AP Psychology Unit 1 Biological Bases of Behavior (1.1, 1.2, 1.3, 1.4, 1.5, 1.6)

Sensation

the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment

synesthesia

A condition in which one sense is simultaneously perceived as if by one or more additional senses.

absolute threshold

The minimum stimulus intensity required to detect a stimulus 50% of the time.

weber's law

The principle that to perceive their difference, two stimuli must differ by a constant proportion, not a constant amount.

sensory adaptation

tendency of sensory receptor cells to become less responsive to a stimulus that is unchanging

lens

the transparent structure behind the pupil that changes shape to help focus images on the retina

accommodation

The process by which the eye's lens changes shape to focus near or far objects on the retina.

retina

the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information

cones

Photoreceptors that detect color and detail, functioning in daylight or well-lit conditions.

rods

Photoreceptors that detect black, white, and gray; necessary for peripheral and twilight vision.

trichromatic theory

The theory that the retina contains three different color receptors—one most sensitive to red, one to green, one to blue—which, when stimulated in combination, can produce the perception of any color

opponent-process theory

the theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision.

Transduction

The conversion of one form of energy into another. In sensory processing, it refers to transforming stimulus energies into neural impulses.

Perception

The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

Just-noticeable Difference (JND)

The smallest difference in stimulus intensity that a specific sense can detect.

Blind Spot

The point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there.

Visual Nerve

Another term for the optic nerve that carries neural impulses from the eye to the brain.

Nearsightedness

A condition in which nearby objects are seen more clearly than distant objects.

Farsightedness

A condition in which far objects are seen more clearly than near objects.

Photoreceptors

Cells in the retina that respond to light.

Afterimages

Images that occur when a visual sensation persists for a brief time even after the original stimulus is removed.

Fovea

The central focal point in the retina, around which the eye's cones cluster.

Ganglion Cells

Neurons that relay information from the retina to the brain via the optic nerve.

Wavelength

The distance between successive peaks of a wave, typically used in physics and communications to specify wave frequencies.

Pitch

A tone's experienced highness or lowness; depends on frequency.

Amplitude

The height of a wave, determining the loudness of sounds.

Loudness

A sound's intensity.

Pitch Perception

How high or low a sound seems.

Sound Localization

The process by which the location of sound is determined.

Mid ear

the chamber between the eardrum and cochlea contains three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea's oval window (contains ossicles)

inner ear

contains cochlea, semicircular canals, and vestibular sacs

sensorineural hearing loss

Hearing loss caused by damage to the cochlea's receptor cells or to the auditory nerves.

conduction hearing loss

Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea.

place theory

The theory that links the pitch we hear with the place where the cochlea's membrane is stimulated.

frequency theory

The theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, enabling us to sense its pitch.

Volley Theory

The theory that frequencies of sound are coded by the rate of firing of neurons in the auditory nerve.

Consciousness

awareness of unique thoughts, memories, feelings, sensations, and environments

Circadian rhythm

the biological clock; regular bodily rhythms that occur on a 24-hour cycle

Jet lag

a disruption of circadian rhythms due to crossing time zones

Shift work

a pattern of work in which a person sometimes works during the day and sometimes during the night

REM sleep

characterized by rapid eye movements and a high level of brain activity; accounts for about 25% of a person's total sleep

REM rebound

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

NREM stage 1

a transition period between wakefulness and sleep ("nodding off") characterized by relaxation and easy arousal

NREM stage 2

characterized by continued slowing of heartbeat, breathing, muscle activity, and eye movements; accounts for about half of a person's total sleep

NREM stage 3

characterized by muscle relaxation, lowered blood pressure, and slower breathing; deepest sleep occurs in this stage

Hypnagogic sensations

imaginary images or sensations (e.g., falling or floating) that seem real and occur as a person is falling asleep

