Age, Sex, and Inhibitory Control: Identifying a Specific Impairment in Memorial, But Not Perceptual, Inhibition in Older Women

Abstract

Objectives: Declines in the ability to inhibit information, and the consequences to memory of unsuccessful inhibition, have been frequently reported to increase with age. However, few studies have investigated whether sex moderates such effects. Here, we examined whether inhibitory ability may vary as a function of age and sex, and the interaction between these two factors.

Method: 202 older (mean age = 69.40 years) and younger (mean age =30.59 years) participants who had equivalent educational attainment and self-reported health completed 2 tasks that varied only in the time point at which inhibition should occur: either prior to, or after, encoding.

Results: While we did not find evidence for age or sex differences in inhibitory processes when information needed to be inhibited prior to encoding, when encoded information being actively held in working memory needed to be suppressed, we found that older women were particularly impaired relative to both younger women and men of either age group.

Discussion: These results provide further support for the presence of memorial inhibitory deficits in older age, but add nuance by implicating biological sex as an important mediator in this relationship, with it more difficult for older women to inhibit what was once relevant in memory.

Keywords: Aging; Control; Inhibition; Sex; Working memory.

Figure 1.

Younger and older men and women’s mean Inhibition Index scores (mean lure RT – control RT) for correct trials on the Ignore task (left panel) and the Suppress task (right panel). Error bars represent ±1 SEM. RT = reaction time.