Chapter 4: Consciousness

Attentional Processes

Attention: a state of awareness that consists of the sensations, thoughts, and feelings that a person is focused on at a given moment

Consciousness has a limited capacity

• Whether you are mentally focused on a memory, a conversation, a foul odor, this sentence, or your growling stomach, consciousness is like a spotlight.

• It can shift rapidly from one stimulus to another, but it can shine on only one stimulus at a time.

Selective Attention

In a classic test of this cocktail party phenomenon, Colin Cherry (1953) presented subjects wearing headphones with two different messages, played simultaneously, one to each ear. In this dichotic listening task, subjects were told to “shadow”—that is, follow and repeat aloud, word for word—only one of the two messages. Even when they were stopped in the middle of the presentation and asked to repeat the unattended message, their ability to do so was limited.

• Cocktail party phenomenon: The ability to attend selectively to one person’s speech in the midst of competing conversations.

• Selective attention: The ability to focus awareness on a single stimulus to the exclusion of other stimuli, as in the cocktail party phenomenon.

Ulric Neisser and Robert Becklen (1975) devised a visual analog of the dichotic listening task. They simultaneously showed subjects two videotapes, one superimposed over the other.

• One video: 3 people passing a basketball.

• Other video: 2 people playing a hand-slapping game.

Participants could attend to only one visual stimulus at a time. Out of 24 participants focusing on the basketball game, 23 did not notice when the hand-slapping players stopped and shook hands. When shown later, participants were surprised they had missed it.

Divided Attention

Our consciousness is limited, but not completely closed off. Even when focusing on one task, some important or salient information from the unattended stream can be detected:

Selective attention can sometimes be divided, depending on how effortful each task is.

Experience and practice allow better divided attention in complex activities like sports:

A classic study on divided attention was devised in 1935 by John Stroop, using a test aptly called the Stroop test. When Stroop first presented his subjects with 100 colored items, he found that the task in which participants were presented with blocks of color to name took an average of 63 seconds, whereas the task in which participants were presented with words in colored font took 110 seconds—a 74 percent slowdown in performance time.

Because the test words contradict the colors (when they don’t, performance is quicker), reading interferes with the color-naming task

• Shows interference in attention: automatic reading of words competes with color naming, making it harder to focus on the intended task.

• Past experiments also show that personally relevant and emotionally provocative words interfere with color naming more than neutral words do.

Influence without Awareness

According to Freud

• conscious sensations, thoughts, and feelings that are currently in the spotlight of attention;

• preconscious material that is temporarily out of awareness but is easy to bring to mind;

• unconscious reservoir of material that is suppressed, banned from awareness.

Studies suggest that people can be influenced in subtle ways by subliminal messages—information that is presented so faintly or so rapidly that it is perceived “below” our threshold of awareness

Mere Exposure

The more often you see a stimulus—whether it’s a word, an object, a melody, or a face—the more you come to like it

This type of learning begins even before birth, with mere exposure to the flavors of foods in a mother’s diet being later preferred by newborns, and children learning to like novel (i.e., new) flavors simply by increased exposure to them

In a typical study with children and adults, subjects are shown pictures of geometrical objects, each for only 1 to 5 milliseconds, which is too quick to register in awareness—and too quick for anyone to realize that some objects appear more often than others.

• The more frequently presented the object, the more subjects like it.

• And when asked if they’ve ever seen the liked objects before, they say no.

Priming

The tendency for a recently presented concept to “prime” responses to a subsequent “target” question. Thus, when subjects are asked to decide if the letters D-O-C-T-O-R form a word, they are quicker to say yes if the previous item was N-U-R-S-E than if it was A-P-P-L-E

What if the prime word is presented subliminally, below our threshold of awareness?

• When that is done, the result is the same—even when the prime word is presented so quickly that subjects could only recall seeing a flash of light

Priming can be any stimulus, even images, that can influence your behavior. For example, images depicting delicious-looking fruits and vegetables can be used to prime healthy eating.

Motivations and Emotions

In one study, subjects took part in a “word search” puzzle that contained either neutral words or words associated with achievement motivation (strive, win, compete, succeed, master). Afterward, they were left alone and given 3 minutes to write down as many words as they could generate from a set of Scrabble letter tiles. When the 3-minute limit was up, subjects were signaled over an intercom to stop.

