Chapter 10 discusses various theories about why we dream and what dreaming is. The author states, “Although our understanding of sleep and dreams continues to grow, major questions remain.”

Prior to reading the text material about dreams, what was (is) your belief about why we dream, and what our dreams may mean? Tell us about a weird dream you had and how you made sense of it at the time.  After reading the material related to theories of why we dream, apply what you learned to your past ideas about dreams….do you think any different about dreams and dream interpretation?

3-4 pages

at least four citation

10
Consciousness

© 2019 Cengage. All rights reserved.

1

module 10.1
Conscious and Unconscious Processes
After studying this module, you should be able to:
Explain why early psychologists abandoned the study of consciousness and why new developments now make such a study possible.
List methods of presenting a stimulus while preventing conscious perception of it.
Describe how a consciously perceived stimulus activates brain areas differently from the same stimulus when not consciously perceived.
Cite evidence that the brain processes some information unconsciously.
Discuss cases in which people in a vegetative state showed evidence of consciousness.
Describe and evaluate evidence that brain activity responsible for a movement begins before the conscious decision to make that movement.

© 2019 Cengage. All rights reserved.

2

Measuring Consciousness
Psychologists long ago abandoned the study of consciousness, but today research is possible because of:
An operational definition
“If a cooperative person reports being conscious (aware) of one stimulus and not of another, then he or she was conscious of the first and not the second.”
Limited research questions
Methods of measuring brain activity
Ways of controlling consciousness of a stimulus
Masking – a procedure of preceding or following a stimulus with an interfering pattern that might prevent consciousness of the stimulus
Flash suppression – a procedure of blocking consciousness of a stationary visual stimulus by surrounding it with rapidly flashing items
Binocular rivalry – alteration between seeing the pattern in the left retina and the pattern in the right retina

© 2019 Cengage. All rights reserved.
Psychology began in the late 1800s as the scientific study of the conscious mind. However, researchers soon abandoned the effort. The behaviorists argued convincingly that consciousness is an internal, private experience that researchers cannot observe or measure. At the time they were certainly right, as they had no method to measure brain activity or anything else that might correlate with a private experience. Therefore, psychologists redefined their field as the study of behavior.
Although the behaviorists were right at their time that research on consciousness was impossible, times have changed. Four advances have facilitated meaningful research:
An operational definition of consciousness
Limited, answerable questions
Modern methods to measure brain activity
Ways of controlling consciousness of a stimulus
A dictionary might define consciousness as the subjective experience of perceiving oneself and one’s surroundings. However, that definition relies on the phrase “subjective experience,” which is no better defined than consciousness itself. Researchers use this operational definition: If a cooperative person reports being conscious (aware) of one stimulus and not of another, then he or she was conscious of the first and not the second.
For the time being, we postpone the questions that are hardest to answer and focus on limited, answerable questions such as, “How does the brain activity when someone is conscious of a stimulus differ from the activity when someone is not conscious of the same or a similar stimulus?”
Researchers today have several methods to record brain activity without invading the brain, such as EEG, MEG, and fMRI.
Masking, flash suppression, and binocular rivalry are among the methods to present a stimulus while preventing conscious perception of it.
3

Brain Activity, Conscious or Unconscious
When someone is conscious of a stimulus, the following occurs:
The stimulus activates neurons more strongly.
Their activity reverberates through other brain areas.
That activity rebounds to magnify the original response.
The process inhibits responses to competing stimuli.

© 2019 Cengage. All rights reserved.
When you become conscious of a stimulus, it produces more brain activity and more spread of the activity across brain areas. It also produces more inhibition of other, competing brain activity.
4

Unconscious Processing of a Suppressed Stimulus
The brain processes stimuli even without consciousness, enough to evaluate their importance.
Unconscious processes are an important part of cognition.

© 2019 Cengage. All rights reserved.
Your brain notices that something is meaningful or important even before you become conscious of it. Unconscious processes can do a good bit more than we once imagined they could.
5

Consciousness as an All-or-None Phenomenon
Consciousness of a stimulus appears to be an all-or-none process.
Either the brain activity spreads strongly through the brain, or it does not.

© 2019 Cengage. All rights reserved.
Consciousness of a stimulus appears to be an all-or-none phenomenon. A stimulus either reaches a threshold necessary for spread, or it does not.
6

Consciousness as a Construction
Conscious experience of a stimulus is a construction that can occur slightly after the stimulus itself, rather than simultaneously with it.

