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 FiresIt 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 re-uptake

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