• Through the use of hidden cameras, the experimenters observed that 57 percent of the subjects primed with achievement-related words continued to write after the stop signal—compared to only 22 percent in the control group.

Subjects took part in a “reaction-time” task in which they were subliminally exposed to words that evoked strongly positive emotional reactions (music, friends), strongly negative reactions (cancer, cockroach), or more neutral—only mildly positive and negative—reactions.

• Compared to those in the neutral-word groups, those previously exposed to positive words were in a happier mood, and those exposed to negative words were in a sadder mood.

Sleep

The average person spends about 8 hours a day sleeping and 90 minutes dreaming.

• Given an average life expectancy of 75 years, that amounts to about 25 years of sleep and 5 years of dreaming in a lifetime.

• Yet until recently, we knew very little about this important aspect of our lives. Shakespeare once referred to sleep as “the death of each day’s life.” Others, too, think of sleep as a state of complete dormancy. They are wrong. As we’ll learn, the sleeping brain is humming with activity

Sleep Wake Cycle

Biological rhythm: Any periodic, more or less regular fluctuation in a biological organism.

Circadian rhythm: A biological cycle, such as sleeping and waking, that occurs approximately every 24 hours.

Humans tend to be most active and alert during the middle of the day, when body temperature peaks, and least active and alert at night, when body temperature drops to its low point.

fluctuations in

• blood pressure

• pulse rate

• blood sugar level

• potassium level

• growth hormone secretions

• cell growth

Across a whole range of cognitive activities that require vigilance, research shows that people perform better during their “preferred” time of day

In January 1989, Stefania Follini lived alone in an underground cave for 131 days, completely isolated from sunlight, clocks, temperature changes, and outside time cues. This allowed her body to follow its own natural rhythm without external influences. Her only contact with the outside world was a computer.

Key findings from Follini and other isolated volunteers:

• Most people naturally follow a cycle slightly longer than 24 hours (about 25 hours).

• Sleep, wake cycles, body temperature, and hormone levels all shift together.

• Over time, people fall asleep and wake later each day without sunlight cues.

• People tend to underestimate how much time has passed.

• Exposure to sunlight resets the biological clock back to a normal 24-hour cycle.

Circadian rhythm is controlled by the suprachiasmatic nuclei (SCN), located in the hypothalamus above the optic nerves. The SCN act as the body’s master biological clock.

Light signals from the retina travel through the optic nerve, and some of this information is sent directly to the SCN.

This allows the SCN to adjust the body’s rhythm based on light and darkness.

The pineal gland helps regulate sleep by releasing melatonin.

• Darkness → melatonin increases → promotes sleep

• Light → melatonin decreases → promotes wakefulness

Melatonin regulates the sleep–wake cycle and is sometimes used to treat insomnia.

Inner Clock

Jet lag occurs when flying across time zones disrupts the body’s circadian rhythm.

The body becomes out of sync with the new local time, causing sleep at incorrect times.

• Flying west is easier because it lengthens the day, which matches the body’s natural tendency toward a longer cycle.

• Flying east is harder because it shortens the day, forcing the body to adjust more quickly.

In 1998, researchers Scott Campbell and Patricia Murphy claimed jet lag could be reduced by shining light on the backs of the knees. They believed light could affect the circadian clock through blood vessels, sending timing signals through the body.

Later research by Kenneth Wright and Charles Czeisler (2002) tested this claim by measuring melatonin levels.

• Light exposure to the eyes shifted circadian rhythms.

• Light exposure to the back of the knee had no effect.

Night Work, Sleeping, Health

• Shift workers struggle with sleep because biological and social clocks promote daytime activity and nighttime sleep.

• Night workers often experience:

  • Less total sleep

  • Disrupted sleep from daytime noise

  • Drowsiness, slower reaction times, and lower productivity

• Rotating shifts are harder than permanent night shifts because the body cannot adjust consistently.

• Nearly half of night-shift flight controllers reported disordered sleepiness.

Sleep deprivation causes dangerous driving impairment.

• Up to 6,000 fatal crashes per year in the U.S. are sleep-related.

• 37% of drivers report falling asleep at the wheel at least once.

Monitoring of EEG activity shows that those who drive in the middle of the night often take quick, 2- to 3-second microsleeps, which elevates the risk of accident

• Microsleep: A brief episode of sleep that occurs in the midst of a wakeful activity.

