what is consciouness
Consciousness: “one’s subjective experience of the world, resulting from brain activity”
All conscious activity is related to brain activity
another definiton of consciousness
a state of awareness
a state of wakefulness
Consciousness & Attention
Consciousness results from brain activity.
Brain activity depends on attention.
what can we deduce
No conscious experience of stimuli that do not arouse attention
Inattentional blindness
Change blindness
Consciousness and Selective Attention
Not every experience is a conscious one
Only occurs in certain parts of certain kinds of nervous systems; only occurs some of the time
Dual-Process Model
Automatic Processing System vs. Controlled Processing System
Altered States of Consciousness
Sleep: altered state of consciousness that brain activity produces.
Still somewhat aware of your surroundings
Your brain still processes stimuli, but has a decreased response
Altered States of Consciousness
Coma: an extended period of unconsciousness
unconsciousness
Causes:
Head trauma
Stroke
Disease
Prognosis:
Either death or begins to recover in a few weeks
Altered States of Consciousness
Vegetative state: alternates between periods of sleep and moderate arousal
Is a person in a vegetative state aware of his/her surroundings during arousal periods?
No speech production
No responding to speech
No purposeful activity
Altered States of Consciousness
Minimally conscious state: a less severe, vegetative state
Is a person in a minimally conscious state aware of his/her surroundings during arousal periods?
Occasional, brief periods of purposeful activity
Limited speech production
Altered States of Consciousness
Brain death: no sign of brain activity or response to any stimulus
After 24 hours, physicians may remove life support
Circadian Rhythms
Endogenous circadian rhythms: a consistent rhythm of activity and sleep in a given 24-hour cycle
what else does the circadian rhytms affect
also affect other behaviors and variables, such as:
eating/drinking
urination
secretion of hormones
sensitivity to drugs
Disruptions in Circadian Rhythms
Jet lag: a disruption of circadian rhythms due to crossing time zones
what are some symtoms of disruptions in circadian rhythms
Symptoms:
Sleepiness during day
Sleeplessness during night
Impaired concentration
what are the two phases of jet lag
Phase-delay and phase-advance
Phase-delay
Phase-delay: staying awake later at night and awakening late the next morning
Phase-advance
Phase-advance: going to sleep earlier and awakening earlier
Retinohypothalamic path
a branch in the optic nerve that conveys light information to a region in the hypothalamus
Melatonin
A hormone that influences circadian rhythms
Located in pineal gland, just behind the thalamus
sleep deprivation
Recall concepts of selective attention
Sleep and its Functions
Rests muscles
Decrease metabolism (conserve energy)
Rebuild proteins in brain
Memory consolidation
Conservation of Energy
We conserve energy when we are most inefficient
Reliant on vision vs. olfaction
Body temperature drops
Muscle activity decreases
Enhancement of Memory
“The hippocampal replay”
Sleep improves memory
