Unit 2A - Biological Basis of Behavior

lesion

tissue destruction

electroencephalogram (EEG)

waves of electrical activity sweeping across the brain's surface; measured by electrodes on the scalp

magnetoencephalography (MEG)

a brain imaging technique that measures magnetic fields from the brain's natural electrical activity

computed tomography scan (CT/CAT)

X-ray photographs taken from different angles and combined into a composite representation of a slice of the brain's structure

positron emission tomography scan (PET)

a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task

magnetic resonance imaging (MRI)

a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue; shows brain anatomy

functional MRI (fMRI)

a technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans; fMRI scans show brain function as well as structure

brainstem

begins at where the spinal cord swells as it enters the skull; responsible for automatic survival functions

medulla

the base of the brainstem; controls heartbeat and breathing

thalamus

the brain's sensory control center, located on top of the brainstem; directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla

reticular formation

a nerve network that travels through the brainstem into the thalamus and plays an important role in controlling arousal

cerebellum

at the rear of the brainstem; functions: processing sensory input, coordinating movement and balance, and enabling nonverbal learning and memory

limbic system

neutral system located below the cerebral hemispheres; associated with emotions and drives

*amygdala*

2 neutral clusters in the limbic system; linked to *emotion*

*hypothalamus*

a neural structure below the thalamus' directs+regulates several maintenance activities (eating, drinking, body temp.), linked to emotion and reward

*hippocampus*

a neural center located in the limbic system; helps make storage explicit (conscious) *memories* of facts and events long term

cerebral cortex

outer level of cerebral hemispheres; body's ultimate control and info-processing center (of receiving and process sensory info and direct movement)

frontal lobes

a part of cerebral cortex; involved in *speaking* and muscle movements and in *making plans and judgements*

parietal lobes

in cerebral cortex @ top; receives *sensory input* for *touch* and body position

*occipital lobes*

cerebral cortex; includes areas that receive information from the *visual* fields

*temporal lobes*

cerebral cortex; includes the *auditory* areas, each receiving information primarily from the opposite ear

motor cortex

frontal lobes; controls voluntary movements

somatosensory cortex

parietal lobes; registers and processes body touch and movement sensations

association areas

areas of the cerbral cortex that are involved in higher mental functions: learning, remembering, thinking, speaking

plasticity

the brain's ability to change, especially during childhood by reorganizing after damage or by building new pathways based on experience

neurogenesis

the formation of new neurons

neuron

a nerve cell; the basic building block of the nervous system

cell body

the part of a neuron that contains the nucleus

dendrites

a neuron's extensions that receive and integrate messages, conducting impulses toward the cell body

axon

the neuron extension that passes messages through its branches to other neurons or muscles

myelin sheath

a fatty tissue layer encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next

glial cells

cells in the nervous system that support, nourish, and protect neurons; play a role in learning, thinking, and memory

action potential

a neural impulse; a brief electrical charge that travels down an axon

threshold

the level of stimulation required to trigger a neural impulse

refractory period

a brief resting pause that occurs after a neuron has fired; action potentials cannot occur until the axon returns to its resting state

all-or-none response

a neuron's reaction of either firing or not firing

synapse

junction between the axon tip of the sending neuron and the cell body of the receiving neuron

neurotransmitters

chemical messengers that cross the synaptic gaps between neurons; when released, they travel across the synapse and bind to receptor sites on the receiving neuron influencing whether that neuron will generate an impulse

reuptake

a neurotansmitter's reabsorption by the sending neuron

endorphins

natural, opiate-like neurotransmitters linked to pain control and pleasure

agonist

a molecule that increases a neurotransmitter's action

antagonist

a molecule that inhibits or blocks a neurotransmitter's action

nervous system

the body's electrochemical communication network, consisting
of all the nerve cells and central nervous systems

central nervous system (CNS)

the brain and spinal cord

peripheral nervous system (PNS)

sensory and motor neurons that connect the CNS to the rest of the body

divided by the autonomic and somatic systems

nerves

bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sense organs

sensory (afferent) neurons

neurons that carry incoming information from the body tissues and sensory receptors to the brain and spinal cord

motor (efferent) neurons

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands

interneurons

neurons within the brain and spina cord; communicate internally and process info between the sensory inputs and motor outputs

somatic nervous system

the division of the peripheral nervous system that controls the body's skeletal muscles

autonomic nervous system (ANS)

the part of the peripheral nervous system that controls the glands and muscles of the internal organs (like the heart). Its sympathetic division arouses; its parapsympathetic division calms

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy

reflex

a simple, automatic response to a sensory stimulus (like doctors tapping the knee)

interneurons to reflex to brain

endocrine system

the body's "slow" communication system; glands that secrete hormones into the bloodstream

hormones

chemical messengers that are manufactured by the endocrine glands; travel through the bloodstream and affect other tissues

adrenal glands

a pair of endocrine glands that sit just above the kidneys and secrete hormones that help arouse the body in times of stress

pituitary gland

under the influence of the hypothalamus; regulates growth

Wernicke's Area

language comprehension

Broca's Area

muscles involved in speech

behavior genetics

the study of the relative power and limits of genetic and environmental influences on behavior

heredity

the genetic transfer of characteristics from parents to offspring

environment

every nongenetic influence from prenatal nutrition to the people and thing around

chromosomes

threadlike structures made of DNA molecules that contain the genes

DNA

a complex molecule containing the genetic information that makes up the chromosomes

genes

the biochemical units of heredity that make up the chromosomes, segments of DNA capable of synthesizing proteins

genome

the complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes

identical (monozygotic) twins

develop from a single fertilized egg that splits in two, creating two genetically identical organisms

fraternal (dizygotic) twins

develop from separate fertilized eggs. They are genetically no closer than ordinary brothers and sisters, but they share a prenatal environment

heritability

the proportion of variation among individuals in a group that we can attribute to genes;

interaction

the interplay that occurs when the effect of one factor (such as environment) depends on another factor (such as heredity)

molecular genetics

the subfield of biology that studies the molecular structure and function of genes

epigenetics

"in addition to" genetics; the study of environmental influences on genetic expression that occur without a DNA change

evolutionary psychology

the study of the evolution of behavior and the mind using principles of natural selection

mutation

a random error in gene replication that leads to a change

serotonin

mood regulation, hunger regulation, sleep, emotion
too much: hallucinations
too little: depression

dopamine

pleasure; reward and motivation, attention and emotion
too much: schizophrenia
too little: Parkinson's

GABA

inhibitory neurotransmitter which means it blocks signals from getting sent

too little: tremors and insomnia

used to treat **GA**~~**D**~~

Glutamate

excitatory neurotransmitter which means it causes too many signals to be sent

too little: seizures, migraines, and strokes if there is an oversupply