Chapter 3 - Behavioral Neuroscience

nervous system

consists of all neurons that transfer information to and from the brain, as well as neurons within the brain itself

spinal cord

connects somatic and autonomic nervous systems with the brain, and relays sensory information to the brain from the outside world and information from brain to muscles

survival

staying alive because critical brain areas function

sensation

the detection of information from the environment

perception

process by which the brain organizes and interprets sensory information

movement

engaging in smooth, coordinated changes in position of body as a result of different areas throughout the brain working together

emotion

a complex internal state that involves physiological, cognitive, and behavioral components

learning and memory

the acquisition and retention of information; involves hippocampus

highly complex behaviors

examples include executive functions and language, as well as personality.

language

spoken and written communication involving specific areas in the cerebral cortex

brain damage

injury to a particular part or parts of the brain; neuropsychologists determined what functions were disrupted or lost when a particular part of the brain was injured

localization

particular brain areas are critical for specific functions

lateralization

functions become localized in right or left hemisphere

neurons

brains cells that communicate with other cells in order to generate behavior and mental activity

structure

organization and elements (of the brain or personality)

function

an activity or purpose

information transfer

communication between neurons; occurs from outside world to brain, within brain for integration and processing, and back out again to muscles and glands

conduction

transfer of information within a neuron; involves production and transfer of an electrical signal

synaptic transmission

transfer of information between neurons (at the synapse) via release of chemical molecules

neurotransmitters

specialized chemicals that travel across the synapse to transfer information

psychoactive drugs

substance that affects behavior and mental processes by altering information transfer within the brain

plasticity

process of structural and functional changes in the brain caused by life experiences

endocrine system

communication system that is made up of a set of glands that release chemical messengers into the blood

central nervous system (CNS)

brain and spinal cord—encased in bone for protection, surrounded by cerebrospinal fluid

peripheral nervous system (PNS)

consists of neurons outside the central nervous system; allows the brain and spinal cord to communicate with the rest of the body

somatic nervous system

consists of the neurons that gather and transfer sensory information from all over the body to the spinal cord, as well as the neurons that send information from the central nervous system out to the muscles

autonomic nervous system

controls the internal organs in the body, does so automatically

sympathetic nervous system

branch of the autonomic nervous system associated with activation; mediates fight-or-flight response in stressful or threatening situations

fight or flight response

coordinated set of activites that prepares the body for action; coordinated in part by the sympathetic nervous system

parasympathetic nervous system

branch of the autonomic nervous system associated with rest and regeneration

sensory neuron

communicates sensory information to the spinal cord

motor neuron

initiates a muscle response after receiving communication from the spinal cord

interneuron

as opposed to a sensory or motor neuron, a neuron that connects two other neurons

spinal reflex

rapid, automatic response involving three neurons (sensory, motor, interneuron) in the spinal cord

medulla

a structure within the hindbrain that is responsible for basic life functions and reflexes

reticular formation

runs through the core of the hindbrain and midbrain (i.e., the brainstem), involved in regulating arousal, attention, and sleep

hypothalamus

regulates body temperature, hunger, thirst, and sexual behavior, plays a role in sleep; link between brain and endocrine system, controls autonomic nervous system

thalamus

forebrain structure; processes all sensory information except smell, and then relays the information to higher brain areas in the cerebral cortex

occipital lobe

brain area that processes incoming visual information in the primary visual cortex

temporal lobe

brain area that receives incoming information about sounds that are processed in the primary auditory cortex

parietal lobe

brain area that processes information about body sensations, such as touch, temperature and pain

somatosensory cortex

brain area in parietal lobe that receives information from touch receptors located in specific locations of the body

pons

hindbrain structure where motor information crosses to the opposite side, important for coordinating movement

cerebellum

hindbrain structure important in coordinating smooth, accurate movements and physical balance

substantia nigra

midbrain structure that contains dopamine cell bodies involved in the initiation and fluidity of movement

striatum

forebrain structure that consists of caudate and putamen; part of the pathway involved in the initiation and fluidity of movement

basal ganglia

collection of subcortical brain areas involved in the control of movement

frontal lobe

largest lobe of cerebral cortex; processes voluntary motor movements in the motor cortex

motor cortex

area in frontal lobe, controls movements of different body parts, with some areas of the body having a much greater representation, allowing for greater precision and variety of movement

mirror neurons

located in the motor cortex; active when preparing to make a movement and when watching others perform the same movement; may allow humans to identify with other people, understand and imitate them

limbic system

set of forebrain structures that play a critical role in regulating emotion or feelings

amygdala

limbic system structure involved in a variety of emotions and emotional memories; important for recognizing and responding to stimuli that induce fear

orbitofrontal cortex

located behind the eye sockets; plays a role in mediating bodily responses associated with emotion

hippocampus

limbic system structure concerned with basic drives, emotions, and memory; its neurons have a high level of plasticity

prefrontal cortex

part of frontal lobes; area involved in working (or short-term) memory; implicated in higher executive functions such as reasoning, planning, decision making, and inhibition of inappropriate behavior

prefrontal cortex

part of frontal lobes; area involved in working (or short-term) memory; implicated in higher executive functions such as reasoning, planning, decision making, and inhibition of inappropriate behavior

insula

cortical structure involved in self-awareness and processing a variety of stimuli so they may be used to influence decision making

