AP Psychology: Biological Bases of Behavior

biological psychology

scientific study of the links between biological (genetic, neural, and hormonal) and psychological processes

neuron

nerve cell aka the building block of the nervous system

dendrites

branchy extenstions that receive messages from other cells

axon

passes messages from the cell body through its branches (terminal) to other neurons, muscles, or glands

myelin sheath

fatty tissue layer that insulates the axon and speeds up neural impulses

action potential

electrical charge that travels down a neuron’s axonl; causes neuron to fire

refractory period

period of inactivity after a neuron is fired

ions

charged particles

resting potential

when more negative ions are inside the neuron than outside it

depolarization

no charge, neutral

excitatory and inhibitory signals

(excitatory) - pushing a neuron’s accelerator; (inhibitory) - pushing its brake

threshold

level of stimulation required to trigger a neural impulse

all-or-none response

neuron’s reaction of either firing at full strength or not at all

synapse

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

synaptic gap

tiny gap at the synapse junction

neurotransmitters

chemical messengers that cross synaptic gaps between neurons; travel across across the synapse and bind to receptor sites

reuptake

neurotransmitters re-absorption by the sending neuron

acetylcholine (ach)

enables muscle action, learning, and memory; an undersupply can lead to alzhiemers disease; learning neurotransmitter

dopamine

influences movement, learning, attention/alertness, and pleasure; undersupply can lead to parkinson’s disease and an oversupply can lead to schizophrenia; pleasure neurotransmitter

serotonin

involved in mood control, appetite, sleep; undersupply can lead to depression; mood neurotransmitter

norepinephrine

helps control adrenaline, alertness, arousal; undersupply can lead to depression; concentration neurotransmitter

GABA

major inhibitory neurotransmitter (calming); undersupply linked to seizures, tremors, and insomia; calming neurotransmitter

glutamate

major excitatory neurotransmitter, involved with memory; oversupply overstimulates the brain producing migraines or seizures; memory neurotransmitter

endorphins

natural opiate-like neurotransmitters linked to pain control and pleasure; euphoria neurotransmitter

agonist

mimics neurotransmitters or prevents reuptake, makes neurons fire

antagonist

blocks neurotransmitters, stops neural firing

nervous system

the body’s electrochemical communication network, consisting of all the nerve cells (peripheral and central)

central nervous system

the brain and the spinal cord

peripheral nervous system

sensory and motor neurons that connect the central nervous system to the rest of the body; (everything other than the brain and spinal cord)

nerves

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

sensory (afferent) neurons

send information to the brain from the body

motor (efferent) neurons

send information from the brain to the body

interneurons

neurons within the brain/spinal cord that communicate internally and intervene between the sensory inputs and motor outputs

somatic nervous system

division of the peripheral nervous system that controls the voluntary movements of the skeletal muscles

autonomic nervous system

controls the self-regulated actions of internal organs and glands

sympathetic nervous system

arouses the body; arouses and expends energy

examples include:

• increases heartbeat and blood pressure

• dilates pupils

• stimulates glucose release by liver

• inhibits digestion

parasympathetic nervous system

calms the body, conserves energy;

examples include:

• contracts pupils

• slows heart rate

• stimulates digestion

• stimulates gallbladder

reflex

simple, automatic response to sensory stimulus

endocrine system

the body’s “slow” chemical communication system; set of glands that secretes hormones into the bloodstream

hormones

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

adrenal gland

pair of endocrine glands that sit above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress; trigger flight or fight response

pituitary gland

endocrine system’s most influential gland; under influence of the hypothalamus it regulates growth nd controls other glands

lesion

tissue destruction

electroencephalogram (EEG)

amplified recording of electrical activity sweeping across the brain’s surface

CT Scan

computer assisted x-ray that views the overall structure of the brain

PET Scan

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)

