Drinking alcoholic beverages is more likely to cloud the short-term memory of people as their age increases, a new study shows.

People depend on their “short-term,” memory for temporarily holding ideas and recent events in the mind for quick recall.  This type of memory, known also as “working” memory often declines with age, and now a new study offers more evidence it may also be susceptible to interactions between age and alcohol use.

Frontal theta power (FTP) and posterior alpha power (PAP) are electrophysiological measures of brain activity associated with cognitive effort and maintenance of visual information. This study looks at alcohol effects on FTP and PAP during a working memory task in younger and older social drinkers.

Researchers at the University of Florida recruited two groups of participants for this study:  51 older (55-70 years of age; 29 women, 22 men), and 70 younger (25-35 years of age; 39 women, 31 men). All were moderate drinkers living in the community.

Participants were given either a placebo or an active dose designed to produce a breath alcohol concentration of 0.04 or 0.065 g/dL. Following absorption, participants completed a visual working-memory task in which they were required to remember briefly shown images during a nine-second delay period, and the amount of alcohol concentration was reported.

During working memory maintenance, PAP was lower in the older than the younger adults. In addition, active alcohol doses increased PAP in younger adults but decreased PAP in older adults. These results support a small but growing body of evidence that older adults are more sensitive than younger adults to the neurobehavioral effects of moderate alcohol use, and further demonstrate that PAP activity may help to identify alcohol’s negative effects on working-memory efficiency in older adults.

The study appears in the current issue of Alcoholism: Clinical & Experimental Research.