Glossary
accommodation
adapting one's current understandings (schemas) to incorporate new information; the process by which the eye's lens changes shape to focus the image of near objects on the retina.
acquisition
the initial stage of learning, during which a response is established and
gradually strengthened. In classical conditioning, the phase in which a stimulus comes to evoke a conditioned response. In operant conditioning, the strengthening of a reinforced response.
action potential
a neural impulse; a brief electrical charge that travels down an axon, produced by rapid fluctuations in the concentrations of sodium and potassium ions in the fluid inside and outside the axon membrane.
affective disorder
a group of disorders primarily characterized by a disturbance of
mood
alcohol dependence
disorder characterized by habitual consumption of alcohol in quantities large enough to interfere with daily activities
assimilation
interpreting one's new experience in terms of one's existing schemas concrete operations period - in Piaget's theory, the stage of cognitive development (from about 6 or 7 to 11 years of age) during which children gain the mental operations that enable them to think logically about concrete events
alpha waves
the relatively slow brain waves of a relaxed, awake state
amnesia
loss of memory; psychogenic amnesia, a dissociative disorder, is selective memory loss often brought on by extreme stress
amplitude
the distance from the crest (top) to the trough (bottom) of a wave
anions
negatively-charged particles.
antisocial personality
a personality disorder in which the person (usually a man) exhibits
a lack of conscience for wrongdoing, even toward friends and family members; may be aggressive and ruthless or a clever con artist
anvil
the middle of the three bones or ossicles in the middle ear; also called the incus
anxiety disorder
psychological disorders characterized by distressing, persistent anxiety
or maladaptive behaviors that reduce anxiety
attention
selective perception
auditory cortex
area of the cerebral cortex located in the temporal lobe
auditory nerve
the cranial nerve that contains the sensory neurons for hearing and the
vestibular sense
axon
part of a neuron specialized to send impulses to other neurons.
axonal conduction
electrochemical process by which the neural impulse (action potential) is passed along the axon to the axon terminals.
axon terminals
branching fibers at the end of an axon (also called synaptic knobs, synaptic terminals, or terminal buttons). Contain the synaptic vesicles which release neurotransmitters into the synaptic cleft.
base rate
the relative frequency; for a given set of possible outcomes, the relative frequency of each outcome is the number of times that particular outcome has occurred in the past divided by the total number of times that any of the outcomes in the set have occurred
basilar membrane
a flexible membrane in the cochlea of the inner ear; the wavelike
movement of this structure in response to sound stimulates the receptor cells for hearing
beta waves
the relatively fast and irregular waves of an awake, alert state
biological clock
also called the circadian rhythm
bipolar disorder
a mood disorder in which the person alternates between the
hopelessness and lethargy of depression and the overexcited state of mania
bipolar neuron
type of neuron in the retina of the eye; receives signals from the rods and cones.
catatonic schizophrenia
a type of schizophrenia primarily characterized by strange motor patterns, such as prolonged immobility or repetitive motions
cations
positively-charged particles.
cell body
part of a neuron that contains the nucleus. Also called the soma.
central tendency
the center or middle of a distribution of scores, computed as the mean, the median, or the mode
chained associations
conditioned associations; associative links formed between two
stimuli (as in classical conditioning) or between a response and a rewarding or punishing stimulus (as in operant conditioning)
chance
unpredictable fluctuations; events occurring at random
circadian rhythm
the biological clock; regular bodily rhythms (for example, of temperature and wakefulness) that occur on a 24-hour cycle
classical conditioning
a type of learning in which an organism comes to associate events.
