Consciousness and Altered States

Consciousness

5.1 Biological Rhythms of Consciousness

• Consciousness: A person’s subjective awareness, including thoughts, perceptions, self-awareness, experiences of the world.

• Awareness vs. wakefulness: Self-awareness is not the same as being awake. Wakefulness refers to the body being physically present and responsive to stimuli in the environment.

Hormones and the Endocrine System

• Endocrine System: A collection of glands that produce and release hormones.

• Hormones: Chemicals secreted into the bloodstream that travel throughout the body.

  • Effects are slower than neurotransmitters.

  • Contribute to homeostasis.

  • Regulate energy, metabolism, body temperature, and other basic functions.

• Endocrine System Components:

  • Hypothalamus: Receives input from other brain areas to communicate.

  • Pituitary gland: 'Master gland' that produces hormones and sends commands about hormone production to other glands in the endocrine system.

  • Adrenal gland: Releases stress hormones (e.g., cortisol and epinephrine) in response to danger or stress, following instructions from the hypothalamus.

Biological Rhythms

• Circadian rhythms: Internally driven daily cycles of approximately 24 hours affecting physiological and behavioral processes.

  • Examples: Sleep-wake cycle, hunger, concentration.

• Brain structures:

  • Suprachiasmatic nucleus (SCN): Located in the hypothalamus.

  • Pineal gland

  • Process: Retina stimulated by light communicates information about the environment to the SCN (Hypothalamus) which then signals the Pineal Gland to release melatonin. The hypothalamus regulates the body to facilitate sleep.

• Entrainment: When biological rhythms become synchronized to external cues such as light, temperature, or a clock.

• Endogenous rhythms: Biological rhythms that are generated by our body independent of external cues, helping to maintain our circadian rhythm.

The Stages of Sleep

• Polysomnography: A set of objective measurements used to examine physiological variables during sleep.

  • Includes respiration (breathing), body temperature, and muscle activity.

• Electroencephalogram (EEG): Produces a waveform used to measure and interpret excitatory and inhibitory activity in groups of neurons in the brain.

Sleep Stages and Brain Waves

• Beta Waves: Occur when a person is awake and alert.

  • High frequency (15-30 Hz), low amplitude.

• Alpha waves: Occur during daydreaming, meditating, or falling asleep.

  • Lower frequency (8-14 Hz).
    *Frequency (Hz): Cycles per second
    *Amplitude: Height of the wave

• Stage 1: Theta waves

  • Lower frequency (4-8 Hz), higher amplitude.

  • Breathing, blood pressure, and heart rate decrease.

  • Still sensitive to external stimuli.

  • Lasts roughly 15-20 minutes.
    *First 4 stages

• Stage 2: Theta waves

  • Lower frequency (4-8 Hz), higher amplitude.

  • Characterized by:

    • Sleep spindles: Clusters of high-frequency, low-amplitude waves.

    • K-complexes: Small groups of larger amplitude waves.
      *Asleep but can easily be woken up

• Stages 3 & 4 (Deep-sleep): Delta waves

  • Low frequency (<3 Hz), high amplitude.

  • Brief, fragmented dreams; least sensitive to external stimuli.

• REM (Rapid eye movement) sleep:

  • Quickening brain waves.

  • Inhibited body movement.

  • Rapid eye movements.

  • Dreaming typically occurs during REM sleep.
    *Most important stage
    *low on wakefulness

*Humans spend approximately 20% - 25% of total sleep in REM sleep

• REM Rebound: After REM sleep deprivation, the body goes directly to REM sleep.
  *Naps:
  90 mins
  1hr
  sleep cycle
  90 mins
  1hr
  ideal
  productive

Theories of Sleep

• Restore and Repair Hypothesis:

  • Our bodies need to restore energy levels and repair any wear and tear experienced during the day.

  • Lack of sleep is associated with cognitive decline, emotional disturbances, and impaired immune system functioning.

  • Sleeping helps the clearing of waste products and excess proteins from the brain.

• Preserve and Protect Hypothesis:

  • Sleep is important for preserving energy and protecting the organism from harm.

  • Prey tends to sleep in safe locations, while predators are awake and hunting.

  • Evidence from animal sleep patterns: Animals higher on the food chain sleep more.

Theories of Dreaming

• The Psychoanalytic Approach (Sigmund Freud):

  • Freud viewed dreams as unconscious expression of wish fulfillment.

  • Primal urges (sex and aggression).

  • Manifest Content: Images and storylines we dream about.

  • Latent Content: 'Symbolic' meaning of a dream, usually tied to sex and aggression.
    *Freud's Suggestion

• The Activation-Synthesis Hypothesis:

  • Suggests dreams arise from brain activity, particularly bursts of excitatory messages from the Pons (in the Brainstem).

  • Two steps: Activation & Synthesis

    • Pons → Activation: Explains REM (eye movements and EEG patterns resembling wakefulness).

    • Stimulation of the Occipital and Temporal lobes could produce imaginary sights and sounds.

    • Different regions of the cortex trying to make sense of this information → Synthesis.

