states of consciousness

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States of

Consciousness

Introducing Consciousness

Sleep and Dreaming

How Psychoactive Drugs Impact the Brain

Other Ways to Impact Consciousness

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• Describing Consciousness

• Levels of Consciousness

• Unconscious Perception and Influences on Behavior

• Neural Underpinnings of Consciousness

Introducing Consciousness

States of Consciousness > Introducing Consciousness


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• Philosophers since the time of Descartes and Locke have struggled to

comprehend the nature of consciousness and pin down its essential properties.

• The study of consciousness helps scientists shed light on the inner workings of

psychology and neuroscience.Scientists who study consciousness examine the

relationship between stated perception and neural activity.

• The majority of experimental studies assess consciousness by asking human

subjects for a verbal report of their experiences and then comparing their answers

with the corresponding neural activity.

• While primary sensory areas of the brain are often involved in perception, it is the

higher brain areas such as the primary cortex that are required for consciousness

to occur.

• Issues of interest within consciousness research include phenomena such as

perception, subliminal perception, blindsight, anosognosia, brainwaves during

sleep, and altered states of consciousness produced by psychoactive drugs or

spiritual or meditative techniques.

Describing Consciousness


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Prefrontal cortex

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• First appearing in the historical records of the ancient Mayan and Incan

civilizations, various theories of multiple levels of consciousness have pervaded

spiritual, psychological, medical, and moral speculations in both Eastern and

Western cultures.

• The Ancient Mayans were among the first to propose an organized sense of each

level of consciousness, its purpose, and its temporal connection to humankind.

• Sigmund Freud divided human consciousness into three levels of awareness: the

conscious, preconscious, and unconscious.

Levels of Consciousness


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Freud's levels of consciousness



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• Perception is an extremely personal faculty because it requires the use of internal

references from previously learned patterns.

• A lot of information that enters our brain goes unnoticed by our conscious

mind.Despite not being consciously aware of it, much of this information still

influences how we perceive the world, and in turn how we act.

• Subliminal messages are an example of the power of unconscious information to

influence our perceptions, which then shape our behavior.

• During a hypnotic state, an individual is in a trance state in which he or she is

highly suggestible to outside information.There is debate about whether or not

hypnosis targets the conscious or unconscious mind.

Unconscious Perception and Influences on Behavior


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Painting of a hypnotic trance



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• Consciousness is the awareness of the self in space and time.Researchers

attempt to study states of human consciousness and differences in perception in

order to understand how the body works to produce conscious awareness.

• Neural correlates of consciousness (NCC) are sets of neurons and series of

events necessary for conscious perception.Neural correlates in the brain have

been found to be both redundant and parallel which makes pinpointing brain

activity difficult for researchers.

• Consciousness varies in both arousal and content.We have two types of

conscious experience: phenomenal, or in the moment, and access, which recalls

experiences from memory.

• Neural correlates of consciousness are studied using fMRI and EEG scans which

attempt to locate brain activity.The most popular stimuli for these studies has

become visual tests as these are easily recorded and manipulated.

Neural Underpinnings of Consciousness


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Neural Correlates of Consciousness



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• Reasons for Sleep and Required Amount of Sleep

• Circadian Rhythms

• Stages of Sleep

• Sleep Disorders

• The Nature and Meaning of Dreams

• New Concept

Sleep and Dreaming

States of Consciousness > Sleep and Dreaming




• Sleep is essential for life.Though we do not have any direct evidence on how

extended sleeplessness affects humans, lab rats have been deprived of sleep for

up to two weeks, resulting in loss of immune function and death.

• Sleep has been linked to psychological, emotional, and mental recovery, as well

as learning and memory.Recent research shows that sleep is vital in consolidating

memories, both intellectual and physical.

• Sleep deprivation can inhibit your productivity and ability to remember and

consolidate information.It can also lead to serious health consequences such as

increased risk of heart disease and obesity.

• The amount of sleep we need varies depending on multiple factors: age, physical

condition, psychological condition, or energy exerted.Therefore, sleep

requirements depend on the individual.

Reasons for Sleep and Required Amount of Sleep


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• Circadian rhythms are important in determining human sleep patterns.The body's

master clock, or the suprachiasmatic nucleus (SCN), controls the production of

melatonin, a hormone that makes a person sleepy.

