CH. 2 Flashcards
behavioral neuroscientists/biopsychologists
psychologists who specialize in considering the ways in which the biological structures and functions of the body affect behavior
neurons
nerve cells, the basic components of the nervous system
Where are neurons physically held?
glial cells
What do glial cells do? (4)
- provide nourishment to neurons
- insulate neurons
- help repair damage
- support neural functioning
In contrast with most other cells, what can neurons do? (2)
- communicate with other cells
- transmit information across relatively long distances
dendrite
a cluster of fibers at one end of a neuron that receive messages from other neurons
axon
carries messages received by dendrites to other neurons
terminal buttons
the part of the axon, like a small bulge, at the end, that sends messages to other neurons
myelin sheath
a protective coating of fat and protein that wraps around the axon
What does the myelin sheath do?
increases the velocity with which electrical impulses travel through axons
What do the axons that carry the most important and urgent information have?
the greatest concentration of myelin
What law do neurons follow?
all-or-none law
all-or-none law
they are either on or off
resting state
state before a neuron is triggered, in which there is a negative electrical charge of about -70 millivolts within the neuron
action potential
an electric nerve impulse that travels through a neuron’s axon when it is set off by a “trigger,” changing the neuron’s charge from negative to positive
What determines the speed at which an action potential travels along an axon? (2)
- axon’s size
- thickness of the myelin sheath
What do neurons differ in terms of?
- quickness of an impulse moving along the axon
- potential rate of firing
What determines how much of a neuron’s potential firing rate is reached?
the intensity of a stimulus
mirror neurons
specialized neurons that fire not only when a person enacts a particular behavior but also when a person simply observes another individual carrying out the same behavior
What does the discovery of mirror neurons suggest? (2)
- human’s capacity to imitate others may be an inborn behavior
- why humans have the capacity to understand others’ intentions
Who may be helped by the stimulating of the mirror neuron system? (2)
- stroke victims
- those with emotional problems
What are mirror neurons the possible basis for? (2)
- feelings of empathy
- development of language in humans
synapse
the space between two neurons where the axon of a sending neuron communicates with the dendrites of a receiving neuron by using chemical messages
neurotransmitters
chemicals that carry messages across the synapse to the dendrites (and sometimes the cell body) of a receiving neuron
When is successful chemical communication possible?
only possible when a neurotransmitter fits precisely into a receptor site
What are two types of chemical messages delivered by neurotransmitters?
- excitatory message
- inhibitory message
excitatory message
a chemical message that makes it more likely that a receiving neuron will fire and an action potential will travel down its axon
inhibitory message
a chemical message that prevents or decreases the likelihood that a receiving neuron will fire
What would happen if neurotransmitters remained at the site of the synapse?
it would produce constant stimulation/constant inhibition of the receiving neurons and effective communication would no longer be possible
What do enzymes do to ensure effective communication?
enzymes deactivate the neurotransmitters, or–more commonly–the terminal button sucks them back up
reuptake
reabsorption of neurotransmitters by a terminal button
What has our understanding of the reuptake process led to?
the development of certain drugs that treat psychological disorders
SSRIs (selective serotonin reuptake inhibitors)
permit certain neurotransmitters to remain active for a longer period at certain synapses, reducing the symptoms of depression
What are neurotransmitters a particularly important link between?
the nervous system and behavior
Why is the neurotransmitter link between the nervous system and behavior important?
- important for maintaining vital brain and body functions
- deficiency or excess can produce severe behavior disorders
How many chemicals have been found to act as neurotransmitters?
more than a hundred
How many other neurons can each neuron be connected to?
80,000 other neurons
What 2 basic structures does the human nervous system use?
- central nervous system
- peripheral nervous system
central nervous system (CNS)
the part of the nervous system that includes the brain and spinal cord
spinal cord
the bundle of neurons that leaves the brain and runs down the length of the back
What does the spinal cord do?
- main means for transmitting messages between the brain and the body
- controls simple behaviors on its own, without any help from the brain
reflex
an automatic, involuntary response to an incoming stimulus
What 2 kinds of neurons are involved in reflexes?
- sensory (afferent) neurons
- motor (efferent) neurons
sensory (afferent) neurons
transmit information from the perimeter of the body to the nervous system and brain
motor (efferent) neurons
communicate information from the brain and nervous system to the muscles and glands
peripheral nervous system
the part of the nervous system that includes the autonomic and somatic subdivisions
What is the peripheral nervous system made up of?
neurons with long axons and dendrites, it branches out from the spinal cord and brain and reaches the extremities of the body
somatic division
specializes in the control of voluntary movements and the communication of information to and from the sense organs
autonomic division
controls the involuntary movement of the heart, glands, lungs, and other organs
sympathetic division
prepares the body for action in stressful situations, engaging all the organism’s resources to respond to a threat
parasympathetic division
acts to calm the body after an emergency has ended
What is the sympathetic division often called?
