Alpha wave in EEG are seen in: March 2008
**Core Concept**
Alpha waves in EEG are a type of rhythmic brain wave activity that occurs in the frequency range of 8-12 Hz. They are typically seen in relaxed, closed eyes, and awake states, particularly in the posterior regions of the brain.
**Why the Correct Answer is Right**
Alpha waves are generated by the synchronized activity of pyramidal neurons in the cerebral cortex, particularly in the parietal and occipital lobes. This synchronized activity is thought to be mediated by the inhibitory neurotransmitter GABA, which helps to reduce the excitability of neurons and promote a state of relaxation. The alpha rhythm is often seen in individuals who are in a state of reduced cortical activity, such as when they are resting or engaging in a quiet activity.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because alpha waves are not typically seen in states of high cortical activity, such as during intense mental effort or physical exercise.
**Option B:** This option is incorrect because beta waves, not alpha waves, are typically seen in states of high cortical activity, such as during attention or problem-solving.
**Option C:** This option is incorrect because theta waves, not alpha waves, are typically seen in states of drowsiness or sleep.
**Clinical Pearl / High-Yield Fact**
It's worth noting that alpha waves can be affected by various factors, such as age, sleep deprivation, and certain medications. For example, alpha waves may be reduced in individuals with attention deficit hyperactivity disorder (ADHD).
**Correct Answer: B. Beta waves are typically seen in states of high cortical activity, such as during attention or problem-solving.