Question

Describe in words each phase of wakefulness and sleep. Be sure to include the brain wave rhythm(s) and characteristic of each phase. You should have seven total phases.

What brain areas control sleep and arousal? Describe at least three.

Most researchers believe that consciousness is distributed across much of the brain; describe their thinking about networks in relation to consciousness.

Answer 1

1).

Electroencephalograph (EEG) is an instrument used to record the electrical activities occurring in the brain. The electrical activities are recorded in graphical form, and this graphical representation of the electrical activities is called as electroencephalogram.

A typical encephalogram contains four waves of different frequencies.

1. Alpha waves or alpha rhythm
2. Beta waves or beta rhythm
3. Delta waves or delta rhythm
4. Theta waves.

During sleep we experience two patterns of sleep. They are,

• Non- REM sleep (randomised eye movement)
• REM sleep (random eye movement sleep)

Both the sleep patterns follow one another in episodes. During the REM sleep, some of the brain regions remain active, so it is also known as “paradoxical sleep.”

The 1^st stage of sleep is non-REM sleep, which is characterised by slow EEG (electroencephalogram) wave pattern, and it makes about 80% of the total sleep. This sleep improves the performance.

During REM sleep, rapid eye movement occurs and we dream during this phase. The duration of REM sleep is about 20% of the total sleep. Both the REM and non-REM sleep cycle at least 5 times in a complete sleep cycle.