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.
what data was collected on split brain patients with regard to touch
When a split-brain patient touches an unknown, familiar object with only their left hand (in the absence of visual cues), they cannot identify the object out loud
what data was collected on split brain patients with regard to vision
When split-brain patients are shown an image only in their left visual field (left peripheral vision), which is processed on the right side of the brain, they cannot verbalize what they have seen. Split brain patients simply cannot say out loud what the right brain is seeing.
what was the conclusion of the data collected on split brain patients with regard to touch and vision
Split brain patients appear to unconscious of – cannot verbalize –
any stimuli directed exclusively to their right brain
Split brain patients find ways to compensate for their deficits in perception. And the hemispheres learn to work together fairly quickly. One hemisphere will usually take the lead in a situation dependent manner. Also, well-practiced bimanual skills are typically coordinated at the subcortical level, so split-brain people are able to smoothly choreograph their body after practice on any given task
We have known for over a century that most human language ability, our comprehension of language and our ability to talk and write is generally located where
in our left cerebral cortex
The right hemisphere of the cerebral cortex is in general not that sophisticated with language.
Sperry discovered that the right brain of some of the split brain patients could understand simple questions.
this means that the right brain had a bit of what
Their right brain had a bit of a “dictionary” and could understand simple numbers, letters, and short statements. Understanding long sentences was generally beyond the capabilities of their right brain.
Their left hand (controlled by the right hemisphere) could even write some information with a pen.
When the Sperry lab asked split-brain patients to explain in words (left hemisphere) why they performed an action that had been initiated by their right hemisphere, what explanation did they give
often made up a post hoc answer.
For example, when the command ‘laugh’ was directed to the right hemisphere of one patient, he laughed. When asked why he was laughing, he said “you guys come up and test me every month – what a way to make a living!”
Another example: when a patient’s right brain was instructed to walk, he walked out of the room. When asked why he did that, he immediately responded “to get a Coke.” It seemed that the left brain was constantly coming up with explanations for actions the right brain instigated.
what is the interpreter theory
Gazzaniga developed the Interpreter Theory to explain these phenomena and more importantly why people — including split-brain patients — have a unified sense of self and mental life. He was fascinated by the fact that split brain patients never reported feeling anything less than whole. Their hemispheres didn’t miss each other.
Gazzaniga’s Interpreter Theory says that the left-brain creates what
narratives that make sense of the world. It weaves disparate points of information into a story that has meaning.
what does Gazzaniga’s Interpreter Theory say about free will
Basically, free will is an illusion. Consciousness is just storytelling. And since storytelling relies on language, consciousness must only be located in the left cerebral hemisphere of the human brain
what does the textbook say consciousness is
involves awareness of – and ability to tell other about – our thoughts, perceptions, memories and feelings
what does the textbook say the ability to communicate is
Enables us to send and receive our messages to others and to ourselves, inside our own heads
Over the last 500 years humanity has developed an increasing appreciation of math and the scientific method for explaining physical phenomena.
Before the scientific revolution, philosophers like Plato and Aristotle (circa 350 BCE) created theories of the world and how things worked using what logic
intuition and deductive logic (e.g., it doesn’t feel like the earth is moving, so what does that imply?).
Before the scientific revolution, philosophers like Plato and Aristotle (circa 350 BCE) created theories of the world and how things worked using intuition and deductive logic (e.g., it doesn’t feel like the earth is moving, so what does that imply?). Experiments and mathematical formalizations were rare and underappreciated. People tended to give more credence to what
their intuition than math.
Faith in math and science grew immensely during the scientific revolution, starting with who
Copernicus in the mid 1500s and culminating in Newton’s ideas of universal gravity and the laws of motion (F=ma) in the late 1600s
In the midst of the scientific revolution, Rene Descartes started questioning everything, doubting everything. If our intuitions and perceptions are misleading (the earth is actually spinning and hurtling through space?!), what can we trust?
what did Rene Descartes conclude
“I think, therefore I am.” He argued the main thing we know is that thinking is real, consciousness is real, because we must be conscious to think that
what is mind-body dualism
The body may be a mechanical device and the world deterministic, but the mind (or soul) is something else, something immaterial that can exist without a body
was Rene Descartes skepticism (hyperbolic doubt) about the truth of all beliefs true
Rene Descartes skepticism (hyperbolic doubt) about the truth of all beliefs
what is Consciousness
not an illusion or a hallucination that serves no purpose. It is an evolutionary adaptation that surely improves cognition. It didn’t evolve for no reason or just to make us feel a little better about ourselves. Complex traits evolve because they serve a function, they have a purpose, that ultimately serves survival and reproduction
what is natural selection
Population growth and environmental change leads to a “struggle for existence” in which favourable variations prevailed as others perished. This process is called natural selection
At the end of the enlightenment period (circa 1800), Immanuel Kant suggested what
that consciousness and perception might create new natural laws
At the end of the enlightenment period (circa 1800), Immanuel Kant suggested that consciousness and perception might create new natural laws.
explain this
With consciousness, we not only have the ability to ponder why something happened in the world, but we can also ask why we did something.
Because the mind acknowledges that it is a part of an entity that can alter its surroundings, it leads to a desire to understand the world not only for how it is, but how it ought to be, how it might otherwise be
why was Gazzaniga’s thinking problematic
After Gazzaniga observed the left brain consciousness could rationalize behaviour with plausible stories, he argued that our ability to communicate and make up stories might have given rise to our ability to think and be aware of our own existence. Specifically, the evolution of speech gave rise to consciousness.
Does the phenomenon of consciousness depend on language? Certainly humans capacity for language and information sharing through stories gave rise to modern civilization, but is storytelling a requirement for consciousness?
Gazzaniga probably never spoke with the current Dalai Lama or others who advocate using meditation to quiet the mind in order to achieve a higher state of awareness.
