Lecture 3: Neuropsychology
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in order to interact with your environment effectively, two things must occur:
1. You must be able to detect the world outside of yourself (sensation and perceptual
process) and then be able to interpret the detections.
2. And in turn, you must be able to respond/behave to your world.
i.e.: Baseball coming at your face.
**Incoming processes is known as an afferent process, and outgoing processes are known as
Virtually all of our thoughts, feelings, and actions can be brought down to a neuron’s reaction.
•Neurons vary widely in shape and size. They all contain:
1. Cell body (soma); nerve centre of the cell, contains the nucleus.
2. Dendrites; extensions of the cell body, branchlike in appearance.
3. Axon; a stem that comes out of the nucleus, varies dramatically in length.
4. Terminal endings; essential part of the neuron.
There are different types of neurons, categorized by their job.
1. Sensory neurons; devoted to the afferent process (getting information to the brain).
a. Afferent direction
b. Comes from the sensory organs via the dendrites
c. Goes to the CNS via the axons
d. Approx. 2-3 million
2. Motor neurons; devoted to the efferent process (taking information out of the brain and
transmit it to the muscles/glands of the body to trigger a reaction).
a. Efferent direction
b. Comes from the CNS via the dendrites
c. Goes to the Muscles and Glands via the axons
d. Approx. 2-3 million
3. Interneurons; exist directly inside the CNS; complete all the translations/interpretations.
a. Communicates only with other neurons
b. Approx. 10-100 billion
c. Using their terminal endings, they communicate with the motor and sensory
•There was a debate about whether the brain was run on electrical currents or chemical
reactions. The first discovery on the matter (base work on the electric theory) was
founded by Galvani (1737-98); an Italian physicist.
•He took a frog and killed it, then hooked electric wires to the legs of the frog. The frog
would jump. Galvani deduced that this was because the frog’s muscles reacted to
electricity and thereby proving in his opinion that the brain ran on electricity.
•**It is rumoured that Mary Shelly got her idea for Frankenstein from this experiment.**
•People disputed his idea, but there was no experiment to go against it. Auto Loewi
wished to prove that the neurotal messaging was run by chemicals. He failed several