Week 5 Flashcards
Describe Consciousness
Everything of which we are aware at any given time—our thoughts, feelings, sensations, and perceptions of the external environment
Consciousness relates to your awareness of:
- external events
- internal events
- self as the unique being having these experiences
- your thoughts about these experiences
William James describes consciousness as:
- A stream of thoughts and feelings
Freud said the unconsciousness is:
a part of conscious experience but not easily accessible or understandable
Where is the consciousness in the brain?
- no single area of the brain has been identified
- likely to be a neural network
- possibly areas of the brain involved with attentional processes
Types of Conscious Experience
- Focused awareness
- Drifting Consciousness (daydreaming)
- Divided Consciousness
- Automation
- Sleep and dreaming
- Altered states of consciousness
How do we measure consciousness
- historically this has been done by EEG
- records activity in the cortex with a series of brain wave tracings
Measuring consciousness: Beta Waves
- Conscious Mind
- Frequency 12-30Hz
- normal waking state
- alertness, concentraion, focus
- cognition engaged
- 5 senses activating
Measuring consciousness:
Alpha Waves
- Gateway to the subconscious mind
- Frequency 7.5-30Hz
- Deep relaxation and light meditation
- usually eyes are closed
- visualisation, creativity and super learning
Measuring consciousness:
Theta Waves
- Subconscious Mind
- Theta Waves - 4-705Hz
- Usually light sleep including REM Dream state
- deep meditation, intuition, memory and vivid visual imagery
Measuring consciousness:
Delta Waves
- Unconscious or Supra-conscious Mind
- Frequency up to 4HZ
- Usually deep sleep
- dreamless state
- Transcendental Meditation state
- Automatic self-healing, immune system function.
Is there a “third factor” in measuring consciousness
- signals may come from the subcortical area of the brain - changes in brain wave activity may lead to changes in consciousness
Why do we sleep?
- Protective function - Energy conservation - restore bodily processes - consolidate newly learned information into lasting memories - may bolster immune system
Circadian Rhythms
- Run in 24 hour biological cycles - regulate sleep, temperature, blood pressure and hormone release - Alertness - Short Term Memory - Attention - Memory Consolidation - Decision Making
Circadian Rhythms: Physiological pathway of the biological clock
- light level decrease
- Retina
- Suprachiasmtic nucleus of the hypothyalamus
- Pineal gland
- Secretion of melatonin hormone
- BUT Rhythms remain even when cues to light and dark are removed
Melatonin
A hormone associated with regulation of the biological clock
24 Hour Circadian Rhythm
Within each 24 hour period the regular fluctuation from high to low points of certain bodily functions and behaviours
Suprachiasmatic Nucleus (SCN)
- A pair of tiny structures in the hypothalamus that control the timing of circadian rhythms - directs the biological clock by secretion or suppression of melatonin
24 Hour Circadian Rhythm Diagram
Alertness and Body Temperature
- Natural body temperature falls during sleep
- body temp is highest at the end of the day
- Does this trigger release of Melatonin?
What interferes with Circadian Rythms?
- Shift Work
- Jet lag -
- light cues and bodily rhytms are desinchronsied
- flying East to West or West to East
Interventions
* Melatonin
* Bright lights
* Starting gradually later
* rotating shift work is difficult
What do sleep labs study?
Electroencephalograph - Brain Activity
Electromyograph - Muscle Activity
Electrooculograph - Eye
Heart rate, breathing rate and temperature
Stages of sleep
Stage 1: Brief, transitional (10-12 minutes)
- gradual, no obvious transition point
- Alpha to theta
- considered to be asleep at theta
Stage 2: light sleep (10-25 minutes)
- respiration, heart rate, muscle tension, body temperature all go down
- mixed activity: burst of high frequency “sleep spindles”
Stage 3 & 4: slow-wave sleep (20-40 minutes)
- lower frequency, higher amplitude delta waves
Stage 5: REM
- EEG similar to wakefulness
- irregular pulse & breathing, loss of muscle tone, vivid dreaming, hard to waken
What are Sleep Spindles
sudden bursts of oscillatory brain activity generated in the reticular nucleus of the thalamus that occur during stage 2 of light sleep.
Brain wave patterns during wakefuness and sleep
REM Sleep Stage
- Rapid eye movements
- Paralysis of large muscles
- Fast and irregular heart and respiration rates
- Increased brain wave activity
- Vivid dreams
Posture Positions Diagram
Physiological recordings of Sleep stages
- Usually 4-5 cycles of REM & NREM sleep per night
- Sleep cycles last around 90-110 minutes
- More deep sleep earlier in the night
- REM sleep increase in the 2 cycles before narural awakening
- Infants have greater REM sleep than adults (50%vs20%)
- Stage 3&4 decreses in adults while Stage 1 increases
Change in sleep needs
The amount of REM sleep and total sleep decreases as we age
Problems of sleep deprivation
Sleep deprivation may lead to suppression of neurological activity in the temporal lobes
Sleep Deprivation risks:
- Sleepinesss factors in about 20% of traffic accidents
- Sleepiness contributes to accidents in the workplace
- Both total and type of sleep affect funcitioning.
