Effects of Brain Stimulation During a Daytime Nap on Memory Consolidation in Older Adults

Impact of Transcranial Slow Oscillating Stimulation on Memory Consolidation During Slow Wave Sleep in Older Adults

The beneficial effect of nocturnal as well as daytime sleep on memory consolidation is well-documented in young, healthy subjects. Slow wave sleep (SWS), in particular, with its slow oscillating activity have shown to enhance declarative, hippocampus-dependent memory representations. This impact of sleep on memory performance can be additionally enhanced by exogeneous induction of transcranial slow oscillating stimulation (tSOS) within the frequency range of SWS in humans (0,7- 0,8 Hz) during sleep, as has been demonstrated in young, healthy subjects. If older adults that commonly experiencing cognitive decline, including long-term retention of declarative memory - benefit from transcranial slow oscillatory stimulation (tSOS) during sleep in the same way has not been studied so far. The primary goal of the study is therefore to investigate the impact of oscillating current stimulation (tSOS) during a daytime nap on declarative memory consolidation in older adults.

Inclusion Criteria:

• age: 50-90 years
• right handed
• inobtrusive neuropsychological examination

Exclusion Criteria:

• untreated severe internal or psychiatric diseases
• epilepsy
• other severe neurological diseases eg., previous major stroke, brain tumour
• dementia
• contraindications to MRI