Transcript Chapter 3
Body Rhythms and Mental States Chapter 3 What is the Nature of Consciousness? Consciousness – The brain’s awareness of internal and external stimulation (*filter or interpretation of events NOT a direct copy) The Functions and Structures of Consciousness • Restricts attention • Combines sensation with learning and memory • Helps us select personally meaningful stimuli • Allows us to draw on lessons stored in memory Mental Control • Attention (limited resource) *White Bear Study • Automatic vs. Contolled Processes • Preattentive Processes Sleep and Dreaming • • • • • Circadian rhythms Rapid eye movements (REM) Sleep paralysis, ‘paradoxical sleep’ REM rebound Non-REM (NREM) sleep Sleep Cycle • NREM = 4 stages *deepest sleep early in night • REM replaces Stage 1 • 60-90 between REM (most people have 4-6 cycles per night) Realms of Sleep • • • • • Stage 1. Feel self drifting on the edge of consciousness. Stage 2. Minor noises won’t disturb you. Stage 3. Breathing and pulse have slowed down. Stage 4. Deep sleep. REM. Increased eye movement, loss of muscle tone and dreaming. The Sleep Cycle The Need for Sleep Over the years, the need for REM sleep decreases considerably, while the need for NREM sleep diminishes less sharply Why We Sleep • The exact function of sleep is uncertain but the possible functions include: – – – – – – eliminate waste products from muscles repair cells strengthen the immune system recover abilities lost during the day conserve energy Aid in learning/memory Why We Dream: A Cross-Cultural Perspective • Folk theories (visions, religion) • Scientific approach – Dreams as meaningful events – Dreams as random brain activity Dreams as Meaningful Events • To guard sleep (disguising images) • To serve as sources of wish fulfillment • Differences in dream content by age, gender, and culture Dreams as Random Brain Activity Hypnosis Hypnosis – Induced state of altered awareness, characterized by heightened suggestibility and deep relaxation Hypnotizability – Degree to which an individual is responsive to hypnotic suggestions Altered Consciousness Psychoactive drugs – Chemicals that affect mental processes and behavior by their effects on the nervous system Depressants Opiates Stimulants Hallucinogens The Psychology of Drug Effects. • Reactions to psychoactive drugs depend on: – Physical factors such as body weight, metabolism, initial state of emotional arousal and physical tolerance. – Experience or the number of times a person has used a drug. – Environmental factors such as where and with whom one is drinking. – Mental set or expectations for drug’s effects. Process of Addiction Psychological • Dependence • Associations • People, Places, & Things Biological/Physical • Tolerance/dependence • Withdrawal