesized to correlate positively with N2 magnitude. EEG data from 35 healthy participants (mean age 32.3 [14.1]) were obtained. Stimulus-locked components at Fz and FCz were used to calculate difference waves between SRT and SST at 250-350 ms post-stimulus. The mean SST RT and RT difference were correlated with the N2 difference wave. The RT difference correlated positively with the N2 difference wave at Fz (r = .38, p < .05). The SST RT did not correlate with the N2. Longer conflict resolution time was associated with larger N2 magnitude. The N2 did not correlate with SST RT, indicating that the subtraction method was necessary to isolate conflict monitoring. These findings provided support for a novel behavioral measure of conflict monitoring. Replication to establish its validity, reliability, and application with other tasks (e.g., Stroop) is required.
Topic Area: EXECUTIVE PROCESSES: Monitoring & inhibitory control