J Psychiatry Neurosci 2018;43(6):396-406
Ann-Christine Ehlis, PhD; Saskia Deppermann, MA; Andreas J. Fallgatter, MD
Background: Recently, research into attention-deficit/hyperactivity disorder (ADHD) has focused increasingly on its neurobiological underpinnings, revealing (among other things) frontal lobe alterations. Specifically, action-monitoring deficits have been described, including impaired behavioural adjustments following errors. Our aim was to examine the neurophysiological background of post-error behavioural alterations in an adult ADHD sample for the first time, hypothesizing that people with ADHD would differ from controls in neurophysiological markers of cognitive preparation and stimulus processing, specifically following errors.
Methods: In total, 34 people with ADHD and 34 controls participated in an electroencephalography measurement while performing a flanker task. The final number of electroencephalography samples included in the analyses ranged from 23 to 28. We recorded event-related potentials for the erroneous response itself (error-related negativity) and for events following errors (intertrial interval: contingent negative variation; next flanker stimulus: P300).
Results: Over frontal electrode sites, error-related negativity amplitudes were significantly reduced in people with ADHD across response conditions. Both groups showed reduced P300 amplitudes on flanker stimuli following errors. Moreover, during the intertrial interval, patients exhibited significantly reduced contingent negative variation, specifically following errors. At the behavioural level, we observed no significant group differences in post-error data.
Limitations: Only adults were examined (no longitudinal data).
Conclusion: Based on previous reports of post-error behavioural alterations in childhood samples, we conclude that people with ADHD develop compensatory strategies across the lifespan that lead to inconspicuous post-error behaviour in adulthood. Neurophysiologically, however, subtle alterations remain, indicating a perseverance of at least some frontal lobe deficits in people with ADHD who are partially medicated, particularly with respect to action-monitoring and post-error adaptation.
Submitted June 20, 2017; Revised Jan. 3, 2018; Accepted Feb. 26, 2018; Published online Jul. 31, 2018
Acknowledgements: This study was supported by IZKF Tübingen (Junior Research Group grant 2115-0-0). The authors thank Betti Schopp and Ramona T?glich for their proficient and dedicated technical assistance, and Stefanie Kettner for adapting the paradigm.
Affiliations: From the Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany (Ehlis, Deppermann, Fallgatter); the Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany (Fallgatter); and the LEAD Graduate School and Research Network, University of Tübingen, Tübingen, Germany (Ehlis, Fallgatter).
Competing interests: None declared.
Contributors: A.-C. Ehlis and A. Fallgatter designed the study. S. Deppermann acquired and analyzed the data, which A.-C. Ehlis also analyzed. A.-C. Ehlis and S. Deppermann wrote the article, which all authors reviewed. All authors approved the final version to be published and can certify that no other individuals not listed as authors have made substantial contributions to the paper.
Correspondence to: A.C. Ehlis, Psychophysiology and Optical Imaging, Department of Psychiatry and Psychotherapy, University of Tübingen, Calwerstrasse 14, 72076 Tübingen, Germany; email@example.com