A neutral stimulus that signals an unconditioned stimulus (US) begins to produce a response that anticipates and prepares for the unconditioned stimulus. (Also known as Pavlovian conditioning.)
classical conditioning
a type of learning in which a stimulus which automatically provokes a behavioral response comes to be associated with a neutral stimulus; the neutral stimulus then is able to provoke the response. See the PsychSim module called "Classical Conditioning" for more information.
cochlea
a coiled structure in the inner ear in which the receptor cells for hearing are located; consists of a canal that spirals for two and a half turns around a central bone core
cognitive map
a mental representation of the layout of one's environment; for example,
after exploring a maze, rats act as if they learned a cognitive map of it
concrete operations period
in Piaget's theory, the stage of cognitive development (from about 6 or 7 to 11 years of age) during which children gain the mental operations that enable them to think logically about concrete events
conditional probability
the probability that a particular event will occur, given that another event has already occurred
correlation
a statistical measure that indicates the extent to which two factors vary together and thus how well either factor predicts the other
correlation analysis
a statistical technique that indicates the extent to which two factors vary together and thus how well either factor predicts the other
correlation coefficient
a statistical measure of how much two factors vary together (and thus how well either predicts the other); referred to as r
conditioned response
in classical conditioning, the learned response to a previously
neutral conditioned stimulus
conditioned stimulus
in classical conditioning, an originally neutral stimulus that, after association with an unconditioned stimulus, comes to trigger a conditioned response
CR
CR stands for conditioned response. This response is the same as the unconditioned response, except that it is produced by the conditioned stimulus rather than by the unconditioned stimulus.
CS
CS stands for conditioned stimulus. This formerly neutral stimulus gradually begins to produce a conditioned response, as it becomes associated with the unconditioned stimulus. An example of a CS would be a dinner bell.
extinction -- the diminishing of a response when, in classical conditioning, an unconditioned stimulus (US) does not follow a conditioned stimulus (CS); or when, in operant conditioning, a response is no longer reinforced
conditioned association
the formation of associative links between two stimuli (as in classical conditioning) or between a response and a rewarding or punishing stimulus (as in operant conditioning)
conditioned associations
associative links formed between two stimuli (as in classical conditioning) or between a response and a rewarding or punishing stimulus (as in operant conditioning)
continuous reinforcement
reinforcing the desired response every time it occurs
conservation
the principle (which Piaget believed to be a part of concrete operational
reasoning) that changing the shape or form of an object or group of objects doesn't change the amount
conservation of liquid quantity
the principle (which Piaget believed to be a part of concrete operational reasoning) that volume remains the same despite changes in the forms of objects
conservation of number
the principle (which Piaget believed to be a part of concrete operational reasoning) that number remains the same despite changes in the forms of
objects
conversion reaction disorder
a rare somatoform disorder in which a person experiences very specific genuine physical symptoms for which no physiological basis can be found
corpus callosum
the largest bundle of neural fibers connecting and carrying messages between the two brain hemispheres
CR
CR stands for conditioned response. This response is the same as the unconditioned response, except that it is produced by the conditioned stimulus rather than by the unconditioned stimulus.
CS
CS stands for conditioned stimulus. This formerly neutral stimulus gradually begins to produce a conditioned response, as it becomes associated with the unconditioned stimulus. An example of a CS would be a dinner bell.
deductive reasoning
logical reasoning from the general to the specific; the reasoner begins by accepting the truth of one or more general premises or axioms and uses them to assert whether a specific conclusion is true, false, or indeterminate; also called hypothesis construction
deep sleep
stages 3 and 4 of the sleep cycle
delta waves
the large, slow brain waves associated with deep sleep (stages 3 and 4)
dendrites
parts of a neuron specialized to receive messages from other neurons.
depolarization
sudden positive shift in the electrical potential inside a neuron, caused by the inflow of positively-charged sodium ions. When this occurs at an excitatory synapse, it becomes temporarily easier for the neuron to fire.
descriptive statistics
mathematical methods for summarizing sets of data
discrimination
In classical conditioning, the ability to distinguish between a conditioned stimulus and similar stimuli that do not signal an unconditioned stimulus. In operant conditioning, responding differently to stimuli that signal that behavior will be reinforced or nonreinforced.