Stages of Sleep

Electrodes are then taped to your scalp to record brain-wave activity, near your eyes to measure eye movements, and under your neck and chin to record muscle tension

Awake

Typical of a person who is awake and alert, your EEG shows short, quick beta waves. This pattern indicates that different parts of your brain are producing small bursts of electrical activity at different times.

• Stage 1 (light sleep, hypnagogic state)

  • Lasts a few minutes; theta waves appear

  • May see flashes, feel falling, or jerk limbs

  • Breathing, heart rate, blood pressure slow

  • Very easy to wake

• Stage 2 (deeper light sleep)

  • ~10 minutes in; body more relaxed, eye movements stop

  • Sleep spindles: periodic bursts of rapid brain activity seen on EEG

    • Help protect sleep from minor disturbances

  • External sounds mostly ignored (3% detection)

• Stages 3 & 4 (deep/slow-wave sleep)

  • ~20 minutes after Stage 2; delta waves dominate

  • Very hard to wake; may feel dazed if awakened

  • Behaviors: sleepwalking, sleep talking, bedwetting

  • Important stimuli (e.g., baby crying) can still be detected

REM (Rapid Eye Movement) Sleep

• After about an hour of deep NREM sleep, the brain cycles back through stage 3 and stage 2, then enters REM sleep.

• Each sleep cycle lasts roughly 90 minutes and repeats 4–6 times per night. Early cycles have short REM periods (~10 minutes), while later cycles have longer REM (30–60 minutes).

• REM sleep characteristics:

  • The EEG shows beta waves, similar to when awake.

  • Blood flow, breathing, and pulse increase, and genital arousal may occur even without sexual thoughts.

  • Skeletal muscles are paralyzed, except for occasional twitches, giving REM the name paradoxical sleep.

  • Rapid eye movements occur under closed eyelids.

• Dreaming:

  • 80% of awakenings during REM reveal vivid, storylike dreams.

  • NREM dreams are shorter and less detailed (~50% report).

  • Everyone dreams, but REM dreams are more immersive and visual.

Why do we sleep?

• Randy Gardner (1964):

  • 17-year-old stayed awake 264 hours (11 days) for a science project.

  • Initially reported feeling fine after 14 hours of sleep, but daily tests showed:

    • Fragmented thinking, slurred speech, memory lapses, hallucinations, poor concentration

  • Later developed insomnia and fear of missing sleep

4 Theories

• 1. Restoration Theory:

  • Sleep recharges the body and brain, restoring energy and repairing cognitive, emotional, and physical function.

  • Deep sleep (stages 3 & 4) is particularly important for restoration.

• 2. Circadian Theory:

  • Sleep evolved to conserve energy and reduce predation risk during inactive periods.

  • Species-specific patterns:

    • Animals with safe environments and easy food sleep longer.

    • Animals with high foraging needs sleep less.

  • Humans sleep at night due to limited ability to forage and defend at night.

• 3. Memory Consolidation Theory:

  • Sleep converts short-term memory into long-term memory (hippocampus + motor cortex).

  • REM sleep is especially important for organizing and consolidating memories.

• 4. Activation-Synthesis Theory:

  • Sleep functions to allow the synthesis (or merging) of random neural activity.

  • Dreams arise from random neural activity in the hindbrain, processed in the cortex

  • Visual regions and the amygdala (emotion) are active during dreaming.

  • Dreams are a by-product of brain synthesizing random signals.

Dreams

Researchers believe REM sleep and dreaming are adaptive, based on three main findings:

1. Present in most mammals (and many birds)

2. Greatest early in life (brain development): REM is highest when the brain is maturing.

3. REM rebound effect: When deprived of REM, people experience extra REM the next night, indicating biological necessity.

Longer REM periods → longer, more elaborate dream reports.

Common Dream Content

• Certain dream themes occur frequently across people.

• The three most common dreams are:

  • Falling

  • Being chased or attacked

  • Being back in school

Influences on Dream Content

• 1. Everyday concerns:

  • Stress, relationships, exams, or emotional events often appear in dreams.

• 2. External stimuli:

  • Real-world sensory input can be incorporated into dreams.

  • Example: water sprayed on hands → dreams of rain or swimming

Lucid Dreaming

• Lucid dreaming: being aware that you are dreaming while still asleep.

• Most people experience it occasionally, but it can be developed as a skill.

Freud's Interpretation

Sigmund Freud believed dreams express unconscious sexual and aggressive urges.

