Glossary of Terms for Operant Conditioning

Glossary of Terms for Operant Conditioning

This glossary of terms will be helpful in your training program planning and explaining your reptile training program.

Absolute Threshold	The minimum amount of stimulus energy to which a receptor will respond 50% of the time.
Abulia	An organism whose performances are occurring at a low frequency because the number of performances required for reinforcement is too high. The state of an organism in which there is a loss of will power; there is an inability to act or make decisions. The term usually refers to a performance that occurs at a low rate as a result of its schedule of reinforcement.
Acclimatization	To accustom or become accustomed to a different climate, environment, or circumstances, as by a physiological or psychological changes.
Accommodation	The process of changing rules or schemes to acquire new information that does not fit existing schemes.
Activation Syndrome	A large group of responses that are elicited by the environment, usually paired with emotions such as fear or anger, and characterized by flight or fight. The effect of a large group of responses that are elicited together by certain stimuli.
Adaptation	Adjustment to new surroundings, characterized by a decrease in excitability.
Adverse	Tending to discourage, retard, or make more difficult.
Affiliation	A form of integration involving the maintenance of proximity to other individuals.
Aggression	Behavior aimed—consciously or unconsciously—at hurting someone, or the impulse to do so.
Alternate Response Training	A technique in which the individual is trained to engage in a response that interferes with or replaces another response to be controlled or eliminated.
Ambivalence	Feelings of both liking and disliking someone or something.
Amplitude	The degree of displacement of a sound wave; a physical property of sound. The psychological term for amplitude is loudness.
Anatomical	The structure or form of the individual parts of the body, both external and internal.
Androgen	Any of the hormones that develop and maintain masculine characteristics.
Ankus	A tool used in elephant training that consists of a short rod ending in a pointed hook. It is used to guide or direct the animal during training or work sessions.
Anterior	Before or in front of.
Anticipation	The condition of expecting something.
Anti-Social Behavior	An undesirable response that is beyond the usual parameters of a specific culture.
Anxiety	A descriptive term that refers to changes in behavior produced by the onset of an aversive stimulus. The emotional predisposition that is generated by a conditioned aversive stimulus.
Appendages	A smaller part of a body (e.g., flippers, arms) attached to a larger part of the body.
Approach-Approach Conflict	A situation in which an organism is faced with the choice between two desirable goals.
Approach-Avoidance Conflict	A situation in which an organism wants something but is afraid of obtaining it; opposition between two incompatible response tendencies of desire and fear.
Approximation	The process of approximation is the reinforcement of partial or preliminary responses on the way to the organism’s emitting the complete form of the desired response.
Arousal	The inciting and energizing of behavior by an internal or external stimulus.
Assimilation	The concept that new information is acquired through the application of existing rules or schemes.
Association	Process by which an organism connects related elements such as perceptions, memories, or ideas with each other.
Attachment	A form of integration involving the maintenance of proximity to both individuals and aspects of the environment.
Attitude	The evaluative and affective aspect of an organism’s responses and perceptions toward a given object or situation.
Attraction	A form of integration involving primarily the gaining of proximity and the capacity of an object to elicit approach behavior.
Autonomic Conditioning	Operant conditioning technique for controlling autonomic responses (blood pressure, intestinal contractions, et cetera) that are normally not under the organism’s control.
Aversion	A dislike or avoidance of something.
Aversive Conditioning	Technique in which a painful or discomforting stimulus is paired with a stimulus in order to extinguish the undesirable response to that stimulus.
Aversive Stimulus	A stimulus whose termination or avoidance thereof increases the frequency of a response it precedes. An increase in the frequency of a behavior to terminate an aversive stimulus is said to have been negatively reinforced, where a decrease in frequency is said to have been punished.
voidance-Avoidance Conflict	Situation in which an organism is forced to choose one of two undesirable goals.
Avoidance Behavior	Behavior that increases in frequency because it postpones the onset of an aversive stimulus (and is, thus, negatively reinforced).
Avoidance Conditioning	A response to a cue that is instrumental in avoiding a painful experience.
Avoidance Learning	Conditioning technique in which the subject learns to avoid an unpleasant stimulus or situation.