disorganized schizophrenia
a type of schizophrenia characterized by disorganized
thinking, incoherent speech, and inappropriate emotional outbursts
dissociative disorder
disorders in which conscious awareness becomes separated
distribution
a set of scores arranged in order from lowest to highest
distributions
sets of scores arranged in order from lowest to highest
distribution of scores
a set of scores arranged in order from lowest to highest
ear
the organ of hearing, composed of the outer, middle, and inner ears
ear canal
the chamber in the outer ear extending from the pinna to the eardrum
eardrum
a thin, tense membrane separating the ear canal from the middle ear; vibrates in
resonance to incoming sound waves; also called the tympanic membrane frequency the number of waves that pass a point in a given time (for example, per second)
egocentrism
in Piaget's theory, the inability of the preoperational child to take another's
point of view
electrode
a conductor, such as a wire, through which an electric current enters or leaves
electroencephalogram (EEG)
an amplified recording of the waves of electrical activity that sweep across the brain's surface. These waves are measured by placing electrodes on the scalp.
emotions
responses of the whole organism, involving physical arousal, expressive behaviors, and conscious experiences
encode
to process information into the memory system, for example by extracting
meaning
encoding
the processing of information into the memory system, for example by extracting meaning
excitatory synapses
synaptic connections which, when stimulated, increass the likelihood that the receiving neuron will fire.
extinction
the diminishing of a response when, in classical conditioning, an unconditional
stimulus (US) does not follow a conditioned stimulus (CS); or when, in operant conditioning,
a response is no longer reinforced
facial code
the system of emotional signals displayed by altering the positions of the facial muscles around the eyes and the mouth
FI
(fixed-interval schedule); in operant conditioning, a schedule of reinforcement that
reinforces a response only after a specified time has elapsed
fixed-interval schedule
in operant conditioning, a schedule of reinforcement that reinforces a response only after a specified time has elapsed
fixed-ratio schedule
in operant conditioning, a schedule of reinforcement that reinforces
a response only after a specified number of responses
FR
(fixed-ratio schedule); in operant conditioning, a schedule of reinforcement that
formal operations period
in Piaget's theory, the stage of cognitive development (normally beginning about age 12) during which people begin to think logically about
formal thought
type of thinking that becomes possible when the individual enters the formal operations period
frequency
the number of complete wavelengths that pass a point in a given time (for example, per second)
frequency distribution
a method of summarizing a distribution of scores by indicating the number of times that each score occurs in the distribution
frequency histogram
a graph that illustrates a frequency distribution, with a rectangle for each score in the distribution. The height of each rectangle represents the frequency of that score.
frequency polygon
a graph that illustrates a frequency distribution, with points representing the frequency of each score and lines connecting the points
hair cells
the receptor cells for hearing, which are arranged in rows along the basilar
membrane of the cochlea in the inner ear
hammer
the largest of the three bones or ossicles in the middle ear; attached to the eardrum laterally and to the anvil or incus medially; moves in resonance to the vibrations of the eardrum; also called the malleus
hemisphere
one half of the brain
Hertz
a unit of frequency; one cycle per second
Horizontal-vertical illusion
a visual illusion in which a vertical line perpendicular to a horizontal line of the same length appears longer than the horizontal line
hyperpolarization
sudden negative shift in the electrical potential inside a neuron. When this occurs at an inhibitory synapse, it becomes temporarily more difficult for the neuron to fire.
hypothalamus
a neural structure lying below ("hypo") 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
hypothesis
a testable prediction, often implied by a theory
random - occurring by chance
iconic memory
a momentary sensory memory of visual stimuli; a photographic or
picture-image memory lasting no more than a second or so
inductive reasoning
logical reasoning from the specific to the general; the reasoner begins with a set of specific observations or facts and uses them to infer a more general rule to account for those observations or facts; also called hypothesis construction
inhibitory synapses
synaptic connections which, when stimulated, decrease the likelihood that the receiving neuron will fire.
inner ear
the innermost part of the ear, containing the cochlea and the semicircular
canals
interference
failure to encode, store, or retrieve items because of interference from items learned before or after
interneurons
neurons in the brain and spinal cord that link the sensory and motor neurons. They do the additional processing of the information needed to make sense of the events occurring within your body and outside in the environment. Most of the neurons in the central nervous system are of this type.
