Theories of Sleep and Dreaming - AP Psychology

This theory of dreaming was first proposed by Allan Hobson and Robert McCarley in 1977. According to the theory of activation synthesis, circuits in the brain are activated during REM sleep. These brain circuits, in turn, help to activate areas of the limbic system. All of this internal activity is synthesized and interpreted by the brain. The signals are then given meaning via dream states.

The most pervasive theory of dreaming is that dreams are a result of electrical impulses in our brains that occur only while we sleep. Allan Hobson and Robert McCarley came up with this theory in 1973, and proposed that the reason why dreams have come to garner so much meaning for people is that our waking minds will give them a narrative. In other words, our actual dreams are not stories; they are instead random memories strung together. When we wake up, we try to make them into stories that make sense to us.

Sigmund Freud is the founder of dream theory. He approached dreams from a psychoanalytic perspective, which posits that most of our actions are the result of repressed feelings and desires. Freud thought these feelings and desires came out unrestricted in our dreams.

Many older civilizations believed that dreams were metaphysical experiences wherein the soul was transported from the body to a completely different realm or spiritual plane.

Physiological theories claim that dreams are a product of neural firing in the brain, which can sometimes, according to some theorists, aid in the process of learning. This is why it is recommended to get good sleep before a test!

Psychological theories claim dreams are a way of processing issues in our lives, founded in Freud's initial dream theory, which posited dreams as ways we process repressed feelings and desires.

There are many who believe dreams are a combination of both theories; they are random, but still serve some purpose.

Sleep apnea is characterized by pauses or lack of breathing when sleeping. A lack of oxygen to the brain causes a buildup of carbon dioxide in the bloodstream. Accumulated carbon dioxide causes the person to wake up, gasping for air. Normal breathing upon wakefulness will allow normal oxygen flow until the person falls back asleep. Sleep apnea is more common among middle aged and overweight individuals. While genetics play a significant role, those with enlarged tonsils, allergies (which may cause swelling of the throat), sinus problems, or enlarged necks are also at risk of sleep apnea.

Memory is encoded during REM sleep. In the hippocampus, neurons fire four times as opposed to once as a result of ponto-geniculo-occipital (PGO) spikes. Memories from a day's activities and learning are encoded in the hippocampus four times, contributing to long-term memory. Theta waves are also associated with this stage of sleep and contribute to REM's restorative nature.

REM sleep (or Rapid Eye Movement) is the stage in which dreams occur, because even though the body is essentially paralyzed, this stage is accompanied by intense activity in the brain.

Out of the 4 stages of sleep, NREM-1, NREM-2, NREM-3, and REM, the third stage is where the brain will emit delta waves. These waves are large and slow, as such, this stage of sleep is also known as slow-wave sleep. It is during this stage where it may be difficult to wake someone up.

Dreaming has been observed during REM sleep. Brain waves at this stage resemble the brain waves of an individual who is awake. The person's heart rate will increase as well as his or her breathing. Every few seconds, the individual's eyes may be observed darting from side to side. This movement signifies the beginning of a dream.

While the recuperation explanation may seem like a good answer, it cannot be considered a theory on its own.

"Sleep protects" is a theory that a species will adjust its sleep pattern in a manner where it is optimal given that species niche, or environmental context. For instance, if an animal has a limited ability to hide from its predators, it may sleep less.

The term "healthy lifestyle" may be broadly defined from culture to culture. While sleep is healthy and good for the body, too much sleep may also be detrimental, or a sign of severe depression. This answer choice is too broad, and not specific enough in its limitations on sleep, to be accurate.

All the other answers are well known theories about the function of sleep.

Sigmund Freud is well-known for his ideas of psychoanalysis—where an individual's personality is based on childhood memories. He is particularly famous for his concept of childhood progression through psychosexual stages. During the id phase, a child is consumed by his desires and need of instant gratification. Freud theorized that once a child graduated from the id stage, then he will achieve the ego stage and ultimately superego. At this time, the adult will have buried and overcome his desires in his unconscious and be able to pay attention to the conscious thoughts associated with morally and socially acceptable behaviors. Given this information, Freud would most likely be in support of dreams serving the purpose to satisfy one's wishes. He believed that dreams provided a platform to act out an individual's latent content—buried unconscious wishes and desires—in a censored symbolic version by way of manifest content. Manifest content is what the individual will remember as the dream's content and main storyline (i.e. what the dream was at "face value").

Dreaming has been observed to predominantly occur during rapid eye movement (REM) sleep. A dream may be noted at the beginning of REM sleep. If dreaming is to serve one function of reorganizing information into memory, then as some studies have indicated, uninterrupted REM sleep is most beneficial for integrating new information. Given that no stage 5 sleep has yet been identified, this would be an incorrect answer. Although some studies may counter-argue that interruptions in non-REM stages will yield poor memory integration, it is important to remember that a majority of dreaming does not occur in these stages.

Theta waves are usually connected to emotions, memories, and other activities in the limbic system. These cognitive processes calm when a person is transition from awake to stage 2 of sleep; therefore, the waves will be less frequent and higher in amplitude.

REM sleep is characterized by all of the listed answer choices except slower brain activity. REM sleep helps us remember more and is the stage of sleep where dreams occur. Our brain activity is actually intensified during this stage.

The activation-synthesis model of dreaming suggests that during REM sleep, different neurons in different brain areas randomly fire (possibly to keep the brain active and “working”). The brain interprets these random neural signals, which largely come from areas associated with emotion and memories like the limbic system and hippocampus, and attempts to shape them into coherent perceptions of the information being passed by these sensory neurons. We experience this shaping as dreams.

Stage 4 sleep is referred to as delta sleep, or deep sleep. It is very hard to wake someone in this stage of sleep. Unlike REM sleep, there are no eye or muscle movements. This is the time during which young children may wet their beds and/or experience night terrors.

This theory of dreaming was first proposed by Allan Hobson and Robert McCarley in 1977. According to the theory of activation synthesis, circuits in the brain are activated during REM sleep. These brain circuits, in turn, help to activate areas of the limbic system. All of this internal activity is synthesized and interpreted by the brain. The signals are then given meaning via dream states.