Psychology Sept 24th 2013
Biological Foundation of Behaviour
• Phineas Gage (1823-1860)
• Sept 13, 1848
• While working on a railroad line, sparks accidentally ignited and blasted a
tamping rod through his left cheek and out through the frontal portion of his
brain. The rod was made of iron and was 3 feet 7 inches long. The rod landed
40 feet away.
The equilibrium or balance, between his intellectual faculties and animal
propensities, seems to have been destroyed. He is irreverent, indulging at
times in the grossest profanity, manifesting but little deference for his fellows,
impatient of restraint or advice.
• Before the accident he had been the most capable and efficient foreman, one
with a well balanced mind, and who was looked on as a shrewd smart business
man. He was now fitful, irreverent, and grossly profane. His friends said he was
“No longer Gage.”
• Nervous System
• A major control system of the body
• Controls much voluntary and involuntary behaviour
• Knowledge of system can account for many aspects of behaviour
• Enormous complexity
Integration of information
• Constantly adapting
• Nervous System Pathways
• Afferent Nerves: Sensory nerves that transport information to the brain
• Efferent Nerves: Motor nerves that carry information from the brain (Effect ->
• Neural Networks: Clusters of neurons that are interconnected.
• Central (CNS): Brain, Spinal cord
• Peripheral (PNS): Somatic, Autonomic
• Autonomic Nervous System: Sympathetic nervous system (arousing),
parasympathetic nervous system (calming)
• Neural impulse: travels down the axon towards dendrites of the next neuron
• Glial Cells: provides support and nutritional benefits in the nervous system Psychology Sept 24th 2013
• Cell Body (Soma): contains the nucleus, which directs the manufacture of
substances that the neuron needs for its growth.
• Dendrites: receive and direct info toward the cell body; most nerve cells have
• Axon: carries info away from the cell body to other cells
• Axon Hillock: Where the axon and cell body connect.
Myelin Sheath: layer of fat cells that encases.
• How Neurons Work
• Resting Potential:
• -70 millivolts
• Action Potential:
• Movement of sodium and potassium ions into and out of the axon
• All or none principle
• After an action potential occurs, Calcium migrates into the terminal button,
signaling synaptic vesicles containing Neurotransmitters to be released into the
synaptic gap. The neurotransmitters act like a key into the receptor site in the
membrane of the receiving dendrite.These neurotransmitters open up channels
that lead into the post synaptic dendrite.
• Types of Neurotransmitters
• Acetylcholine: excitatory - muscles, learning, and memory
• GABA: Inhibitory: 1/3 synapses in brain
• Norepinephrine: aka adre