conciousness
a person’s subjective awareness; thoughts, perception, experience, self-awareness
Difficult to define and study due to subjectivity
biological rhythms of consciousness
different rhythms have different times
Circadian rhythms – internally driven daily cycles; last 24 hours
o Sleep and wakefulness – regulate psychological and behavioural processes at different times of the day
circadian rhythms
Effected by:
Bidirectional influences – rarely only body influencing, usually external cues
set of objective measurements used to examine physiological variables during sleep (respiration, body temp, muscle activity)
measures excitatory and inhibitory activity in groups of neurons in the brain
Waveform – represents amount of activity in a particular area; frequency and amplitude
Examining populations of neurons – not just one
Types of waves & stages of sleep:
Awake:
1. Beta waves – high frequency (15-30Hz); low amplitude
o Wakefulness – alert and awake; focussed on something
Sleeping – 4 stages; constantly moving through 4 stages throughout the night
1. Theta waves (stage 1-2) – just fallen asleep; lower frequency (4-8Hz); higher amplitude
o Breathing, BP, and HR decrease
o Still sensitive to external stimuli
a) Stage 2 – may be important in memory formation and maintaining sleep
- Sleep spindles – clusters of high-frequency, low amp waves; wakeful patterns
- K complexes – clusters of large amp waves
2 theories of sleep
2 complimentary hypotheses about why we sleep (do not contradict one another)
sleep deprivation vs displacement
Deprivation – occurs when an individual cannot or does not sleep; external and internal factors
Displacement – when individual is prevented from sleeping at their normal time; same amount of sleep may occur but at different times
2 approaches to dreaming
3 sleep disorders
3 movement disturbance disorders
sleep apnea
characterized by an obstruction of air flow; temporarily causes inability to breathe during sleep
Causes snoring and non-restful sleep (difficulty entering deep sleep)
Treatments
o Dental devices holding mouth in specific condition
o Weight loss
o CPAP machine – continuous positive air pressure
Can be caused by brain’s inability in regulate breathing
o Medulla – responsible for controlling chest muscles when breathing
narcolepsy
extreme daytime sleepiness and sleep attacks
Can last few seconds or minutes – enter into REM immediately
Associated with intense emotion – laughing can cause you to fall asleep
- Emotional parts of brain are very active during or shortly before sleep attack
Treated with medication
Causes
hypnosis
procedure for inducing a heightened state of suggestibility (not a trance/magic/control you)
types of suggestions
a. ideomotor – perform a specific action
b. challenge – do not perform a specific action
c. cognitive perceptual – remembering or forgetting specific info; experiencing altered perception
- ex. reducing pain sensation
- Freud – used to recall forgotten memories from childhood
2 theories
1. Dissociation theory – hypnosis is a unique state in which consciousness is divided into 2 parts
2 parts
a. Low level system – perception and mvmt
o Automatic system of mvmt
b. Executive system – evaluates and monitors these behaviours
o Decision making and manual process
o Hypnosis cuts out this process – reduced activity in anterior cingulate cortex (frontal lobe)
Suggestion -> executive process (removed) -> perception and mvmt
Often paired with other psychotherapies – cognitive hypnotherapy
Cognitive hypnosis = cognitive behavioural theory (CBT) + hypnosis
a. Used to treat: Depression, anxiety, eating disorders, hot flashes of cancer survivors, IBS, smoking cessation
b. Pain – 60-75% report relief (more effective with acute; not chronic)
• Used in addition to medication
Connection involving the anterior cingulate gyrus – differ between hypnotizable people and non
o Anterior cingulate gyrus – involved in perception of pain
o Gyrus – out folding portion of brain (sulcus is between gyrus’)
mind wandering
unintentional redirection of attention from the current task to an unrelated thought
Associated with poor memory retention in university
Active networks in mind wandering (Network – light up and shut down together)
1. Default mode network – network of brain regions that most active when an individual is awake but not responding to external stimuli
Includes:
• Medial prefrontal cortex
• Posterior cingulate gyrus
• Medial and lateral regions of the parietal lobe
disorders of consciousness
lack full consciousness; can be due to trauma; unable to fully experience sensation and perception
Brainstem – highly implicated in varying levels of consciousness
o Pons – wakefulness & alertness
o Medulla – life maintaining; breathing and HR
6 levels of consciouness
ways to access consciousness
Testing reflexes
ex. Pupil response related to brainstem damage
o Pupil dilation/constriction – tests comatose state with flashlight; no response indicates damage to brainstem
Glasgow coma scale
Brain imaging
Glasgow coma scale
score on scale indicates level of consciousness
Brain imaging to access consciousness
case studies
can see brain activity even if patient is nonresponsive
Case study 1
- 23 yr old patient in vegetative state (minimal to no consciousness)
- Mental imagery task – imagine playing tennis or imaging the rooms in their house
- Scan brain in response to these requests
• Tennis – activity in brain areas related to movement
• House – activity spatial network (parahippocampal gyrus and parietal lobe)
Confirms a certain level of consciousness & brain activity
Case study 2
Brain activity during a mental imagery task used as a yes/no response
• Yes – imagine playing tennis
• No – imagine rooms in house
Use this technique to ask participant questions (ex. are you in pain
drug
change in psychological experience related to drug use
Short term physical and psychological side effects of drug use
Alters amount of nt released into synapse
a. Agonist – causes more; amplifies
- Direct – binds to receptor; replaces nt
- Indirect – prevent reuptake; causes increased activity of nt
b. Antagonist – cancels out message of nt
- Block receptor that the nt would normally bind to
Dopamine – most often influenced by drugs; reward and pleasure feelings
Setting
o Novel setting – creates more powerful effects (Overdose often occurs because body is not prepared)
o Place associated with drug use – body prepares for metabolization of drug
Previous experience with drug
o First use – body was unprepared and effects were not fully felt
o Subsequent uses – more potent; body learns drug and how to react; pathways are put into motion quicker and easier (Curve eventually dies up – we build up tolerance)
Expectations
o Know what to expect/expect stronger high – more likely to receive high
Long-term physical and psych effects
Tolerance – repeated use of drug results in need for higher dose to obtain intended effect
Dependency
a. Physical – need to ward off unpleasant physical withdrawal symptoms (nausea, increased HR, increased BP, hallucinations and delirium)
- Body relies on drug to produce necessary amount – no longer makes enough internally
b. Psych – emotional need for drugs without any underlying physical dependence
- Can occur with drugs not considered classically addictive
- Ex. weed & alcohol – assists with anxiety and is associated with fun social setting
Biopsychosocial model – factors and effects
o Bio – specific gene related to drug taking behaviour and dependence
o Psych – cognitive factors (memory cues), emotional relationship
o Sociocultural – family attitudes, religion, social isolation (Addiction is more common in people with small social circles)
Psychoactive drugs & types
affect thinking, behaviour, perception, emotion
Stimulants
speeds up activity of NS; enhance wakefulness and alertness; high likelihood of dependence; tolerance develops quickly
Neurotransmitters – increased dopamine, serotonin, norepinephrine