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

functional MRI

technique for revealing bloodflow, and, therefore, brain activity by comparing successive MRI scans, shows brain function as well as structure

brainstem

oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; brain stem is responsible for automatic survival functions

medulla

base of brainstem that controls heartbeat, blood pressure, and breathing

thalamus

brains sensory control center located on top of the brain stem; routes all incoming sensory information except for smell to appropriate areas of the brain

reticular formation (reticular activating system)

nerve network that travels through the brain stem and thalamus; plays an important role in alertness, arousal, and sleep/wakefulness

cerebellum

the “little brain”at the rear of the brainstem; controls coordination, balance, nonverbal learning, and memory

limbic system

neural system (includes hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives

amygdala

controls emotions such as aggression and fear; “attack” response in animals

hypothalamus

regulates hunger, thirst, body temperature, sex drive; contains pituitary gland; (thermometer of the body)

cerebral cortex

deals with higher level functions

glial cells

support, nourish, and protect neurons

frontal lobes

just behind the forehead; involved in speaking, muscles movements, and in making plans and judgement; contains the motor cortex

parietal lobe

top of the head towards the back; receives sensory information for touch and body position; contains the sensory cortex

temporal lobe

lying roughly above the ears; contains the auditory cortex each receiving info primarily from the opposite ear

occipital lobe

lies at the back of the head, includes the visual cortex

motor cortex

largely responsible for the voluntary movement of parts of the body

somasensory cortex (sensory cortex)

largely responsible for perceiving touch and pressure on parts of the body

association areas

areas not involved in the primary motor or sensory functions;

broca’s area

area in left frontal lobe that directs muscle movements involved in speech

wernicke’s area

area in left temporal lobe that is involved in language comprehension and expression

prefrontal cortex

plays a critical role in directing thought processes, acts as the brains central executive and is believed to be important in predicting consequences pursuing goals, maintaining emotional control, and engaging in abstract thought

Phineas Gage

railroad worker that was involved in an accident where a pole went through his head and damaged his frontal lobe; caused a major chance in his personality

brain plasticity

brains ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience

corpus callosum

large band of neural fibers connecting the two brain hemispheres and carrying messages between them

split brain

condition resulting from surgery that isolates the brain’s two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them

right hemisphere

gets sensory messages and controls motor function on the left half of the body

left hemisphere

gets sensory messages and controls motor function on the right half of the body

conciousness

our awareness of ourselves and our environment

cognitive neuroscience

interdisciplinary study of the brain activity linked with cognition

dual processing

principle that information is often simultaneously processed on separate conscious and unconscious tracks

behavior genetics

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

environment

every external influence, from prenatal nutrition to the people and things around us

chromosomes

threadlike structures made of DNA molecules that contain genes

DNA

complex double-helix molecule containing genetic information that makes up the chromosomes

genes

biochemical units of heredity that make up the chromosome; segments of DNA capable of synthesizing proteins

genome

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

identical (monozygotic) twins

twins that develop from a single fertiliezd egg that split in two, creating two genetically identical organisms

fraternal (dizygotic) twins

twins who develop from separate fertilized eggs; genetically no closer than brothers and sisters, but they share a fetal environment

molecular genetics

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

heritability

proportion of variation among individuals that we can attribute to genes; heritability of a trait may vary, depending on the range of populations and environments studied

interaction

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

evolutionary psychology

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

epigentics

study of environmental influences on gene expression that occur without a DNA change

natural selection

principle that, among the range of inherited trait variations, those contributing to reproduction and survival will most likely be passed on to succeeding generations

mutation

random error in gene replication that leads to a change

phenylketonuria (PKU)

rare inherited disorder that causes an amino acid called phenylalanine to build up in the body

pons

regulate sensory information and facial expressions

parathyroids

regulate calcium in the blood

pineal gland

sleep/wake cycle > secretes melatonin

thyroid gland

produces thyroxine(stimulates chemicals important to all body tissues), affects metabolism

selective serotonin reuptake inhibitor

blocks reuptake

Franz Gall

pioneered phrenology which studied bumps on the skull that was believed to reveal information about the brain