eye opening or mental exertion. Hence, it is described as an index of relaxed wakefulness. Alpha is slower in young children (closer to theta frequency) and increases with age into high alpha frequencies and is a key feature of EEG maturation (Niedermayer and Lopes Da Silva, 1999); alpha power is stable throughout adult life. Beta rhythm is present all over the scalp but predominantly at frontocentral loci and is enhanced in response to certain barbiturates, sedatives, and tranquilizers.
