Chapter 17, Problem 1RQ

Summary Introduction

Introduction:

Sleep is defined as a partial state of natural unconsciousness in humans. It can be categorized on the basis of the pattern of the brain waves and the activity of the neurons involved. The two types of sleep patterns observed in human beings are rapid eye movement (REM) sleep and non-rapid eye movement sleep (NREM), which is based on the mobility of the eye and muscular activity of the body.

Answer to Problem 1RQ

Correct answer:

REM sleep.

Explanation of Solution

Justification/ Explanation for the correct answer:

Option (e) is, ‘REM sleep.’ Paradox sleep is also known as REM sleep. The REM sleep pattern is observed by studying the electrical activity of the brain using electroencephalogram (EEG). The EEG reveals that the pattern of the brain waves in REM sleep is similar to the awakened state. Irregular diaphragm activity, breathing rate, and heart rate are observed in this type of sleep. The skeletal muscles activity is greatly reduced, thus a sense of paralysis is felt by the sleeper. Hence, option (e) is correct.

Explanation for the incorrect answer:

Option (a) is, ‘stage N1 non-REM sleep.’ The stage N1 non-REM sleep pattern shows that the muscular activity is decreased, slow rolling eye movement is observed, the heart rate is reduced, and the respiratory pattern is regular. This stage is the lightest stage of sleep and the skeletal muscle activity is not reduced by much extent, thus sleep paralysis does not occur. So, it is an incorrect option.

Option (b) is, ‘stage N2 non-REM sleep.’ The stage N2 non-REM sleep is also a form of light sleep in which major metabolic activities are reduced. The brain metabolic activities are also lower as compared to REM sleep, thus the sleeper is not in the stage of consciousness and sleep paradox cannot occur. So, it is an incorrect option.

Option (c) is, ‘stage N3 non-REM sleep.’ The stage N3 non-REM sleep is also known as deep sleep. It is the stage of least consciousness in humans as the brain activity and the muscular

movement are severely reduced in this stage. Although the skeletal muscle activity is reduced severely, the sleeper does not feel sleep paralysis as the self-awareness level is low. Thus, sleep paradox cannot occur. So, it is an incorrect option.

Option (d) is, ‘stage W (wake).’ The stage W has a similar EEG pattern to the REM sleep, although the movement of eyes in this type stage is much lower and the activity of the brain is similar to REM. The individual is partially conscious and alert of its external stimuli and the skeletal muscle activity is moderate. Thus, sleep paradox cannot occur. So, it is an incorrect option.

Hence, options (b), (c), and (d) are incorrect.

Conclusion

Therefore, it can be concluded that sleep paradox is a state of partial consciousness where the sleep is aware of its surroundings but is unable to perform any physical movements. This occurs during the REM stage of sleep due to high brain activity but a reduced muscular activity, which leads to a feeling of paralysis as the sleeper transits from sleep to wake form.