• Consciousness
– The combination of a person’s subjective experience of the external world and the
person’s mental activity; this combination results from brain activity
• When we are fully conscious, we are very alert
– Have you ever begun
daydreaming while reading
and then realized you had no
idea what you had just read?
You were going through the
motions of reading, but you
were essentially unconscious of what you read
• Subliminal perception
– The processing of information by sensory systems without a person’s conscious
awareness
• Though material presented subliminally can influence how people process
information, it has little or no effect on complex thinking and actions
• Global workspace model
• The key idea of the global workspace model is that no single area of the brain is
responsible for general “awareness”
– A condition in which the corpus callosum is surgically cut and, as a result, the two
hemispheres of the brain do not receive information directly from each other
• Just as the brain has been split in two, so has the conscious mind
• Provides many important insights into the basic organization and specialized
functions of each brain hemisphere
– Split brain experiment
• The hemispheres normally work together
• By contrast, in split-brain patients, the hemispheres are separated, so
communication between the hemispheres cannot take place
• This split allows psychologists to separately test the functions of the two
hemispheres
– The sense-constructing activity in the left hemisphere is called the interpreter
, • This term means that the left hemisphere is interprets what the right
hemisphere has done
• People commonly think that the brain shuts itself down during sleep, but in fact, many brain
regions are more active when we are asleep than when we are awake
• Circadian rhythms
– The regulation of biological cycles into regular, daily patterns
• Changes in light register in the suprachiasmatic nucleus of the hypothalamus,
which triggers the production of melatonin
• Melatonin
– A hormone released in the brain that aids the regulation of circadian rhythms, as bright
light reduces production and darkness increases production
– The electroencephalograph (EEG) records electrical brain activity during different stages
of sleep
• Four stages of sleep
– Stage 1 begins when sleepers drift off, shown on the EEG as theta waves
– In Stage 2 breathing becomes more regular, and sleepers become less sensitive to
external stimulation.
• The EEG shows bursts of brain activity called K-complexes
– Slow-wave sleep: Stages 3 and 4 of deep sleep, when EEGs reveal large, regular delta
waves and sleepers are hard to awaken
– REM sleep: EEGs show beta wave activity associated with an awake, alert mind, and
sleepers experience rapid eye movements, dreaming, and paralysis of motor systems
• The repeating sleep cycle
– Over the course of a typical night, we cycle through the stages of sleep about five times
– Products of consciousness during sleep in which a person confuses images and fantasies
with reality
• On average people spend 6 years of their lives dreaming
• REM dreams and non-REM dreams
– REM dreams are more likely to be bizarre
– Non-REM dreams feel normal, like everyday life
• What do dreams mean?
– The combination of a person’s subjective experience of the external world and the
person’s mental activity; this combination results from brain activity
• When we are fully conscious, we are very alert
– Have you ever begun
daydreaming while reading
and then realized you had no
idea what you had just read?
You were going through the
motions of reading, but you
were essentially unconscious of what you read
• Subliminal perception
– The processing of information by sensory systems without a person’s conscious
awareness
• Though material presented subliminally can influence how people process
information, it has little or no effect on complex thinking and actions
• Global workspace model
• The key idea of the global workspace model is that no single area of the brain is
responsible for general “awareness”
– A condition in which the corpus callosum is surgically cut and, as a result, the two
hemispheres of the brain do not receive information directly from each other
• Just as the brain has been split in two, so has the conscious mind
• Provides many important insights into the basic organization and specialized
functions of each brain hemisphere
– Split brain experiment
• The hemispheres normally work together
• By contrast, in split-brain patients, the hemispheres are separated, so
communication between the hemispheres cannot take place
• This split allows psychologists to separately test the functions of the two
hemispheres
– The sense-constructing activity in the left hemisphere is called the interpreter
, • This term means that the left hemisphere is interprets what the right
hemisphere has done
• People commonly think that the brain shuts itself down during sleep, but in fact, many brain
regions are more active when we are asleep than when we are awake
• Circadian rhythms
– The regulation of biological cycles into regular, daily patterns
• Changes in light register in the suprachiasmatic nucleus of the hypothalamus,
which triggers the production of melatonin
• Melatonin
– A hormone released in the brain that aids the regulation of circadian rhythms, as bright
light reduces production and darkness increases production
– The electroencephalograph (EEG) records electrical brain activity during different stages
of sleep
• Four stages of sleep
– Stage 1 begins when sleepers drift off, shown on the EEG as theta waves
– In Stage 2 breathing becomes more regular, and sleepers become less sensitive to
external stimulation.
• The EEG shows bursts of brain activity called K-complexes
– Slow-wave sleep: Stages 3 and 4 of deep sleep, when EEGs reveal large, regular delta
waves and sleepers are hard to awaken
– REM sleep: EEGs show beta wave activity associated with an awake, alert mind, and
sleepers experience rapid eye movements, dreaming, and paralysis of motor systems
• The repeating sleep cycle
– Over the course of a typical night, we cycle through the stages of sleep about five times
– Products of consciousness during sleep in which a person confuses images and fantasies
with reality
• On average people spend 6 years of their lives dreaming
• REM dreams and non-REM dreams
– REM dreams are more likely to be bizarre
– Non-REM dreams feel normal, like everyday life
• What do dreams mean?
