PSYCHOLOGY Third Edition by Drew Westen PowerPoint Presentation Chapter 9 CONSCIOUSNESS John Wiley & Sons, Inc. Lecture Outline Nature of Consciousness Perspectives on Consciousness Sleep and Dreaming Altered States of Consciousness © 2002 John Wiley & Sons, Inc. Consciousness William James (1890): Consciousness is a constantly moving stream of thoughts, feelings, and emotions Consciousness can be viewed as our subjective awareness of mental events Functions of consciousness: Monitoring mental events Control: consciousness allows us to formulate and reach goals Consciousness may have evolved to direct or control behavior in adaptive ways © 2002 John Wiley & Sons, Inc. Cortex and Consciousness The dorsolateral prefrontal cortex is activated during conscious control tasks Subjects asked to name the ink color in the Stroop task below have difficulty when the word name and color are different This color-naming task was associated with activation of the dorsolateral prefrontal cortex © 2002 John Wiley & Sons, Inc. Attention Our conscious awareness is limited in capacity and we are aware of only a small amount of the stimuli around us at any one time Attention refers to the process by which we focus our awareness Three functions of attentional processes: Orienting function toward the environment Control of the content of consciousness • I will think about this issue but not that one… Maintaining alertness © 2002 John Wiley & Sons, Inc. Divided Attention Divided attention refers to a task in which a person is asked to attend to two tasks at the same time Subject may be asked to listen to one conversation (shadowing) delivered via the left ear Some information on the other channel (right ear) is processed (as shown in priming tasks) © 2002 John Wiley & Sons, Inc. Flow of Consciousness Day-dreams are shifts in attention toward internal thoughts and imagined scenarios College students may spend as much as 50% of their waking time in a day-dream (uhh, are you folks paying attention out there????) Beeper studies of high-school students have noted the predominance of negative thoughts when students are with their families as opposed to others © 2002 John Wiley & Sons, Inc. Psychodynamic View of Consciousness Freud argued that three mental systems form consciousness Conscious: mental events that you are aware of Preconscious: Mental events that can be brought into awareness Unconscious: Mental events that are inaccessible to awareness; events are actively kept out of awareness © 2002 John Wiley & Sons, Inc. Subliminal Perception Notion that brief exposure to sub-threshold stimuli can influence awareness Study: subjects are shown aggressive (A) or positive (B) stimuli and then rate a neutral stimulus (C) Subjects shown panel A first subsequently rated the boy in panel C more negatively © 2002 John Wiley & Sons, Inc. (Figure adapted from Eagle, 1959) Unconscious Cognitive Processes Information-processing view can be extended to analyses of unconscious processes Notion is that many brain mechanisms operate in parallel Some of these mechanisms operate outside of the level of consciousness Functional significance of unconscious mechanisms: Are efficient and rapid Can operate simultaneously Operate in the absence of consciousness? © 2002 John Wiley & Sons, Inc. Blindsight People with damage to the central portion of the occipital cortex are blind in the sense that they are unable to see objects placed before them are able to provide partial information about the geometric shape of an object (blindsight) Blindsight may involve a primitive visual system in the midbrain © 2002 John Wiley & Sons, Inc. Neurology of Consciousness Consciousness is distributed throughout the brain Hindbrain and midbrain are important for arousal and for sleep Damage to the reticular formation can lead to coma Prefrontal cortex is key for conscious control of information processing © 2002 John Wiley & Sons, Inc. Sleep and Dreaming Behavioral characteristics of sleep Minimal movement Stereotyped prone posture Require a high degree of stimulation to arouse organism Physiological characteristics of sleep Brain wave activity (seen in the EEG) Paralysis of muscles (seen in the EMG) Cardiovascular changes (alternating cycles of arousal) © 2002 John Wiley & Sons, Inc. Species Variation in Sleep (Figure adapted from Kripke et al., 1979) © 2002 John Wiley & Sons, Inc. Function of Sleep Memory consolidation Energy conservation Preservation from predators Restoring bodily functions Sleep deprivation can alter immune function and lead to early death Sleep deprivation can also lead to hallucinations and perceptual disorder © 2002 John Wiley & Sons, Inc. Mortality Rates and Sleep (Figure adapted from Kripke et al., 1979) © 2002 John Wiley & Sons, Inc. EEG Stages of Sleep (Figure adapted from Cartwright, 1978) © 2002 John Wiley & Sons, Inc. REM Sleep Characteristics of REM sleep Presence of rapid-eye-movements Presence of dreaming Increased autonomic nervous system activity EEG resembles that of awake state (beta wave) Motor paralysis (except for diaphragm) © 2002 John Wiley & Sons, Inc. Dreaming Psychoanalytic view: Dreams represent a window into the unconscious The latent content (meaning) can be inferred from the manifest content (the actual dream) Cognitive view: Dreams are constructed from the daily issues of the dreamer Biological view: Dreams represent the attempt of the cortex to interpret the random neural firing of the brain during sleep © 2002 John Wiley & Sons, Inc. Sleep Disorders Insomnia is the inability to achieve or maintain sleep Many causes for insomnia: Stress Depression Sleeping pills (iatrogenic means physician-caused) Some suggestions for treating insomnia Only use your bed for sleeping Avoid physical activity prior to sleep Avoid consumption of caffeine and alcohol before bed Keep a regular sleep schedule Go to bed when you are ready(do not force sleep) Do not sleep during the day if you have insomnia © 2002 John Wiley & Sons, Inc. Other Sleep Disorders Nightmares are vivid fear-evoking dreams Occur during REM sleep Night Terrors: are episodes of intense panic Occur during delta sleep (early in night) Sleep apnea: refers to awakening brought on by cessation of breathing during sleep Narcolepsy: falling asleep during the day © 2002 John Wiley & Sons, Inc. Altered States of Consciousness Changes in consciousness can be brought on by Meditation Hypnosis Drug ingestion Religious experiences © 2002 John Wiley & Sons, Inc. Hypnosis Hypnosis is a state of consciousness characterized by Deep relaxation Suggestibility Effects observed during hypnotic state: Age regression Change in pain perception Ability to recall memories into consciousness © 2002 John Wiley & Sons, Inc. Changes in Pain Perception during Hypnosis Hilgard’s demonstration of the “Hidden Observer” Subjective pain report depends on the aspect of consciousness that is reporting on pain (Figure adapted from Hilgard, 1986, p. 190) © 2002 John Wiley & Sons, Inc. Drug-Induced States of Consciousness Drug effects on consciousness depend on: Biological actions of the drug • Usually involve drug action at brain synapses Expectations of drug effect (what effect are you expecting from the drug?) Drug classes Depressants (including alcohol) Stimulants (amphetamine, cocaine) Hallucinogens (LSD) Marijuana © 2002 John Wiley & Sons, Inc. Copyright Copyright 2002 by John Wiley & Sons, Inc., New York, NY. All rights reserved. No part of the material protected by this copyright may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without written permission of the copyright owner. © 2002 John Wiley & Sons, Inc.