The brain waves in REM sleep are similar to those of what stage?

Learning Objectives

Past the end of this section, you will exist able to:

• Differentiate betwixt REM and non-REM sleep
• Describe the differences between the iv stages of non-REM sleep
• Sympathize the function that REM and not-REM sleep play in learning and retentiveness

Sleep is not a uniform land of being. Instead, sleep is composed of several unlike stages that can be differentiated from 1 another by the patterns of brain wave activeness that occur during each stage. These changes in encephalon wave activeness tin can exist visualized using EEG and are distinguished from one another by both the frequency and amplitude of encephalon waves ([link]). Sleep can be divided into ii different general phases: REM sleep and non-REM (NREM) sleep. Rapid eye movement (REM) slumber is characterized by darting movements of the eyes under closed eyelids. Encephalon waves during REM sleep announced very similar to brain waves during wakefulness. In dissimilarity, non-REM (NREM) sleep is subdivided into four stages distinguished from each other and from wakefulness by characteristic patterns of brain waves. The first iv stages of slumber are NREM sleep, while the fifth and final stage of slumber is REM slumber. In this section, we will discuss each of these stages of sleep and their associated patterns of brain wave activity.

Brainwave action changes dramatically across the different stages of sleep. (credit "sleeping": modification of work by Ryan Vaarsi)

NREM STAGES OF Sleep

The starting time phase of NREM sleep is known as phase 1 sleep. Stage 1 sleep is a transitional phase that occurs between wakefulness and slumber, the catamenia during which we drift off to sleep. During this time, there is a slowdown in both the rates of respiration and heartbeat. In addition, phase 1 sleep involves a marked decrease in both overall muscle tension and core torso temperature.

In terms of brain wave activity, stage 1 sleep is associated with both blastoff and theta waves. The early portion of stage 1 slumber produces blastoff waves, which are relatively low frequency (8–13Hz), high aamplitude patterns of electric activity (waves) that become synchronized ([link]). This pattern of encephalon moving ridge activity resembles that of someone who is very relaxed, nonetheless awake. Every bit an individual continues through stage ane sleep, in that location is an increase in theta wave activity. Theta waves are even lower frequency (four–7 Hz), higher aamplitude brain waves than blastoff waves. Information technology is relatively easy to wake someone from stage 1 sleep; in fact, people often report that they have not been asleep if they are awoken during phase ane sleep.

Brainwave activity changes dramatically across the different stages of sleep.

As we movement into stage 2 sleep, the body goes into a land of deep relaxation. Theta waves withal dominate the activity of the brain, but they are interrupted by brief bursts of activity known equally sleep spindles ([link]). A slumber spindle is a rapid flare-up of higher frequency brain waves that may be of import for learning and retentivity (Fogel & Smith, 2011; Poe, Walsh, & Bjorness, 2010). In addition, the advent of K-complexes is often associated with stage 2 sleep. A K-complex is a very loftier aamplitude pattern of brain activity that may in some cases occur in response to ecology stimuli. Thus, K-complexes might serve as a span to higher levels of arousal in response to what is going on in our environments (Halász, 1993; Steriade & Amzica, 1998).

Stage ii slumber is characterized by the appearance of both sleep spindles and Thou-complexes.

Phase three and stage 4 of slumber are often referred to as deep slumber or tiresome-wave sleep because these stages are characterized by depression frequency (up to four Hz), loftier amplitude delta waves ([link]). During this time, an private's middle rate and respiration ho-hum dramatically. It is much more difficult to awaken someone from sleep during phase 3 and stage 4 than during earlier stages. Interestingly, individuals who have increased levels of alpha brain moving ridge activity (more ofttimes associated with wakefulness and transition into stage ane sleep) during stage 3 and stage 4 often written report that they do not feel refreshed upon waking, regardless of how long they slept (Rock, Taylor, McCrae, Kalsekar, & Lichstein, 2008).

(a) Delta waves, which are low frequency and loftier amplitude, characterize (b) slow-moving ridge phase 3 and stage 4 sleep.