Broca's area

area located in the frontal lobe that is critical for the production of language

Wernicke's area

area located in the temporal lobe that is critical for the understanding of language

association cortex

the majority of the cerebral cortex that is not primary sensory or motor cortices that functions to produce cognition

case studies

study of persons with brain damage in order to demonstrate localization of behaviors and mental functions

amnesia

partial or total loss of memory

aphasia

condition resulting in impairment of speaking or comprehending written or oral language

brain stimulation

applying electrical stimulation to specific brain areas to examine localization of brain function and observing how this affects behavior

split-brain operation

surgery that involves separating the two cerebral hemispheres by cutting the corpus callosum

corpus callosum

thick band of myelinated axons (white matter) that connects the two cerebral hemispheres

electroencephalograph (EEG)

technique where electrodes are placed on a person's scalp, allowing measurement of changes in electrical activity in the brain

neuroimaging

techniques that allow researchers and clinicians to study the brain in awake, healthy people; includes positron emission tomography (PET) and magnetic resonance imaging (MRI)

cell body

contains structures that synthesize proteins, produce energy for the neuron, and contain genetic material; also known as soma

dendrites

receive information from other neurons, look like tree branches extending out from the cell body

axon

extends from cell body, carries information to other neurons

axon terminal

located at the end of the axon, contains everything needed for transfer of information to another neuron

myelin sheath

a fatty covering that insulates axons and increases the speed of information transfer

glial cells

provide structural and functional support for neurons - provide nutrition, regulate chemicals in the brain, remove waste products, create a blood-brain barrier

resting potential

internal charge of a neuron, around -70 millivolts compared to outside the neuron; allows neuron to respond quickly to incoming information from other neurons

ion channels

specialized pores in cell membrane that allow the passage of ions

action potential

electrical signal down the axon caused by the movement of ions across the membrane

refractory period

brief period after an action potential, with no further firing until the membrane restores the balance of ions

all-or-none principle

once threshold is reached, the electrical signal travels the entire length of the axon; the action potential either happens or it doesn't

saltatory conduction

process of action potential jumping down the axon of myelinated neurons at nodes of Ranvier

synapse

area where the axon terminal of one neuron (the presynaptic neuron) communicates with the dendrite or cell body of another neuron (postsynaptic neuron)

vesicles

small spheres filled with the chemicals released into the synapse

receptors

proteins in the cell membrane of the receiving neuron; can only recognize specific chemicals in a lock and key manner

postsynaptic potential

an electrical event; localized change in internal charge of neuron, either excitatory or inhibitory

reuptake

chemicals are taken back up into the presynaptic axon terminal where they are repackaged into vesicles

acetylcholine

neurotransmitter that enables muscle action; regulates attention, learning, memory, sleeping, and dreaming

dopamine

neurotransmitter that influences movement, motivation, emotional pleasure, and arousal

serotonin

neurotransmitter that regulates hunger, sleep, arousal, and aggressive behavior; undersupply linked to depression

norepinephrine

neurotransmitter that helps control mood and arousal; undersupply can depress mood

GABA

major inhibitory neurotransmitter; undersupply linked to seizures, anxiety, and insomnia

glutamate

major excitatory neurotransmitter; oversupply can overstimulate the brain

endorphins

neurotransmitters that act within the pain pathways and emotion centers of the brain; lack of endorphins could lower pain threshold or reduce ability to self soothe

agonists

drugs that mimic the effect of a neurotransmitter by binding to its receptor and causing the same effect

antagonists

drugs that bind to the receptor, but don't fit properly; prevent the neurotransmitter from transferring information

stimulants

psychoactive drugs that increase levels of activity, energy, attention, and alertness

CNS depressants

psychoactive drugs that decrease brain activity and arousal

opioids

class of drugs used to relieve pain, mimic endorphins and bind to same receptors in brain

hallucinogens

diverse group of drugs, cause sensory and perceptual distortions

cannabinoids

chemicals that alter perception, increase relaxation, induce time distortion, and impair coordination

tolerance

the same dose has less of an effect, or more drug is needed to achieve the same effect