Consciousness, Sleep, and Psychoactive Drugs

Consciousness and Attention

• Consciousness: Immediate awareness of mental activity, internal sensations, and external stimuli.
• William James described consciousness as a stream or river; allows integration of past, present and future behavior; guides future actions; and maintains a sense of self.
• Attention:
  • Has limited capacity
  • Is selective
  • Can be "blind"

Attention Phenomena

• Inattentional Blindness: Failure to notice a significant object or event in clear field of vision.
• Inattentional Deafness: Failure to hear an auditory message when attention is elsewhere.
• Change Blindness: Failure to notice when something changes.
• Misdirection: Magicians exploit the limited, selective nature of attention.

Multitasking

• Involves division of attention, creating less attention for each task.
• Less interference when significant task variation is present.
• Visual task absorption can produce inattentional deafness; auditory task absorption can produce inattentional blindness.
• Cell phone use is more dangerously distracting than drunk driving.
• Using a handset or Bluetooth device does not improve safety while driving.

Circadian Rhythms and Sleep

• Consciousness varies systematically over a 24-hour period.
• Circadian Rhythm: A roughly 24-hour cycle or rhythm in biological and psychological processes synchronized by environmental clues like sunlight.
• Suprachiasmatic Nucleus (SCN): A cluster of neurons in the hypothalamus that governs the timing of circadian rhythms.
• Bright light, especially sunlight, regulates sleep-wake cycle and other circadian rhythms, detected by photoreceptors signaling the SCN.
• Melatonin, a hormone of the pineal gland, produces sleepiness.
• Internal body clock drifts to its natural (intrinsic) rhythm of about 24.2 hours.
• Deprivation of environmental time cues desynchronizes sleep-wake, body temperature and melatonin circadian rhythms.
• Jet Lag: Circadian rhythms out of sync with daylight and darkness cues, impairing thinking, concentration and memory.

Sleep Research and Brain Activity

• Modern sleep research began with electroencephalography (EEG), discovering sleep is marked by distinct physiological processes and stages.
• EEG (electroencephalogram): Graphic record of brain activity.
• Brain remains active during sleep, with activity patterns differing from waking state.
• Two basic types of sleep:
  • REM (Rapid Eye Movement): Associated with dreaming.
  • NREM (Non-Rapid Eye Movement, or Quiet Sleep): Divided into four stages.
• Beta Brain Waves: Associated with alert wakefulness.
• Alpha Brain Waves: Associated with relaxed wakefulness and drowsiness.
• Hypnagogic Hallucinations: Vivid sensory phenomena during sleep onset.
• Sleep Paralysis: Temporary inability to move upon awakening.

Sleep Stages

• NREM sleep has a four-stage progression, with decreasing brain and body activity in each progressive stage.
• Stages 1-4 of NREM sleep occupy the first 50-70 minutes.
• After 80-100 minutes of total sleep time, sleep lightens, returning through stages 3 and 2.
• REM sleep emerges, characterized by EEG patterns resembling beta waves of alert wakefulness.
• Four or five sleep cycles occur in a typical night; less time in slow-wave, more in REM.
• First REM period is about 5-15 minutes; lengthens in later periods.

Sleep Characteristics

• During REM sleep:
  • Brain is more active; smaller, faster brain waves occur
  • Dreams usually occur
  • Voluntary muscles are inactive
  • Eyes dart back and forth (physiological arousal)
  • Heart rate, blood pressure, and respirations can fluctuate
• Each sleep cycle is approximately 90 minutes.
• Sleeper shifts position before and after REM periods.
• REM episodes lengthen, and NREM shorten as sleep progresses through the night.

Sleep Patterns and Deprivation

• Sleep increases during childhood and adolescence, remains stable throughout adulthood, and decreases during late adulthood.
• Sleep is important for clearing brain metabolic waste products, maintaining immune function, learning and memory, and regulating mood.
• New memories are strengthened and integrated with existing networks, and emotional memories are preserved during sleep.
• Sleep deprivation studies include microsleep and sleep restriction leading to diminished concentration, vigilance, reaction time, memory skills, risk assessment ability; more calorie consumption and weight gain; REM rebound and NREM rebound.
• The sleep-deprived brain reacts strongly to negative stimuli and may lead to risky or addictive behavior due to unrealistically positive responses.

Dreams and Mental Activity

• A dream is an unfolding sequence of perceptions, thoughts, and emotions experienced as a series of actual events during sleep.
• Sleep thinking occurs during NREM slow-wave sleep, consisting of vague, bland ruminations about real-life events.
• Most dreams happen during REM sleep (about 90% of the time/ 4-5 dreaming episodes each night).

