1PRE MID ASSIGNMENT NO 2TOPIC: PHYSIOLOGICAL AND BEHAVIORAL DISCRIPTION OF SLEEPNAME: SYEDA NUSHRAH NOORMAJOR: APPLIED PSYCHOLOGYCOURSE TITLE: NEUROPSYCHOLOGYCOURSE CODE: APSY305SECTION: BSEMESTER: 3SUBMITTED TO: MISS SONIA NAEEMDATE OF SUBMISSION: 1stOctober, 2018SESSION: 2017-2021KINNAIRD COLLEGE FOR WOMEN, LAHORE
2INTRODUCTION:Sleep is defined as a state of perceptual disengagement from and unresponsiveness to theenvironment, by a behavioral point of view. However, until 1950s people thought sleep to be aflaccid and dormant part of our daily lives, and an intermediate state between wakefulness anddeath. But now, with advancement of knowledge, we know that brain is in fact, very much activeduring sleep. ANATOMY OF SLEEPSLEEP CYCLE:A Sleep cycle is approximately 90 minutes long and it refers to the period in which individualprogress through the stage of sleep discussed below. On average humans go through around fourto five sleep cycle every night. However an individual does not go to REM sleep directly fromdeep sleep. Rather there is a transition from light to deep sleep as the cycle progress. And then areverse transition from deep to light sleep occur ending with REM sleep. The cycle repeats overthe night. The order of the sleep cycle looks something like this:Light sleep (stage 1) Light sleep (stage 2) Deep sleep (stage 3&4) light sleep (stage2) light sleep (stage 1) REM sleep. As the night progress we spend more time in REM sleep as compared to earlier 2-3 sleep cyclesthat incudes longer NERM stages(“Stages of Sleep and Sleep cycle”, 2018). STAGES OF SLEEP:Sleep is a complex process involving both physiological and psychological processes. There aretwo distinct states exist between sleep i.e. Non rapid eye movement (NREM) and rapid eyemovement (REM). Each of this stage is involved in its own neural activity and brain waves. NERM sleep:During NERM sleep, rain waves recorded on EEG are typically slow and high voltage. Nonrapid eye movement is further divided into four stages which are explained below:
3Stage 1: Stage 1 is typically 1- 7 minutes long and it’s the initial stage of sleep where an individual’s sleepcan easily be discontinued if the person is being called softly or touched lightly etc. ForExample: a person may experience a sudden muscle contraction proceeded by sensation offalling, in this stage(Carskadon and Dement, 2005). Therefore this stage is being associated with low arousal threshold. Stage 1 occurs as atransitional stage throughout the night in addition to being just an initial wake to sleep transitionstage. For this reason, an increase in the amount and percentage of stage 1 indicates the severelydisrupted sleep. Stage 2:Stage 2 continues for about 10 to 15 minutes. In this stage eye movement stops and brain wavesslow down with occasional outburst of brain waves known as sleep spindles andK- complex.