Lecture 1 Flashcards
define consciousness
the state or quality of awareness – awareness of our thoughts, perceptions, memories, feelings…
the state of awareness creates what kind of experience
subjective
This state of awareness creates a subjective experience. If a being is capable of having subjective experiences, then …
there is something that it is like to be that being.
What is it like to be a rock or a house plant or an ant?
What is it like to be a calculator or computer or robot?
Neuroscientists generally believe that consciousness and “the mind” arise from what
neural processes located somewhere in the brain
They are physiological functions that evolved through evolution.
Neuroscientists generally believe that consciousness and “the mind” arise from neural processes located somewhere in the brain. They are physiological functions that evolved through evolution.
In part, this idea comes from where
fact that consciousness can be profoundly altered by physical or chemical alterations to the brain (i.e. brain damage & psychotropic drugs).
Many studies have tried to determine exactly where consciousness is located in the brain using what techniques
surgical and pharmacological techniques
These approaches have not really answered the question, but they have been informative nonetheless
a big Medical Fad in the 1940s was…
Lobotomy
what was the Lobotomy used for
The frontal lobotomy was used to treat psychosis, depression, anxiety, etc… (cutting out what the problem was)
The Nobel Prize was awarded for this procedure in 1949.
By the 1950s, over 20,000 lobotomies had performed in the US.
what is Generalized epileptic seizure
Both sides of the brain engage in wild activity and stimulate each other
what was the solution to Generalized epileptic seizure
Split-brain operation
what was the Split-brain operation
A surgical approach to treat epilepsy (seizure disorder) that involves cutting the corpus callosum, the bundle of nerve fibers that connect the left and right sides of the cerebral cortex. The surgery is generally effective but has side effects.
Our cerebral hemispheres are critical for what
our ability to process sensory information (sights, sounds, touch, etc).
Our cerebral hemispheres also regulate/control what
the movement of our body in space (hand movements, leg movements, etc).
Each cerebral hemisphere is responsible for what part of the body
one half of the body
wat is important to remember about the cerebral hemisphere responsibilities
that all the fibers crisscross
aka The left brain is responsible for the right side of the body and the right brain is responsible for the left side of the body
is the way our vision works easy to understand?
no– When it comes to our eyes and vision, the left/right distinction is confusing
But our brain keeps it simple. The right brain sees everything on our left side. The left brain sees everything on our right side
even though one half of each eye gets criss crossed
what is The corpus callosum
is a bundle of fibers that interconnects the two cerebral hemispheres. It enables the two hemispheres to share information so that each side knows what the other side is perceiving and doing
If the corpus callosum is cut what happens
the two cerebral hemispheres cannot directly talk to each other
if the corpus callosum is cut and cannot directly talk to each other how do they convey information to echother
they can still send information downwards, down to the midbrain, hindbrain, and spinal cord.
If the corpus callosum is cut, the two cerebral hemispheres cannot directly talk to each other. However, they can still send information downwards, down to the midbrain, hindbrain, and spinal cord.
These lower brain areas help coordinate body movements by doing what
integrating the information they receive from the two cerebral hemispheres. It is impressive how well they can do this job (coordinate bilateral movements) when the two cerebral hemispheres lose the ability to talk to each other.
give a Brief History of the Split Brain Surgery
In 1939, 10 patients underwent split brain surgery in Rochester NY. 16 additional patients soon followed. The doctor claimed the surgery to be a success (i.e., reduced frequency/intensity of seizures).
Soon afterwards a group scientists re-examined the original split brain patients using a host of neurological and psychological tests (IQ, memory, motor skills, and general interviews). They concluded:
the patients’ improvements were short-lived and/or exaggerated
the corpus callosum was not important for much of anything
Over the next decade Roger Sperry at Caltech (Pasadena, California) became increasingly confident that the corpus callosum was important for something. His lab was doing corpus callosotomies in cats and monkeys and was ensuring the surgeries were clean and absolute. His lab found that splitting the brain in two produced specific cognitive peculiarities.
A neurosurgeon at Caltech was planning to try the split brain procedure on a new patient in 1962. He was familiar with Sperry’s research and invited Sperry’s group to conduct pre- and post-operative examinations.
what is the interesting dilemmas in the split brain patients
In general, when the split brain patients were recovering from their surgery, they reported they felt fine, no different than before. Nothing was weird, nothing was out of the ordinary. Often the frequency and/or severity of their seizures were reduced. The surgeries were a success.
However, a few of the patients said that their left hand sometimes seemed to have a mind of its own. Their left hand sometimes actively worked against what the person was consciously trying to accomplish. One patient reported that one time his left hand suddenly started to attack his wife, and he had to use his right hand to protect her, to thwart his left hand.
It seemed that their left hand was being controlled by processes outside their conscious awareness.
What was happening in their right cerebral hemisphere, which controls the left hand?
(the split brain patients)
The right hand, controlled by the left brain, never acted out of the ordinary. Its actions were always consistent with the person’s conscious intentions. Does this mean that consciousness is located in the left hemisphere? (this was a question that was brought up)
give the story of Viki (split brain patient)
In the first months after her surgery, shopping for groceries was infuriating. Standing in the supermarket aisle, Vicki would look at an item on the shelf and know that she wanted to place it in her trolley — but she couldn’t.
“I’d reach with my right hand for the thing I wanted, but the left hand would come in and they’d kind of fight,” she says. “Almost like repelling magnets.” Picking out food for the week was a two-, sometimes three-hour ordeal.
Getting dressed posed a similar challenge: Vicki couldn’t reconcile what she wanted to put on with what her hands were doing. Sometimes she ended up wearing three outfits at once. “I’d have to dump all the clothes on the bed, catch my breath and start again.”
After about a year, Vicki’s difficulties abated. Conflicts with her left hand became rare. For the most part she was herself: slicing vegetables, tying her shoe laces, playing cards, even waterskiing.
