Further, functional connectivity analyses, which quantify the connections between brain regions based on temporal correlation (Wig et al., 2011), have shown that chronic alcohol use affects relationships among these important regions. For example, compared to healthy controls (HC), recently abstinent alcoholic patients showed reduced fronto-cerebellar functional connectivity derived from a motor task (Rogers et al., 2012) and reduced fronto-striatal connectivity during response inhibition (Courtney et al., 2013). Long-term abstinent alcoholic subjects show reduced resting state synchrony between the nucleus accumbens (NAcc) and thalamus, caudate, postcentral, and parietal regions, yet increases between the NAcc and frontal regions. The authors suggested that reduced connectivity between decision-making regions with appetitive drive regions yet increased connectivity with inhibitory control regions may represent an adaptive mechanism which helps sustain abstinence (Camchong et al., 2013). Further, functional connectivity measured within multiple networks was lower in relapsing alcoholics compared to those who sustained abstinence (Camchong et al., 2012, Beck et al., 2012). These studies converge to support dysfunctional connectivity, associated with sustained alcohol use, as an underlying mechanism contributing to poor inhibitory control.
