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The Mind and Consciousness

Psychological Science, Third Canadian Edition Michael Gazzaniga Todd Heatherton Diane Halpern Steven Heine. The Mind and Consciousness. 4. Questions to Consider:. How Is the Conscious Mind Experienced? What Is Sleep? What Is Altered Consciousness? How Do Drugs Affect Consciousness?.

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The Mind and Consciousness

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  1. Psychological Science, Third Canadian EditionMichael Gazzaniga Todd Heatherton Diane HalpernSteven Heine

  2. The Mind and Consciousness 4

  3. Questions to Consider: How Is the Conscious Mind Experienced? What Is Sleep? What Is Altered Consciousness? How Do Drugs Affect Consciousness?

  4. How Is the Conscious Mind Experienced? • Consciousness Is a Subjective Experience • There Are Variations in Conscious Experience • Splitting the Brain Splits the Conscious Mind • Unconscious Processing Influences Behaviour • Brain Activity Produces Consciousness

  5. Learning Objectives Define consciousness. Summarize research findings on the role played by the interpreter in split-brain and normal people.

  6. Consciousness Is a Subjective Experience • Subjectivity and “qualia”: each of us experiences consciousness subjectively • We cannot know if any two people experience the world in exactly the same way • Two components: the contents of consciousness and level of consciousness • Access to information

  7. One difficult question related to consciousness is how people experience qualia, the phenomenological percepts of the world. For instance, does red look the same to everyone who has normal colour vision?

  8. Consciousness Is a Subjective Experience • Brain imaging research has shown how particular regions of the brain are activated by particular types of sensory information • Miguel Nicolelis and his research on rhesus monkeys • John Donoghue and BrainGate

  9. There Are Variations in Conscious Experience • Consciousness and coma • The persistent vegetative state • Full consciousness • Between these two is the minimally vegetative state • Ethical issues surround the use of brain evidence for end-of-life decisions

  10. There Are Variations in Conscious Experience • Conscious experience is a continuous stream of thoughts that often floats from one thought to another • Consciousness is a unified and coherent experience—there is a limit to how many things you can be conscious of at the same time

  11. Splitting the Brain Splits the Conscious Mind • When you split the brain, do you split the mind? • the corpus callosum connects the brain’s hemispheres • severing the corpus callosum produces split brain • Differences in right and left hemisphere function

  12. Splitting the Brain Splits the Conscious Mind • Left hemisphere: dominant for language • Right hemisphere: dominant for spatial relationships • Splitting the brain splits the mind: the brain halves contain independent perceptions, thoughts, and consciousness • Gazzaniga: split-brain experiments and research

  13. Splitting the Brain Splits the Conscious Mind • The Interpreter: a left hemisphere process that strives to make sense of events • Hemispheres work together to reconstruct experiences • Split brain research: left hemisphere / right hemisphere actions and explanations do not correlate

  14. The Left Hemisphere Interpreter Exercise

  15. ZAPS: The Norton Psychology Labs Split Brain

  16. Unconscious Processing Influences Behaviour • The case for unconscious influence: • Priming effects • Subliminal perception • The “Freudian Slip” • The smart unconscious: research by Dijksterhuis and Nordgren shows unconscious processing valuable for complex decisions where pros and cons are difficult to weigh

  17. Brain Activity Produces Consciousness • “Blindsight” • Global Workspace Model

  18. Areas of Awareness Exercise

  19. A central theme emerging from cognitive neuroscience is that awareness of different aspects of the world is associated with functioning in different parts of the brain.

  20. The Cerebrum Animation

  21. What Is Sleep? • Sleep Is an Altered State of Consciousness • Sleep Is an Adaptive Behaviour • Sleep and Wakefulness Are Regulated by Multiple Neural Mechanisms • People Dream while Sleeping

  22. Learning Objectives List and describe the stages of sleep. Explain why we sleep and dream.

  23. Sleep Is an Altered State of Consciousness • The difference between being awake and being asleep has as much to do with conscious experience as with biological processes. • Using an EEG, researchers have measured the patterns of electrical brain activity during the different stages of normal sleep: • Stage 1 is characterized by theta waves • Stage 2 is characterized by k-complexes • Stages 3 and 4 are characterized by delta waves • REM sleep occurs after approximately 90 minutes of sleep

  24. Using an EEG, researchers measuredthese examples ofthe patterns of electricalbrain activity during different stages of normalsleep.

