PSY 201 Lecture Notes - Lecture 3: Sleepwalking, Polypore, Frontal Lobe
1 Jun 2018
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4.1 What is Consciousness?
Consciousness is a Subjective Experience
• Consciousness: one's moment-by-moment subjective experience, resulting from at least
some aspects of brain activity
o Contents of Consciousness
• Perceptions of the world around us
• Memories of past events
• Intentions concerning future actions
• Imagery of some events that could occur
o Levels of Consciousness
• Levels of arousal (unconscious, sleeping, conscious)
• Potential contents can be subliminal (falling below the threshold)
Consciousness Awareness Involves Attention
• The mind is a continuous stream of thought
• Attention: the manner in which the brain manages its limited information processing
capacities in order to preform a task, through the ability to increase awareness of a subset
of stimuli at a cost to others
o Stimuli OR responses, memories, ideas
o Benefits of attended information:
• Processed more accurately
• Processed more quickly
o Costs of unattended information
• Processed less accurately
• Processed more slowly
• Automatic tasks: Routine tasks such as driving, walking, understanding words on a page.
Tasks that are so well-learned that we do them with little attention
• Controlled tasks: slower than automatic processing, and helps people perform in complex
situations.
o Requires more attention
• Shadowing (cherry): participant wears headphones that deliver one message to one ear
and a different one to the other
SELECTIVE ATTENTION
• Donald Broadbent:
o People have a limited capacity for sensory information
o They let in only the most important info
• Some stimuli demand attention
• Selective Attention:
o Selective Listening Experiments: the participant receives different audio messaged
in each ear but is required to repeat (shadow) only one
• Cannot report the content of the unattended input
• Cannot report oddities (repeated word) in the unattended input
• Can report change in pitch or disappearance of unattended input
▪ Suggests low-level sensory processing is completed
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• Can report the occurrences of the subjects own name in the unattended input
▪ Suggests some amount of semantic processing is completed
CHANGE BLINDNESS
• Change blindness: failure to notice large changes in the environment, when there is so
sudden transient in the image to draw our attention to change
o We don’t fully process all of the rich details in the scenes that we experience
• Simon and Levin's Study:
o Older people were likely not to notice a change
o We can attend to a limited amount of info
LAPTOPS IN THE CLASSROOM
• Students feel like they aren't missing anything when they are multitasking
Unconscious Processing Influences Behavior
• Galton proposed that mental activity below the level of consciousness can influence
behavior
• Freudian slip: when an unconscious though is suddenly expressed at an inappropriate time
or in an inappropriate social context
• Subliminal perception: when a stimuli gets processed by sensory systems but do not reach
consciousness
o Have minimal effects on purchasing behavior
Brain Activity Gives Rise to Consciousness
• Brain imaging can reveal what a person is looking at
• Seeing a house activates different areas of the brain compared to activity triggered by
seeing a face
THE GLOBALWORKSPACE MODEL
• Global workspace model: consciousness arises as a function of which brain circuits are
active
o Experience your brain regions' output as conscious awareness
o No single area of the brain is responsible for general awareness
• Different areas deal with different types of info
• Prefrontal cortex: I understand plans
• Frontal Motor Cortex: I'm all about movement
• Parietal lobe: I'm aware of space
• Temporal lobe: I hear things
• Occipital lobe: I see things
CHANGES IN CONSCIOUSNESS FOLLOWING BRAIN INJURY
• Surviving is the first step towards recovery
• Comas allow the brain to rest
o Some regain consciousness within a few days other a few weeks
o Do not respond to their surroundings
o Can process info
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• Persistent vegetative state: in a coma longer than a month
o Normal brain activity does not occur
o May be brain dead
o The longer it lasts the less likely the person is to recover consciousness
• Minimally conscious state: people with brain injuries are able to make some deliberate
movements
o Following an object with their eyes
o Try to communicate
• Brain death: irreversible loss of brain function
o No brain activity
4.2 What is Sleep?
• Many brain regions are more active during sleep than during wakefulness
• Complex thinking occurs
o Working on difficult problems
• Circadian rhythms: processes that are regulated into patterns
o Body temp, hormone levels, and sleep/wake cycles
o Internal clock
o Influenced by light and dark
• Suprachiasmatic nucleus: small region of the hypothalamus where light is detected and
sends signals to the pineal gland
• Pineal gland: secretes melatonin
o Melatonin: hormone that affects various receptors through the bloodstream
• Suppressed by bright light
• Released by darkness
• Helps people fall asleep
• Sleepless gene: regulates a protein that reduces action potentials in the brain, decreasing
the amount of needed sleep.
• Sleep is important for memory and good health
Sleep Is an Altered State of Consciousness
• When you sleep, your conscious experience of the world is largely turned off
• Remain aware of your surroundings and analyzing potential threats
• Still in control of body movements and maximizing comfort
• Stages of Sleep:
o Alert wakefulness: Beta Waves
o Just before sleep: Alpha waves
o Stage 1: Theta Waves
o Stage 2: sleep spindle and k-complex
o Stage 3/4: Slow-wave sleep and Delta waves
o REM: Beta Waves
• Beta waves: short, frequent, irregular brain signals
• Alpha waves: when attention is focused or are relaxing exhibiting activity that is slow and
more regular
STAGES OF SLEEP
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find more resources at oneclass.com
Document Summary
Consciousness is a subjective experience: consciousness: one"s moment-by-moment subjective experience, resulting from at least some aspects of brain activity, contents of consciousness, perceptions of the world around us, memories of past events. Imagery of some events that could occur: levels of consciousness, levels of arousal (unconscious, sleeping, conscious, potential contents can be subliminal (falling below the threshold) Change blindness: simon and levin"s study, older people were likely not to notice a change, we can attend to a limited amount of info, students feel like they aren"t missing anything when they are multitasking. 4. 2 what is sleep: many brain regions are more active during sleep than during wakefulness, complex thinking occurs, working on difficult problems, circadian rhythms: processes that are regulated into patterns, body temp, hormone levels, and sleep/wake cycles. Insomnia: mental health and ability to function are compromised by the inability to sleep. People dream while sleeping: dreams: products of an altered state of consciousness.
