Neural Responses to Signals for Behavior Change: Greater Within-Person Variability is Associated With Risk Factors...

An impaired ability to change behavior in the face of cues indicating a need for change is one means of defining risk for substance dependence. The present study used a cognitive task administered in a laboratory as a model of this process. It focused on 2 known and related correlates of risk (conduct disorder, borderline personality disorder) and examined their associations with reactivity to cues requesting a change in motor behavior.

A total of 224 teenagers, 14 to 19 years of age, performed a task during which white noise bursts were used to cue a requirement to reverse the mapping of right and left key press responses onto high- and low-frequency pure tones during a subsequent trial block. The amplitude of the P300 electroencephalographic (EEG) response to each cue was summarized by calculating its across-trial average as well as its intertrial variability (ITV). In addition, the number of motor response reversal failures (perseveration errors) was calculated.

The ITV of the P300 response to cues for behavior change was superior to its average amplitude in revealing associations with risk: It was significantly greater among teenagers with more conduct problems and more borderline personality disorder symptoms in comparison with their less-affected peers. ITV was also positively correlated with perseveration errors. No group differences were found in P300 amplitude averaged over trials.

The findings suggest that the measurement of intertrial variability in brain activity may be more valuable than the average level for revealing neurophysiological differences associated with impulsivity and personality risk factors for dependence. EEG measures may be particularly valuable in this context because they offer superior temporal resolution and signal-to-noise characteristics.