Activation-synthesis (dreams)

the theory that dreams are the result of the cerebral cortex interpreting and organizing random flashes of brain activity, originating in the lower brain structures, especially the pons

Consolidation theory (dreams)

the theory that during sleep, the brain is best able to integrate newly encoded memory into long-term store and that dreaming is influenced by this process

Restoration of resources

the theory that people need rest to recover energy lost throughout the day in order to be productive and healthy

Insomnia

recurring problems in falling or staying asleep. (Myers Psychology for AP 2e p. 238)

Narcolepsy

a sleep disorder characterized by unmanageable drowsiness and/or uncontrollably falling into REM sleep during the day

REM sleep behavior disorder

a disorder in which a person physically acts out vivid, often unpleasant dreams with vocal sounds and sudden, often violent, arm and leg movements during REM sleep

Sleep apnea

a disorder in which a person stops breathing for brief periods while asleep

Somnambulism

the condition of walking or performing some other activity without awakening; also known as sleepwalking

heredity

Passing of traits from parents to offspring

nature

the influence of our inherited characteristics on our personality, physical growth, intellectual growth, and social interactions

nurture

external factors that one experiences, such as family interactions or education.

Genetic predisposition

an inherited genetic pattern that makes one susceptible to a certain disease or behaviors

evolutionary perspective

explores how natural selection affects the expression of

behavior and mental processes to increase survival and reproductive success.

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.

eugenics

study of factors that influence the hereditary qualities of the human race and ways to improve those qualities

twin studies

Research comparing the similarities between identical and fraternal twins to understand the influence of genetics versus environment.

family studies

researchers assess hereditary influence by examining blood relatives to see how much they resemble one another on a specific trait

adoption studies

assess hereditary influence by examining the resemblance between adopted children and both their biological and their adoptive parents

central nervous system

brain and spinal cord; interacts with all processes in the body.

peripheral nervous system

relays messages from the central nervous system

to the rest of the body and includes the autonomic and somatic nervous systems.

Autonomic nervous system

governs processes that are involuntary and includes

the parasympathetic and sympathetic nervous systems.

sympathetic nervous system

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

parasympathetic nervous system

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

somatic nervous system

the division of the peripheral nervous system that controls the body's skeletal muscles; governs processes that are voluntary.

neurons

neural cells that transmit information

Glial cells

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

reflex arc

in the spinal cord; demonstrates how neurons within the central and peripheral nervous systems work together to respond to stimuli. Three types of neurons work together: sensory, motor, and interneurons.

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

neural transmission

electrochemical communication within and between neurons and the final destination

action potential

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

all-or-nothing principle

Once action potential reaches threshold, either fires or doesn't

depolarization

change in charge when neuron fired positive ions through the cell membrane

refractory period

the time following an action potential during which a new action potential cannot be initiated

reuptake

a neurotransmitter's reabsorption by the sending neuron

neural threshold

The minimum level of stimulation required to get a neuron to fire.

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

Myasthenia gravis

a chronic autoimmune disease that affects the neuromuscular junction and produces serious weakness of voluntary muscles

excitatory neurotransmitters

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

inhibitory neurotransmitters

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

dopamine

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

Serotonin

Affects mood, hunger, sleep and arousal. Undersupply linked to depression.

Norepinephrine

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

Glutamate

A major excitatory neurotransmitter; involved in memory

GABA

a major inhibitory neurotransmitter; regulates sleep and wake cycles

Endorphines

natural, opiatelike neurotransmitters linked to pain control and to pleasure.

Substance P

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

Acetylcholine

enables muscle action, learning, and memory

Hormones

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

Adrenaline

a hormone secreted by the adrenal glands, especially in conditions of stress, increasing rates of blood circulation, breathing, and carbohydrate metabolism and preparing muscles for exertion.

Leptin

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

Ghrelin

A hunger-arousing hormone secreted by an empty stomach

Melatonin

A hormone manufactured by the pineal gland that produces sleepiness.