Electrical signals recorded from the brain often show fluctuations between 30-80 Hz, which is called the gamma rhythm. These can be induced by simply viewing images with black and white patterns, called gratings. We recorded brain signals using a non-invasive technique called electroencephalogram (EEG) from ~250 elderly subjects while they viewed gratings, and found that even in healthy subjects, gamma waves weaken with age (Murty et al., 2020). Interestingly, in a subset of subjects with Mild Cognitive Impairment (MCI) or early Alzheimer’s Disease (AD), these waves were substantially weaker than their age matched peers (Murty et al., 2021).
Murty DVPS, Manikandan K, Kumar WS, Ramesh RG, Purokayastha S, Nagendra B, Abhishek ML, Balakrishnan A, Javali M, Rao NP and Ray S† (2021). Stimulus-induced Gamma rhythms are weaker in human elderly with Mild Cognitive Impairment and Alzheimer’s Disease. eLife. 10:e61666 DOI: 10.7554/eLife.61666
Murty DVPS, Manikandan K, Kumar WS, Ramesh RG, Purokayastha S, Javali M, Rao NP and Ray S† (2020) Gamma oscillations weaken with age in healthy elderly in human EEG. Neuroimage. Vol 215, Article 116826