026-23 – Testing the Utility of Functional Near Infrared Spectroscopy in Detecting Neurocognitive Differences Across Social Drinking

Heavy alcohol consumption alters neural activity in the prefrontal cortex (PFC) resulting in impaired executive functioning. A variety of neuroimaging tools have investigated this relationship, yet functional near infra-red spectroscopy (fNIRS) has seen little utilisation. fNIRS has fewer running costs than other neuroimaging methods, is portable, and penetrates cortical areas supporting executive functioning. This study investigates the utility of fNIRS in detecting differences in PFC haemodynamics across non-clinical levels of drinking during executive functioning tasks. Thirty non-dependent, social drinkers (mean age 21.40 (± 4.72)) completed questionnaires assessing alcohol use, psychological wellbeing, and subjective executive functioning. LUMO, a high-density fNIRS system, measured cortical haemodynamics in the PFC bilaterally during completion of four tasks assessing executive function. Participants were allocated to light vs. heavy drinking groups based on a median split of AUDIT scores. A MANCOVA comparing light vs. heavy drinkers found that participants who reported greater drinking levels made fewer perseverative errors than those who reported drinking less. No significant differences were found between heavier and lighter drinkers on other executive functioning measures, nor were there any mediating effects of covariates. Ongoing analyses of fNIRS data suggest differences in PFC haemodynamics between drinking groups during executive functioning performance. Fewer perseverative errors, indicating better set-shifting ability, among the heavier drinkers was unexpected given the typical findings of impaired functioning associated with greater consumption. However, this aligns with a minority of findings and supports the goal-shifting hypothesis. These differences across social drinking levels will be further explored with continued analysis of fNIRS data.