In the oldest EEG literature dating back to the 1920s, Greek letters such as alpha, beta, theta, and gamma were used to classify EEG waves falling into specific frequency ranges, with "theta" generally meaning a range of about 4–7 cycles p
Theta waves oscillate about 3.5 – 7.5 times per second (Hz). Some consider Theta to be from 4 – 8 Hz. Theta is normal in small very amounts in the healthy waking adult EEG. Theta in the adult waking EEG should be symmetrically distributed.
Recognizing the frequency of the waveforms is fundamental to interpreting EEG. Frequency describes how many waves there are per second, and is measured in hertz (Hz). There are four main frequencies of the human brain seen on scalp EEG, in increasing orde
Higher theta EEG power during resting state predicts lower cognitive functioning. Increased theta EEG power during cognitive tasks predicts better performance. We discuss potential explanations for theta’s distinct properties across contexts.