- Linked to obesity, diabetes, hypertension and coronary diseas
Types of Sleep Disorders
- Narcolepsy
- Sleep Apnea
- Insomnia
Narcolepsy
- Incurable
- excessive daytime sleepiness
- uncontrollable attacks of REM sleep during waking hours
Sleep Apnea
- Periods during sleep when breathing stops
- must awaken briefly in order to breath
Insomnia
- Difficulty falling asleep or staying asleep
- waking too early
- light, restless, poor qualtiy sleep
Sleep Terrors
- Happen during Stage 4 sleep
- Sleeper awakens in panicked state with racing heart
- Typically resolves quickly and person falls back to sleep
Nightmares
- Frightening dreams occur during REM sleep
- Usually remembered in vivid detail
Sleep Problems
- Nightmares
- Night terrors
- Sleep talking
- Somnambulism
Somnambulism
- Sleepwalking
- 3% of adults and 15% of children
- Slow wave sleep – stages 3 & 4
- Sleeper not fully conscious
Sleep Talking
- Occurs in any stage of sleep
- Mumbled nonsensical words and phrases
Dreams
- Occur during REM sleep
- Vivid imagery
- Story like quality often bizarre
- Seem real to the dreamer
- Sometimes occurs in non-REM sleep but have less vivid quality and are less frequent
Why do we dream? – Freudian Theory
- Emotions in buried in the unconscious
- Wish fulfilment
- Manifest content
- Latent content
Research has not provided much support for this
Why do we dream? Problem Solving theory (Cartwright)
- Dreams offer a chance to work through emotional issues
- Reflect on emotions and regulate emotional tone
- Improve mood when awake
- Engage in creative thinking because dreams are not restricted by logic
Why do we dream?
Activation-Synthesis Model (Hobson et al.)
- Cerebral Cortex trying to make sense of electrical activity during sleep
- Pieces a story together based on memories and emotions
- By-products of neural activation in Beta Brainwaves associate with wakefulness
- This theory downplays the role of emotions
- Doesn’t explain dreams outside of REM Sleep
- Damage to Pons does not eliminate dreams
Psychoactive Drugs
Chemical substances that modify mental, emotional or behavioural functioning
Narcotics (opiates)
- Drugs derived from opium capable of relieving pain
- Morphine, Heroin, Oxycodone
- Desired effects: Euphoria relaxation, anxiety reduction and pain relief
Sedatives
- Sleep inducing drugs decrease CNS activation and behavioural activity
- Barbiturates like Secanol
- Non-Barbiturates like Quaaludes
- Desired Effects: Euphoria, relaxation, anxiety reduction, reduced inhibitions
Commonly Abused Drugs – Stimulants
- Drugs that increase CNS Activation and behavioural activity
- Amphetimines, Cocaine
- Desired Effects: Elation, excitement, increased alertness, increased energy, reduced fatigue
- Halucinations
Commonly Abused Drugs – Hallucinogens
- Very divers group
- Effects on emotional functioning, distortions in sensory and perceptual experience
- LSD, Mescaline, Psilocybin
- Increased sensory awareness, euphoria, altered perceptions, hallucinations, insightful experiences
Commonly Abused Drugs – Cannabis
- Derived from Hemp
- Active ingredient is THC
- Mild Euphoria, relaxation, altered perceptions, enhanced awareness
Commonly Abused Drugs – Alcohol
- Beverages containing ethyl alcohol
- Mild euphoria, relaxation, anxiety reduction, reduced inhibitions
Drug Tolerance
- A progressive decrease in a persons responsiveness to a drug due to repeated use
Types of drug dependence - Physical
Physical dependence is coupled with unpleasant withdrawal sysmptoms
Types of drug dependence – Psychological
Cravings and urges for the drug and its pleasurable effects
Three reasons people become addicted to substances
- Sensitisation of pleasure and reward system in the brain
- Reduction of negative feelings
- Classical Conditioning
Sensitisation of pleasure and reward system caused by drug abuse
- All addictive drugs stimulate dopamine
- They mediate pleasure and reward
- Drugs permanently alter the brains dopamine response by causing sensitisation
Reduction of negative feelings caused by drug abuse
The more drugs consumed the stronger the feeling of withdrawal
Classical Conditioning in drug abuse
- Stimuli that are present when substance is consumed become associated with effects
- Cravings occur when presented with the stimuli
Hypnosis
- Systematic procedure which requires one to narrow our focus of attention
- Heightened state of suggestibility
- Deep relaxation
- Power of suggestion can influence thoughts, feelings, sensations, perception & behaviour
Dissociation – Altered State of Consciousness
Splitting off of mental processes into two separate, simultaneous streams of awareness
Characteristics of Hypnotisable people
- Well-developed fantasy life
- Vivid sense of imagination
- Tendency to be forgetful
- Positive attitude to hypnosis
What is meditation
- Practise that trains attention to heighten awareness
- Gives better control over mental processes
Two main styles of meditation
- Focused Attention
- Open Monitoring
Focused Attention Meditation
- Attention concentrated on a specific object, image or sound
- Awareness of bodily sensation
- Clear the mind of its clutter
Open Monitoring
- Attention directed to the moment to moment experience
- non judgemental, non reactive observation of the flow of sensations, thoughts and feelings
- become detached
Effects of Meditation
Decrease in:
- heart rate,
- respiration rate
- blood pressure
- pain perception
- stress & anxiety
- depression
Increase in:
- Brain activity
- concentration
- awareness
- self esteem
- emotional resilience
- empathy
An EEG in this state with show prominent theta and alha rhythm patterns
CT Scans on Tibetan Buddhist Meditation show
- High activity in the pre frontal cortex
- low activity in parietal lobe that processes body’s location in space
- may explain some of the transcendent experiences reported by many meditators