© 2019 Cengage. All rights reserved.
Consciousness does not occur at exactly the same time as the events. You construct a conscious perception of events that already happened.
7

Can We Use Brain Measurements to Infer Consciousness?
Physicians distinguish various gradations of brain activity that relate to arousal, responsiveness, and presumed consciousness.
Brain death – condition in which the brain shows no activity and no response to any stimulus
Coma – condition in which the brain shows a steady but low level of activity and no response to any stimulus
Vegetative state – condition marked by limited responsiveness to stimuli, such as increased heart rate in response to pain
Minimally conscious state – condition in which someone has brief periods of purposeful actions and speech comprehension
Brain scans provide suggestions of consciousness in certain patients who seem unresponsive to their environment.

© 2019 Cengage. All rights reserved.
Physicians distinguish various gradations of brain activity that relate to arousal, responsiveness, and presumed consciousness.
In brain death, the brain shows no activity and no response to any stimulus. Most people consider it ethical to remove life support for someone who remains steadily in this condition.
In a coma, caused by traumatic brain damage, the brain shows a steady but low level of activity and no response to any stimulus, including potentially painful stimuli. In nearly all cases, someone in a coma either dies or begins to recover within a few weeks.
Someone starting to emerge from a coma enters a vegetative state, marked by limited responsiveness, such as increased heart rate in response to pain. Responsiveness varies between a sleeping state and a waking state, but even in the waking state, brain activity is well below normal, and the person shows no purposeful behaviors. The next step up is a minimally conscious state, in which people have brief periods of purposeful actions and speech comprehension. A vegetative or minimally conscious state can last for months or years.
Because people in a vegetative state do nothing, it is easy to assume that they are unconscious. However, results from brain scans suggest that at least a few patients in a vegetative state are conscious.
8

Consciousness and Action
When people report the time of a conscious decision to make a movement, brain scans indicate the brain activity responsible for the movement began before the reported time of the conscious decision.

© 2019 Cengage. All rights reserved.
Studies have shown that the brain activity responsible for a movement starts before a conscious decision.
9

How Well Can We Measure the Time of a Conscious Decision?
Research promotes skepticism that people can report their decision times accurately.
Voluntary decisions are gradual, not sudden.

© 2019 Cengage. All rights reserved.
We have reasons to doubt that people can accurately state the time that a conscious decision began. Spontaneous movements and the decisions behind them develop gradually, not suddenly. For example, imagine yourself driving along when suddenly a deer darts into the road. You swerve immediately to avoid it. In contrast, if you decide you need to get into the left lane to make a turn, you move slowly. The gradual, spontaneous movements depend on a set of brain areas called the basal ganglia, which contribute much less when you act in response to a stimulus.
10

What Is the Purpose of Consciousness?
A possible function of conscious thought is to prepare for future action when a similar situation arises.

© 2019 Cengage. All rights reserved.
Some theorists have argued that consciousness is an epiphenomenon—an accidental by-product with no purpose. But if consciousness does serve a purpose, what might that purpose be?
One hypothesis is that conscious thought is a way of rehearsing possibilities for future actions. After you do something, you might ponder, “That didn’t go well. What could I have done differently? Then what would have happened? Ah, I see. The next time I’m in a situation like this, here is what I’ll do….” In that way your conscious thinking modifies your behavior on some future occasion.
11

module 10.2
Sleep and Dreams
After studying this module, you should be able to:
Describe how circadian rhythms affect alertness and other functions.
Distinguish between morning and evening people.
Discuss the consequences of jet lag and shift work.
Explain how brain mechanisms control the circadian rhythm.
List known functions of sleep.
Describe the stages of sleep and characterize REM sleep.
Discuss insomnia and other sleep problems.
Evaluate several theories of dreaming.

© 2019 Cengage. All rights reserved.

12

Circadian Rhythms
Circadian rhythm – rhythm of activity and inactivity lasting approximately one day
The rising and setting of the sun provide cues to reset our rhythm, but we generate the rhythm ourselves.
Circadian rhythm controls more than sleeping and waking.
Hunger and thirst
Urine production
Blood pressure
Alertness
Body temperature
Mood

© 2019 Cengage. All rights reserved.
Humans have mechanisms that prepare us for activity during the day and sleep at night. Like other animals, we generate a circadian rhythm, a rhythm of activity and inactivity lasting about a day. The rising and setting of the sun provide cues to reset our rhythm, but we generate the rhythm ourselves.
Your circadian rhythm controls more than sleeping and waking. Over the course of a day, you vary in your hunger, thirst, urine production, blood pressure, alertness, body temperature, and mood.
Certain people have genes that alter their circadian rhythms. Those with genes causing a 23-hour cycle instead of the usual 24-hour cycle get sleepy early in the evening and wake up early.
13

Morning People and Evening People
People vary in their circadian rhythms.
Some people arouse quickly and reach their peak alertness early.
Others increase alertness more slowly and reach their peak in late afternoon or early evening.
Most young adults are either evening people or intermediate, whereas most people over age 65 are morning people.

