Brain frequencies

Brain frequencies are the electrical waves produced by the brain both at rest and during its activities, measurable through EEG. They have been classified by neuroscience research in relation to the brain activities with which they are associated.

Since the discovery of the different frequencies and their correlations was not linear, they were assigned Greek letters without correspondence to the alphabetical order. The frequencies are classified as:

• Gamma 30-42 Hz: characteristic of states of particular tension.
• Beta 13.5-30 Hz: recorded as the prevalent frequency in alert subjects, with open eyes, during intense mental activity and especially in the prefrontal cortexThe prefrontal cortex plays a fundamental role in numerous p... More, but can also appear during REM sleep.
• Alpha 8-13 Hz: recorded during wakefulness and mental rest, but not during sleep, when they are generally absent.
• Theta 4-7.5 Hz: typical frequency of REM sleep, also frequently detected in infants and in meditation states.
• Delta 1-3.9 Hz: recorded during general anesthesia, in some brain pathologies, in non-REM sleep, as well as in deep meditation states associated with the loss of any sense of self.