Can accelerated transcranial direct current stimulation improve memory functions? An experimental, placebo-controlled...

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neuromodulation

Background:

• Aging is associated with cognitive decline, particularly in memory functions.
• Transcranial Direct Current Stimulation (tDCS) is a non-invasive brain stimulation technique explored for cognitive enhancement.
• Previous research suggests tDCS may modulate neural activity to improve cognitive performance.

Purpose of the Study:

• To investigate the efficacy of an accelerated transcranial Direct Current Stimulation (tDCS) protocol on verbal memory in healthy older and younger adults.
• To assess the impact of tDCS on executive functions.
• To evaluate the tolerability of the novel tDCS protocol.

Main Methods:

• Forty healthy participants (20 older, 20 younger) received six 30-minute sessions of 2mA anodal tDCS over the left temporal lobe (T3) over two days.
• Participants were randomized to receive either active tDCS or placebo tDCS.
• Verbal memory was assessed using the California Verbal Learning Test II (CVLT-II), and executive functions using the Trail Making Test (TMT) before and after stimulation.

Main Results:

• No significant differences in verbal memory (immediate recall, delayed recall, recognition) were found between active and placebo tDCS groups.
• A significant improvement in executive function, as measured by the Trail Making Test (TMT), was observed in the active tDCS group compared to placebo.
• The accelerated tDCS protocol was well-tolerated by all participants.

Conclusions:

• The accelerated tDCS protocol, as applied in this study, did not enhance verbal memory functions in healthy older or younger adults.
• Accelerated tDCS may offer benefits for executive functions, warranting further investigation.
• The tested tDCS protocol demonstrates good tolerability in healthy adults.