© 2019 Cengage. All rights reserved.
“Morning people” awaken easily, become alert quickly, and do their best work early. “Evening people” take longer to warm up in the morning and do their best work in the afternoon or evening.
Morning people have advantages in several ways, especially if school or work starts early in the morning. On average, morning-type students maintain attention better in the morning, do better on tests in the morning, and get better grades, even when compared to evening-type students with the same cognitive ability and motivation. However, male evening types have this advantage: They tend to be more extraverted, have a more active social life, and are likely to have more sex partners.
Most young adults are either evening people or intermediate, whereas most people over age 65 are morning people. If you ask people at what time they like to go to bed when they have no obligations, their mean answer shifts later and later during the teenage years, reaches 1 to 2 a.m. at age 20, and then starts reversing, slowly and steadily over decades. The fact that the trend continues gradually over a lifetime suggests a biological basis.
14

Figure 10.8
◄ Figure 10.8 Most people suffer more serious jet lag when traveling east than when traveling west.

© 2019 Cengage. All rights reserved.
If you travel across time zones, your internal rhythm is temporarily out of phase with your new environment. You experience jet lag, a period of discomfort and inefficiency while your internal clock is out of phase with your new surroundings. Most people find it easier to adjust when flying west, where they go to bed later, than when flying east, where they go to bed earlier. If you fly west, your circadian rhythm shifts a bit later each day until it catches up; if you fly east, your rhythm shifts a bit earlier each day.
15

Figure 10.9
▲ Figure 10.9 The graveyard shift is aptly named: Serious industrial accidents usually occur at night, when workers are least alert. As in jet lag, the direction of change is critical. Moving forward—clockwise—is easier than going backward.

© 2019 Cengage. All rights reserved.
Some businesses run three work shifts, such as midnight to 8 a.m., 8 a.m. to 4 p.m., and 4 p.m. to midnight. Because few people want to work regularly on the midnight to 8 a.m. shift, many companies rotate their workers among the three shifts. Employers can ease the burden on their workers in two ways: First, when they transfer workers from one shift to another, they should transfer them to a later shift. That is, someone working from 8 a.m. to 4 p.m. shifts to the 4 p.m. to midnight time (like traveling west) instead of midnight to 8 a.m. (like traveling east). Second, employers can help workers on the night shift by providing bright lights that resemble sunlight.
16

Brain Mechanisms of Circadian Rhythms
An area of the brain, called the suprachiasmatic nucleus, generates an approximately 24-hour rhythm.
Sunlight does not generate this rhythm, but it does reset it.
The suprachiasmatic nucleus exerts its control partly by regulating the pineal gland’s secretions of the hormone melatonin, which is important for circadian rhythms.

© 2019 Cengage. All rights reserved.
The circadian rhythm of sleep and wakefulness is generated within the brain by a tiny structure known as the suprachiasmatic nucleus.
Although the suprachiasmatic nucleus generates a circadian rhythm, light resets the internal clock, causing you to wake up more or less in synchrony with the sunlight.
The suprachiasmatic nucleus exerts its control partly by regulating the pineal gland’s secretions of the hormone melatonin, which is important for both circadian rhythms and many species’ annual rhythms of reproduction, hibernation, and so forth. Ordinarily, the human pineal gland starts releasing melatonin two or three hours before bedtime.
17

Why We Sleep
Sleep serves several functions, including conservation of energy and an opportunity to strengthen learning and memory.
Sleep-deprived people have difficulty maintaining attention.

© 2019 Cengage. All rights reserved.
Scientists have identified several benefits of sleep.
The simplest is that sleep saves energy.
Sleep also strengthens learning and memory to varying degrees, depending on the type of learning. When you learn something, your memory improves if you go to sleep within the next three hours, and it deteriorates after a sleepless night. A good night’s sleep also improves learning the next day.
People suffer when they don’t get enough sleep. Sleep-deprived people become more vulnerable to illness, especially depression and other mental illnesses. They suffer lapses of attention and lapses of ethical behavior.
18

Stages of Sleep
Rapid eye movement (REM) sleep – stage characterized by rapid eye movements, a high level of brain activity, and deep relaxation of the postural muscles; also known as paradoxical sleep
Dreams are common in this stage but not limited to it.

