Focusing on the Alpha waves

We singled out alpha waves as aesthetically pleasing and psychologically relevant.

Alpha waves are a prominent feature of human brain recordings. Indeed, they were the first feature identified within the overall electrical read-out of human brain activity, known as the electroencephalogram (or EEG for short)1. Because they were named first, they took the first letter of the alphabet, with later features of the EEG taking other letters – beta, delta, gamma, etc. Alpha can be seen in the EEG with the naked eye as bursts of rhythmic activity oscillating about ten times per second (10 Hz).

How exactly alpha waves are generated and the functions they serve continue to be debated. In broad strokes, alpha waves reflect rhythmic fluctuations in the excitability (related to the voltage level in the membranes) of populations of neurons in sensory areas. Alpha waves are particularly pronounced in visual areas and, correspondingly, are concentrated over the back of the head. The fluctuations in neuronal excitability result from activity in brain circuits, both local and larger scale.

Since the first descriptions of alpha, these rhythms have been associated with changes in levels of sensory processing and attention. Alpha waves were noted to increase when individuals closed their eyes and diminish when their eyes were open.  Engaging in an attention-consuming act, like performing difficult mental calculations, also strongly diminished the alpha waves. Research today shows exquisite, dynamic, and regionally specific modulation of alpha waves depending on the locations and timings of attended items within the external environment or representations held in mind.