Memory Formation

• NREM slow-wave sleep contributes to forming new episodic memories (personally experienced events).
• REM sleep and NREM stage 2 sleep help consolidate new procedural memories (learning a new skill or task).
• New memories formed during the day are reactivated during the 90-minute cycles of sleep.

Dream Themes

• Most dreams are about everyday things; sex or sexual behaviors are rare.
• Women dream about men and women equally and report more emotions.
• Men dream about other men more frequently and report more physical aggression.
• Negative feelings and events are more common than positive ones.
• Apprehension or fear is a frequently reported dream emotion for both sexes.
• Dreamers are more likely to be victims of aggression than aggressors.

Nightmares vs. Night Terrors

• Nightmares: Vivid, frightening anxiety dreams during REM sleep; dreamer feels helpless.
• Daytime stress, anxiety, and emotional difficulties are often associated with nightmares.
• Nightmares are different from night terrors (sleep terrors).

Dream Theories

• Freud: Dreams are psychological safety valves where symbolic sexual and aggressive frustrations are expressed (fulfilled wishes, manifest vs. latent content) - not entirely supported by research.
• Activation-Synthesis Model (Hobson and McCarley): Sleep brain activity produces dream story (synthesis); dreaming due to automatic activation of brainstem circuits arousing sophisticated brain areas that generate meaning on sensory signals.
• Neurocognitive Theory of Dreaming: Continuity of waking and dreaming is emphasized; dreaming is like thinking with reduced sensory input and voluntary control; external sensory stimuli are cut off so individual sensory data is generated, leading to uncontrollable thought processes.

Sleep Disorders

• Sleep disorders are serious and consistent sleep disturbances causing subjective distress and interfering with daytime functioning.

Types of Sleep Disorders

• Insomnia: Dissatisfaction with sleep quality or duration, experiencing onset insomnia (difficulty falling asleep), maintenance insomnia (difficulty staying asleep), or waking before it is time to get up, caused by hyperarousal, stimulants, or anxiety/worries.
• Obstructive Sleep Apnea (OSA): Repeatedly stopping breathing during sleep, resulting in daytime grogginess, poor concentration, memory and learning problems, irritability due to airway blockage. Treatment includes continuous positive airway pressure (CPAP) device.
• Narcolepsy: Excessive daytime sleepiness and brief lapses into sleep throughout the day (sleep attacks or microsleeps), sudden loss of voluntary muscle control triggered by strong emotions or laughter, lasting seconds to minutes.
• Parasomnias: Undesired arousal or actions during sleep, including sleep terrors, sleepsex, sleepwalking, and sleep-related eating disorder.

Hypnosis

• Hypnosis is a cooperative social interaction where the hypnotized person responds to suggestions with changes in perception, memory, and behavior.
• About 15\% of adults are highly susceptible; 10\% are difficult or impossible to hypnotize.

Effects of Hypnosis

• Profound changes in subjective experience of consciousness, sensory changes (hallucinations, temporary blindness, deafness, or sensation loss), and behavior outside the hypnotic state occur.
• Posthypnotic Suggestion: A suggestion during hypnosis asking a person to carry out a specific instruction following the hypnotic session.
• Posthypnotic Amnesia: Increased confidence in incorrect memories.

Theories of Hypnosis

• Neodissociation Theory (Hilgard): Hypnotized person consciously experiences one stream of mental activity that complies with hypnotist’s suggestion while a dissociated stream of mental activity (hidden observer) processes information unavailable to consciousness.
• Alternative theories include social cognitive theory and suggestibility theories.
• People cannot be hypnotized against their will or perform actions contrary to their morals and values.
• Hypnosis cannot strengthen physical capabilities or create new talents but can help in modifying problematic behaviors.

Meditation

• Meditation involves using a mental or physical technique to induce focused attention and heightened awareness.

Types of Meditation

• General categories:
  • Focused Attention Techniques: Focus on a mantra.
  • Open Monitoring Techniques: Focus on "here and now."

Effects of Meditation

• Improve concentration, perceptual discrimination, and attention.
• Increase working memory in U.S. military personnel during basic training.
• Improve emotional control and well-being.
• Reduce stress and minimize its physical effects.

Psychoactive Drugs

• Psychoactive drugs are chemical substances that can alter arousal, mood, thinking, sensation, and perception.

Categories

• Depressants: Inhibit brain activity.
• Opioids: Chemically similar to morphine, relieve pain, and produce euphoria.
• Stimulants: Excite brain activity.
• Psychedelics: Distort sensory perceptions.

General Drug Effects

• Physical Dependence: Body and brain chemistry adapt to a drug.
• Drug Tolerance: Increasing amounts of drug are needed to gain original effect.
• Withdrawal Symptoms: Unpleasant physical reactions to lack of drug, plus intense craving.
• Drug Rebound Effect: Withdrawal symptoms are opposite to the drug’s action.
• Drug Abuse: Recurrent drug use disrupting academic, social, or occupational functioning and causing legal or psychological problems.
• Change in reward circuitry where normally reinforcing experiences are no longer satisfying.

