5 Flashcards
Consciousness
General state of mind
Awake v Asleep
Aware v Non-aware of information and actions
A state of awareness of internal mental events and the external environment
Contents of consciousness
Thoughts, feelings, perceptions, images, desires, sense of self
Structuralism conscious
Studied contents of the the conscious mind in structured blocks
Wundt, Tichner
Functionalism conscious
Consciousness as a constantly moving stream of thoughts, feeling and emotions
William James 1890
Psychodynamic conscious
3 Systems:
Conscious: mental events we’re aware of
Preconscious: mental events that can be brought to awareness
Unconscious: mental events that are inaccessible, events that are actively kept out of awareness (suppressed traumas)
Freud - iceberg metaphor
Cognitive conscious
Dual process model
Outside of awareness: priming, implicit memory, procedural knowledge
Unconscious: fast and efficient, supportive and adaptive responses to external stimuli, operate simultaneously, can influence behaviour
Conscious: slower, deliberate, more effortful
Functions of un/conscious
Monitoring: self, environment
Regulating: change
Distributed throughout the hindbrain and midbrain, important for sleep and arousal
Reticular formation damage
Can lead to coma.
Prefrontal cortex
Key for conscious control of information processing
Variations of consciousness
- Circadian rhythms
- Sleep
- Meditation
- Hypnosis
- Religious experience
- Mind-altering drugs
Circadian rhythms
Biological process evolved around daily cycle of light and dark (wakefulness, sleep, tired)
Internal biological clock, 18-24 hour cycle involved in arousal level, metabolism, heart rate, body temperature
Peak in the afternoon, during the day, trough during sleep
Circadian rhythms effected by
Sunlight - mismatch (jetlag): fatigue, unusual sleep cycle, change in hunger patterns
Effected by direction of travel and amount of timezones passed
Chronotypes
Morning (lark): early to bed and early to rise
Evening (owl): late to bed and late to rise
The heart is stronger and better able to withstand surgery in the afternoon rather than the morning (can differ due to chronotype).
Sleep characteristics
Minimal movement
Requires high degree of stimuli for arousal (loud noises, noises out of the ordinary)
Functions of sleep
Memory consolidation
Energy conservation
Preservation from predators
Restoring bodily functions
Deprivation of sleep
Can alter immune function
Lead to hallucinations and perception disorders
Sleep research
Electroencephalography (EEG) - measures the brains electrical activity
Electromyography (EMG) - measures muscle activity
Electrooculography (EOG) - measures eye movements
NREM
Non-REM
- stages 1,2,3 and 4
- help recovery from daily fatigue
- no rapid eye movements
- 75-80% of total sleep time
REM
Rapid eye movement
- associated with dreaming
- very light sleep
- 20-25% of total sleep time
- body very still
Sleep cycles
Each cycle (NREM and REM) is approximately 90-100 minutes.
4 stages of NREM (80-90 min)
REM (10 min)
Moving through cycles, NREM stages decrease and REM increases, final cycle of REM is approximately 60 minutes
How many cycles in a night?
4-6 cycles
When is the deepest sleep?
The deepest sleep occurs at the beginning of the night when there are longer NREM stages
EEG patterns while awake
Waves are fast (14 cycles per second) however low voltage (beta waves). When drowsy, alpha waves dominate which are slower (8-12 cycles).
Stages of NREM
Stage 1: Theta waves, 3-7 cycles per second (CPS). Slow eye movement, muscles relax and blood pressure drops
Stage 2: Sleep spindles (low amplitude activity bursts), 12-14 CPS, K complex (high amplitude waves)
Stage 3: appearance of delta waves
Stage 4: deep state of relaxed sleep, large/slow delta waves appear (stage 3) and predominate (stage 4). Low frequency waves 0.5 to 2 CPS, high amplitude with decreased breathing, slowed heart rate, low body temp and relaxed muscles.
- if woken during these stages we feel very groggy and disorientated
REM sleep stage
Rapid eye movement occurs at periodic intervals.
Brain pattern similar to being awake and body activity almost as awake (blood pressure, respiration) due to dreaming in which the brain is active.
Motor paralysis, dreaming, low voltage but high frequency waves occur
Psychodynamic perspective of dreaming
A window into the unconscious. Latent content (meaning) can be inferred from manifest content (dreams).
Cognitive perspective of dreaming
Dreams are constructed from the daily issues of the dreamer
Biological perspective on dreaming
Dreams represent the cortex attempting to interpret random neural firing when there is no external stimuli OR the consolidation of newly learnt material.
