Understanding Consciousness: Key Concepts in Psychology
School
University of British Columbia**We aren't endorsed by this school
Course
PSYC 101
Subject
Psychology
Date
Dec 9, 2024
Pages
34
Uploaded by BrigadierSteelPorcupine28
Psyc 101Introduction to Biological & Cognitive PsychologyJill Dosso, PhDNov 2024Speaking to you from the traditional, ancestral, and unceded territory of the xwməθkwəy̓əm (Musqueam) People.ConsciousnessChapter 5
Learning Objectives: Consciousness1.Describe the range of definitionsfor consciousness2.Identify four basic properties and threelevelsof consciousness3.Explain how Libet’s Clockand Aflalo’s BMI workcan be used to argue for non-conscious intentions in the brain4.Describe a study demonstrating deliberation without awarenessand one demonstrating subconscious thought monitoring5.Differentiate multiple disorders of consciousnessin terms of wakefulness, awareness, and communication/voluntary movement2
Thinking defines consciousness. A nonthinking, nondreaming state is neither conscious nor alive.–Descartes, 1681Nothing but a bundle orcollection of different perceptions, which succeed each other with an inconceivable rapidity, and are in perpetual flux and movement. –Hume, 1888What abandons us every night when we fall into a dreamless sleep–Searle, 1998I know I am conscious: I am seeing, hearing, feeling somethinghere, inside my own head.–Tononi & Koch, 2015Definitions of consciousness… range from the view that it merely refers to complex thought processes to the more slippery implication that it is the subjective experience of awareness–Kolb & Whishaw, Fundamentals of Human Neuropsychology, 20104Attempts to define consciousness…
The textbook implicitly defines consciousness as “having an inner experience” but this is one possible position among manyCommon themes across definitions can include:1.Being awake2.Being oriented to a particular moment in time and space3.Being capable of non-reflexive actions*4.Having subjective experiences5
The nature of consciousnessFour basic properties:1.Intentionality: Directed toward an object (mind-wandering; default mode network). 2.Unity: seamless integration of senses (binding problem)3.Selectivity: capacity to include some contents but not others (cocktail party effect; dichotic listening)4.Transience: tendency to change (bistable figures)6Dichotic listening –“listen to the story in your left ear…”Necker Cube
Levels of consciousness7Minimal consciousnessFull consciousnessSelf consciousnessYou know and are able to report your mental stateLow level of awareness but the mind can input sensations and output behaviourYour attention is drawn to the self as an objectImages: Schacter et al (2023) Psychology (6thCanadian ed) Macmillan“the problem of other minds”
Libet’sclock8In Libet’s experiments, the subject was asked to press a button whenever they wanted.Measures:1.EEG = electroencephalography = measure of brain’s electrical activity with high temporal resolution2.EMG= electromyography = measure of muscle activity in the hand 3.Self-report: note the moment on the clock when you consciously will the action
Libet’s clockLibet’sinterpretation: brain activity comes before conscious experience (“pre-conscious”)9
More modern evidenceWork with tetraplegic patients with implanted electrodes (brain-machinginterfaces) confirms that PPC activity comes before the self-described will to act (W) Note: this still has the same self-report structure (the person notes the clock time)They prefer “implicit” over “pre-conscious”10Neural activity
Deliberation without awareness11Choose the best from 6 cars / apartments / room-matesGroup A (“conscious”): read material - 4 mins to ponder - testGroup B (“unconscious”): read material - 4 mins solving anagrams - test Image: Dijksterhuis et al 2006 Science311: 1005-1007Quality of final choice
Controlling our thoughts•Wegner et al (1987) instructed participants to engage in deliberate thought suppression (“Don’t think of a white bear!”)•Thoughts can’t be fully suppressed•Attempting to suppress thoughts can backfire “ironically”•Possible interpretation: a subconscious monitoring process (the ironic monitor) prevents thoughts from reaching consciousness but can actually activate them12Images: Schacter et al (2023) Psychology (5thCanadian ed) Macmillan
Disorders of consciousnessMany possible causes: stroke, TBI, hypoxia, sedating medications, etc.Disorders affecting: •wakefulness,•awareness, and/or•voluntary movement14Source: From Schacter et al (2018) Psychology (4th ed) Worth
ComaWidespread downregulation of brain activity due to disfacilitation–potassium leaks passively out of neurons and they hyperpolarize, making it harder for them to fireNot awake (no sleep-wake cycles), no evidence of awareness, no voluntary movement beyond simple pain reflexes (at most)15
