Chapter 5: Consciousness And Sleep PDF

10/20/2024 CHAPTER 5 Consciousness: Personal Awareness Awareness of internal and external world ◼ Levels of awareness - James - Freud 1 A Physiological Index of Consciousness EEG...

10/20/2024 CHAPTER 5 Consciousness: Personal Awareness Awareness of internal and external world ◼ Levels of awareness - James - Freud 1 A Physiological Index of Consciousness EEG (monitoring of brain electrical activity) Brain-waves: Amplitude (height) Frequency (cycles per second) 2 Biological Rhythms and Sleep Circadian Rhythms – 24 hr biological cycles ◼ Regulation of sleep/other body functions Physiological pathway of the biological clock: Light levels → retina → 3 1  10/20/2024 Effects of Jet Lag on Sleep Sleep-wake cycle disrupted ✥ fatigue, irritability, poor sleep ✥ travel east ✥ travel west 4 Sleep/Waking Research Instruments: Electroencephalograph Electromyograph Electrooculograph 5 Sleep Stages Stage 1: brief, transitional (1-7 minutes) Stage 2: (10-25 minutes) Stages 3 & 4: (30 minutes) Stage 5 6 2  10/20/2024 Sleep Cycles ❑ 90 minutes cycles ❑ 4 to 6 per night ❑ typical sequence 7 The Neural Bases of Sleep Brain Structures: ◼ Ascending reticular activating system ◼ Pons/ medulla/ thalamus/ hypothalamus/ limbic system Neurotransmitters: ◼ Acetylcholine and serotonin ◼ Also, norepinephrine, dopamine, and GABA 8 Sleep Deprivation Complete deprivation Partial deprivation or sleep restriction ◼ impaired attention, reaction time, coordination, and decision making 9 3  10/20/2024 Sleep Deprivation Selective deprivation ◼ REM and slow-wave sleep: - rebound effect 10 Sleep Problems Insomnia – difficulty falling or staying asleep Narcolepsy – irresistible onsets of sleep Sleep Apnea – reflexive gasping for air 11 Sleep Problems Nightmares – anxiety arousing dreams: REM Night Terrors – intense arousal and panic – NREM Somnambulism – sleepwalking 12 4  10/20/2024 Dreams and Dreaming Dreams – mental experiences during sleep ◼ Content usually familiar ◼ Common themes ◼ “Spillover” from the day – day’s residue Western vs. Non-Western interpretations 13 Why Do We Dream? ❶ Wish Fulfillment (Freud) - “royal road to the unconscious” ❷ Activation Synthesis (Hobson & McCarley) - dreams : by-product of random neural activity ❸ Information Processing (Cartwright) - problem-solving (Crick & Mitchison – “time out” ) 14 Recreational Drugs: Terms of Reference ❶ Psychoactive drugs - those that affect cognitions and behaviour ❷ Substance abuse - use that compromises normal functioning ❸ Tolerance - progressive decrease in response to drug 15 5  10/20/2024 Recreational Drugs: Terms of Reference ❹ Physical dependence - take drug to avoid withdrawal symptoms ❺ Psychological dependence - take drug to satisfy emotional / mental craving 16 Psychoactive Drugs Narcotics (opiates) – pain relieving Sedatives – sleep inducing Stimulants – increase CNS activity 17 Psychoactive Drugs Hallucinogens – distort sensory and perceptual experience Cannabis – produce mild, relaxed euphoria Alcohol – produces relaxed euphoria, decreases inhibitions MDMA – produces a warm, friendly euphoria 18 6  10/20/2024 Drugs & Synaptic Transmission ✥ all drugs affect neurotransmitters ✥ synaptic transmission - synthesis - release - binding - inactivation - reuptake ✥ effects depending on the NT system 19 Drugs & Synaptic Transmission ✥ Amphetamines: affects release & reuptake of monoamines (increases levels of DA & NE) ✥ Cocaine blocks re-uptake of DA, NE & Serotonin ✥ net result : more DA & NE pleasurable effects = increase activity in DA circuit 20 Drugs & Synaptic Transmission Synergistic Effect - combined effect is greater than the sum of individual effects e.g. Alcohol / Sedatives 21 7  10/20/2024 Reward Pathway ❖ increased DA release principal source of reinforcement Pathway : Mesolimbic Dopamine Pathway Midbrain → Medial Forebrain Bundle 22 8