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Computer Science 129

Science, Computing and Society

Week 8

Chapter 6

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GRE/GMAT WORDS

• Veracity – truthful

• Prodigal – wasteful, extravagant

• Alacrity – an eager willingness to do something

• Prosaic – dull and lacking imagination

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Interesting Stories

• Alien hand syndrome is a rare neurological disorder in which one hand functions involuntarily, with the victim completely unaware of its action. Symptoms include involuntary reaching and grasping, touching the face or tearing at clothing. More extreme cases have involved involuntarily stuffing food in the mouth, preventing the normal hand from completing simple tasks and self inflicted punching or choking.

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Interesting Stories

• Think of the corpus callosum as the brain's e-mail server, a bundle of message sending nerves that connect and share information with the two hemispheres. Alien hand syndrome is a result of damage to these nerves. This damage most often occurs in brain aneurysms, stroke patients and those with infections of the brain, but can also manifest as a side effect of brain surgery, most commonly after a radical procedure that treats extreme cases of epilepsy.

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Chapter 6

The brain performs an incredible number of tasks: • It controls body temperature, blood pressure,

heart rate and breathing. • It accepts a flood of information about the world

around you from your various senses (eyes, ears, nose, etc.).

• It handles physical motion when walking, talking, standing or sitting.

• It lets you think, dream, reason and experience emotions.

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Chapter 6

The Brain and Vision:

Class Experiment:

Wave opened fingered hand in front of eyes (notice blur)

Now hold open fingered hand in front of eyes and shake your head (no blur)

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Chapter 6

Why?

Vestibulo-Ocular Reflex (VOR)The vestibulo-ocular reflex, or VOR, is a

reflex eye movement that stabilizes images on the retina during head movement by producing an eye movement in the direction opposite to head movement

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Chapter 6

When the head moves, the VOR responds with an eye movement that is equal in magnitude but opposite in direction.

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Chapter 6

Brain receives input, processes the input, and gives an output

It does this at a cellular level and at the level of an organ

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Chapter 6

Some Scientists do not believe the brain “computes”

Consider the “Chinese room” analogy

Man in room who does not speak or read Chinese

The room is sealed off except for one door

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Chapter 6

Man in room is given cards with Chinese symbols on them and a book of instructions (written in English or his native language)

The instructions tell the person what symbols to send out in response to Chinese messages slipped under the door

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Chapter 6

The Man uses the instructions as a computer uses a computer program

The man does not know what or if he is communicating, but to an outsider his responses could look reasonable

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Chapter 6

Conclusion is that a computer computes whereas a brain thinks, understands and has consciousness

Brain is biological, not a machine

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Chapter 6

Argument seems to be semantical

Definition of “computing” is the debate

I believe our brains compute, it is just our instruction booklet changes minute to minute depending upon what has happened to us.

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Chapter 6

The complete function of the brain is still unknown

4 Regions of Brain:

Cerebrum (4 lobes)

Cerebellum

Diencephalon

Brain Stem

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Chapter 6

The medulla oblongata, located in the brain stem, manages the reflex centers for:

1. Vomiting2. Coughing3. Sneezing4. Swallowing5. Hiccupping6. Respiratory rate7. Vasoconstriction

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Chapter 6

These are perfect examples of input, process, output analogy

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Chapter 6

The Neuron is the basic unit of our central nervous system which includes our brain

Chapter 6• Something activates a dendrite and it passes an

electrical signal down the soma (cell body) and the axon to the tip of the synapses. The presence of this electrical signal causes a change in permeability to the tip of the synapses allowing neurotransmitters to seep out into the synaptic cleft. The neurotransmitters bind to receptor sites on the tip of the post synaptic neurons dendrites. This binding causes an electrical signal to go down the post synaptic neuron and the process repeats. This sends a signal very quickly.

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Chapter 6

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Chapter 6

Neurons use chemical mechanisms to transfer an electric impulse, or action potential, from cell to cell to affect a response

http://www.bristol.ac.uk/synaptic/basics/basics-1.html

Go to this website and read this one page

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What You Should Know

• Know all GRE/GMAT words

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What You Should Know

Define:

Vestibulo-Ocular Reflex (VOR)

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What You Should Know

What are the four primary regions of the brain?

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What You Should Know

SHORT ESSAY:

WHAT SEVEN REFLEX CENTERS DOES THE MEDULLA OBLONGATA CONTROL AND HOW DO THEY RESEMBLE A COMPUTER PROCESS

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What You Should Know

SHORT ESSAY:

EXPLAIN CHINESE ROOM ARGUMENT AND WHAT IT HAS BEEN PURPORTED TO ILLUSTRATE

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What You Should Know

SHORT ESSAY:

HOW DOES A NEURON USE CHEMICAL MECHANISMS TO TRANSFER AN ELECTIRCAL INPULSE