Effects of anodal tDCS on electroencephalography correlates of cognitive control in mild-to-moderate traumatic brain injury

Issue title: Neuropsychiatric Aspects of Neurorehabilitation

Guest editors: Matthew E. Peters, Lindsey J. Gurin, Davin K. Quinn and Durga Roy

Article type: Research Article

Authors: Mertens, Nickolas^a | Cavanagh, James^b | Brandt, Emma^a | Fratzke, Violet^a | Story-Remer, Jacqueline^a | Rieger, Rebecca^a | Wilson, J. Kevin^a | Gill, Darbi^a | Campbell, Richard^c | Quinn, Davin K.^{c; *}

Affiliations: [a] Center for Brain Recovery and Repair, University of New Mexico, Albuquerque, NM, USA | [b] Department of Psychology, University of New Mexico, Albuquerque, NM, USA | [c] Department of Psychiatry and Behavioral Sciences, University of New Mexico, Albuquerque, NM, USA

Correspondence: [*] Address for correspondence: Davin K. Quinn, Health Sciences Center, University of New Mexico, Albuquerque, NM, USA. E-mail: [email protected].

Abstract: BACKGROUND:Transcranial direct current stimulation (tDCS) may provide a potential therapy for cognitive deficits caused by traumatic brain injury (TBI), yet its efficacy and mechanisms of action are still uncertain. OBJECTIVE:We hypothesized that anodal tDCS over the left dorsolateral prefrontal cortex (DLPFC) would boost the influence of a cognitive training regimen in a mild-to-moderate TBI (mmTBI) sample. Cognitive enhancement was measured by examining event-related potentials (ERPs) during cognitive control tasks from pre- to post-treatment. METHODS:Thirty-four participants with mmTBI underwent ten sessions of cognitive training with active (n = 17) or sham (n = 17) anodal tDCS to the left DLPFC. ERPs were assessed during performance of an auditory oddball (3AOB), N-back, and dot pattern expectancy (DPX) task before and after treatment. RESULTS:P3b amplitudes significantly decreased from baseline to post-treatment testing, regardless of tDCS condition, in the N-back task. The active tDCS group demonstrated a significantly increased P3a amplitude in the DPX task. No statistically significant stimulation effects were seen during the 3AOB and N-back tasks. CONCLUSION:Active anodal tDCS paired with cognitive training led to increases in P3a amplitudes in the DPX, inferring increased cognitive control. P3b decreased in the N-back task demonstrating the effects of cognitive training. These dissociated P3 findings suggest separate mechanisms invoked by different neuroplasticity-inducing paradigms (stimulation versus training) in brain networks that support executive functioning.

Keywords: Traumatic brain injury, transcranial direct current stimulation, cognitive control, electroencephalography

DOI: 10.3233/NRE-230014

Journal: NeuroRehabilitation, vol. 53, no. 2, pp. 209-220, 2023