In EEG, what does an increase in beta activity typically indicate?

An increase in beta activity is primarily associated with high cognitive activity. Beta waves are typically defined by their frequency range, which spans from 13 to 30 Hz. This type of brain wave activity is prominent during states of alertness, active thinking, problem-solving, and focused mental tasks. When an individual is engaged in intellectual activity or is under stress, the presence of increased beta activity reflects the heightened level of cognitive processing.

In contrast, the other options refer to different states of brain activity. For instance, relaxation is more commonly associated with the presence of alpha waves, while sleep onset is linked to theta waves. Pathological conditions may manifest with abnormal increases or decreases in various wave types but are not specifically indicated by an increase in beta activity, which is typically a sign of healthy cognitive engagement. Thus, the association of increased beta activity with high cognitive activity stands out as the most accurate interpretation within the context of EEG readings.