These urges are normally blocked by defense mechanisms, but during sleep, defenses weaken.

Dreams allow these urges to be fulfilled in disguised, symbolic form, protecting the mind and preventing emotional distress.

Freud called dreams the “royal road” to the unconscious.”

Manifest content:

• The actual dream remembered upon waking.

• Often symbolic and disguised.

Latent content:

• The hidden unconscious meaning, including true desires, conflicts, and urges.

• Considered the real meaning of the dream.

Freud believed dreams use symbols to disguise unconscious thoughts, such as:

• Kings and queens → parents

• Small animals → children

• House → human body

• Flying → sexual urges

Activation Synthesis Theory

Dreams result from the brain’s attempt to interpret and organize random neural activity during sleep.

• A two-process model:

  • Activation:

    • Random neural signals originate in the brainstem during REM sleep.

    • These signals spread to the cortex.

  • Synthesis:

    • The brain attempts to make sense of this random activity.

    • It creates images and narratives using stored memories.

• Dream features explained biologically:

  • Bright, vivid imagery → bursts of sensory neuron activity

  • Motion dreams (flying, falling) → motor neuron activation

Brain imaging studies (PET scans) show different brain regions are active during REM sleep:

• Limbic system (emotion and motivation) → highly active

• Frontal lobes (logic, planning, attention) → less active or inactive

This explains why dreams are often emotional, bizarre, and illogical.

Dreaming reflects active brain processes during sleep and is influenced by both emotional brain systems and cognitive experiences from waking life.

Sleep Disturbances

At some point in life, nearly everyone suffers from a sleep-related problem. In general, there are three types of sleep disturbances: sleeping too little (insomnia), sleeping too much (hypersomnia), and having disturbed or troubled sleep (parasomnia).

Insomnia

Insomnia: An inability to fall asleep, stay asleep, or get the amount of sleep needed to function during the day.

• Many people overestimate their sleep problems.

• Lab studies show some insomniacs:

  • Think it takes ~1 hour to fall asleep (actual: ~15 min).

  • Think they sleep ~4.5 hours (actual: ~6.5 hours).

• Over 10% are “pseudoinsomniacs”—they sleep normally but believe they don’t.

• Excessive worry and self-monitoring worsen the perception of insomnia.

• Wearable sleep trackers can show patterns, but only provide estimates.

Mimeault and Morin Study

• Aim: To test whether behavioral self-help programs improve insomnia.

• Participants: 58 people with insomnia complaints.

• Method: Participants were divided into 3 groups for 6 weeks:

  • Group 1: Self-help sleep treatment booklets.

  • Group 2: Same booklets + weekly therapist phone calls.

  • Group 3: No-treatment control group.

  • Participants recorded time to fall asleep and total sleep duration.

• Results:

  • Treatment groups:

    • Fell asleep faster.

    • Slept longer.

  • Control group:

    • No improvement.

Treatment

• Over-the-counter sleep aids are often ineffective.

• Prescription sedatives may:

  • Disrupt normal sleep stages

  • Cause rebound insomnia after stopping

• Behavioral approaches are generally more effective long-term than sleeping pills.

Hypersomnia

Hypersomnia: excessive daytime sleepiness + sleeping too much at night.

Occurs in 5–18% of people (varies by country).

Individuals feel sleepy despite adequate or extended nighttime sleep.

Narcolepsy

Narcolepsy: a rare sleep disorder involving sudden, uncontrollable episodes of REM sleep during the day (The term means “sleep seizure.”)

Defined by sudden, irresistible attacks of drowsiness and REM sleep.

• Can occur without warning during normal activities (e.g., eating, talking, working, driving).

• Last 5–30 minutes.

• Person enters REM sleep rapidly.

• Physical symptoms:

  • Jaw sags

  • Head drops

  • Arms fall

  • Knees buckle

• May include hypnagogic hallucinations (vivid dreamlike experiences at sleep onset).

Parasomnias

Sleep Apnea

• Sleep apnea: disorder where breathing repeatedly stops during sleep.

• Affects about 22 million Americans.

• Person falls asleep normally but then:

  • Stops breathing

  • Awakens choking, gasping, or snorting

• Can occur up to 400 times per night.

• CPAP device: pumps air through a mask to keep airway open.

Nightmares (REM)

• Nightmares: vivid, frightening dreams that occur during REM sleep.

