10 Hz flicker improves recognition memory in older people.
BACKGROUND
10 Hz electroencephalographic (EEG) alpha rhythms correlate with memory performance. Alpha and memory decline in older people. We wished to test if alpha-like EEG activity contributes to memory formation. Flicker can elicit alpha-like EEG activity. We tested if alpha-frequency flicker enhances memory in older people. Pariticpants aged 67-92 identified short words that followed 1 s of flicker at 9.0 Hz, 9.5 Hz, 10.0 Hz, 10.2 Hz, 10.5 Hz, 11.0 Hz, 11.5 Hz or 500 Hz. A few minutes later, we tested participants' recognition of the words (without flicker).


RESULTS
Flicker frequencies close to 10 Hz (9.5-11.0 Hz) facilitated the identification of the test words in older participants. The same flicker frequencies increased recognition of the words more than other frequencies (9.0 Hz, 11.5 Hz and 500 Hz), irrespective of age.


CONCLUSIONS
The frequency-specificity of flicker's effects in our participants paralleled the power spectrum of EEG alpha in the general population. This indicates that alpha-like EEG activity may subserve memory processes. Flicker may be able to help memory problems in older people.
Williams
Jonathan
J
OPTIMA, Radcliffe Infirmary, Oxford, OX2 6HE, UK. Jonathan.Williams@pharm.ox.ac.uk
Ramaswamy
Deepa
D
Oulhaj
Abderrahim
A
D000368:Aged; D000369:Aged, 80 and over; D000513:Alpha Rhythm / Q000379:methods*; D004307:Dose-Response Relationship, Radiation; D004599:Electric Stimulation Therapy; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D010364:Pattern Recognition, Visual / Q000502:physiology / Q000528:radiation effects*; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology / Q000528:radiation effects; D021641:Recognition, Psychology / Q000502:physiology / Q000528:radiation effects*