W2 EEG Postlab

Alpha waves

Beta waves

Theta waves

Delta waves

Alpha waves: restful and awake

Beta waves: alert and awake

Theta waves: sleep

Delta waves: deep sleep

Typical frequencies of

Alpha waves

Beta waves

Theta waves

Delta waves

Alpha: 8-13 Hz

Beta: 13-30 Hz

Theta: 4-8 Hz

Delta: 1-5 Hz

What channels were alpha beta delta and theta waves

Alpha: 40

Beta: 41

Delta: 42

Theta 43

Alpha waves have the highest amplitude when

Subject is in awake and relaxed state

Beta waves have highest amplitude when

Subject is in awake and alert state

How does the the amplitude of beta waves change between an eyes closed and eyes open state

Amplitude is lower in eyes closed state(alpha waves higher) and greater in eyes open state(alpha waves lower)

What does an EEG specifically measure

Synchronized neural firings

he amplitude measurements (stddev) are indicative of how much alpha activity is occurring in the subject. But the amplitude values for beta do not truly reflect the amount of mental activity occurring with eyes open. Explain.

Alpha wave activity is synchronized, causing amplitudes to accurately express brain activity. Delta wave activity is desynchronized, causing amplitudes to be lower in value, and not accurately represent activity

When was the general amplitude of the EEG highest? Refer to Table 4.1. Why do you think this is based on the conditions tested?

amplitude of the EEG was highest during the mental arithmetic portion, as it required the most mental focus and highest neural activity

When were the alpha wave levels (alpha RMS) highest? Refer to Table 4.1. Why do you think this is based on the conditions tested?

Alpha waves were highest during mental arithmetic portion(should be during relaxation) due to increased environmental distraction

How would you expect the level of concentration during math problems to affect alpha wave activity?

Alpha wave activity would decrease as the mental focus would increase beta waves activity

What might account for the amplitude difference of waves recorded from a subject tested alone, in a darkened room, and subjects tested in a lab full of students?

Amplitude of alpha waves would be greatest in a dark room, as the subject would be more relaxed, causing greater alpha wave synchronization