REM SLEEP

As mentioned earlier, REM sleep is marked by rapid movements of the eyes. The brain waves associated with this stage of slumber are very similar to those observed when a person is awake, as shown in [link], and this is the period of sleep in which dreaming occurs. Information technology is also associated with paralysis of muscle systems in the torso with the exception of those that brand circulation and respiration possible. Therefore, no motion of voluntary muscles occurs during REM sleep in a normal individual; REM sleep is often referred to as paradoxical sleep considering of this combination of loftier brain activity and lack of muscle tone. Like NREM sleep, REM has been implicated in various aspects of learning and memory (Wagner, Gais, & Built-in, 2001), although there is disagreement within the scientific community almost how important both NREM and REM sleep are for normal learning and memory (Siegel, 2001).

(a) A flow of rapid centre motion is marked past the short red line segment. The brain waves associated with REM sleep, outlined in the ruddy box in (a), wait very similar to those seen (b) during wakefulness.

If people are deprived of REM slumber and then allowed to slumber without disturbance, they volition spend more time in REM slumber in what would appear to be an effort to recoup the lost time in REM. This is known equally the REM rebound, and it suggests that REM sleep is also homeostatically regulated. Bated from the role that REM slumber may play in processes related to learning and memory, REM sleep may too be involved in emotional processing and regulation. In such instances, REM rebound may actually stand for an adaptive response to stress in nondepressed individuals by suppressing the emotional salience of aversive events that occurred in wakefulness (Suchecki, Tiba, & Machado, 2012).

While sleep deprivation in general is associated with a number of negative consequences (Dark-brown, 2012), the consequences of REM deprivation appear to exist less profound (as discussed in Siegel, 2001). In fact, some have suggested that REM deprivation can really be beneficial in some circumstances. For instance, REM slumber deprivation has been demonstrated to improve symptoms of people suffering from major low, and many effective antidepressant medications suppress REM slumber (Riemann, Berger, & Volderholzer, 2001; Vogel, 1975).

It should be pointed out that some reviews of the literature challenge this finding, suggesting that slumber deprivation that is not limited to REM sleep is just as constructive or more constructive at alleviating depressive symptoms amongst some patients suffering from depression. In either case, why sleep deprivation improves the mood of some patients is not entirely understood (Giedke & Schwärzler, 2002). Recently, however, some have suggested that slumber impecuniousness might change emotional processing and then that various stimuli are more than likely to be perceived equally positive in nature (Gujar, Yoo, Hu, & Walker, 2011). The hypnogram beneath ([link]) shows a person'due south passage through the stages of sleep.

A hypnogram is a diagram of the stages of slumber as they occur during a period of sleep. This hypnogram illustrates how an individual moves through the various stages of sleep.

Link to Learning

View this video that describes the various stages of sleep.

Dreams

The meaning of dreams varies across different cultures and periods of time. By the late 19th century, High german psychiatrist Sigmund Freud had become convinced that dreams represented an opportunity to gain access to the unconscious. By analyzing dreams, Freud thought people could increment self-awareness and proceeds valuable insight to help them deal with the problems they faced in their lives. Freud made distinctions between the manifest content and the latent content of dreams. Manifest content is the actual content, or storyline, of a dream. Latent content, on the other hand, refers to the hidden meaning of a dream. For instance, if a woman dreams about being chased by a ophidian, Freud might have argued that this represents the adult female's fear of sexual intimacy, with the snake serving equally a symbol of a homo's penis.

Freud was not the but theorist to focus on the content of dreams. The 20th century Swiss psychiatrist Carl Jung believed that dreams allowed us to tap into the commonage unconscious. The collective unconscious, as described by Jung, is a theoretical repository of data he believed to be shared by anybody. According to Jung, certain symbols in dreams reflected universal archetypes with meanings that are similar for all people regardless of civilisation or location.

The sleep and dreaming researcher Rosalind Cartwright, yet, believes that dreams only reverberate life events that are of import to the dreamer. Unlike Freud and Jung, Cartwright's ideas nigh dreaming have found empirical support. For example, she and her colleagues published a study in which women going through divorce were asked several times over a five month period to written report the caste to which their sometime spouses were on their minds. These same women were awakened during REM sleep in social club to provide a detailed account of their dream content. There was a pregnant positive correlation between the caste to which women thought nigh their former spouses during waking hours and the number of times their former spouses appeared as characters in their dreams (Cartwright, Agargun, Kirkby, & Friedman, 2006). Recent research (Horikawa, Tamaki, Miyawaki, & Kamitani, 2013) has uncovered new techniques by which researchers may effectively detect and classify the visual images that occur during dreaming by using fMRI for neural measurement of brain activity patterns, opening the style for additional research in this area.

