What type of EEG finding is associated with increased drowsiness?

Theta waves are indeed associated with increased drowsiness and are an important part of the EEG findings in this state. As individuals transition from wakefulness to sleep, especially during the early stages or light sleep, theta waves become more prominent. These waves typically have a frequency range of 4 to 8 Hz and can be observed in the posterior regions of the brain during relaxed states, such as when a person is drowsy but still somewhat aware of their surroundings.

In contrast, fast beta activity is generally associated with alertness and active mental engagement, while alpha rhythm is present during relaxed wakefulness, often observed when a person is calm but awake. Delta waves, on the other hand, are characteristic of deep sleep stages and not typically associated with drowsiness. Thus, the finding of theta waves distinctly indicates increased drowsiness, making it the correct response for this question.