Impact of alcohol use on EEG dynamics of response inhibition: a cotwin control analysis

Abstract

Research indicates that alcohol misuse is associated with behavioral disinhibition, but the neurophysiological mechanisms governing this relationship remain largely unknown. Recent work suggests that successful inhibition and cognitive control involve electrophysiological theta-band dynamics, including medial frontal cortex (MFC) power enhancement and functional connectivity between the MFC and dorsal prefrontal cortex (dPFC) regions, which may be disrupted by alcohol misuse. In addition, research suggests that, compared to men, women are at heightened risk of experiencing the negative physical and neurocognitive correlates of drinking. The present study tested the hypothesis that alcohol misuse has a deleterious effect on theta-band response inhibition EEG dynamics in a sample of 300 24-year-old same-sex twins. A cotwin control (CTC) design was used to disentangle premorbid risk for alcohol use from the causal effects of alcohol exposure. Drinking was negatively associated with theta-band MFC power and MFC-dPFC connectivity during response inhibition, and this effect was stronger among women. The CTC analysis suggested that, for women, reduced nogo-related theta-band MFC power and MFC-dPFC connectivity were both consistent with the potential deleterious causal effects of alcohol exposure. These findings suggest that diminished theta-band MFC power and MFC-dPFC connectivity may be neurophysiological mechanisms underlying alcohol-related disinhibition. Although preliminary, these results suggest that normative levels of alcohol use during emerging adulthood have potential sex-specific causal effects on response inhibition EEG dynamics, and thus have potentially significant public health implications.

Testing the effects of adolescent alcohol use on adult conflict-related theta dynamics

“…Prior research offers strong support for the construct and psychometric validity of this composite index, including high internal consistency and expected parent-offspring correlations when assessed throughout adolescence (McGue et al, 2014). In addition, higher index scores have been associated with reduced prefrontal grey matter volume and neurocognitive performance in adolescents (Malone et al, 2014; Wilson et al, 2015), and diminished response inhibition-related theta-band MFC power and MFC-dPFC connectivity in young adults (Harper et al, 2016). …”

“…Guided by prior work (Cohen and Cavanagh, 2011; Harper et al, 2016; Nigbur et al, 2012) and a priori hypotheses regarding theta-band functional connectivity between MFC and dorsal prefrontal cortex (dPFC) electrodes during response conflict/cognitive control (Clayton et al, 2015), pairwise wPLI values were calculated between MFC seed electrode FCz and all other channels. As seen in Figure 1B, the grand averaged plots of connectivity between FCz and a cluster of dPFC electrodes (Fz/F1-4/AFz/AF3-4) revealed a focal connectivity enhancement across a 3–8 Hz and 344–594 ms post-stimulus window.…”

Conflict-related medial frontal theta as an endophenotype for alcohol use disorder

“…Signals were processed using MATLAB (version 7.1, Mathworks, Inc.) and EEGLAB software (Delorme & Makeig, 2004) as described in (Harper et al, 2017a; Harper, Malone, & Iacono, 2017b; Harper et al, 2018). Continuous signals were resampled at 256-Hz, highpass filtered ( firfilt plugin; 0.1 Hz cutoff), and re-referenced to mean earlobe signals.…”

“…Converging evidence suggests the presence of AUD-related anomalies across multiple measures of the prefrontal cortex. These include reduced grey and white matter volume (Welch, Carson, & Lawrie, 2013), suboptimal neurocognitive performance (Lopez-Caneda, Holguin, Cadaveira, Corral, & Doallo, 2014; Smith, Mattick, Jamadar, & Iredale, 2014; VerdejoGarcia, Lawrence, & Clark, 2008), and functional abnormalities during executive functioning tasks (Burwell, Malone, Bernat, & Iacono, 2014; Feil et al, 2010; Goldstein & Volkow, 2011; Harper, Malone, & Iacono, 2018; Kamarajan et al., 2004; Pandey et al, 2012). Strong empirical evidence suggests that cognitive control is potentially biophysically realized (in part) through rhythmic electroencephalographic (EEG) signals, such as medial frontal (MF) cortex theta-band (3–8 Hz) activity (Cavanagh & Frank, 2014; Cohen, 2014a).…”

“…Given the importance of MF theta during cognitive control and response conflict, and work implicating diminished control-related neurocognitive processes in AUD (Dick et al, 2010; Feil et al, 2010; Harper et al, 2018; Kamarajan et al, 2004), diminished MF theta power may be a potential electrophysiological correlate or mechanism of alcohol-related cognitive control anomalies. Parieto-occipital alpha is also an important correlate of the cognitive control system, and has been shown to differ between alcoholics and controls during a go/nogo response inhibition task (Pandey et al, 2016).…”