  25. This chartillustrates the normal stages ofsleep over thecourse ofthe night.

  26. Sleep Is an Adaptive Behaviour • Researchers have proposed three general explanations for sleep’s adaptiveness: • Restoration • Circadian cycles • The facilitation of learning

  27. Sleep Is an Adaptive Behaviour • Restoration: restorative theory suggests sleep allows the brain and body to rest and repair themselves • Sleep deprivation causes mood problems and a decrease in cognitive performance • Microsleeps result from sleep deprivation

  28. Sleep Is an Adaptive Behaviour • Circadian cycles: brain and other physiological processes are regulated into patterns • Body temperature • Hormone levels • Sleep/wake cycles • Sleep is an evolutionary adaptation to avoid danger

  29. Sleep Is an Adaptive Behaviour • The facilitation of learning: sleep is part of the process of strengthening neural connections that serve as the basis of learning • Slow-wave sleep • REM sleep

  30. Sleep and Wakefulness Are Regulated by Multiple Neural Mechanisms • Multiple neural mechanisms are involved in producing and maintaining circadian rhythms of sleep • A tiny structure in the brain called the pineal gland secretes melatonin, a hormone that travels through the bloodstream and affects various receptors in both the body and the brain

  31. The Pineal Gland Exercise

  32. The biological clock signals the pineal gland tosecrete melatonin, which affects bodily statesrelated to being tired.

  33. Sleep and Wakefulness Are Regulated by Multiple Neural Mechanisms • Researchers have identified a gene that influences sleep, called SLEEPLESS • This gene regulates a protein that, like many anaesthetics, reduces action potentials in the brain

  34. People Dream while Sleeping • Dreams occur in REM and non-REM sleep, although the dreams’ contents differ in the two types of sleep: • REM sleep: bizarre, emotion-filled, visual/auditory hallucinations, often illogical • Non-REM sleep: dull, mundane content and activities

  35. People Dream while Sleeping • What do dreams mean? • Freud: dreams have hidden content that represent unconscious conflicts • Manifest content • Latent content

  36. People Dream while Sleeping • What do dreams mean? • Alan Hobson: the activation-synthesis hypothesis • Random neural stimulation activates mechanisms that normally interpret visual input • The mind synthesizes activity in visual/motor neurons with stored memories

  37. People Dream while Sleeping • What do dreams mean? • Antti Revonsuo: evolved threat-rehearsal strategies • Dreams simulate threatening events to allow people to rehearse coping strategies • Dreams are the result of evolution — providing solutions to adaptive problems

  38. What Is Altered Consciousness? • Hypnosis Is Induced through Suggestion • Meditation Produces Relaxation • People Can Lose Themselves in Activities

  39. Learning Objective Understand how different states of consciousness influence behaviour.

  40. Hypnosis Is Induced through Suggestion • Hypnosis involves a social interaction during which a person, responding to suggestions, experiences changes in memory, perception, and/or voluntary action • Psychological scientists generally agree that hypnosis affects some people, but they do not agree on whether it produces a genuinely altered state of consciousness

  41. Hypnosis Is Induced through Suggestion • Theories of hypnosis: • Sociocognitive theory of hypnosis: hypnotized people behave as they expect hypnotized people to behave • Dissociation theory of hypnosis: the hypnotic state is an altered, trance-like state where conscious awareness is dissociated from other aspects of consciousness

  42. This PET image from one of Stephen Kosslyn’s studies shows thatareas in the visual cortex associated with colour perception are activated more whenhypnotized participants are told to imagine colour—a finding that suggests the brainfollows hypnotic suggestions.

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