Using Functional Near Infrared Spectroscopy to Detect Neurocognitive Differences Across Social Drinking Patterns

Understanding the relationship between alcohol consumption and higher level neurocognitive functions (executive functions) is vital for developing public health messaging and interventions for harmful alcohol use. Previous research has demonstrated that heavier alcohol drinking patterns are related to altered prefrontal cortex (PFC) activity and potential impairment of executive control. While traditional neuroimaging methods such as fMRI have been used to investigate structural and functional changes due to heavy alcohol use, the cost and accessibility of fMRI can make it prohibitive. The current study aims to test the utility of functional Near Infrared Spectroscopy (fNIRS) in detecting changes in prefrontal cortex (PFC) haemodynamics across social drinking levels during executive function tasks. Thirty-nine non-dependent, social drinkers (mean age 24.74 (± 7.75)) completed questionnaires assessing alcohol use, psychological wellbeing, and subjective executive functioning. GowerLabs LUMO, a high-density fNIRS system, measured cortical haemodynamics in the PFC bilaterally during completion of four tasks assessing executive function; Go/No-Go, Wisconsin Card Sorting Task, Number-Letter, and N-Back. Participants were categorised as light or hazardous level drinkers based on their AUDIT scores. There were no performance differences between the light and hazardous drinking groups on the neurocognitive tasks, and limited evidence was found for differences in PFC activity during executive function performance. In line with previous research, this study did not find executive functioning differences across levels of non-clinical alcohol consumption. Typically, differences are observed at the neural level, with altered PFC activation which individuals may not be subjectively aware of. Whilst here we found limited evidence for differences in neurovascular activation, future studies with larger sample sizes and refined high density fNIRS analysis techniques may better elucidate any changes due to drinking patterns. Through establishing the use of a non-invasive, portable neuroimaging tool such as fNIRS in alcohol research, there are implications on the capabilities of future studies involving individuals with an alcohol use disorder.