Psychology: Chapter 2
The biology of behavior and consciousness
o The power of neuroplasticity
neuroplasticity
The brains ability to change, especially during childhood, by recognizing after
damage or by building new pathways based on experience
Enables us, more than other species to adapt to our changing world
Cultural neuroscientists
Repeated exposure to different traditions, beliefs, and rituals can lead people from
different cultural groups to have unique behaviors and brain activation patterns
o A neuron’s structure
Cell body: the part of the neuron that contains the nucleus
Cell’s life support center
Neuron: a nerve cell that is the basic building block of the nervous system
Contains
o Dendrites: fibers that receive and integrate information and conduct it
toward the cell body
o Axons: neuron extension that sends messages to other neurons or to
muscles and glands
Action potential: nerve impulse or electrical signals that travel down an axon
Glial cells: cells that support, nourish and protect neurons, provide nutrients and myelin
insulation, and send messages to one another
Synapse: the junction between the axon tip of a sending neuron and the dendrite or cell
body of a receiving neuron
Synaptic cleft: a tiny gap at the synapse
o How neurons communicate
We often look at neurons one at a time to learn its parts
But out billions of neurons exist in a vast and densely interconnected web
Neurons send messages to neighboring dendrites
Each neuron is a miniature decision making device that reacts to excitatory and inhibitory
signals
When excitatory signals exceed inhibitory signals by a threshold, combined
signals trigger an action potential
Refractory period: brief resting pause that occurs after a neuron has fired
, Lasts for a fraction of a second
All or nothing response: neurons reaction of either firing or not firing
Neurotransmitters: neuron produced chemicals that cross the synaptic cleft to carry
messages to other neurons of muscles
Reuptake: reabsorption of a neurotransmitter by the sending neuron
o How neurotransmitters influence us
Different neurons release different neurotransmitters, each carrying specific messages
that influence our motions and emotions
Example:
o Dopamine: influence our movement, learning, attention and feelings of
pleasure and reward
o Serotonin: can make us more or less moody, sleepy, hungry or aroused
Neurotransmitters
Opioid drugs
Endorphins
Commonly studied neurotransmitters and their functions
Neurotransmitter Function Examples of malfunction
Acetylcholine Enables muscle action, With Alzheimer’s disease,
learning and memory Ach producing neurons
deteriorate
Dopamine Influence movement, Oversupply linked to
learning, attention and schizophrenia. Undersupply
emotion linked to tremors and
decreased mobility in
Parkinson’s disease
Serotonin Affects mood, hunger, sleep Undersupply linked to
and arousal depression. Some drugs that
raise serotonin levels are used
to treat depression
Norepinephrine Helps control alertness and Undersupply can depress
arousal mood
GABA (gamma-aminobutyric A major inhibitory Undersupply linked to
acid) neurotransmitter seizures, tremors and
insomnia
Glutamate A major excitatory Oversupply can overstimulate
neurotransmitter, involved in the brain, producing
memory migraines of seizures
Endorphins Neurotransmitters that Oversupply with opioid drugs
influence the perception of can suppress the body’s
pain or pleasure natural endorphin supply
o The nervous system
2
The biology of behavior and consciousness
o The power of neuroplasticity
neuroplasticity
The brains ability to change, especially during childhood, by recognizing after
damage or by building new pathways based on experience
Enables us, more than other species to adapt to our changing world
Cultural neuroscientists
Repeated exposure to different traditions, beliefs, and rituals can lead people from
different cultural groups to have unique behaviors and brain activation patterns
o A neuron’s structure
Cell body: the part of the neuron that contains the nucleus
Cell’s life support center
Neuron: a nerve cell that is the basic building block of the nervous system
Contains
o Dendrites: fibers that receive and integrate information and conduct it
toward the cell body
o Axons: neuron extension that sends messages to other neurons or to
muscles and glands
Action potential: nerve impulse or electrical signals that travel down an axon
Glial cells: cells that support, nourish and protect neurons, provide nutrients and myelin
insulation, and send messages to one another
Synapse: the junction between the axon tip of a sending neuron and the dendrite or cell
body of a receiving neuron
Synaptic cleft: a tiny gap at the synapse
o How neurons communicate
We often look at neurons one at a time to learn its parts
But out billions of neurons exist in a vast and densely interconnected web
Neurons send messages to neighboring dendrites
Each neuron is a miniature decision making device that reacts to excitatory and inhibitory
signals
When excitatory signals exceed inhibitory signals by a threshold, combined
signals trigger an action potential
Refractory period: brief resting pause that occurs after a neuron has fired
, Lasts for a fraction of a second
All or nothing response: neurons reaction of either firing or not firing
Neurotransmitters: neuron produced chemicals that cross the synaptic cleft to carry
messages to other neurons of muscles
Reuptake: reabsorption of a neurotransmitter by the sending neuron
o How neurotransmitters influence us
Different neurons release different neurotransmitters, each carrying specific messages
that influence our motions and emotions
Example:
o Dopamine: influence our movement, learning, attention and feelings of
pleasure and reward
o Serotonin: can make us more or less moody, sleepy, hungry or aroused
Neurotransmitters
Opioid drugs
Endorphins
Commonly studied neurotransmitters and their functions
Neurotransmitter Function Examples of malfunction
Acetylcholine Enables muscle action, With Alzheimer’s disease,
learning and memory Ach producing neurons
deteriorate
Dopamine Influence movement, Oversupply linked to
learning, attention and schizophrenia. Undersupply
emotion linked to tremors and
decreased mobility in
Parkinson’s disease
Serotonin Affects mood, hunger, sleep Undersupply linked to
and arousal depression. Some drugs that
raise serotonin levels are used
to treat depression
Norepinephrine Helps control alertness and Undersupply can depress
arousal mood
GABA (gamma-aminobutyric A major inhibitory Undersupply linked to
acid) neurotransmitter seizures, tremors and
insomnia
Glutamate A major excitatory Oversupply can overstimulate
neurotransmitter, involved in the brain, producing
memory migraines of seizures
Endorphins Neurotransmitters that Oversupply with opioid drugs
influence the perception of can suppress the body’s
pain or pleasure natural endorphin supply
o The nervous system
2