Recently, neuroscientists have also become interested in understanding why we dream. For example, Hobson (2009) suggests that dreaming may stand for a country of protoconsciousness. In other words, dreaming involves constructing a virtual reality in our heads that nosotros might use to assistance us during wakefulness. Among a diversity of neurobiological show, John Hobson cites research on lucid dreams as an opportunity to better sympathise dreaming in general. Lucid dreams are dreams in which sure aspects of wakefulness are maintained during a dream state. In a lucid dream, a person becomes aware of the fact that they are dreaming, and as such, they can control the dream'southward content (LaBerge, 1990).

Summary

The different stages of sleep are characterized past the patterns of brain waves associated with each phase. Equally a person transitions from being awake to falling asleep, alpha waves are replaced past theta waves. Sleep spindles and G-complexes emerge in stage ii slumber. Stage 3 and stage 4 are described as irksome-moving ridge sleep that is marked by a predominance of delta waves. REM sleep involves rapid movements of the eyes, paralysis of voluntary muscles, and dreaming. Both NREM and REM sleep appear to play important roles in learning and memory. Dreams may represent life events that are important to the dreamer. Alternatively, dreaming may represent a state of protoconsciousness, or a virtual reality, in the mind that helps a person during consciousness.

Self Check Questions

Critical Thinking Questions

1. Freud believed that dreams provide important insight into the unconscious mind. He maintained that a dream'southward manifest content could provide clues into an private's unconscious. What potential criticisms exist for this particular perspective?

2. Some people merits that sleepwalking and talking in your slumber involve individuals interim out their dreams. Why is this particular explanation unlikely?

Personal Application Question

3. Researchers believe that 1 important part of sleep is to facilitate learning and memory. How does knowing this help you in your college studies? What changes could y'all brand to your study and sleep habits to maximize your mastery of the material covered in grade?

Answers

ane. The subjective nature of dream analysis is one criticism. Psychoanalysts are charged with helping their clients translate the true pregnant of a dream. There is no way to refute or confirm whether or non these interpretations are accurate. The notion that "sometimes a cigar is only a cigar" (sometimes attributed to Freud merely not definitively shown to be his) makes information technology clear that there is no systematic, objective system in place for dream analysis.

2. Dreaming occurs during REM slumber. I of the hallmarks of this detail phase of slumber is the paralysis of the voluntary musculature which would make acting out dre

Glossary

alpha wave type of relatively low frequency, relatively loftier amplitude brain moving ridge that becomes synchronized; characteristic of the beginning of stage 1 sleep

delta moving ridge type of low frequency, loftier amplitude brain wave characteristic of stage 3 and stage 4 sleep

commonage unconscious theoretical repository of information shared by all people across cultures, as described by Carl Jung

K-complex very high amplitude blueprint of encephalon action associated with stage two sleep that may occur in response to environmental stimuli

latent content subconscious meaning of a dream, per Sigmund Freud's view of the function of dreams

lucid dream people go aware that they are dreaming and tin command the dream'due south content

manifest content southtoryline of events that occur during a dream, per Sigmund Freud'south view of the function of dreams

not-REM (NREM) menses of sleep outside periods of rapid eye motion (REM) slumber

rapid eye move (REM) sleep period of sleep characterized by encephalon waves very similar to those during wakefulness and by darting movements of the eyes under closed eyelids

sleep spindle rapid flare-up of high frequency brain waves during stage 2 slumber that may exist of import for learning and memory

stage 1 sleep showtime stage of sleep; transitional phase that occurs between wakefulness and slumber; the catamenia during which a person drifts off to sleep

phase 2 sleep second phase of sleep; the body goes into deep relaxation; characterized past the appearance of sleep spindles

stage iii sleep third stage of sleep; deep sleep characterized past low frequency, high amplitude delta waves

stage four slumber fourth stage of sleep; deep sleep characterized past low frequency, loftier aamplitude delta waves

theta wave type of low frequency, low aamplitude brain wave characteristic of the end of stage one sleep

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Source: https://courses.lumenlearning.com/wsu-sandbox/chapter/stages-of-sleep/

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