Unresponsive wakefulness syndromeformerly vegetative state•“Arousal without awareness”•Preserved sleep/wake cycles and spontaneous eye movements•Reflexive behaviours such as withdrawing from pain, yawning, chewing•No evidence of awareness: cannot follow commands, anticipate sensations, speak•Often but not always (66-90%) will ultimately progress to aminimally conscious state (some/fluctuating awareness)16
Covert consciousness: Cognitive Motor Dissociation (CMD)17https://www.youtube.com/watch?v=LaiQ7sEVLD8
Using fMRI to evidence consciousnessOwen et al: somepatients in UWS (5/54) can generate differential brain responses on command as seen on fMRI or EEG→Indicates primary deficit is with communication / voluntary movement for these individualsWe now know that this preserved ability (CMD) predicts progression to a minimally conscious state for 80% of patientsHowever, permanent and severe disability is still the most likely outcome18Images: Schacter et al (2023) Psychology (6thCanadian ed) Macmillan
Disorders of Consciousness: SummaryDiagnosisWakefulnessAwarenessCommunicationComaDo not open eyes, no sleep-awake patternNo evidenceNoneVegetative stateOpen eyes, sleep-awake patternNo evidenceNoneCognitive-motor dissociationOpen eyes, sleep-awake patternEvidence only via neuroimagingOnly via neuroimagingMinimally conscious stateOpen eyes, sleep-awake patternInconsistentVariableLocked-in syndromeOpen eyes, sleep-awake patternFully awareConsistent w. eye movements19Source: Modified from Schacter et al (2018) Psychology (4th ed) Worth
Questions? Consciousness1.Describe the range of definitionsfor consciousness2.Identify four basic properties and threelevelsof consciousness3.Explain how Libet’sClockand Aflalo’sBMI workcan be used to argue for non-conscious intentions in the brain4.Describe a study demonstrating deliberation without awarenessand one demonstrating subconscious thought monitoring5.Differentiate multiple disorders of consciousnessin terms of wakefulness, awareness, and communication/voluntary movement20
Psyc 101Introduction to Biological & Cognitive PsychologyJill Dosso, PhDNov 2024Speaking to you from the traditional, ancestral, and unceded territory of the xwməθkwəy̓əm (Musqueam) People.SleepChapter 5
Learning Objectives: Sleep1. Definesleep and differentiateit from other states2. Link the circadian rhythmto a brain structure3. Identify the stages of sleepand describe the way that they unfold across the sleep period (with their neural and behaviouralcharacteristics)4. Describe four sleep disorders5. Recognize impacts of sleep deprivation6. Describe trends in sleep across early life22
What is sleep?A recurring body state where:•Consciousness is suspended (or in dreaming: an altered state of consciousness different from normal wakefulness)•Sensory input is dulled•Voluntary motor movement is suspendedNot: coma, minimally conscious state, UWS…24
Circadian Rhythm•24-hour cycle regulated by the supra-chiasmatic nucleus (SCN) in the hypothalamus•The “biological clock,” just 20k neurons!25Image: NIGMS, https://www.nigms.nih.gov/education/fact-sheets/Pages/circadian-rhythms.aspx
Circadian RhythmWithout natural light, we naturally lengthen to a ~25-hour cycle26Image: Kandel Principles of Neural Science
Psychologists learn about sleep by collecting EEG and other physiological measures from volunteers while they sleep in a specialized lab28
Narcolepsy29https://www.youtube.com/watch?v=d41BfD21b48
Sleep disorders•Insomnia: difficulty falling asleep or staying asleep•Sleep paralysis: Waking up unable to move•Narcolepsy: sudden sleep attacks that occur in the middle of wakefulness•Sleep apnea: Brief pauses in breathing during sleep30
33Images: Schacter et al (2023) Psychology (6thCanadian ed) MacmillanStage 1: light sleep (hypnagogic states)Stage 2: approaching deep sleepStage 3-4: slow-wave sleep = deep sleepStage 5: REM sleep = dreaming
34People awoken during REM were more likely to remember their dream (Dement, 1950s)Images: Schacter et al (2023) Psychology (6thCanadian ed) Macmillan
REM sleep features rapid eye movements, a more rapid heart rate, and a higher rate of respiration35
Brain activity during REM sleep 36↑ Amygdala↑ Visual Cortex↑ Motor Cortex (but prevented from causing movement)↓ Prefrontal Cortex
Sleep deprivationREM deprivation•Ultimately fatal•REM reboundSlow-wave sleep deprivation•Also rebounds•Perceived “tiredness”Effects•Memory•Reaction time, coordination•Mood and irritability (“emotion regulation”)38
Sleep developmentKandel Principles of Neural Science39
Sleep development40https://www.reddit.com/r/dataisbeautiful/comments/e1kg7t/visualization_of_sleeping_patterns_in_a_newborns/Newborns sleep 16-18 hours a day (50% REM!), waking around the clockDiurnal rhythms emerge around 4m, but many children continue to wake at night until 1-2y (+)
Questions? Sleep1. Definesleep and differentiateit from other states2. Link the circadian rhythmto a brain structure3. Identify the stages of sleepand describe the way that they unfold across the sleep period (with their neural and behaviouralcharacteristics)4. Describe four sleep disorders5. Recognize impacts of sleep deprivation6. Describe trends in sleep across early life41