    • Frontal lobe may play a key role in synthesizing a 'coherent' story.
      *A More viable than Freud's theory

Disorders and Problems with Sleep

• Insomnia:

  • Onset insomnia: Difficulty falling asleep.

  • Maintenance insomnia: Difficulty returning to sleep.

  • Terminal insomnia: Waking too early.

  • Can be further classified as:

    • Primary insomnia: Due to an internal source (e.g., worrying).

    • Secondary insomnia: Result of other disorders.

• Nightmares: Particularly vivid and disturbing dreams that occur during REM sleep.
  *Occur during REM sleep

• Night terrors: Intense bouts of panic and arousal that awaken the individual, typically in a heightened emotional state.
  *Occur during NREM sleep
  no relation to dream

• Movement Disturbances:

  • REM behavior disorder: Acting out dreams due to failure to inhibit motor signals.

  • Somnambulism (sleepwalking): A disorder that involves wandering and performing other activities while asleep.

• Sleep Apnea: Temporary inability to breathe during sleep as the airway becomes obstructed.

  • Obesity, damage to the medulla.
    *FETTLE EFFI prevents the tongue from falling backwards tongue obstructing

• Narcolepsy: Extreme daytime sleepiness and even sleep attacks.

  • Lasts from a few seconds to a few minutes.

  • Immediately enters REM sleep.

5.2 Altered States of Consciousness

• Brainstem
  Breathing
  Heart rate
  Sleep
  Wakefulness
  *Pons are involved in:
  Relay of neural impulses
  Control of voluntary movement
  Transfer of information between the medulla and cortex
  pons
  medulla

• Brain death: Brain (including Brainstem) does not function.
  *Brainstem regions responsible for basic life functions do not function

• Coma: Complete loss of consciousness.

  • Typically caused by:

    • Damage to the brainstem → suppressed reflexes (pupil dilation/constriction).

    • Widespread damage to both hemispheres.

  • Possible to recover to higher levels of consciousness within 2-4 weeks.
    treatable
    untreatable

• Persistent vegetative state: State of minimal to no consciousness.

  • Eyes may be open.

  • Individuals will develop sleep-wake cycles.

  • Typically caused by extensive brain damage (damaged grey and white matter in both hemispheres).

• Minimally conscious state (MCS): Patient may show some behaviors, suggesting partial consciousness, even on an inconsistent basis.

  • E.g.:

    • Following simple commands.

    • Gesturing yes/no responses.

    • Physical or emotional reactions.

  • Neuroimaging shows some activity in higher-order sensory and cognitive regions.

• Locked-in syndrome: Patient is aware and awake but unable to move their body and appears unconscious.

  • May be caused by damage to the Pons.
    *either Actual connectivity structure damage damage

Assessing Consciousness in the Vegetative State

• Case Study:

  • 23-year-old patient in vegetative state (minimal to no consciousness).

  • Mental imagery task: Imagine playing tennis or imagine the rooms in their house.

  • Tennis: Activity in brain areas related to movement.

  • House: Activity in spatial network (parahippocampal gyrus and parietal lobe).

  • Conclusion: Patient could hear and follow commands.

5.3 Drugs and Conscious Experience

Chemical Messengers

• Drug Effects on Neurotransmission:
  *Direct Agonists
  *Indirect Agonist
  *Direct Antagonist
  *Indirect Antagonist
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Short-Term Effects

*Alteration of the effectiveness of a neurotransmitter
* Synthesis
*Precursor chemicals
Neurotransmitter
* Storage
6 Reuptake
- Release
* Receptor interaction
*Inactivation

Short-term effects - Example

• Acetylcholine (ACh) Synapse *Acetylcholine is a neurotransmitter that triggers muscle contractions, stimulates some hormones, and controls the heartbeat. It is an excitatory neurotransmitter.

  • An ACh Agonist would excite muscles, increasing muscle tone.

  • An ACh Antagonist would inhibit muscles, decreasing muscle tone.

Short-Term Effects

• Dopamine → Neurotransmitter most often influenced by drugs.

  • Involved in motivation and reward.

  • When released in the nucleus accumbens and the ventral tegmental area, produces the 'high' associated with many drugs.

  • Reinforces drug-taking behavior.

  • Anticipation alone is enough to release dopamine.
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Long-Term Effects

• Substance abuse is the result of multiple factors

  • Physical Dependence: The need to take a drug to ward off unpleasant physical withdrawal symptoms.

    • E.g., Nausea, increased heart rate, increased blood pressure, hallucinations, and delirium (confusion)

  • Psychological Dependence: An emotional need for a drug develops without any underlying physical dependence.

Long-Term Effects

• Substance abuse is the result of multiple factors

  • Tolerance: When repeated use of a drug results in a higher dose to get the intended effect.