ions
positively-charged or negatively-charged particles (atoms or molecules).
lateral
on the side; opposite of medial
lateral hypothalamus
region in the left or right side of the hypothalamus
learning
a relatively permanent change in an organism's behavior due to experience
lesion
tissue destruction; a naturally or experimentally caused destruction of brain tissue
LH
lateral region of the hypothalamus
likelihood estimation
calculating how likely it is that a certain event will occur
long-term memory
the relatively permanent and limitless storehouse of the memory
system
loudness
the quality of the psychological experience (sensation) of a sound that is most related to the amplitude of the physical sound stimulus
mean
the arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores
median
the middle score in a distribution; half the scores are above it and half are below it
memory
the relatively permanent and limitless storehouse of the memory system
proactive interference - the disruptive effect of prior learning on the recall of new
information
mental operations
logical thought processes that are reversible
middle ear
the chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup) that transmit the vibrations of the eardrum to the cochlea's oval window
minimax strategy
in gaming situations, a strategy that minimizes potential losses and
maximizes potential gains under the worst situation that an opponent can produce.
mode
the most frequently occurring score in a distribution
motor neurons
neurons that carry instructions from the central nervous system to the body's organs and tissues; also called efferent neurons.
Müller-Lyer illusion
a visual illusion in which a horizontal line looks longer if attached at each end to an outward-extending, V-shaped object, and looks shorter if attached at each end to an inward-extending, V-shaped object
negative correlation
scores that are negatively correlated are associated in such a way that one score falls as the other rises (as in the relationship between self-esteem and depression); correlation coefficient is negative
negatively correlation
scores that are negatively correlated are associated in such a way that one score falls as the other rises (as in the relationship between self-esteem and depression); correlation coefficient is negative
negative reinforcement
in operant conditioning, a situation in which the subject's response terminates (by escaping) or prevents (by avoiding) the delivery of an aversive stimulus. Thus the removal of the aversive stimulus increases the likelihood that the response will occur.
nervous system
the body's speedy , electrochemical communication system, consisting of all the nerve cells of the peripheral and central nervous systems.
neurons
nerve cells; for more information, see the Neural Messages module
neurotransmitters
molecules released by the axon terminal into the synapse, influencing the firing rate of the next neuron.
no correlation
correlation coefficient is near zero
non-zero-sum environment
a situation in which shared resources are not limited. This means that certain sets of decisions could lead to gains for all, while other sets of decisions could produce losses for everyone.
non-zero-sum game
a laboratory game in which shared resources are not limited. This
means that certain sets of decisions could lead to gains for all, while other sets of decisions could produce losses for everyone.
normal
with reference to a distribution, normal means a symmetrical bell-shaped curve that describes the distribution of many physical and psychological attributes. Most scores fall near the average, and fewer and fewer scores lie near the extremes.
not correlated
correlation coefficient is near zero
object permanence
the awareness that things continue to exist even when not perceived.
occipital
with reference to the brain, the portion of the cerebral cortex lying at the back of the head; includes the visual areas, each of which receives visual information from the opposite visual field
operant behavior
behavior that operates on the environment, producing consequences.
operant conditioning
a type of learning in which a behavior is strengthened or diminished, depending on the nature of the consequences that follow it
optic nerve
the nerve that carries neural impulses from the eye to the brain
outer ear
the part of the ear consisting of the pinna, the ear canal, and the eardrum
oval window
an opening in the medial wall of the entrance or vestibule of the cochlea; closed by the foot of the stirrup or stapes; converts the mechanical vibrations of the ossicles into pressure changes in the cochlea; also called vestibular window
partial reinforcement
reinforcing a response only part of the time; results in slower acquisition of response but much greater resistance to extinction than does continuous reinforcement
payoff matrix
in decision games, this matrix shows the outcome of each possible
decision one player could make, given each possible decision the other player could make.
person-centered therapy
therapy developed by Carl Rogers. The therapist provides a warm, supportive, non-judgmental environment in which the person can explore feelings and gain self-awareness.
pinna
the shell-shaped part of the outer ear that protrudes from the side of the head; also called the auricle
pitch
the quality of the psychological experience (sensation) of a sound that is most related to the frequency of the physical sound stimulus
Poggendorf illusion
a visual illusion in which the center portion of a diagonal straight line is hidden by a rectangular object, but the two ends are visible. The two ends appear offset; that is, they don't appear to be part of the same line.
