The Biology of Mind
Biological Psychology
◦ Branch of psychology concerned with
the links between biology and behavior
◦ Some biological psychologists call
themselves:
◦ Neurobehavioral neuroscientists
◦ Neuropsychologists
◦ Behavior geneticists
◦ Physiological psychologist
◦ Biopsychologists
It all Starts with the Neuron
Neuron
Neuron Structure
Neurons do NOT touch each other- the space in
between is call the synapse.
How a Neuron Fires
It is an electrochemical process
Electrical inside the neuron
Chemical outside the neuron (in
the synapse in the form of a
neurotransmitter)
The firing is call Action Potential
The All or None Response
The idea that either the neuron
fires or it does not
No part-way firing
Action Potential
How Neurons Communicate
Neurotransmitters
Chemical messengers released by
terminal buttons through the synapse.
We should know at least 4 types and
what they do
Acetylcholine
Enables muscle action, learning & maybe memory
Lack of ACh has been linked to Alzheimer's
Too much means muscle spasms & death
Too little can mean paralysis
Dopamine
Influences learning, meaning &
attention
Too much is linked to
schizophrenia
Too little is linked to Parkinson’s
Serotonin
Affects mood, hunger, sleep & arousal
Too little is linked to depression
Too much Serotonin Syndrome
Endorphins
Natural pain killer
“Runner’s High”
Linked to pain control & pleasure
Drugs can be . . .
Agonists: Make neurons fire
Antagonists: Stop neural firing
Re-uptake inhibitors: Block reuptake
Agonists and Antagonists
Types of Neurons
Afferent (Sensory)
Neurons
Efferent (Motor)
Neurons
Interneurons
Sensory Neurons
(Afferent Neurons)
Take information from the senses
to the brain.
Motor Neurons
(Efferent Neurons)
Take information from brain to the
rest of the body.
Inter Neurons
Take messages from Sensory
Neurons to other parts of the
brain or to Motor Neurons
Divisions of the Nervous
System
Sympathetic Nervous System
Flight or Fight Response
• Automatically
accelerates
heart rate,
breathing,
dilates pupils,
slows down
digestion
Parasympathetic Nervous System
Automatically
slows the body
down after a
stressful event.
Heart rate and
breathing slow
down, pupils
constrict and
digestion speeds
up.
Peripheral Nervous
System
All nerves that are not
encased in bone.
Everything but the brain and
spinal cord.
Is divided into two
categories….somatic and
autonomic.
Somatic Nervous System
Controls
voluntary muscle
movement.
Uses motor
(efferent)
neurons.
Autonomic Nervous
System
Controls the
automatic
functions of the
body.
Divided into two
categories…the
sympathetic and
the
parasympathetic
Reflexes
Normally, sensory
(afferent) neurons
take info up through
spine to the brain.
Some reactions
occur when sensory
neurons reach just
the spinal cord.
Survival adaptation.
A Simple Reflex
A Simplified Neural Network
Neurons that learn to work together as a team.
The Endocrine System
A system of glands that secrete
hormones.
Similar to nervous system,
except hormones work a lot
slower than neurotransmitters.
The Major Endocrine Glands