© 2019 Cengage. All rights reserved.
In the mid-1950s, French and American researchers independently discovered a stage of sleep called paradoxical sleep, or rapid eye movement (REM) sleep. REM sleep is characterized by rapid eye movements, a high level of brain activity, and relaxed muscles. REM sleep is paradoxical because it is light in some ways and deep in others. It is light because the brain is active and the body’s heart rate, breathing rate, and temperature fluctuate substantially. It is deep because the large muscles of the body that control posture and locomotion are deeply relaxed.
Adults who are awakened during REM sleep report dreams about 85 to 90 percent of the time, whereas those awakened during NREM (non-REM) sleep report dreams on 50 to 60 percent of occasions.
19

Figure 10.14

► Figure 10.14 During sleep, people progress through stages of varying brain activity. The blue line indicates brain waves, as shown by an EEG. The red line shows eye movements. REM sleep resembles stage 1 sleep, except for the addition of rapid eye movements.

© 2019 Cengage. All rights reserved.
Sleep researchers distinguish among sleep stages by recording brain waves with electrodes attached to the scalp. An electroencephalograph (EEG) measures and amplifies tiny electrical charges on the scalp that reflect patterns of brain activity. Sleep researchers combine an EEG measure with a simultaneous measure of eye movements to produce a polysomnograph. A sleeper first enters stage 1, when the eyes are nearly motionless and the EEG shows many short, choppy waves that indicate a fair amount of brain activity.
As sleep continues, a person progresses into stages 2, 3, and 4. These stages differ in the number of long, slow waves. Stage 2 has the fewest and stage 4 has the most. These waves indicate synchrony among neurons, related to decreased brain activity. Stage 2 is marked by sleep spindles, waves of activity at about 12 to 14 per second that result from an exchange of information between the cerebral cortex and the underlying thalamus. Sleep spindles are important for storing memory, and the improvement of memory that often occurs after sleep depends on the amount of sleep spindles.
A sleeper progresses through stages 2, 3, and 4 then gradually back through stages 3 and 2, and then to REM sleep. The EEG in REM sleep resembles that of stage 1, but the eyes move steadily. At the end of REM sleep, the sleeper cycles again through stages 2, 3, 4 and then back to 3, 2, and REM. In a healthy young adult, each cycle lasts 90 to 100 minutes on average.
20

Insomnia
Insomnia – condition of not getting enough sleep to feel rested the next day
Insomnia results from causes including:
Noise
Worries
Indigestion
Uncomfortable temperatures
Use of alcohol or caffeine
Medical or psychological disorders

© 2019 Cengage. All rights reserved.
Insomnia means “lack of sleep.” More specifically, insomnia is not enough sleep for the person to feel rested the next day. Insomnia results from causes including noise, worries, indigestion, uncomfortable temperatures, use of alcohol or caffeine, and medical or psychological disorders.
Persistent insomnia should be treated by a physician. However, doing the following can help occasional or minor insomnia:
Keep a regular time schedule for going to bed and waking up each day.
Spend some time in the sunlight to set your circadian rhythm.
Minimize exposure to television and computers in the hours before bedtime.
Avoid caffeine, nicotine, and other stimulants, especially in the evening.
Don’t rely on alcohol or tranquilizers to fall asleep. After repeated use, you may be unable to sleep without them.
Keep your bedroom cool and quiet.
Exercise daily but not shortly before bedtime.
21

Sleep Apnea/Narcolepsy
Sleep apnea – condition in which someone fails to breathe for a minute or more during sleep and wakes up gasping for breath
Sleep apnea is most common in overweight middle-aged men whose breathing passages become narrower than usual.
Narcolepsy – condition characterized by sudden attacks of sleepiness during the day

© 2019 Cengage. All rights reserved.
Apnea means “no breathing.” People with sleep apnea fail to breathe for a minute or more and then wake up gasping for breath. Sleep apnea is most common in overweight middle-aged men whose breathing passages become narrower than usual. While awake, they compensate by breathing frequently and vigorously, but they cannot keep up this pattern while they are asleep.
Treatment includes recommendations to lose weight and to avoid alcohol and tranquilizers before bedtime. Surgeons can remove tissue to widen the airways. Some people with sleep apnea use a device that pumps air into a mask, covering the nose and mouth during sleep, forcing the person to breathe.
People with narcolepsy experience sudden attacks of sleepiness during the day. They also experience sudden attacks of muscle weakness or paralysis and occasional dreamlike experiences while awake.
A combination of stimulant and anti-depressant drugs maintains wakefulness during the day and blocks the attacks of muscle weakness.
22

