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Electrocortical Measures of Conflict Monitoring and Physiology: Heart Rate as a Predictor of Attentional Control

Electrocortical Measures of Conflict Monitoring and Physiology: Heart Rate as a Predictor of Attentional Control

Danielle Taylor


Theories of anxiety suggest cognitive control may be affected downstream from long-term effects of anxiety symptoms, including anxious arousal or anxious apprehension. One component that may be impaired is inhibition, hindering a prepotent response (Eysenck et al., 2007). Research has focused on studying neural indicators of inhibition using event-related potentials (ERPs). However, few studies have tested theoretical predictions of the role of anxious arousal in predicting cognitive control. Heart-rate variability (HRV) also has been associated with anxiety disorders, specifically low HRV suggests low self-regulation, which in turn has been linked to poor emotion regulation and decreased executive function efficiency (Friedman, 2007). The current study examined the N2, an ERP component maximal at anterior electrodes about 200 milliseconds post-stimulus, and which has decreased amplitude for monitoring two prepotent responses prior to responding to such stimulus (Folstein & Van Petten, 2008). This study investigated the effects of HRV on the N2 during a performance monitoring task. We hypothesized that a baseline measurement of HRV would predict N2 amplitude, even when controlling for a measure of flexibility in attentional control.

Fifty-five undergraduates from a large Midwestern university were recruited through an online research participation system. The Attention Control Scale (ATTC; Derryberry & Reed, 2002) was used to assess for flexibility in attention control, with higher scores indicating better attention control. While EEG data was being collected, participants engaged in the arrow version of the Flankers task (Eriksen & Eriksen, 1974), which consisted of either congruent (>>>>>, >>). Participants were to indicate the direction of the middle arrow using either left or right button presses.

Two multiple regressions assessed for the effects of baseline HRV and attentional control on the N2 for both trial types. Results suggested that baseline HRV and attention control explain a significant amount of variance in the N2 amplitude for congruent trials, F(2,52) = 4.59, p = .015, R2 = .15 and for incongruent trials, F(2, 52) = 4.15, p = .021, R2 = .14. The analyses further show that on congruent trials baseline HRV significantly accounted for variance in the N2, β = 1.81, t(54) = 2.81, p = .007, but attention control did not. Additionally, on incongruent trials baseline HRV significantly accounted for variance in the N2, β = 1.92, t(54) = 2.87, p = .006, but attention control did not.

These results are in line with our hypothesis that baseline HRV would significantly predict N2 amplitude, and also support previous theories suggesting that anxiety can result in poor self-regulation, as indicated here by HRV. These long-term effects of poor self-regulation and inflexible functioning may have broader impacts on cognitive control, including inhibition. These findings may replicate for other executive functions, including shifting and updating, and while this study did not examine a clinical population, HRV is highly associated with anxiety and other forms of psychopathology; therefore, future studies should investigate this relationship among anxious populations. Furthermore, clinical improvements may be assessed with measurements of HRV (Hurley et al., 2002; Middleton & Ashby, 1995), so the N2 also may be a useful measure of treatment outcomes, as well.

Derryberry, D. & Reed, M.A. (2002). Anxiety-related attentional biases and their regulation by attentional control. Journal of Abnormal Psychology, 111(2), 225-236.
Eriksen, B.A. & Eriksen, C.W. (1974). Effects of noise letters upon the identification of a target letter in a nonsearch task. Perceptions and Psychophysics, 16(1), 143-149.
Eysenck, M.W., Derakshan, N., Santos, R., & Calvo, M.G. (2007). Anxiety and cognitive performance: attentional control theory. Emotion, 7(2), 336-353.
Folstein, J.R. & Van Petten, C. (2008). Influence of cognitive control and mismatch on the N2 component of the ERP: A review. Psychophysiology, 45(1), 152-170.
Friedman, B.H. (2007). An autonomic flexibility – neurovisceral integration model of anxiety and cardiac vagal tone. Biological Psychology, 74(2), 185-199.