“flight-or-fight” response
What are the 2 subdivisions in which the autonomic division is further divided?
- sympathetic division
- parasympathetic division
evolutionary psychology
the branch of psychology that seeks to identify behavior patterns that are a result of our genetic inheritance
behavioral genetics
the study of the effects of heredity on behavior
endocrine system
a chemical communication network that sends messages throughout the body via the bloodstream
hormones
chemicals that circulate through the blood and regulate the functioning or growth of the body
pituitary gland
the major component of the endocrine system; the “master gland” that secretes hormones that control growth and other parts of the endocrine system
electroencephalogram (EEG)
records electrical activity in the brain through electrodes places on the outside of the skull
functional magnetic resonance imaging (fMRI)
provides a detailed, three-dimensional computer-generated image of brain structures and activity by aiming a powerful magnetic field at the brain/other parts of the body
positron emission tomography (PET) scans
show biochemical activity within the brain at a given moment
How do PET scans begin?
begins with the injection of a radioactive liquid
transcranial magnetic stimulation (TMS)
electrical activity in a tiny region of the brain is interrupted by bombarding it with a strong magnetic field, and researchers note the effects on brain functioning
What may TMS be able to do?
may be able to treat certain kinds of psychological disorders
optogenetics
views individual circuits of neurons
hydrogel-embedding methods
allow observation of individual brain cells and the wiring of brain circuitry
neuropixels
implanted probes that allow neuroscientists to read activity in hundreds of neurons in multiple parts of the brain simultaneously
central core
the “old brain”, which controls basic functions such as eating and sleeping and is common to all vertebrates
What does the hindbrain contain?
the medulla, pons, and cerebellum
medulla
controls a number of critical body functions, the most important of which are breathing and heartbeat
pons
a bridge in the hindbrain that acts as a transmitter of motor information, coordinating muscles, regulating sleep, and integrating movement between the right and left halves of the body
cerebellum
the part of the brain that controls bodily balance
reticular formation
the part of the brain extending from the medulla through the pons; it is related to changes in the level of arousal of the body
Where does reticular formation pass through?
passes through the middle of the brain, called the midbrain, and into the front-most part of the brain, called the forebrain
thalamus
the part of the brain located in the middle of the central core that acts primarily to relay information about the senses
hypothalamus
a tiny part of the brain, located below the thalamus, that maintains homeostasis–a steady internal environment for the body–and produces and regulates behavior critical to the basic survival of the species (ex: eating, drinking, and sexual behavior)
limbic system
the part of the brain that controls eating, aggression, and reproduction–functions related to emotions and self-preservation
What does the limbic system include? (2)
- amygdala
- hippocampus
What does the limbic system (particularly the hippocampus) play an important role in?
learning and memory
What is the limbic system sometimes referred to as?
the “animal brain”
cerebral cortex
the “new brain”, responsible for the most sophisticated information processing in the brain
lobes
the four major sections of the cerebral cortex
What are the four major sections of the cerebral cortex?
- frontal lobes
- parietal lobes
- temporal lobes
- occipital lobes
Where are the frontal lobes?
the front center of the cortex
Where are the parietal lobes?
behind the frontal lobes
Where are the temporal lobes?
the lower-center part of the cortex
Where are the occipital lobes?
behind the temporal lobes
What are the four sets of lobes physically separated by?
deep grooves called sulci
motor area
the part of the cortex that is largely responsible for the body’s voluntary movement
sensory area
the site in the brain of the tissue that corresponds to each of these senses, with the degree of sensitivity related to the amount of tissue
What is the auditory area located in the temporal lobe responsible for?
sense of hearing
Where is the visual area located?
the occipital
The somatosensory area in the parietal lobe encompasses specific locations associated with what?
the ability to perceive touch and pressure in a particular area of the body
association areas
one of the major regions of the cerebral cortex; the site of the higher mental processes, such as thought, language, memory, and speech
What can injuries to the association areas produce?
aphasia (problems with language)
Broca’s aphasia
difficulty speaking
Wernicke’s aphasia
difficultly understanding others’ speech and in producing language
What is a famous example of the effects of damage to association areas?
railroad worker Phineas Gage, who suffered an injury to an association area of his cerebral cortex and underwent a notable change in personality
neuroplasticity
the brain’s ability to change throughout the life span through the addition of new neurons, new interconnections between neurons, and the reorganization of information-processing areas.
neurogenesis
the creation of new neurons, is now known to occur in certain areas of the brain in adulthood
hemispheres
symmetrical left and right halves of the brain that control the side of the body opposite to their location
How does the left hemisphere tend to process information?
sequentially, particularly in verbal areas
How does the right hemisphere tend to process information?
globally, particularly in nonverbal areas
lateralization
the dominance of one hemisphere of the brain in specific functions, such as language
In split-brain patients, how is the corpus collosum different?
it has been cut or injured