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Baiting	A training technique in which the deliberate movement or placement of food is used to maneuver an animal to a desired location. Generally considered an ineffective training method as the response is entirely food dependent and the animal is not under any form of stimulus control.
Baseline	The frequency that behavior is performed prior to initiating a behavior modification program.
Behavior	A broad term to connote all the responses, overt or implicit, muscular or glandular, of an organism.
Behavioral Chain	A group of behaviors in a specific order forming a more complex behavior and defined as a unit to the organism. See Chain.
Behavioral Drift	A change or stray from the norm in standard of response. The result of drift over a period of time is deviation.
Behavioral Enrichment	Stimuli and methods used as tools to increase interest in the environment and decrease the frequency of stereotypical behaviors.
Behaviorism	School of psychology that relies on objective observation of overt behavior.
Behavior Modification	The differential reinforcement of successive approximations leading to a target behavior pattern.
Binocular Vision	The fusion of the two separate retinal images as the two eyes function in unison.
Blind Spot	The point where the optic nerve leaves the eye. At this point there are no light receptors.
Bond	A relationship that an organism maintains with a conspecific towards which certain behavior is exclusively or preferentially directed.
Bridging Stimulus	A stimulus that pinpoints in time the precise moment of a desired behavior and bridges the gap in time between that point and when the organism may receive further reward. A stimulus that signals the delivery of a reinforcer. Often called a secondary or conditioned reinforcer because it acquires its effectiveness through a history of being paired with primary reinforcement.
Brightness	The psychological property of color, usually determined by the amount of light energy emitted by an object.

- C -
Catharsis	The reduction in the strength of an impulse following expression of the impulse.
Cerebral Cortex	The highest region of the brain that controls the more complex functions of the organism; composed of deep infoldings that cover parts of the forebrain.
Cerebrotonia	A temperament type that is characterized by restraint, inhibition, and a desire for solitude.
Chain	Two or more behaviors linked together as a single unit. One behavior produces the conditions that make the next behavior possible. The stimulus linking the behaviors together serves as both as a conditioned reinforcer, maintaining the topography and frequency of the behaviors produced, and as the stimuli setting the occasion for the following behaviors. A series of behaviors that are linked by stimuli that act both as conditioned reinforcers and discriminative stimuli. Chains are always trained in reverse sequence.
Chaining	The process of learning a sequence of behaviors that proceed semi-automatically in a determinate order; the last previous response provides the stimulus for the succeeding behavior and the succeeding behavior reinforces the behavior that precedes it. A chain consists of two or more behaviors linked by a common stimulus. A chain is trained backwards, beginning with the last behavior, then the second-to-last behavior, etcetera.
Classical Conditioning	A form of conditioning in which stimuli associated with naturally meaningful stimuli tend to become substitutes for the stimuli themselves and to elicit similar responses. A cause-and-effect event where the stimulus is an adequate explanation for the response. The response is elicited reflexively where the organism exercises no control in the situation and the organism’s action produces no change in its environment. Technically, the pairing of a conditioned stimulus (CS) with an unconditioned stimulus (US) elicits a conditioned response (CR) similar to the unconditioned response (UR) originally elicited by the unconditioned stimulus.
Coercive Incentive	An incentive that is imposed upon an organism to get it to behave in a certain way regardless of its needs.
Cognition	The mental processes—including perception, memory, and thinking—by which an organism acquires knowledge, makes plans, and solves problems.
Communication	A general term for changes or information and feelings between two or more individuals. The passing of information from one organism to another (and so influencing its behavior) by means of signals that have developed for that purpose.
Concurrent Behavior	A response occurring simultaneously with another.
Conditioned Fear	Anxiety that results from a neutral stimulus that has been associated with one that elicits fear.
Conditioning	The process by which a response is made stronger (increasing the probability of its recurrence in a similar situation) by pairing a reinforcer with the response.
Conditioned Aversive Stimulus	An event that is initially neutral but has acquired aversive properties by virtue of being paired with aversive events or with a signal that no reinforcement will be coming.
Conditioned Reinforcer	A previously neutral stimulus that has become reinforcing because of its association with a primary reinforcer; it derives its meaning as a result of its association with basic, unconditioned reinforcers. See Secondary Reinforcer.
Conditioned Response (CR)	A new or modified response that is elicited only by a given stimulus after conditioning has occurred. In classical conditioning, a response that develops to the conditioned stimulus after a number of pairings of the conditioned stimulus with an unconditioned stimulus. The conditioned response is similar to the unconditioned response.
Conditioned Stimulus (CS)	A stimulus that has the property of producing a response through pairing or association. In classical conditioning, a stimulus with which the unconditioned stimulus is paired; as a result of the pairing, the CS comes to elicit a response similar to the original response (UR) to the unconditioned stimulus (US).
Conditioning	A change in the frequency and form of a behavior due to the influences of the environment. It can be brought about by the application of reinforcers or punishers.
Cones	Receptors within the retina of the eye that transform light energy into nerve impulses. Cones are found predominately in the fovea and are responsible for color vision.
Conflict	A state in which an organism is simultaneously motivated in two or more incompatible ways.
Conformity	Behaving in accordance with established social norms; it contributes to uniformity within a community.
Constitutional Traits	Traits that are determined by heredity.
Contiguity	The closeness in time or space of the stimuli to be associated.
Continuous Reinforcement	A schedule of reinforcement in which each correct response is followed by a primary reinforcer.
Creative Thinking	Thinking that results in the discovery of new ideas and solutions to problems.
Critical Thinking	Thinking that consists of examining and testing new ideas to see whether they will work.
Cue	A signal that will elicit a specific behavior or reflex as a result of a learned association. See Conditioned Stimulus and Positive Discriminative Stimulus.

