What effect does eye closing have on alpha rhythm?

Eye closing has a specific effect on alpha rhythm observed in an EEG. When a person closes their eyes, it often leads to an increase in alpha rhythm expressed in the background brain activity. This is typically due to the reduction of visual stimuli, allowing the brain to enter a more relaxed and less alert state.

However, if one were to consider the scenario of more focused mental activity or eye opening, alpha waves may be diminished or attenuated. Therefore, while the closed eyes facilitate a more robust alpha rhythm under relaxed conditions, they do not completely prevent alpha rhythms from appearing.

Overall, the natural occurrence of alpha rhythm can indeed be attenuated when visual stimuli are reintroduced or during alert states, aligning with the understanding that eye closing can help modulate the brain's electrical activity conducive to relaxation and a meditative state.