Sleep’s role in recovery/repair Growth hormone is released during the deep stages of sleep. deep sleep Sleep onset
Recovery/Repair Longer sleep time improves the function of the immune system and helps fight off infection ↑Number of white blood cells More sleep = more immune system cells Less sleep = fewer immune system cells
Neuronal Energy Production In wake promoting areas of the brain, ATP (the energy currency of brain cells) increases during the first few hours of sleep. This surge in ATP increases with deeper stages of sleep.
1/3 of life asleep! Sleep Deprivation Fatigue and subsequent death Impaired concentration Emotional irritability Depressed immune system Greater vulnerability Why Sleep?
% of physicians reporting a serious conflict with co-workers Sleep loss impairs social interactions Less sleep leads to more arguments More sleep leads to fewer arguments
Sleep habits influence physical health Short sleep times (≤7 hrs per night) are associated with increased: Appetite Body mass (obesity) Risk of diabetes Risk of cancer Incidence of cardiovascular disease
Why Sleep? Sleep is essential for life. World record for no sleep = days ( hours) 18 days? Hallucinations, vision/speech/memory problems but with full recovery.
Animal Sleep 20 hr 18 hr 16 hr 13 hr 4 hr 3 hr
Unusual Animal Sleep New calves/mothers: No sleep for 3 weeks!
Insomnia: Persistent inability to fall asleep. (30-40%) Narcolepsy: Overpowering urge to fall asleep that may occur while talking or standing up. Sleep apnea: Failure to breathe when asleep. (2-3%) Night terrors: Sudden arousal from sleep, intense fear, rapid heart rate, sweating, Stage 4 disorder. Sleepwalking: Stage 4 disorder, usually harmless, no recall (1-15%) Sleeptalking: Stage 1-4 disorder, runs in families Restless Legs Syndrome: unusual feelings at bedtime (10%) Sleep Disorders
Why Dream? Wish Fulfillment (Freud): safety valve to discharge unacceptable feelings; symbolic meanings. Problem: Theory lacks support; interpretation of dreams difficult. Information Processing: Dreams may help sift, sort, and fix a day’s experiences in our memories. Problem: dreams can contain events not experienced. Sigmund Freud ( )
Why Dream? Physiological Function: Develop neural pathways. Babies develop many new neural connection and require more sleep. Cognitive Development: Brain maturation and cognitive development.
Why Dream? Activation-Synthesis Theory: random neural activity; dreams attempt to make sense of this activity. REM sleep is essential! If deprived of REM sleep, REM rebound occurs.
Hypnosis Hypnos: Greek god of sleep One person (the hypnotist) suggests to another (the subject) that certain perceptions, feelings, thoughts, or behaviors will spontaneously occur.
Hypnosis: Facts and Myths Power of Suggestion Can anyone experience hypnosis? Yes, to some extent. Can hypnosis enhance recall of forgotten events? No. Can hypnosis be therapeutic? Yes. Can hypnosis alleviate pain? Yes. Can hypnosis force people to act against their will? No.
What Causes Hypnosis? Social Influence Theory: Playing acting; expectations. Divided Consciousness Theory: Special state of consciousness
Example Bad smell attention is diverted Social Influence Theory: told to ignore smell Divided Consciousness Theory: consciousness/awareness split
Drugs and Consciousness Psychoactive Drug: A chemical substance that alters perceptions and mood (affects consciousness). Heroin Inhalants LSD Marijuana Nicotine PCP Rohypnol 1,4-Butanediol Alcohol Amphetamines Barbiturates Caffeine Cocaine Ecstasy GHB Hallucinogenic Mushrooms
Dependence & Addiction Continued use of a psychoactive drug produces tolerance. With repeated exposure to a drug, the drug’s effect lessens. Thus it takes greater quantities to get the desired effect.
Withdrawal & Dependence Withdrawal: Upon stopping use of a drug (after addiction), users may experience the undesirable effects of withdrawal. Dependence: Absence of a drug may lead to a feeling of physical pain, intense cravings (physical dependence), and negative emotions (psychological dependence).
Psychoactive Drugs Psychoactive drugs are divided into three groups. 1.Depressants 2.Stimulants 3.Hallucinogens
Depressants Depressants: reduce neural activity and slow body functions. 1.Alcohol 2.Barbiturates 3.Opiates
Depressants Alcohol: affects motor skills, judgment, and memory; increases aggressiveness while reducing self awareness. Drinking and Driving Daniel Hommer, NIAAA, NIH, HHS Ray Ng/ Time & Life Pictures/ Getty Images
Depressants Barbiturates: reduce the activity of the central nervous system; reduce anxiety but impair memory and judgment. Opiates (morphine and heroin): reduce neural activity, reduce pain and anxiety; highly addictive.
Stimulants Stimulants: excite neural activity and speed up body functions. Caffeine Nicotine Cocaine Ecstasy Amphetamines Methamphetamines
Caffeine & Nicotine Caffeine and nicotine increase heart and breathing rates and other autonomic functions to provide energy.
Why Do People Smoke? 1.Socially rewarding. 2.Genetic factors. 3.Reduce unpleasant cravings 4.Rewarding
Cocaine Cocaine induces immediate euphoria followed by a crash. Crack, a form of cocaine, can be smoked. Other forms of cocaine can be sniffed or injected.
Ecstasy (Methylenedioxymethamphetamine, MDMA) Stimulant, mild hallucinogen. Can damage serotonin-producing neurons Possible depression, memory problems.
Image courtesy of Dr. GA Ricaurte, Johns Hopkins University School of Medicine
LSD: (lysergic acid diethylamide) powerful hallucinogenic drug. THC (delta-9-tetrahydrocannabinol): major active ingredient in marijuana (hemp plant) Hemp Plant Hallucinogens Distort perceptions; create sensory images without sensory input.