Practice question
Question
Which EEG waves occur below 4 Hz?
Explanation
Scalp electroencephalographic rhythms are classified by dominant frequency: beta 13-30 Hz low amplitude for alertness, alpha 8-13 Hz moderate for relaxed wakefulness, theta 4-8 Hz for drowsiness, delta 0.5-4 Hz high amplitude slow waves for deep sleep. Frequency below 4 Hz signifies delta activity generated by prolonged hyperpolarization in thalamocortical circuits during restorative slow-wave sleep, also seen pathologically in encephalopathy. Therefore oscillations under 4 Hz belong to delta band, distinct from faster theta, alpha or beta rhythms reflecting higher arousal states.
Related blogs
Guides and insights connected to this topic
SARS-CoV-2 Coronavirus: Structure, Genome, Proteins, Replication, Pathogenesis, and Host Interaction
Coronavirus Overview Coronaviruses (CoVs) are enveloped viruses (surrounded by a lipid membrane derived from host cells), belonging to the s...
Coronavirus Structure, Genome, Replication, Symptoms, Pathogenesis, and Prevention
Structure of Coronavirus Coronaviruses (enveloped RNA viruses) fall in the virus family Coronaviridae, order Nidovirales. They are enveloped...
Cucumber Mosaic Virus (CMV): Structure, Genome, Symptoms, Disease Cycle and Management
Cucumber Mosaic Virus (CMV): Introduction and Importance Cucumber Mosaic Virus (CMV) (plant-infecting RNA virus) is one of the most economic...