  • Down-regulation
    example higher
    Beforedrug Affrug cellular
    Tolerance
    Drug abuser i I i has down leads to tolerance regulationof drugs neglects everything only goal forgets all do drugs other priorities need more dopamine to get simple rewards ex showering bfast

• Behavioural tolerance: learned compensatory mechanisms to overcome the effect of the drug
  *Act sober even though they're not

Long-Term Effects

Drug zbusers usually prefor the same environment to protect drugs
180
160
140
Heart Rate
120
100
80
60
40
20
0
Familiar environment
Novel environment

Commonly Abused Illegal Drugs

• Psychoactive drugs: Substances that affect thinking, behavior, perception, and emotion.
  STOP
  May 27 2025

Stimulants

• Stimulants: Drugs that speed up the nervous system, typically enhancing wakefulness and alertness.

  • E.g., Cocaine, amphetamines, ecstasy.

  • Euphoria, increased energy, lowered inhibitions.

  • Increased dopamine, serotonin, norepinephrine.

  • Tolerance develops quickly, with a high risk of dependence.
    quickly high

• Physical deterioration:

  • Hygiene neglected.

  • Drug cocktail often includes ingredients such as hydrochloric acid and farm fertilizer.

• Cognitive deterioration:

  • Structural abnormalities in cells of the frontal lobe.

  • Stroop test measures 2personsability to ignore irrelevant stimuli.

Hallucinogens

• Hallucinogens: Produce perceptual distortions.

  • E.g., LSD, ketamine, DMT, psilocybin, salvia divinorum.

  • Experiences range from euphoria to fear, panic, and paranoia.

  • Increased serotonin, blocks glutamate receptors.

  • Low likelihood of dependence; tolerance develops slowly.
    mushroom serotonin glutamate

Opiates

• Opiates (narcotics): Drugs that reduce pain and induce extremely intense feelings of euphoria.

  • E.g., Morphine, heroin, fentanyl, oxycodone, oxycontin, codeine, opium.

  • Intense euphoria, pain relief (common in emergency rooms).

  • Stimulate endorphin receptors.

  • Tolerance develops very quickly; very high risk of dependence.
    Phlever endorphin receptors

Naloxone: Treating Overdoses

• Endorphins are endogenous pain-relieving neurotransmitters in the brain.

• Drugs that promote endorphin release (i.e., opioids) act as powerful pain relievers.

• Naloxone: Drug that blocks endorphin receptor sites to negate the effects of opiates and acts as direct antagonists.

Sedatives

• Sedatives ('downers'): Depress activity of the central nervous system.

  • E.g., Xanax, Valium.

  • Drowsiness, relaxation, sleep.

  • Increase GABA activity.

  • Tolerance develops quickly; high risk of dependence.
    *Barbiturates vs benzodiazepines

Alcohol

• Alcohol: Most commonly used drug.

  • Euphoria, relaxation, lowered inhibitions.

  • Initially stimulates GABA receptors (relaxation). Then stimulates opiate/endorphin and dopamine receptors (euphoria, feelings of reward).

  • Increased consumption leads to increased GABA:

    • Impaired balance and coordination.

    • Inhibition of the Frontal lobes.

Alcohol Myopia

• Narrow focus on cues related to a person’s current desires and impulses while ignoring everything else.

• Youth & people with low self-esteem are particularly susceptible.

Cannabis

• Marijuana: Produces a combination of hallucinogenic, stimulant, and relaxing (narcotic) effects; low likelihood of dependence.

• Anandamide agonist (THC compound in marijuana mimics anandamide and binds to cannabinoid receptors).

• Induces feelings of euphoria, relaxation, reduced pain, heightened and sometimes distorted sensory experiences, as well as stimulate appetite.
  *May decrease nausea and increase appetite
  Anandamide: Endogenous cannabinoid; a type of chemical that occurs naturally in the brain and peripheral nerves
  Cannabinoid Receptors: Receptors for endocannabinoids, endogenous compounds in the brain

Cannabis, Memory, and Cognition

• Impairs short-term and long-term memory, as well as executive functions (decision making, attentional control).

• Decreased activity in Frontal Lobe regions (memory retrieval).

• Cannabinoid receptors are found throughout the hippocampus and medial frontal lobes.

• Long-term use is associated with reduced grey and white matter in memory regions of temporal lobe.

Sedatives: barbiturates, benzodiazepines

Table 5.3 The Major Categories of Drugs
Drugs
Stimulants: caffeine, cocaine,
amphetamine, ecstasy
Hallucinogens: LSD, psilocybin,
DMT, ketamine
Opiates: heroin
Psychological Effects
Euphoria, increased energy,
lowered inhibitions
Major distortion of sensory
and perceptual experiences.
Fear, panic, paranoia
Intense euphoria, pain relief
Chemical Effects
Increase dopamine, serotonin,
norepinephrine activity
Increase serotonin activity;
block glutamate receptors
Stimulate endorphin receptors
Likelihood of
Tolerance Dependence
Develops quickly High
Develops slowly Very low
Develops quickly Very high
Sedatives: barbiturates,
benzodiazepines
Alcohol
Drowsiness, relaxation, sleep
Euphoria, relaxation, lowered
inhibitions
Increase GABA activity
Primarily facilitates GABA
activity; also stimulates
endorphin and dopamine
receptors
Develops quickly High
Develops gradually
Moderate to high
Cannabis
Euphoria, relaxation, distorted
sensory experiences, paranoia
Stimulates cannabinoid
receptors
Develops slowly Low