Some Other Sleep Experiences
Sleep talking
Sleepwalking
Lucid dreaming
Periodic limb movement disorder – condition marked by unpleasant sensations in the legs and repetitive leg movements strong enough to interrupt sleep
Night terror – condition that causes someone to awaken screaming and sweating with a racing heart rate, sometimes flailing with the arms

© 2019 Cengage. All rights reserved.
Sleep talking is a common experience that ranges from a grunted word to a clear paragraph. Many people talk in their sleep more often than they realize because they do not remember sleep talking and usually no one else hears them. Sleep talking is most common during stage 2 sleep, but it occurs in all stages.
Sleepwalking tends to run in families, mostly in children and mainly during stage 4 sleep. Some adults sleepwalk also, mostly during the first half of the night’s sleep, and not while dreaming. They have clumsy, apparently purposeless movements with only limited responsiveness to their surroundings. Sleepwalking occurs when the motor cortex and few other areas are active while most of the brain remains asleep.
Lucid dreaming is another example in which part of the brain is awake and another part asleep. Lucid dreaming occurs during periods of increased activity at 40 Hz (cycles per second) in the frontal and temporal cortex, with less arousal in the rest of the brain.
Some people have prolonged “creepy-crawly” sensations in their legs, accompanied by repetitive leg movements strong enough to awaken the person, especially during the first half of the night. This condition is known as periodic limb movement disorder.
A night terror causes someone to awaken screaming and sweating with a racing heart rate, sometimes flailing with the arms and pounding the walls. Night terrors occur during stage 3 or stage 4 sleep, not REM, and their dream content, if any, is usually simple, such as a simple image.
23

Descriptive Studies of Dreaming
More dreams are threatening than pleasant.
Most dreams are similar to what we think about in everyday life.
However, we do not dream about everything we do in daily life.
Whether or not blind people have dreams depends on the age they lost their eyesight.

© 2019 Cengage. All rights reserved.
Common usage implies that dreams are happy. For example, in the Disney movie, Cinderella sings, “A dream is a wish your heart makes.” Martin Luther King Jr.’s famous “I Have a Dream” speech described a wonderful future. However, much or most of dream content is unpleasant, such as falling, being chased, or being unable to do something.
Although some dreams are bizarre, most are similar to what we think about in everyday life. For example, preteens seldom dream about the opposite sex, but teenagers do. However, we do not dream about everything we do in daily life. People seldom dream about reading, writing, using a computer, or watching television.
People who become blind because of damage to the visual cortex lose visual dreaming as well as visual imagery. People who experience eye damage after about age 5 to 7 continue to have visual dreams, although their frequency of visual dreams declines over time. People who were born blind or who became blind in early childhood have no visual imagery in their dreams. Instead, they dream of sounds, touch, smells, and tastes.
24

Freud’s Theory of Dreams
Manifest content – according to Freud, content that appears on the surface of a dream
Latent content – according to Freud, hidden ideas that the dream experience represents symbolically

© 2019 Cengage. All rights reserved.
The Austrian physician Sigmund Freud, founder of psychoanalysis, maintained that dreams reveal the dreamer’s unconscious thoughts and motivations. To understand a dream, he said, one must probe for hidden meanings. Each dream has a manifest content—the content that appears on the surface—and a latent content—the hidden ideas that the dream experience represents symbolically.
25

Modern Theories of Dreaming
Activation-synthesis theory of dreams – theory that dreams occur because the cortex takes the haphazard activity that occurs during REM sleep plus whatever stimuli strike the sense organs and does its best to make sense of this activity
An alternative view, known as the neurocognitive theory, is that dreaming is simply a kind of thinking, similar to daydreaming or mind wandering, that occurs under these conditions:
Reduced sensory stimulation, especially in the brain’s primary sensory areas
Reduced activity in the prefrontal cortex, important for planning and working memory
Loss of voluntary control of thinking
Enough activity in other brain areas, including those responsible for face recognition and certain aspects of motivation and emotion

© 2019 Cengage. All rights reserved.
Modern theorists describe dreaming as a kind of thinking that occurs under conditions of low sensory input and no voluntary control of thinking.
26

module 10.3
Hypnosis
After studying this module, you should be able to:
Describe methods of inducing hypnosis.
List uses of hypnosis that the evidence supports, and those that it does not support.
Describe the evidence indicating that hypnosis does not improve memory.
Discuss the issue of whether we should regard hypnosis as an altered state of consciousness.