• Since it is located just above the optic nerves, which relay information from the

eyes to the brain, the SCN receives information about incoming light.When there

is less light—such as at night—the SCN tells the brain to make more melatonin so

a person gets drowsy.

• The circadian rhythm rises and falls at different times of the day, making us feel

more alert or sleepy at certain points in the day.This may vary by a few hours

depending on whether a person is naturally a "morning person" or a "night

person."

Circadian Rhythms


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The Suprachasmatic Nucleus



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• The overall sleep cycle is comprised of two broad alternating cycles, REM (rapid

eye movement), and NREM (non-rapid eye movement), which consists of three

individual phases - N1, N2 and N3.

• Stage 1 NREM is the "drifting off" stage, characterized by lowered brain activity,

blood pressure, and muscle tone.During this 10-minute period, a sleeper may

experience twitches and may even deny having slept at all.

• Stage 2 NREM is characterized by sleep spindles and K-complexes.During this

stage, muscular activity decreases, and conscious awareness of the external

environment disappears.

• Stage 3 NREM (formerly two stages - 3 and 4) is the deepest stage of NREM

sleep.It is characterized by delta waves, and is also called slow-wave sleep or

SWS.It occurs 30-45 minutes after falling asleep, and many environmental stimuli

no longer produce any reactions.

• REM sleep is characterized by partial paralysis, vivid dreaming, and an EEG that

resembles waking brain activity.It is also referred to as paradoxical sleep because

the sleeper, although exhibiting waking-state EEG waves, is harder to arouse

than at any other sleep stage.

Stages of Sleep


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Sleep Waves



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• Some sleep disorders can interfere with normal physical, mental and emotional

functioning.

• Sleep disorders are divided into two categories: dyssomnias (which affect the

amount, quality, and timing of sleep) and parasomnias (marked by irregular

behavior or physiological occurrences).

• Common dyssomnias include insomnia, sleep apnea, and narcolepsy.

• Common parasomnias include sleep walking, sleep talking, and sleep terrors.

Sleep Disorders


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Narcolepsy



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• Sigmund Freud and Carl Jung put forth some of the most well-known modern

theories of dreaming.Freud believed that dreaming allows us to sort through

unresolved, repressed wishes.Jung believed that dreams present the dreamer

with revelations to resolve emotional or religious problems and fears.

• Freud's theory describes dreams as having both latent and manifest

content.Latent content relates to deep unconscious wishes or fantasies while

manifest content is superficial and meaningless.

• Threat-simulation theory suggests that dreaming should be seen as an ancient

biological defense mechanism that provides an evolutionary advantage because

of its capacity to repeatedly simulate potential threatening events, thus enhancing

the mechanisms required for efficient threat avoidance.

• Activation-synthesis theory states that dreams don't actually mean

anything.Instead, dreams are merely electrical brain impulses that pull random

thoughts and imagery from our memories.The theory posits that humans

construct dream stories after they wake up, in an attempt to make sense of it all.

• The continual-activation theory proposes that dreaming is a result of brain

activation and synthesis; its assumption is that, during REM sleep, the

unconscious part of a brain is busy processing procedural memory.

The Nature and Meaning of Dreams


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The Long-standing Mystery of Dreams



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• Depressants

• Stimulants

• Narcotics

• Hallucinogens

How Psychoactive Drugs Impact the Brain

States of Consciousness > How Psychoactive Drugs Impact the Brain




• Depressants do not directly reduce arousal in the brain; they enhance the activity

of a neurotransmitter that reduces arousal in the brain.

• The main types of depressants are alcohol, barbiturates, benzodiazepines,

cannabinoids, and opioids.

• Examples of common depressants include pain killers, social anxiety medications,

which all have similar effects on the brain.

Depressants


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Alcohol as a depressant



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• Stimulants increase the activity of either the central nervous system, the

sympathetic nervous system, or both.

• Most stimulants work by facilitating the activity of certain neurotransmitters, such

as dopamine or norepinephrine.

• Stimulants are often used medically to boost endurance, counteract fatigue,

promote weight loss, improve mood, or relieve anxiety; they are also often used to

treat conditions such as narcolepsy, ADHD, and certain forms of depression.

• Examples of well-known stimulants include amphetamines, MDMA, NDRIs,

cocaine, caffeine, and nicotine.

