Unit 1: Biological Basis of Behavior

AP Psychology

Evolutionary Perspective

Perspective that focuses on the biological bases of universal mental characteristics that all humans share

Natural Selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits

Behavior Genetics

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

Identical (Monozygotic) Twins

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

Environment

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

Heredity

the passing on of physical or mental characteristics genetically from one generation to another.

nature-nurture issue

the longstanding controversy over the relative contributions that genes and experience make to the development of psychological traits and behaviors. Today's science sees traits and behaviors arising from the interaction of nature and nurture

Eugenics

the (psudo) science of improving a human population by controlled breeding to increase the occurrence of desirable heritable characteristics

Nervous System

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

Central Nervous System

brain and spinal cord

Autonomic Nervous System

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

Sympathetic Nervous System

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

Peripheral Nervous System

A division of the nervous system consisting of all nerves that are not part of the brain or spinal cord.

Somatic Nervous System

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

Parasympathetic Nervous System

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

Neurons

nerve cells

Cell Body

Largest part of a typical neuron; contains the nucleus and much of the cytoplasm

Synapse

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

Glial Cells

cells in the nervous system that support, nourish, and protect neurons

Reflex Arc

A relatively direct connection between a sensory neuron and a motor neuron that allows an extremely rapid response to a stimulus, often without conscious brain involvement.

Sensory Neurons

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

Motor Neurons

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

Interneurons

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

Action Potential

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

All-or-Nothing Principle

The principle that once the electrical impulse reaches a certain level of intensity (its threshold), it fires and moves all the way down the axon without losing any intensity.

Depolarization

The process during the action potential when sodium is rushing into the cell causing the interior to become more positive.

Reuptake

a neurotransmitter's reabsorption by the sending neuron

Multiple Sclerosis

A chronic disease of the central nervous system marked by damage to the myelin sheath. Plaques occur in the brain and spinal cord causing tremor, weakness, incoordination, paresthesia, and disturbances in vision and speech

Neurotransmitters

chemical messengers that cross the synaptic gaps between neurons

Excitatory Neurotransmitters

chemicals released from the terminal buttons of a neuron that excite the next neuron into firing

Dopamine

A neurotransmitter associated with movement, attention and learning and the brain's pleasure and reward system.

Norepinephrine

A neurotransmitter involved in arousal, as well as in learning and mood regulation

GABA

a major inhibitory neurotransmitter

Substance P

A neurotransmitter that is involved in the transmission of pain messages to the brain.

Hormones

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

Leptin

A hormone produced by adipose (fat) cells that acts as a satiety factor in regulating appetite.

Melatonin

sleep-inducing hormone

Refractory Period

a period of inactivity after a neuron has fired

Resting Potential

Threshold

he level of stimulation required to trigger a neural impulse

Myasthenia Gravis

a chronic autoimmune disease that affects the affects the relationship between acetylcholine (ACh) and muscles and produces serious weakness of voluntary muscles that in the following ways

Inhibitory Neurotransmitters

chemicals released from the terminal buttons of a neuron that inhibit (stop) the next neuron from firing

Serotonin

A neurotransmitter that affects hunger,sleep, arousal, and mood.

Glutamate

A major excitatory neurotransmitter; involved in memory

Endorphins

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

Acetylcholine

neurotransmitter that enables muscle action, learning, and memory

Adrenaline

A hormone released into the bloodstream in response to physical or mental stress

Ghrelin

A hunger-arousing hormone secreted by an empty stomach

Oxytocin

hormone that is released during labor, nursing, sexual response cycle and hugging

Psychoactive Drugs

a chemical substance that alters perceptions and moods

Antagonist

a substance that binds to synaptic receptors and decreases the effect of a neurotransmitter

Stimulants

Drugs (such as caffeine, nicotine, and the more powerful amphetamines, cocaine, and Ecstasy) that excite neural activity and speed up body functions.

Caffeine

a stimulant drug found in coffee, tea, cola drinks, chocolate, and many over-the-counter medications

Cocaine

A stimulant drug derived from the coca tree.