© 2019 Cengage. All rights reserved.

27

Hypnosis
Hypnosis – a condition of focused attention and increased suggestibility that occurs in the context of a special hypnotist–subject relationship

© 2019 Cengage. All rights reserved.
Hypnosis is a condition of increased concentration and suggestibility that occurs in the context of a special hypnotist–subject relationship.
28

Ways of Inducing Hypnosis
A hypnotist induces hypnosis by repeating suggestions, relying on the hypnotized person’s cooperation and willingness to accept suggestions.

© 2019 Cengage. All rights reserved.
To induce hypnosis, a hypnotist asks a person to concentrate and then makes repetitive suggestions. The first steps toward being hypnotized are the willingness to be hypnotized and the belief that one is becoming hypnotized.
29

The Uses and Limitations of Hypnosis
What Hypnosis Can Do
One well-established effect of hypnosis is to inhibit pain.
Another use of hypnosis is the posthypnotic suggestion.
Posthypnotic suggestion – a suggestion to do or experience something after coming out of hypnosis
Posthypnotic suggestions help some people break unwanted habits.
What Hypnosis Does Not Do
Hypnosis does not give people special strength or unusual powers.
It does not improve memory accuracy.
When asked to report their memories under hypnosis, people report a mixture of correct and incorrect information with much confidence.

© 2019 Cengage. All rights reserved.
Hypnosis can alleviate pain, and through posthypnotic suggestion, it sometimes helps people combat bad habits, such as smoking.
Many of the spectacular claims about the power of hypnosis become less impressive on closer scrutiny.
Many people have attempted to use hypnosis to enhance memory. As recently as the 1990s, almost one-fourth of psychotherapists believed that all memories stated under hypnosis must be true, and almost half believed that hypnosis could recover memories going back to the time of birth. Today, only about 10 percent hold either of those beliefs.
Under hypnosis, people do report additional details, mostly with great confidence. However, most of the additional details turn out to be factually wrong. Hypnotized people have an “illusion of memory,” but all the evidence says that hypnosis fails to improve the accuracy of memory, and probably harms it.
30

Is Hypnosis an Altered State of Consciousness?
Hypnosis is not greatly different from normal wakefulness, but it is also not just something that people pretend.
Apparently, people pretending to be hypnotized can mimic almost any effect of hypnosis that they know about.

© 2019 Cengage. All rights reserved.
At one extreme, some psychologists regard hypnosis as a special state of consciousness characterized by increased suggestibility. At the other extreme, some psychologists emphasize the similarities between hypnosis and normal wakeful consciousness. Most psychologists regard hypnosis as a special state in some ways but not others.
Apparently, people pretending to be hypnotized can mimic almost any effect of hypnosis that they know about. However, hypnosis is ordinarily not just role-playing. The effects that role-players learn to imitate happen spontaneously for the hypnotized people.
31

Other States of Consciousness
Meditation – a systematic procedure for inducing a calm, relaxed state through the use of special techniques
Meditation increases relaxation, decreases anxiety, and enhances attention.
Déjà vu experience – feeling that an event is uncannily familiar
In some cases (probably not all), it relates to abnormal activity in brain areas responsible for memory.

© 2019 Cengage. All rights reserved.
Meditation is a systematic procedure for inducing a calm, relaxed state through the use of special techniques.
Many studies document that meditation increases relaxation, decreases pain, decreases anxiety, and improves health in several ways. It is particularly useful for increasing people’s ability to control their attention and resist distraction.
People sometimes feel that the current experience is uncannily familiar. Because it takes several forms, a single explanation may not suffice. Occasionally, someone is somewhere for the first time and sees it as familiar, as if he or she had been there before. Perhaps the person really had seen something similar, possibly in a movie or photo.
More commonly, people report déjà vu in a familiar setting. You might be sitting in your room or having an everyday conversation, when you suddenly feel, “This has happened before!” In a sense, of course it has happened before, but your sense is not that it’s just similar to a past experience. Instead, it seems this particular event happened before.
One man with epilepsy originating in his temporal cortex had a special feeling, an aura, before each of his seizures that included a strong sense of déjà vu. Brain scans suggested that his déjà vu experiences correlated with abnormal activity in parts of the temporal lobe that are important for memory.
32