Why do we sleep?
Conservation and Restoration
REM is necessary for development of vision, motor systems and sensory systems as infant and needed for learning and memory in adults
Conservation theory
NREM sleep has evolved to conserve an organisms energy when not searching for food/mates, etc.
Restorative theory
The brain works hard an sustains damage while awake, NREM provides an opportunity for the brain to interrupt damage and repair cells
Narcolepsy
A sleep disorder, an irresistible compulsion to sleep during the day, often accompanied by cataplexy (muscle weakness and loss of control resulting in unconsciousness)
Affects 1 in 2000 people and runs in families - possibly a genetic basis
Sufferers immediately enter REM
Negative social and psychological impact on sufferers
CNS disorder
Due to the loss of cells in the hypothalamus, emotional responses tend to bring on an episode
Stimulants can help slightly
Sleep apnea (apnoea)
Upper respiratory disorder where individuals stop breathing while asleep.
The blood oxygen level drops which activates the sympathetic system with emergency hormones waking the person up.
Can occur hundreds of times a night, affecting 2% of adults however frequent with premature infants
Somnambulism
Sleep walking
Affects 7% of children and 2% of adults
Associated with stages 3 & 4 of NREM, first 1/3 of the night
A failure of muscle paralysis
Nightmares
Occur during REM
Relatively infrequent in adults however more frequent in children. Can be frequent in adults who have experienced a traumatic event (rape, war)
Night Terrors
Associated with NREM
Intense autonomic arousal and feelings of panic
More common in children, very rare in adults
Not indicative of emotional disturbance
Psychoactive drugs
Chemicals that affect mental processes and behaviour by changing conscious awareness of reality
Affect neural communication by blocking or stimulating activity at synapses
Continued use leads to a tolerance, requiring more to produce the same effect
Physiological dependence
Occurs when the body becomes adjusted and dependent on a drug. Tolerance and dependence create an addiction
Classes of drugs
- Depressants
- Stimulants
- Hallucinogens
- Opiates
Depressants
Ex: barbiturates, rohypnol, GHB, alcohol, benzodiazepines (anti-anxiety agents)
Slow down mental and physical activity by inhibiting neural transmission to CNS
Facilitate transmission at GABA synapses (inhibitory)
Alcohol
Alcohol stimulates the release of dopamine and enhances GABA activity, inhibiting motor control.
At small amounts, people are more relaxed and have quicker reactions however large amounts overtax the CNS
Impacts occipital lobe, affecting vision especially at night
Neg impacts thinking, problem solving, judgment, emotional stability and loss of motor coordination
Prolonged heavy drinking leads to a physical dependence, tolerance and addiction, brain damage - cognitive impairment
Stimulants
Caffeine, nicotine, cocaine, amphetamines
Increase neurotransmitter levels (norepinephrine, serotonin and dopamine)
Effects: maintain arousal levels (greater energy/ hyper alertness), increased self-confidence, mood alteration approaching euphoria, paranoid delusions (belief others may harm them)
Can lead to long term change in neurotransmitters
Cocaine
Increases activity of norepinephrine (NE) and dopamine
Produces high arousal
Chronic use depletes NE and dopamine which can lead to chronic depression, diminished judgement, inflated sense of own abilities, paranoia, anxiety and panic
Amphetamines
Molecular structure similar to dopamine and NE, mimicking neurotransmitters
Produces hyper arousal, feeling of speeding, euphoria and increased motor activity
Can induce psychosis, death (OD) and ill health chronic users
Hallucinogens
Psychedelics
Produce the most drastic changes in consciousness, alter perceptions of external environment and inner awareness
Create hallucinations, vivid perceptions that occur in absence of objective stimulation (seeing/ hearing things that aren’t there)
Can lead to loss of boundary between self and non-self
LSD
Binds to serotonin receptors which can lead to prolonged activation
These types of drugs (hallucinogens) have long lasting effects
Opiates (Narcotics)
Morphine and heroin bind to same receptor sites as endorphins (naturally occurring substances that affect mood, pain and pleasure [joggers high])
Suppress physical sensation and response to stimulation
Withdrawal: harsh physical symptoms, confusion, strong craving for drug
Heroin
Intravenous injections lead to initial rush of pleasure (euphoria)
Artificial stimulation of endogenous opiate system
Long term: Dependence, depression, cognitive impairment
Theories
Allow a description to turn into an explanation
Positive emission tomography
A PET scan has a patient take radio-active glucose with equipment monitoring where it appears in the brain