• Often wake the sleeper.

• Common in children.

• Usually not dangerous unless persistent.

REM Sleep Behavior Disorder (RBD)

• Definition: Skeletal muscles are not paralyzed during REM sleep, allowing the person to act out dreams.

• Occurs: During REM sleep, usually later in the night.

• Symptoms:

  • Punching, kicking, thrashing

  • Talking, shouting, or screaming

  • Acting out violent or emotional dreams

Night Terrors (NREM)

• Occur during deep NREM sleep.

• Person suddenly wakes in panic and screams.

• More common in children.

• Person usually does not remember the event.

Sleepwalking (NREM)

• Occurs during deep slow-wave sleep.

• Person may:

  • Sit up

  • Walk around

  • Eat, dress, or open doors

• Eyes open but person appears unaware.

• Usually no memory of the event.

Hypnosis

Definition: Attention-focusing procedures where changes in behavior or mental state are suggested.

• Origins:

  • Franz Anton Mesmer (1734–1815) – Viennese physician who used “animal magnetism” to cure illness.

  • Patients entered a trance and often felt better afterward.

Modern Use

• Used in healthcare to control pain and break bad habits

• Considered effective in some clinical settings.

Hypnotic Induction

Two Stages:

1. Induction: Guides the subject into a focused, suggestible state.

   • No magic words; key is attention-focusing.

   • Techniques: slow, soft, monotonous voice; concentrate on an object, a spot, or imagination.

   • Goal: filter out distractions and enter “relaxed alertness.”

2. Suggestion: Hypnotist gives specific instructions once subject is focused.

   • Examples:

     • Physical suggestions (e.g., arm rising, eyes locked shut)

     • Cognitive/emotional (e.g., block pain, recall or forget events, break habits)

Hypnotic Responsiveness

• Definition: The degree to which an individual is responsive to hypnosis.

• Key Points:

  • You cannot be hypnotized against your will.

  • People differ in responsiveness: highly susceptible, low susceptibility, or moderate.

• Measurement:

  • Stanford Hypnotic Susceptibility Scale (SHSS) – 12-item behavioral test (Hilgard, 1965).

  • Tests include: eye closure, swaying, stiffening an arm, visualizing imaginary scenarios.

• Individual Differences:

  • Stable over time: High/low scores similar over 25 years (Piccione et al., 1989).

  • Not weakness: High scorers are not more conforming or obedient.

  • Traits of high susceptibility:

    • Open to experience

    • Vivid imagination

    • Ability to become deeply absorbed in books, movies, or activities

• Example: Highly susceptible “virtuosos” can experience dramatic changes in self-perception under hypnosis.

Coercion

• Key Idea: People cannot be hypnotized against their will, nor are they completely under a hypnotist’s control.

• Self-Hypnosis:

  • Hypnosis is essentially self-hypnosis; the subject remains in control (Olness, 1993).

  • Hypnotized individuals generally reject immoral commands.

• Hypnotic Coercion:

  • Can reduce inhibitions, leading to antisocial or risky behaviors (e.g., stealing, handling dangerous objects, illegal acts).

  • Example: Orne & Evans (1965) – subjects told to throw “nitric acid” did so; however, those pretending to be hypnotized also complied, suggesting obedience to authority rather than hypnosis itself.

Pain Relief

• Classic Study: Hilgard, Morgan, & MacDonald (1975)

  • Task: Subjects immersed one hand in ice water for ~1 minute.

  • Two groups:

    1. Hypnosis + suggestion: Told they would feel no pain.

    2. Control: No hypnosis, no suggestion.

  • Result: Hypnotized group reported less pain.

• Key Findings:

  • Hypnosis reduces perceived pain, especially in highly hypnotizable individuals.

  • Pain relief can occur with or without counter-pain imagery (e.g., imagining the hand as wood or in a glove).

• Applications:

  • Medical settings: dental work, childbirth, chronic pain (headaches, back pain, arthritis).

  • Effectiveness varies depending on hypnotic susceptibility.

Posthypnotic Suggestion

• Definition: A suggestion made during hypnosis that the subject carries out after the session ends.

• Effectiveness: Works only for some individuals, usually those high in hypnotic susceptibility.

• Example Study:

  • Barnier & McConkey (1998): 120 highly susceptible subjects were told to mail one prepaid postcard daily for four months.

  • Result: More than half of the postcards were mailed as suggested.