• Examples of well-known stimulants include amphetamines, MDMA, NDRIs,

cocaine, caffeine, and nicotine.

Stimulants



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Cocaine



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• In addition to helping in the clinical treatment of pain, cough, and acute diarrhea,

narcotics produce a general sense of well-being, known as euphoria, and reduce

tension, anxiety, and aggression.

• Typical classes of narcotics include morphine, opium, and heroin; contrary to

popular belief, marijuana is not a narcotic—nor is LSD or other psychedelic drugs.

• Narcotics bind to painkilling sites throughout the brain, leading to slower uptake of

neurotransmitters such as dopamine.Immediate effects include pain reduction,

drowsiness, and a feeling of well-being.

• Addiction occurs when the brain stops producing its own natural painkilling

chemicals, called endorphins, and depends on the narcotics instead.

Narcotics



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Opium



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• Hallucinogens are drugs that alter sensory input to the brain.They are divided into

three categories: psychedelics, dissociatives, and deliriants.

• Psychedelics work by interacting with serotonin receptors in the brain and

produce a state of empathetic well-being and visual distortion.

• Dissociatives are a subclass of hallucinogens that work by blocking or altering

sensory perception.

• Deliriants are very similar to dissociatives; they are considered to be "true

hallucinogens" because the visuals they produce are hard or impossible to tell

apart from reality.

• Common hallucinogens include MDMA, PCP, and LSD.

Hallucinogens



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Naturally occuring hallucinogen



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• Hypnosis

• Meditation

Other Ways to Impact Consciousness

States of Consciousness > Other Ways to Impact Consciousness




• Hypnosis can be used for many things, including pain management, addiction

management, and weight loss.

• When a person is in an altered state of perception under hypnosis, it is thought

that they can be guided to experience a reduction in pain, change ineffective

cognitions or beliefs, or remember forgotten memories.

• The three main components of hypnosis are absorption, suggestibility, and

dissociation.

• A trance is an induced mental state that facilitates the acceptance of instructions

or suggestions.

Hypnosis


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Hypnotic colors



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• Meditation has a variety of health benefits, including lowered stress levels, boosts

in immune system function, and decreased muscle tension.

• Techniques of meditation vary from person to person and from culture to culture.

• Meditation can be personalized to fit a person's needs and daily schedule, as it

can be done anywhere and at any time of day or night.

• Breathing meditation involves focusing on the breath entering and leaving the

body.

• Devotional meditation involves focusing on a particular object or concept.

• Relaxation meditation involves tensing and relaxing different muscle groups to

achieve relaxation of the mind and the entire body.

Meditation


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Meditation



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Appendix

Key terms

• anosognosia The inability of a person to recognize his or her own illness or handicap.

• antagonist A chemical that binds to a receptor but does not produce a physiological response, thereby blocking the action of

agonist chemicals.

• anxiolysis The reduction of anxiety by means of sedation or hypnosis.

• arousal A physiological and psychological state of being awake or reactive to stimuli, including elevated heart rate and blood

pressure and a condition of sensory alertness, mobility, and readiness to respond.

• ataxia Lack of coordination while performing voluntary movements, which may appear to be clumsiness, inaccuracy, or

instability.

• blindsight The responsivity shown by some blind or partially blind people to visual stimuli of which they are not consciously

aware.

• chronobiology The study of the effects of time on biological systems, especially the effects of periodicity

• circadian of, relating to, or showing rhythmic behaviour with a period of 24 hours; especially of a biological process

• consciousness The state of being aware; awareness to both internal and external stimuli.



• dissociation A defense mechanism in which certain thoughts or mental processes are compartmentalized in order to avoid

emotional stress to the conscious mind.


States of Consciousness

• dopamine A neurotransmitter associated with movement, attention, learning, and the brain's pleasure and reward system.

• dopamine A neurotransmitter associated with movement, attention, learning, and the brain's pleasure and reward system.

• DSM-IV-TR The Diagnostic and Statistical Manual of Mental Disorders, published by the APA; provides a common language

and standard criteria for the classifcation of mental disorders.

• Electroencephalography better known as EEG; the recording of electrical activity along the scalp; it measures voltage

fluctuations resulting from ionic current flows within neurons.

• entrainment The alignment of an organism's circadian rhythm to that of an external rhythm in its environment

• glutamate An important neurotransmitter that plays a key role in long-term potentiation and is important for learning and

memory.