Ponzo illusion
a visual size illusion in which two converging lines cause objects between the two lines to look larger near the converging ends of the lines and smaller near the diverging ends
positive correlation
scores that are positively correlated go up and down together (as with high school and college GPAs); correlation coefficient is positive
positively correlated
scores that are positively correlated go up and down together (as with high school and college GPAs); correlation coefficient is positive
positive reinforcement
in operant conditioning, a situation in which the subject receives a reinforcer after performing a particular operant behavior and does not receive a reinforcer if that operant behavior is not performed. Thus the presence of the reinforcer increases the likelihood that the behavior will occur.
preoperational period
in Piaget's theory, the stage (from about 2 to 6 or 7 years of age) during which a child learns to use language but does not yet comprehend the mental operations of concrete logic
primary affects
according to Paul Ekman, the six basic emotions that are displayed on the face: surprise, fear, disgust, anger, happiness, sadness
prisoners' dilemma game
a laboratory game which pits competition against cooperation.
The highest combined payoff to the two players occurs if both choose a cooperative response, but a higher individual payoff goes to a player choosing a competitive response while the other chooses a cooperative response.
proactive interference
the disruptive effect of prior learning on the recall of new information
probability
a ratio expressing the likelihood of an occurrence
pyramidal neuron
neurons whose cell body has the shape of a pyramid; found in the neocortex and hippocampus.
r
the correlation coefficient; a statistical measure of how much two factors vary together (and thus how well either predicts the other)
range
the difference between the highest and lowest scores in a distribution
raw scores
scores that have not been averaged, sorted, or processed yet
recall
to get information out of memory storage
receptor
special area on a neuron's membrane that can interact with neurotransmitter molecules. When a molecule binds to the receptor, changes occur in the membrane.
reinforcer
in operant conditioning, any event that strengthens the behavior it follows
relative frequency
for a given set of possible outcomes, the relative frequency of each outcome is the number of times that particular outcome has occurred in the past divided by the total number of times that any of the outcomes in the set have occurred
REM
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 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
repolarization
negative shift in the electrical potential inside the axon, caused by the outflow of positively-charged potassium ions. This produces a return to the resting potential of the axon.
respondent behavior
behavior that occurs as an automatic response to some stimulus; Skinner's term for behavior learned through classical conditioning
resting potential
the axon's electrical state during the period between action potentials. The fluid inside the axon membrane is electrically negative compared to the fluid outside the axon.
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
retrieval
the process of getting information out of memory storage
retrieve
to get information out of memory storage
retroactive interference
the disruptive effect of new learning on the recall of old
information
retroactive interference
the disruptive effect of new learning on the recall of old information
Rogerian approach
pioneered by Carl Rogers, this perspective on therapy focuses on the person or client rather than the therapist. The therapist provides a warm, supportive, non-judgmental environment in which the person can explore feelings and gain self-awareness.
saddle point
in decision games based on a payoff matrix, the point at which the minimax strategies of the two players converge.
scatterplot
a graphed cluster of dots
schema
a concept or framework that organizes and interprets information
semicircular canals
three small semicircular tubes or ducts in the bony labyrinth of the inner ear; the anterior, lateral, and posterior canals lie in planes at right angles to each other; involved in sensing rotational motion and head position
sensorimotor period
in Piaget's theory, the stage (from birth to about 2 years of age) during which infants know the world mostly in terms of their sensory impressions and motor activities
sensory neurons
neurons that carry information from the body's tissues and organs to the central nervous system; also called afferent neurons.