• Applications:

  • Can be paired with therapy to help with insomnia, obesity, high blood pressure, and other behavior-related issues.

  • Can aid in healing warts, skin conditions, asthma, nausea, and other conditions with a psychological component.

Memory Enhancement

• Posthypnotic Amnesia:

  • Subjects may forget events that occurred during hypnosis.

  • Memories are not permanently lost; can be retrieved with a cue (e.g., snap of fingers).

  • Occurs without effort or intention (Bowers & Woody, 1996).

• Hypermnesia:

  • Claimed enhancement of memory during hypnosis.

  • Historically linked to psychoanalysis and retrieval of repressed memories.

  • Research findings:

    • Subjects can “recall” events before age 2, even as early as before age 1 (Malinoski & Lynn, 1999; Green, 1999).

    • Raises concerns about accuracy and false memories.

Altered State

• Special-process theorists:

  • Hypnosis induces a distinct state.

  • People are more responsive to suggestion under hypnosis (Bowers, 1992; Yeh, Schnur, & Montgomery, 2014).

• Social-cognitive theorists:

  • Hypnosis is not a distinct state.

  • Effects can arise from relaxation, role-playing, expectation, or suggestion without induction.

Special Process Theories

• Dissociation:

  • Division of consciousness into independent parts.

  • One part follows suggestions; another part (the hidden observer) is aware but does not act.

  • Everyday example: “zoning out” while driving.

• Pain-tolerance study (Hilgard et al., 1975):

  • Subjects immersed hand in ice water.

  • Hypnotized group: reported very low pain (never above 2/10).

  • Hidden observer test: pressed key if any pain felt → aware of pain despite reporting low levels.

  • Implication: hypnosis can create simultaneous, separate streams of consciousness.

Social Cognitive Theories

• Skeptical view:

  • Hypnosis effects stem from social influence, not a special trancelike state.

  • Highly responsive subjects may comply or become absorbed in their role (like actors).

  • Pain tolerance and other effects can sometimes occur without hypnosis if motivated.

• Evidence against mere compliance:

  • Perugini et al. (1998) – highly responsive subjects continued suggestions alone, while simulators did not.

  • Hypnotized subjects are not just deceiving the experimenter; behavior persists outside the hypnotist’s presence.

• Additional findings:

  • Highly focused attention and absorption can make hypnosis feel “special”.

  • EEG: alpha waves increase during hypnosis in highly responsive subjects.

  • PET scans: cerebral cortex areas activated during hypnosis.

  • Social influence, expectations, motivation, and rapport with hypnotist still matter.

• Conclusion:

  • Hypnosis may work through two routes: special state of consciousness or social-cognitive compliance, both producing similar outcomes.

Conscious Altering Drugs

Psychoactive drug: chemical that alters perceptions, moods, thoughts, or behavior.

• History:

  • Alcohol (~10,000 years) was widely used before safe water.

  • Opium (~6,000 years), hallucinogenic mushrooms and weeds (~4,000 years).

  • Cultural uses: tobacco (Native Americans), kava (South Pacific), wine/celebrations (Europe).

  • Even some animals seek mind-altering substances (e.g., baboons, rabbits, elephants).

• Legality:

  • Legal: caffeine, tobacco, alcohol, tranquilizers, sleeping pills.

  • Illegal/illicit: cocaine, crack, heroin, LSD.

• Addiction and dependence:

  • Physical dependence: body needs drug to prevent withdrawal (shaking, sweating, vomiting).

  • Tolerance: higher doses needed for the same effect.

  • Psychological dependence: need drug to maintain well-being or relieve negative emotions.

There are four major classes of psychoactive drugs: sedatives, stimulants, hallucinogens, and opiates

Sedatives (Depressants)

Definition: Drugs that slow activity in the central nervous system → produce calmness, drowsiness, and, in high doses, loss of consciousness.

Common Types: Barbiturates, benzodiazepines, alcohol.

Highly addictive substances

Barbiturates:

• Treat epilepsy, anxiety, insomnia.

• Effects similar to alcohol: drowsiness, slower reactions, impaired cognition.

• High doses → anesthetic; hangovers common.

• Rapid tolerance; dangerous with alcohol.

Benzodiazepines:

• Minor tranquilizers (e.g., Valium, Librium, Xanax).

• Treat anxiety and insomnia.