Drug Interactions in the Brain

• Drugs influence brain activity by;
  • Altering synaptic transmission among neurons.
  • Increasing or decreasing neurotransmitter amounts.
  • Blocking, mimicking, or influencing a particular neurotransmitter’s effects.
• Addictive drugs activate dopamine-producing neurons in the brain’s reward system.

Depressants and Opioids

• Depressants inhibit central nervous system activity, while opioids are addictive drugs that relieve pain and produce euphoria.
• Depressants produce drowsiness, sedation, or sleep; relieve anxiety and lower inhibitions; produce addictive effects (increased sedative effects when combined).

Alcohol

• Considered to have highest social costs of all addictions.
• 17 million Americans are dependent or have serious problems.
• Accounts for estimated 90,000 deaths annually in the United States; including 1,400 college students.
• Involved in assaults, homicides, motor vehicle accidents, domestic, partner and child abuse, and birth defects.

Psychological Effects of Alcohol

• Produces mild euphoria, talkativeness, and feelings of good humor and friendliness.
• Lessens inhibitions by depressing brain centers responsible for judgment and self-control.
• Withdrawal causes rebound hyperexcitability in the brain.
• Binge Drinking: Five or more drinks in a row for men; four or more for women.

Barbiturates and Tranquilizers

• Barbiturates: Reduce anxiety and promote sleep by depressing activity in brain centers; withdrawal causes irritability and REM rebound nightmares (low doses) or hallucinations, disorientation, restlessness, and life-threatening convulsions (high doses).
• Tranquilizers: Are less potent and used to treat anxiety.

Opioids

• Addictive drugs that relieve pain, produce euphoria, and occupy endorphin receptor sites in the brain, mimicking the effect of endorphins.
• Withdrawal is not life-threatening but produces unpleasant drug rebound symptoms, intense craving for heroin, fever, chills, muscle cramps, and gastrointestinal problems.
• Types include natural opiates (opium, morphine, codeine) and synthetic/semisynthetic opiates (heroin, methadone, oxycodone).

Stimulants and Psychedelics

• Stimulant drugs increase brain activity, while the psychedelic drugs create perceptual distortions, alter mood, and affect thinking.

Stimulants

• Caffeine: Promotes wakefulness, mental alertness, faster thought processes, stimulates dopamine in the prefrontal cortex, blocks adenosine receptors in the brain, but can produce anxiety, restlessness, increased heart rate, disrupt normal sleep patterns, and contribute to sleep disorders.
• Nicotine: Increases neural activity in many brain areas (frontal lobes, thalamus, hippocampus, amygdala), increases mental alertness and reduces fatigue/drowsiness; withdrawal symptoms include jumpiness, irritability, tremors, and headaches.
• Amphetamines: Stimulate brain activity, increasing mental alertness, reducing fatigue, elevating mood, and suppressing appetite; methamphetamine (meth) is an illegal drug; withdrawal symptoms include fatigue, deep sleep, intense mental depression.
• Cocaine: Illegal stimulant derived from coca plant, produces intense euphoria, mental alertness, and self-confidence by blocking reuptake of dopamine, serotonin, and norepinephrine; prolonged use can result in stimulant-induced psychosis.

Psychedelics

• Create profound perceptual distortions, alter mood, and affect thinking.
• Mescaline: Derived from peyote cactus.
• LSD: Synthetic drug that mimics serotonin in the brain, stimulates receptor sites in the somatosensory cortex; adverse reactions include flashbacks, depression, long-term psychological instability, and prolonged psychotic reactions.
• Marijuana: Active ingredient is tetrahydrocannabinol (THC); at high doses, produces sensory distortions and can interfere with muscle coordination and perception; THC may be helpful in treating pain, epilepsy, hypertension, and nausea from chemotherapy.

Club Drugs

• MDMA (Ecstasy): Synthetic club drug that has stimulant, emotional and mild psychedelic effects, causes neurons to release serotonin (amplifying and prolonging serotonin effects). But it causes dehydration, rapid heartbeat, tremors, muscle tension, hyperthermia and it damages serotonin nerve endings in the brain causing depression, memory and verbal reasoning problems.
• Dissociative Anesthetics (PCP and Ketamine): PCP affects levels of the neurotransmitter glutamate in the brain, indirectly stimulating the release of dopamine. It reduces sensitivity to pain and produces feelings of detachment. High doses of PCP can cause hyperthermia, convulsions, and death.

Overcoming Insomnia

• Monitor intake of stimulants.
• Establish a quiet bedtime routine.
• Create conditions for a restful sleep.
• Establish a consistent sleep-wake schedule.