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Data	Observable events or phenomena that can be detected and agreed upon.
Delayed Conditioning	In classical conditioning, a sequence in which the unconditioned stimulus is presented after the conditioned stimulus has been turned off.
Delay of Reinforcement	The interval between a behavior and the delivery of reinforcement.
Delta	See Negative Discriminative Stimulus.
Deoxyribonucleic Acid (DNA)	A complex type of biochemical substance which determines the genetic composition of the organism.
Dependent Variable	In an experiment, the variable that is measurably affected when the independent variable is manipulated.
Deprivation	Occurs when a primary reinforcer or strongly conditioned secondary reinforcer is withheld for a period of time.
Desensitization	The lessening or disappearance of a response accomplished by the paring of a positive reinforcer with the presentation of the stimulus.
Deviation	A distinct departure from what is prescribed or considered the norm.
Differential Reinforcement	The selective reinforcement of one aspect of a behavior pattern to the exclusion of other aspects.
Differential Reinforcement of Incompatible Behavior (DRI)	The delivery of a reinforcer following a response that is incompatible or competes with a target response that is to be suppressed. The effect is to increase the frequency of the incompatible response and to decrease the frequency of the undesired target response.
Differential Reinforcement of Other Behavior (DRO)	A procedure in which a reinforcer follows any performance an organism emits except a particular one. The DRO schedule specifies the performance that is to be non-reinforced rather than the one that is increased in frequency. The result is a decrease in the frequency of the particular performance that is specified.
Differentiation	A type of social interaction in which individuals by virtue of forming affective bonds with certain individuals necessarily and simultaneously separate and segregate themselves from some others.
Discrimination	The ability of an organism to distinguish and respond to differences in various aspects of its environment.
Discrimination Process	The process by which an organism distinguishes between closely related items and thus responds differentially; an element in both classical and operant conditioning.
Discriminative Stimulus (SD)	See Positive Discriminative Stimulus.
Displaced Aggression	Aggression directed against someone or something as a substitute for the original cause of one’s anger.
Displacement Activity	An indicator of a state of conflict existing in an organism. An organism having difficulty with conflict resolution will often perform a trivial or abbreviated action in an attempt to break the stalemate in which it finds itself.
Dissipate	The process of a body or an object losing or giving up a physical property, such as heat, cold, or water.
Distractions	Qualitative aspects of the environment, things such as bells, applause, audience, animals, the feelings of pressure, etcetera.
Domesticate	To train to live with and be of use to man.
Dominance	The social structure within a group of organisms that consists of the relative status among the members of the group. The ranking of one organism over another in a fairly stable hierarchy.
Dominant Behavior	A response that exercises controlling power, authority, or influence.
Dorsal	Of, toward, on, in, or near the back.
Drive	An incitement to action that has its origin in an internal bodily state (e.g., hunger), or that has been learned (e.g., the drive to obtain approval).

