Which statement best describes the effect of opening the eyes on alpha activity?

Which statement best describes the effect of opening the eyes on alpha activity?

• A. Eye opening increases alpha activity
• B. Eye opening suppresses alpha activity
• C. Eye opening has no effect on alpha activity
• D. Alpha activity shifts to higher frequencies with eye opening

Answer: (B)

Eye opening reduces alpha power because the alpha rhythm reflects a relaxed, idle brain state when the eyes are closed. When the eyes are opened, visual input activates the occipital cortex and the neuronal activity becomes more desynchronized. This desynchronization suppresses the rhythmic, synchronized activity in the alpha band, leading to a decrease in alpha power. It’s a well-known effect called alpha desynchronization or alpha blocking. The change is mainly in the amount of alpha activity, not a simple shift to higher frequencies, though there can be a general rise in alertness-related activity in other bands as well.

Eye opening reduces alpha power because the alpha rhythm reflects a relaxed, idle brain state when the eyes are closed. When the eyes are opened, visual input activates the occipital cortex and the neuronal activity becomes more desynchronized. This desynchronization suppresses the rhythmic, synchronized activity in the alpha band, leading to a decrease in alpha power. It’s a well-known effect called alpha desynchronization or alpha blocking. The change is mainly in the amount of alpha activity, not a simple shift to higher frequencies, though there can be a general rise in alertness-related activity in other bands as well.