• hypnosis a trancelike state, artificially induced, in which a person has a heightened suggestibility, and in which suppressed

memories may be experienced

• hypnosis An artificially induced trancelike state in which a person has heightened suggestibility and may experience

suppressed memories.

• latent Existing or present but concealed or inactive.

• LD50 In toxicology, the median lethal dose of a toxin, radiation, or pathogen required to kill half the members of a tested

population after a specified test duration.

• manifest Obvious to the understanding; apparent to the mind; easily apprehensible; plain; not obscure or hidden.

• mantra A sound, word, or phrase repeated to assist concentration during meditation; originated in Hinduism.



• meditation A practice in which an individual trains the mind and/or induces a mode of consciousness to realize some benefit; a

devotional exercise of or leading to contemplation.

• narcolepsy A disorder characterized by sudden, uncontrollable, and often brief attacks of deep sleep, sometimes accompanied

by paralysis and hallucinations.

• narcotic Any class of substances or drugs that reduce pain and induce sleep and may alter mood or behavior.

• neurotransmitter Any substance responsible for sending nerve signals across a synapse between two neurons, such as

acetylcholine or dopamine.

• Parasomnia category of sleep disorders that involve abnormal movements, behaviors, emotions, perceptions, and dreams that

occur during sleep.

• polysomnography A multiparameter technique which which documents multiple different physiological procedures during the

night, for the purpose of diagnosing sleep-related disorders.

• priming The implicit memory effect in which exposure to a stimulus influences response to a subsequent stimulus.

• REM sleep The stage of sleep during which most brain activity and dreams occur, characterized by rapid eye movement

(REM).

• serotonin An indoleamine neurotransmitter (5-hydroxytryptamine) that is involved in depression and is crucial in maintaining a

sense of well-being and security.

• Sigmund Freud (1856-1939) An Austrian neurologist who became known as the founding father of psychoanalysis.

• subliminal message A signal or message embedded in another object, designed to pass below the normal limits of perception.

• subliminal perception Perception that is below the threshold of consciousness



• trance A state of concentration, awareness, or focus that filters information and experience; e.g. meditation, possession, etc.



Prefrontal cortex

This image shows the location of the prefrontal cortex, an area of the brain heavily involved in consciousness.


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Freud's levels of consciousness

This figure illustrates the respective levels of the id, ego, and superego.The part above water is known as the conscious level; the top level of waves just

below the surface and above the white line is the preconscious level; and the bottom level is the unconscious.


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Painting of a hypnotic trance

A hypnotic trance state is an example of unconscious perception influencing behavior.


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The Necker Cube

The Necker Cube is a popular visual stimulus used to study differences in human visual perception.


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Neural Correlates of Consciousness

The study of neural correlates of consciousness seeks to link activity within the brain to subjective human experiences in the physical world.


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Circadian Rhythms Influence Sleep

Circadian rhythms have a hand in determining when we are alert and when we become sleepy.


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The Suprachasmatic Nucleus

The SCN contains about 20,000 nerve cells, and is located in the hypothalamus, above the optic nerves.


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Sleep Waves

An EEG recording allows us to distinguish between different brain activity during sleep.


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Sleep Spindles and K-Complexes

Sleep spindles and K-complexes are defining characteristics and indicate the onset of stage 2 NREM sleep.


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Narcolepsy

Narcolepsy is characterized by an individual uncontrollably falling asleep very suddenly, and typically in inappropriate situations.


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The Long-standing Mystery of Dreams

Since ancient times, humans have been trying to understand the purpose of dreams.


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Alcohol as a depressant

Though initially a stimulant, alcohol ultimately depresses the brain, resulting in relaxation and impaired judgment.


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Cocaine

Cocaine, in powder form, is a commonly abused stimulant that produces a sense of euphoria in the user.


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Opium

The narcotic opium has been used among various cultures for centuries.


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Naturally occuring hallucinogen

Hallucinogenic mushrooms often have a characteristic blue bruising on their stems.


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Hypnotic colors

The use of colorful images can help people relax to the point of a hypnotic state.


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Meditation

Meditation allows a person to achieve a mental and physical state of relaxation.


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states of consciousness

Documents

consciousness perception

study of consciousness

human consciousness

level of consciousness

consciousness research

nature of consciousness

levels of consciousness

subliminal perception