Effects of Age and Acute Moderate Alcohol Administration on Electrophysiological Correlates of Working Memory Maintenance

Abstract

Background Previous studies suggest older adults may be differentially susceptible to the acute neurobehavioral effects of moderate alcohol intake. To our knowledge, no studies have addressed acute moderate alcohol effects on the electrophysiological correlates of working memory in younger and older social drinkers. This study characterized alcohol-related effects on frontal theta (FTP) and posterior alpha power (PAP) associated with maintenance of visual information during a working memory task. Methods Older (55–70 years of age; n = 51, 29 women) and younger (25–35 years of age; n = 70, 39 women) community-dwelling moderate drinkers were recruited for this study. Participants were given either placebo or an active dose targeting breath alcohol concentrations (BrACs) of 0.04 or 0.065 g/dL. Following absorption, participants completed a visual working memory task assessing cue recognition following a 9s delay. FTP and PAP were determined via Fourier transformation and subjected to 2 (age group) X 3 (dose) X 2 (repeated: working memory task condition) mixed models analysis. Results In addition to expected age-related reductions in PAP, a significant age group X dose interaction was detected for PAP such that 0.04 g/dL dose level was associated with greater PAP in younger adults but lower PAP in their older counterparts. PAP was lower in older vs younger adults at both active doses. Further mixed models revealed a significant negative association between PAP and working memory efficiency for older adults. No effects of age, dose, or their interaction were noted for FTP. Conclusions Results bolster the small but growing body of evidence that older adults exhibit differential sensitivity to the neurobehavioral effects of moderate alcohol use. Given the theoretical role of PAP in attentional and working memory function, these findings shed light on the attentional mechanisms underlying effects of acute moderate alcohol on working memory efficiency in older adults.

Effects of Age and Acute Moderate Alcohol Administration on Neurophysiology During Simulated Driving

“…The current data bear comparison with our recent investigation of working memory (Boissoneault et al., ). In contrast to the driving task, which requires externally directed attention, we utilized a memory maintenance task requiring the inhibition of attention to external stimuli to protect an internal representation of a recently viewed image.…”

“…Placebo beverages consisted only of the vehicle solution, but were sprayed with a small amount of surface alcohol to provide sensory cues, enhance placebo effectiveness, and improve control of alcohol expectancy effects. Consistent with our previous work (e.g., Boissoneault et al., ), beverages were consumed within 5 minutes (2 min/beverage with 1 minute in between). Twenty‐five minutes after beverage consumption, an additional beverage was administered to all participants.…”

“…Based on our previous work, we hypothesized age‐by‐alcohol interactions in alpha power during simulated driving. Specifically, due to the attentional components of the driving task, we hypothesized that under acute conditions, younger individuals would display lower alpha power, associated with facilitation of attention to external stimuli, while older individuals would fail to engage this suppression, consistent with the findings during working memory maintenance (Boissoneault et al., ). Whether this interaction would persist across driving scenarios and alcohol doses remained an empirical question.…”

“…Epochs containing deflections larger than ±150 μ V were rejected. Consistent with our previous work (Boissoneault et al., ), individuals were included in these analyses only if their EEG contained at least 20 epochs/scenario, in at least 3 scenarios. Of the 120 individuals meeting the criteria for inclusion, an average of 40.1 (SD = 10.1) epochs per participant/scenario were collected.…”

“…Further, we have detailed age‐by‐alcohol interactions in simulated driving behavior, with older adults exhibiting greater impairments in steering rate and speed deviation following low‐to‐moderate doses (Sklar et al., ). Most recently, we investigated alterations in spectral power during working memory maintenance (Boissoneault et al., ), demonstrating age‐by‐alcohol interactions in alpha band power under low‐dose conditions (0.04 g/dl).…”