Illustration of Alzheimers disease, showing a close-up (left) of the neurotransmitter gamma-aminobutyric acid (GABA, orange) binding its receptor (blue) causing reduced gamma brain waves (orange lines). Gamma waves are associated with higher brain functions like working memory, attention, and perceptual grouping. GABA and its receptors have inhibitory effects on gamma oscillations. Abnormal gamma waves area associated with Alzheimers disease.