set-point
point of equilibrium, as in a thermostat
skewed
with reference to a distribution, skewed means that more of the scores are clustered toward one end of the distribution
skewed distribution
a distribution that is not symmetrical; more of the scores are clustered toward one end of the distribution
Skinner Box
a chamber containing a bar or key that an animal can manipulate to obtain a food or water reinforcer, and devices to record the animal's rate of bar pressing or key pecking; used in operant conditioning research
sleep spindles
very brief bursts of rapid brain activity observed in stage 2 of the sleep cycle
soma
another name for the cell body of a neuron.
somatosensory neuron
neuron that carries information from the skin to the spinal cord.
split-brain
a condition in which the two hemispheres of the brain are isolated by cutting the connecting fibers (mainly those of the corpus callosum) between them
spontaneous recovery
the reappearance, after a rest period, of an extinguished conditioned response
standard deviation
a measure of score variability, computed by (1) calculating the difference between each score and the mean, (2) squaring those differences, (3) calculating the mean of the squares of the differences, and (4) taking the square root of this mean
statistics
special numbers that have been computed from a set of scores to tell us something about the scores
stirrup
the smallest of the three bones or ossicles in the middle ear; attached to the oval window medially and to the anvil or incus laterally; transmits the vibrations of the ossicles to the oval window; also called the stapes
storage
the maintenance of encoded information over time
symmetrical distribution
a distribution that is balanced; the pattern of scores below the midpoint of the distribution is the mirror-image of the pattern of scores above the midpoint of the distribution
synapse
the junction of the axon tip of the sending neuron with the dendrite or cell body of the receiving neuron. Technically, a synapse consists of the pre-synaptic membrane, the synaptic gap or cleft, and the post-synaptic membrane.
synaptic transmission
chemical process by which the neural impulse is passed from the axon terminal of one neuron to the dendrite or cell body of another neuron.
synaptic vesicles
sacs in the axon terminals that contain the neurotransmitter molecules.
timbre
the quality of a sound that enables us to tell what sort of object produced the sound; related to the waveform of the sound wave.
trucking game
a laboratory game in which two players share a single road (limited resource), and must choose to cooperate or compete with each other for the use of the road.
uncorrelated
correlation coefficient is near zero
unconditioned response
in classical conditioning, the unlearned, naturally occurring response to the unconditioned stimulus, such as salivation when food is in the mouth
unconditioned stimulus
in classical conditioning, a stimulus that unconditionally (naturally and automatically) triggers a response
UR
UR stands for unconditioned response. This is an automatic response that is always produced by an unconditioned stimulus. For example, lemon juice in your mouth (an unconditioned stimulus) triggers the release of saliva (the unconditioned response).
US
US stands for unconditioned stimulus. This type of stimulus always produces a response. The association doesn't need to be learned. An example of a US would be lemon juice, which always produces salivation.
variable-interval schedule
in operant conditioning, a schedule of reinforcement that reinforces a response at unpredictable time intervals
variable-ratio schedule
in operant conditioning, a schedule of reinforcement that reinforces a response after an unpredictable number of responses
variability
the degree to which the scores are clustered or scattered around the middle of the distribution; low variability means that the scores are packed tightly around the middle of the distribution
ventromedial
medial means "in the middle," ventro means on the same side of the body as the stomach (as opposed to the back)
ventromedial hypothalamus
region in the bottom/middle of the hypothalamus
visual field
the portion of the visual environment that is projected to one hemisphere
VMH
ventromedial region of the hypothalamus
waveform
the shape of a wave; pure single-frequency waves produced by a tuning fork or flute have a smooth, rounded shape, while complex waves produced by a piano have an irregular shape with many small waves (harmonics) of different frequencies embedded in the main wave
zero-sum environment
a laboratory game in which shared resources are strictly limited. If one person gains, the others lose.
zero-sum game
a laboratory game in which shared resources are strictly limited. If one person gains, the others lose.