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Echolocation	The ability of an animal to orient itself by the reflection of the sound it has produced. The ability to generate sound and then use the returning echo to determine a bearing, range, or the characteristics of the echoing object.
Elicit	To automatically bring about a response. Respondent or reflex behaviors are elicited by unconditioned stimulus.
Emit	The act of causing an operant behavior by the presentation of a conditioned stimulus.
Emotion	Any strong feeling, always accompanied by physiological activity of the internal organs.
Epinephrine	A hormone secreted by the adrenal medulla that releases energy, increases metabolism, and produces a mechanism for distributing the effects of sympathetic activity throughout the bloodstream; also called adrenalin.
Escape or Escape Behavior	The relationship between a performance and an aversive stimulus in which the performance terminates the aversive stimulus. The actual behavior that terminates an aversive stimulus. Not to be confused with avoidance, where the aversive stimulus does not occur at all as long as the avoidance performance continues to postpone it.
Escape Learning	Conditioning technique in which the subject learns to escape or terminate an unpleasant stimulus. The process of learning to emit a behavior in order to escape an aversive event in progress.
Estrogen	A female sex hormone that controls the development of secondary sex characteristics and the reproductive functions.
Evolution	A gradual process by which simple forms have significantly changed into those that are more complex.
Experimental Chamber	An apparatus designed by B.F. Skinner to test operant conditioning techniques. It usually contains a lever, a food hopper, and wire grids for the passing of electric shocks; also known as a Skinner box.
Experimental Extinction	The specific procedure of presenting the conditioned stimulus unaccompanied by the usual reinforcement; also the decrement in a conditioned response that results from that procedure.
Experimental Method	The rigorous scientific process by which hypotheses are tested under laboratory conditions.
Experimental Psychology	The study of different components of the behavior of humans and other animals under laboratory conditions, in which a variable or variables can be manipulated to determine their effect on another variable or variables.
Extinction	In psychology, the gradual disappearance of learned behavior when the reinforcement is removed. In classical conditioning, removal of the unconditioned stimulus causes extinction; in operant conditioning, removal of the stimulus that causes the emitted response to persist causes extinction. In biology, the disappearance of a species from the earth.
Extinction Burst	An increase in responses or performance that is brought about by the withdrawal of reinforcement. Extinction bursts occur just prior to the decline of behavior (due to lack of reinforcement) prior to extinction.

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Fading Procedure	A technique for gradually changing one stimulus controlling an organism’s behavior to another stimulus.
Fear	An emotional reaction to threat or danger from specific stimuli.
Fixed-Interval Schedule of Reinforcement	A schedule of reinforcement in which organisms are reinforced for the first correct response that occurs after a fixed period of time has elapsed since the previous reinforced response. This schedule of reinforcement produces a scalloped response curve and is a poor motivator.
Fixed-Ratio Schedule of Reinforcement	A schedule of reinforcement in which the organism is reinforced after a set number of nonreinforced correct responses.
Forgetting	The loss or losing, temporary or permanent, of something earlier learned.
Fovea	A recessed area of the retina in which cones predominate. It is the region of greatest visual acuity in daylight.
Free Contact	A training situation in which the animal and the trainer have equal access to the work area. The animal is not restrained, muzzled, or confined in any way.
Frequency	The number of sound waves per second. Measured in hertzes, it is one of the objective, physical properties of sound.
Frustration	Environmental or personal obstacle that prevents an organism from obtaining a desired goal; also, a condition caused by the blocking of a goal. Emotional behavior prompted by the thwarting or interruption of goal seeking activity.

