Consciousness Flashcards
What did Descartes proposed regarding the mind and brain?
proposed that mind and brain are separate entities, thought that the mind was controlled by the pineal gland
Define subjective experience
continuous flow of thoughts, feelings, and perceptions that one is privy to throughout life
Define intentionality
the idea that consciousness includes mental states that are about something (consciousness = entity that includes intentionality)
Searle compared the mind to computers; how6
Computers organize info w/out intentionality (purpose, meaning, understanding)
Describe the Chinese room experiment and what it teaches us about the mind
You + computer in a room, Chinese instructions slipped under the door; with the computer you are able to respond in Chinese, but you have no idea of what it means, just like the computer can follow instructions without understanding the output it produces
> Illustrates the concept of intentionality
What are the 2 problems of consciousness?
Easy problem: explanation of mental phenomena that are testable by standard methods of science
• Ex: recognition of stimuli, cognitive processes, wakefulness and sleep
Hard problem: how mechanisms give rise to the subjective experience
Define neural correlates of consciousness
the minimal neuronal events jointly sufficient for any one specific conscious precept.
Name a structure that has a great role in consciousness
• Midbrain Reticular Formation in the Thalamus: big role in consciousness
Define blindsightedness
people w perfect retinas, but their blindness has its source in the cortex (cortical blindness), can still act upon stimuli that they cannot consciously “see” (their eyes will see it but their brain wont bring an image into consciousness)
Describe the case study of DB
right occipital cortex (contains visual cortex) ablated to remove a tumor (left him blind to stuff on his left visual field) - still able to perceive movements
Describe the case study of TN
damage to primary visual cortex in both hemispheres (blind to both sides) - can still navigate his environment while avoiding objects
Define affective blindsight
people can still react appropriately to faces showing a certain emotion even though they are blindsight
Define binocular rivalry
phenomenon by which visual perception spontaneously switches between 2 different images that are presented simultaneously to each eye
• Only 1 of the 2 enters visual consciousness at a time
Describe the monkey experiment about binocular rivalry
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Describe the human experiment about binocular rivalry - what parts of the brain were involved?
Same procedure but with humans - with a face and a house (through red-green glasses)
Fusiform Face Area (FFA) - activated when the subjects were consciously aware of the face
Paraphippocampal Place Area (PPA) - activated when the subjects were consciously aware of the house
• These activations may be NCC for perceiving faces/objects
Define what is level of consciousness
extent to which a person is awake
Define what is the content of consciousness
extent to which ongoing stimuli are being processed
Define coma
state of unresponsiveness that results form brain injury, have closed eyes, cannot be awakened, do not respond to stimulation
Name the characteristics of a coma, including the possibles causes of comas
- NOT sleeping (no REM)
- can react to pain (normal reflexes responses, which do not require the brain), but not if in a deep coma, reflexes can decrease as the coma goes on
- Show brain waves that resemble stages 3-4 sleep, but they do NOT sleep
- Brain damage that can induce coma: stroke, physical trauma (automobile accident), diabetes (brain levels of glucose too low), cardiac arrest
- Stopping of the ascending activating system in the brainstem, includes raphe nuclei, locus coeruleus
- Retrograde amnesia is possible - according to the “use it or lose it” law of neurons
What scale is used to assess comatose state? How many points indicate a coma?
Glasgow coma scale: 8 or less = coma
Define brain death
when comatose patients lose function of their brainstem
Explain the main difference between brain death and coma
• Main difference btw brain dead and coma: coma has enough activity in brainstem to maintain activity (breathing, maintain organ function, etc), while brain dead patients do not have this activity (has to be sustained artificially)
People are pronounced clinically dead when there is no longer activity in the brain
Define unresponsive wakefulness and its main characteristics. How is it also called?
show high levels of wakefulness but have no conscious awareness (open eyes but show no signs of being conscious, can only perform reflexive responses) (AKA persistent vegetative state)
• Go through normal sleep-wake cycles
• No conscious awareness due to damage of the cortices, do not know what is going on in their environment
• Loss of connectivity btw the frontal and parietal cortices and loss of connectivity btw primary sensory areas and association areas of the cortex
Define unimodal association areas
adjacent to their respective primary sensory cortex and integrate types of sensory info from those areas
What is the role of limbic association areas
links emotions and memories to sensory input
What is the role os posterior association areas
links together the info from primary sensory areas and unimodal association areas
What is the role of anterior association area of the prefrontal cortex
links info from all association areas and is involved in higher mental functions
Define the minimally conscious state
higher levels of responsiveness (follow simple commands, give simple verbal an yes-no answers)
• Depends on the amount of brain damage
Define the locked-in syndrome
intact awareness, wakefulness, cognitive function, but paralyzed and unable to speak
Define the concept of hidden consciousness
No signs of consciousness does not mean no consciousness
• Patients diagnosed with unresponsive wakefulness were actually found to be minimally conscious
• fMRI scans of unresponsive wakefulness demonstrated that they actually had consciousness
• Possible that the brain activity demonstrated was only the result of stimuli unconsciously perceived
• Asked to imagine different situations to answer yes or no - only one patient was able to do it - therefore showing that he consciously perceived stimuli
Define the sense of agency
Despite sense of agency: feeling of initiating and controlling one’s actions
Describe Libet’s famous experiment
people asked to press a button while watching a clock when they felt the urge to press the button; their brain activity was initiated 800ms before the actual pressing
• The intention to act had been formulated before they felt the urge to press a button - called readiness potential
What does Libet’s experiment suggests?
• Suggests that motor actions may be the product of unconscious brain processes
