tDCS selectively improves working memory in older adults with more education

Area of Science:

• Neuroscience
• Cognitive Psychology
• Gerontology

Background:

• Cognitive functions, particularly working memory (WM), decline with age.
• Altered brain activation patterns, such as increased bilateral frontal activity in older adults, are linked to age-related WM decline.
• Neuroimaging studies suggest differences in frontal lobe engagement during WM tasks between younger and older adults.

Purpose of the Study:

• To investigate if stimulating the prefrontal cortex using transcranial direct current stimulation (tDCS) can enhance working memory (WM) performance in healthy older adults.
• To explore the influence of education level on the efficacy of tDCS for improving WM in older individuals.

Main Methods:

• Employed transcranial direct current stimulation (tDCS), applying anodal stimulation or sham stimulation to the left (F3) or right (F4) prefrontal cortex.
• Participants included healthy older adults who performed verbal and visual 2-back working memory (WM) tasks across three sessions.
• Participants were categorized into groups based on their education level to assess differential effects of tDCS.

Main Results:

• Transcranial direct current stimulation (tDCS) demonstrated a uniform benefit across stimulation sites and WM tasks, but exclusively in older adults with higher education levels.
• Older adults with less education did not exhibit any improvement in verbal or visual WM performance following tDCS.
• The findings suggest that educational background may modulate the effectiveness of prefrontal cortex stimulation for cognitive enhancement in aging.

Conclusions:

• The results indicate that transcranial direct current stimulation (tDCS) can enhance working memory (WM) performance in specific subgroups of older adults.
• Differential frontal recruitment strategies, potentially influenced by education, may underlie the varied responses to brain stimulation in older adults.
• Future research should consider educational attainment and cognitive strategies when investigating brain stimulation interventions for age-related cognitive decline.