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Generalization	The process whereby an organism responds similarly to stimuli which resemble one another. The reciprocal of stimulus discrimination; the organism will increase in the strength of responses to a variety of stimuli. An adaptive learning process. To the extent that stimuli generalization occurs, stimulus control is lost.
Genes	The basic units of heredity; composed of the biochemical substance deoxyribonucleic acid (DNA) which provides the basic heredity information and controls.
Genetic Diversity	The variety of genetic composition of individuals within a species.
Genetic Drift	Relatively large increases or decreases in the frequencies of certain genes from generation to generation.
Geologic Time	Time as measured by the changing development of the earth and its structures, e.>g., the ice age.
Goal Gradient	The term used to describe the fact that as one approaches a goal, the drive to reach it becomes stronger.
Gonads	The sex glands, either testes or ovaries.
Group	A number of individuals associated through feelings of attachment and affiliation; usually long term.

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Habit	A recurrent pattern of behavior acquired through experience and made more or less permanent by various reinforcing events.
Habituation	The lessening or disappearance of a response with repeated presentations of the stimulus. The relatively persistent waning of a response as a result of repeated stimulation that is not followed by any kind of reinforcement. Also known as passive desensitization. See Desensitization.
Hands-Off Training	A protected form of training interaction that entails no physical contact of any kind. Since voice and eye contact can still be made, relationships and trust between the trainer and the animal can still be established. The lack of physical contact does not prevent training from taking place.
Hemispheres (right and left)	The two halves of the brain joined by the corpus callosum.
Heritability	The ability to inherit genes that determine behavioral traits.
High Probability Behavior	A response that is performed with a relatively high frequency when the organism is given the opportunity to select among alternate behaviors.
Homeostasis	The processes that maintain balance in the operation of the internal bodily functioning.
Hormones	Chemicals produced by the endocrine glands that have a powerful and profound effect on bodily function and behavior.
Husbandry	Long-term physiological and psychological management ensuring the viability of a species.
Hypothalamus	A region at the bottom of the brain, just above the midbrain, that plays a critical role in the motivational and emotional aspects of behavior and also in endocrine gland functions.
Hydrodynamic	The movement or force of a body or structure in water.

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Immediacy of Reinforcement	The act of reinforcing exactly following the behavior that is intended to increase in frequency. A critical feature of conditioning; if reinforcement is delayed by as little as a couple of seconds, it may follow some other behavior.
Imprinting	The process by which a young animal forms a lasting attachment to and preference for some object, usually a parent.
Incentive	An external inducement to act in a certain way; money and encouragement are common examples of incentives.
Incompatible Behavior	A kind or type of behavior that would conflict or be contradictory to that behavior’s antithesis. Behaviors are said to be incompatible when they may not occur in a single organism at the same time.
Independent Variable	In an experiment, the variable that the experimenter can manipulate to determine its effects upon the dependent variable.
Innate	Those characteristics that an organism is born with (that is, genetically determined) as opposed to those that are acquired through experience.
Insight	In problem solving, a solution that appears suddenly.
Instinct	An inborn predisposition to behave in a specific way when appropriately stimulated. Instincts are complex behaviors that are characteristic of a species.
Instrumental Behavior	Behavior emitted by an organism in order to obtain a goal, i.e., behavior that is instrumental in obtaining a goal.
Instrumental Conditioning	See Operant Conditioning.
Instrumental Objects	In organically motivated behavior, objects required to satisfy the drive source.
Integration	A type of social interaction in which individuals form affective bonds through group affiliation.
Intelligence	The capacity of organisms to deal effectively with the environment.
Intensity	Loudness, in subjective terms.
Interference	The hindrance of learning and memory caused by intervening events.
Intermittent/Partial Reinforcement	Any schedule of reinforcement which does not provide reinforcement following each correct response (partial reinforcement).
Inter-Stimulus Interval (ISI)	In classical conditioning, the time elapsed between the conditioned stimulus and the unconditioned stimulus. In habituation, the time between exposures to a stimulus.
Interval Schedule of Reinforcement	Reinforcement based on the passage of time.
Isolation	The separation of one group from another by physical barriers which causes inbreeding and separate development to occur within each group.