• Calming, relaxing, induce sleep.

• Safer than barbiturates but addictive with prolonged use; dangerous with alcohol.

Alcohol:

• Most widely used depressant.

• Effects: decreased visual acuity, slower reactions, impaired balance, slurred speech, impaired cognition.

• Hastens sleep onset but suppresses REM → disrupted sleep quality.

• Behavioral effects:

  • Emotional regulation: Social drinking (celebration) vs. solitary drinking (coping with negative emotions).

  • Risk-taking: Lowers anxiety, reduces inhibitions → more aggression and accidents.

Stimulants

Definition: Drugs that excite the central nervous system and energize behavior.

Effects: Speed up bodily functions, increase heart and breathing rates, heighten alertness, suppress appetite, boost mood, self-confidence, and energy.

Risks: High doses → anxiety, jitteriness, hyperalertness; “crash” after use; addictive.

Common Stimulants:

• Caffeine & Nicotine: Mild stimulants used daily worldwide.

• Amphetamines:

  • Synthetic; prescribed for asthma, narcolepsy, ADHD, depression, obesity.

  • Low doses: increased alertness, energy, appetite suppression.

  • High doses: confusion, mania, aggression; chronic use → schizophrenia-like symptoms.

  • MDMA (Ecstasy): Designer amphetamine; stimulant + social euphoria.

  • Methamphetamine (“speed/ice”): smokable, highly addictive, potentially fatal.

• Cocaine:

  • Natural stimulant from coca leaves.

  • Powder: snorted → quick euphoria, short-lived, followed by crash.

  • Crack: smoked or injected → more intense, addictive, rapid onset.

Halucinogens

Definition: Psychoactive drugs (psychedelics) that distort perceptions of time and space and produce hallucinations.

Effects: Altered sensory perception, vivid colors, distorted shapes, slowed sense of time, euphoria, panic, emotional responsiveness, increased suggestibility.

Mechanism: Many act by blocking serotonin activity.

Common Hallucinogens:

• LSD (acid): Synthetic; powerful; first synthesized by Albert Hofmann (1938); effects last ~14 hours; can produce euphoria or panic.

• Psilocybin (“shrooms”): Natural hallucinogen from mushrooms.

• PCP (“angel dust”): Potent, dangerous; originally a painkiller; causes hallucinations and dissociation.

• Cannabis (marijuana): Mild hallucinogen; effects vary with dose:

  • Low dose: Relaxation, mild euphoria, heightened sensory awareness.

  • High dose: Distorted perceptions of time/space.

  • Active components: THC (psychoactive) and CBD (therapeutic, non-intoxicating).

  • Forms: Marijuana (dried leaves/flowers), Hashish (resin), Hash oil (most potent).

  • Usage: Widely used; medical and recreational legalization expanding in the U.S.

Opiates

Opiates: A class of highly addictive drugs that depress neural activity and provide temporary relief from pain and anxiety. Related to opium (an extract of the poppy plant).

• Effects: Euphoria, analgesia (pain relief), drowsiness, lethargy, constipation; changes in consciousness are mild.

• Medical Use: Prescribed to alleviate pain.

• Addiction: Highly addictive; rapid development of tolerance and dependence.

• Common Opiates: Morphine, codeine, heroin.

• Risks: Overdose, contaminated drugs, disease transmission (e.g., HIV/AIDS from shared needles).

Consciousness and Control

Ironic Processes (Daniel Wegner, 1994–1998)

• Definition: Mental control attempts can backfire; the harder you try to suppress a thought or action, the more likely it is to occur.

• Mechanism:

  • Intentional process: conscious effort to control thought or action.

  • Ironic operating process: automatic monitoring of failure, which ironically brings the unwanted thought/action to mind.

  • Failure more likely under distraction, fatigue, stress, or multitasking.

• Examples:

  • Thought suppression: “Don’t think about a white bear” → frequent intrusion of the thought.

  • Sleep: Trying not to worry about falling asleep → staying awake longer.

  • Motor control:

    • Pendulum experiment: Subjects told not to swing horizontally → pendulum swayed more in the forbidden direction.

    • Distraction (counting backward) increased the ironic effect.

    • Golf putting: Trying not to overshoot while distracted → more overshoots.

• Implications:

  • Efforts at self-control can backfire.

  • Key for psychologists and everyday life: minimize distractions, stress, and over-monitoring when attempting mental control.