Opioids

opium and its derivatives, such as morphine and heroin; depress neural activity, temporarily lessening pain and anxiety

Heroin

depressant; rush of euphoria, relief from pain; depressed physiology, agonizing withdrawal

Addiction

compulsive drug craving and use, despite adverse consequences

Agonist

a molecule that increases a neurotransmitter's action my imitating it

Reuptake Inhibitor

Chemical that binds to the terminal buttons and prevents reuptake, thereby causing an excess of that NT

Depressants

drugs (such as alcohol, barbiturates, and opiates) that reduce neural activity and slow body functions

Alcohol

a depressant that causes inhibitions, relaxation, and side effects such as brain shrinking

Hallucinogens

psychedelic ("mind-manifesting") drugs, such as LSD, that distort perceptions and evoke sensory images in the absence of sensory input

Marijuana

a drug, often smoked, whose effects include euphoria, impairment of judgment and concentration and occasionally hallucinations; rarely reported as addictive

Tolerance

the diminishing effect with regular use of the same dose of a drug, requiring the user to take larger and larger doses before experiencing the drug's effect

Withdrawal

the discomfort and distress that follow discontinuing the use of an addictive drug

Brain Plasticity (neuroplasticity)

The brain's ability to rearrange the connections between neurons due to learning or experience

EEG

An amplified recording of the waves of electrical activity that sweep across the brain's surface. These waves are measured by electrodes placed on the scalp.

fMRI

A technique for revealing blood flow and, therefore, brain activity b comparing successive MRI scans.

Lesions

removal or destruction of part of the brain

Brain Stem

Connects the brain and spinal cord

Medulla

the base of the brainstem; controls heartbeat and breathing

Reticular Activating System (Reticular Formation)

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

Cerebellum

A large structure of the hindbrain that controls fine motor skills.

Cerebral Cortex

The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center.

Limbic System

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

Thalamus

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

Hypothalamus

A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.

Pituitary Gland

The endocrine system's most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.

Hippocampus

A neural center located in the limbic system that helps process explicit memories for storage.

Amygdala

A limbic system structure involved in memory and emotion, particularly fear and aggression.

Corpus Callosum

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

Broca's Area

Controls language expression - an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech.

Wernicke's Area

controls language reception - a brain area involved in language comprehension and expression; usually in the left temporal lobe

Cortex Specialization

The tendency for one side or area of the brain to carry out specific brain activities. Even though both sides of the brain are almost identical, one hemisphere primarily carries out some functions over others.

Contralateral Hemispheric Organization

left side of brain controls right side of body while right brain controls left body except smell

Aphasia

impairment of language, usually caused by left hemisphere damage either to Broca's area (impairing speaking) or to Wernicke's area (impairing understanding).

Occipital Lobe

A region of the cerebral cortex that processes visual information

Temporal Lobe

A region of the cerebral cortex responsible for hearing and language.

Parietal Lobe

A region of the cerebral cortex whose functions include processing information about touch.

Somatosensory Cortex

area at the front of the parietal lobes that registers and processes body touch and movement sensations

Frontal Lobe

A region of the cerebral cortex that has specialized areas for movement, abstract thinking, planning, memory, and judgement

Prefrontal Cortex

part of frontal lobe responsible for thinking, planning, and language

Motor Cortex

an area at the rear of the frontal lobes that controls voluntary movements

consciousness

our awareness of ourselves and our environment

circadian rhythm

the biological clock; regular bodily rhythms (for example, of temperature and wakefulness) that occur on a 24-hour cycle

jet lag

a disruption of circadian rhythms due to crossing time zones

NREM

refers to sleep during which there is no rapid eye movement

hypnagogic sensation

As you are falling asleep, you may have a sensation of falling (where your body may suddenly jerk) or floating weightlessly.

REM Sleep

Rapid eye movement sleep, a recurring sleep stage during which vivid dreams commonly occur. Also known as paradoxical sleep, because the muscles are relaxed (except for minor twitches) but other body systems are active.

REM Rebound

the tendency for REM sleep to increase following REM sleep deprivation (created by repeated awakenings during REM sleep)