- J -
Just Noticeable Difference (j.n.d.)	The least amount of change in a stimulus necessary for an organism to be able to detect a difference.

- L -
Laminar Flow	The act of moving through the water without causing any friction or drag.
Language	A formal means of communication that possesses a grammatical structure.
Latency	The time between a discriminative stimulus (SD) and the organism’s response to it (the performance of a behavior).
Latent Learning	Learning that does not become manifest until an incentive is introduced.
Law of Effect	The concept that an organism will tend to repeat and learn behavior that has a satisfying or reinforcing outcome; behaviors that cause pain or discomfort will not be repeated or learned.
Learned Drives	Drives that are acquired through learning.
Learned Helplessness	A condition created by exposure to inescapable aversive events. This can retard or prevent learning in subsequent situations in which escape or avoidance is possible. The state of considering oneself helpless because of the failure of attempts to control a situation.
Learning	A relatively permanent change in response patterns which occurs as a result of reinforced practice; behavior that has been modified as a result of an organism’s experience.
Learning Plateau	A period in which early progress in learning appears to have stopped and improvement is at a standstill; the plateau is followed by a new period of progress.
Learning Set	Learning how to learn a particular task.
Ligament	A sheet of strong fibrous tissue connecting the ends of bones; used to facilitate movement.
Loudness	The psychological property of hearing, determined by the intensity of a sound as judged by an individual; amplitude is the physical correlate of loudness.

- M -
Magnitude of Reinforcement	Refers to the size, strength, or duration of a reward following a behavior.
Mammalia	The scientific class of vertebrate animals that are distinguished by self-regulating body temperature, hair, and in the females, milk-producing mammae. From the Latin mammalis, meaning “of the breast”.
Mania	A type of affective disorder characterized by extreme excitation.
Marking Up	A technique that requires an animal to station before the trainer enters its enclosure. See Station.
Matching-to-Sample	A procedure in which the choice of a stimulus that matches a sample stimulus is followed by the delivery of a reinforcer.
Melon	The large, bulbous “forehead” of toothed whales containing fat, muscles, and nasal passage and sacs; generally thought to act as an acoustic lens that focuses sound waves used for echolocation and communication.
Method of Approximation	A method used to shape organism’s behavior whereby successive approximations of the desired behavior are reinforced. Learning that takes place in a series of steps in which the amount of learning increases, sometimes quickly, sometimes slowly, until the learning is complete. Also known as incremental learning.
Mesomorphy	The dimension of physique that is characterized by muscularity.
Metabolic Rate	Speed of physical and chemical changes that take place within the body. Frequently used to refer to those changes involving the conversion of food to useful energy.
Mimicry	The act, practice, or art of copying the manner or expression of another.
Modeling	A type of learning or relearning in which behavior is learned or modified as a result of observing the behavior of others; also called observational learning.
Motivation	The non-stimulus variables controlling behavior; the general name for the fact that an organism’s acts are partly determined in direction and strength by its own nature and/or internal state.
Motive	Anything that initiates behavior.
Motor-Skill Learning	The ability to coordinate skills requiring the use of the muscles in an integrated whole pattern.
Multiple Schedule	A combination of several schedules of reinforcement, each of which is accompanied by a characteristic stimulus. For example, in the presence of a red light, behavior is reinforced on a fixed-ratio schedule while in the presence of a green light, behavior is reinforced on a fixed-interval schedule.
Mutation	A change in the chemical composition of a gene.

- N -
Natural Selection	The principle by which those members of a species whose genetic makeup produces certain characteristics promoting adaptation to their environment constitute an increasing proportion of their species in the environment with each succeeding generation.
Nature-Nurture Issue	The question of the extent to which environment and heredity determine behavior.
Need	An internal or external deficiency; often used as a synonym for drive.
Negative	To remove from the environment.
Negative Discriminative Stimulus (Ss)	In operant conditioning, the stimulus to which responses are nonreinforced or negatively reinforced; also known as a stimulus delta.
Negative Punishment	In operant conditioning, the removal of a positive stimulus—something the organism seeks to encounter—from the organism’s environment following a response, thereby decreasing the frequency of that response.
Negative Reinforcer	In operant conditioning, a stimulus whose withdrawal increases the probability that the response leading to its termination will persist. Any stimulus that when removed, reduced, or prevented increases the probability of a given response over time.
Negative Reinforcement	An organism is said to be negatively reinforced when the performance of a behavior serves to terminate an aversive stimulus or event. Negative reinforcement has occurred when the frequency of a behavior increases in order to avoid the onset of, or to terminate, an aversive stimulus. Not to be confused with punishment.
Neurosis	A functional disorder involving an inability to cope appropriately, adequately, or satisfactorily with the environment. Anxiety plays an important role. Failure to maintain rewarding interpersonal relationships is characteristic.
Neutral Stimulus	Any stimulus that has no effect on behavior before conditioning.
Nocturnal Eye	Specifically adapted to night vision.
Norm	A set standard of achievement derived from the average achievement of a large group.
Normal Distribution	The bell-shaped curve formed by the distribution of scores from a random sampling of a population.

- O -
Observational Learning	A type of learning in which the behavior of another organism is observed and imitated.
Olfactory	Referring to the sense of smell.
Ontogenetic History	Types of behavior an organism produces caused by its experience and interaction with the existing environment.
Operant	Operating or producing an effect or effects on the environment.
Operant Behavior	Emitted behavior that is controlled by its consequences.
Operant Conditioning	The procedure of presenting an organism with a reinforcing stimulus immediately following the occurrence of a desired response; the persistence of a response emitted by an organism depends on its effect on the environment. In this method of conditioning, the organism obtains reinforcement by operating on the environment in some fashion. Operant conditioning is based on the premise that all behavior is determined by its consequences. Also known as instrumental conditioning.
Operant Level	The rate of occurrence of an operant response before the response has been experimentally reinforced, or the rate of occurrence after the response has been extinguished.
Orienting Response	A response to a stimulus in which the organism turns toward the source of the stimulus.
Ovaries	The female reproductive glands that produce ova.

- P -
Paradigm	A pattern, example, or model.
Partial Reinforcement	Maintenance (or restoration) of a conditioned response by presentation of a part of the original rewarding or reinforcing conditions (intermittent reinforcement).
Pectoral	Pertaining to the breast or chest.
Perception	A psychological function which—by means of the sense organs—enables the organism to receive and process information on the state of, and alterations in, the environment.
Perception Modification	The process of changing an organism’s perception of an event or stimulus as evidenced by its changed response to the event or stimulus when compared to a previous baseline. This is most effectively accomplished through a conditioning process where the event/stimulus is paired with a conditioned reinforcer or punisher in order to transfer the value of the reinforcer or punisher to the event/stimulus.
Performance	Measures of observed behavior; generally referred to as the form and frequency of behavior.
Phase	The differential pressure exerted on the ear by a sound wave.
Phobia	A type of neurotic behavior involving an unrealistic fear of some aspect of the environment.
Phobic Reactions	Reactions such as blushing, fainting, vomiting, or abnormal compulsive behavior used to overcome irrational, strong fears (phobias) of objects or situations that are not usually thought of as frightening.
Phoneme	The smallest possible subdivision of language that can still be identified as a discrete sound.
Phylogenetic History	The types of behavior produced by a given species that have been determined by evolutionary history in order to survive.
Physiological Psychology	The study of the relationship between biological processes in humans and other animals and behavior.
Pitch	Psychological property of hearing, determined by the frequency of sound waves entering the ear.
Plasticity	The capacity of an organism to modify its responses through changes in its neuron connections; the ability of learning and memory.
Pleasure-Pain Principle	The principle that organisms are motivated to seek pleasure and avoid pain.
Positive	To add to the environment.
Positive Discriminative Stimulus (SD)	In conditioning, the stimulus to which responses are positively reinforced. A stimulus which consistently elicits a particular response because previous experience with the stimulus has led to reinforcement. Unless a differential response can be shown, the stimulus is not an SD.
Positive Punishment	In operant conditioning, the addition of an aversive stimulus—something the organism seeks to avoid—to the organism’s environment following a response, thereby decreasing the frequency of that response.
Positive Reinforcer	In operant conditioning, a stimulus whose presentation increases the probability that the response leading to it will persist.
Positive Reinforcement	The presentation of a reinforcer following the performance of a correct response which increases the probability that the response will reoccur in the future. Any event that serves to strengthen those responses that precede the event.
Positive Transfer	The facilitation of the learning of responses in new situations as a result of past learning.
Posterior	Pertaining to the caudal end of the body in an animal or the dorsal side in man.
Pre-Aversive Stimulus	A stimulus that has been conditioned through generalization as a predecessor to an aversive stimulus.
Premack Principle	A principle that states that of any pair of responses or activities in which an individual freely engages, the more frequent one will reinforce the less frequent one.
Primary Drive	An organic drive, such as thirst; also called an unlearned drive.
Primary Memory	The storage system in which information is kept for only short periods of time; also called short-term memory.
Primary Reinforcer	An unconditioned reinforcer. Anything of intrinsic value to an organism; examples are biological needs for food, water, sex, and social needs.
Primary Reinforcement	A reinforcing event that does not depend on learning to achieve its reinforcing properties.
Principle of Symmetry	The concept that individuals tend to react in the same way that they are acted upon; for example, matching aggression with aggression.
Proactive Inhibition	The process whereby the retention of new learning is interfered with by previously learned material.
Probability	The likelihood that a given behavior will occur.
Progesterone	The maternal hormone.
Prompt	An antecedent event that helps initiate a response. A discriminative stimulus that occasions a response.
Protected Contact	A training situation in which the trainer is protected from the possibility of injury by the animal. In this type of training, contact is made with only portions of the animal’s body at a time.
Psychobiology	The scientific study of the biological bases of behavior.
Psychology	The scientific study of behavior.
Psychophysical Task	Experiments designed to study the threshold or near threshold for various senses such as hearing or vision.
Punisher	A painful or discomforting or aversive stimulus; something the organism seeks to avoid. The application of a punisher will decrease the likelihood that the response leading to it will persist.
Punishment	Occurs when the frequency of a behavior decreases due to the onset of an aversive stimulus immediately following its performance; presentation of a painful or discomforting stimulus, or the removal of the opportunity to obtain reinforcement, which decreases the probability that the response leading to it will persist.

- R -
Rationalization	Self-justification; a defense mechanism whereby the individual tries to give reasons for irrational behavior.
Reasoning	A type of thinking which involves the systematic solving of a specific problem.
Recall	A measure of retention whereby the individual is able to extract from memory a specific piece of information, usually devoid of context.
Recognition	A measure of retention whereby the individual is able to identify stimuli to which it has been previously exposed.
Redirected Activity	An activity, recognizable from its form as being usually directed toward a particular stimulus, but on this occasion directed toward another stimulus. The classic human illustration is that of an aggressive person slamming his fist into a wall rather than into an opponent.
Reflex	An involuntary, spontaneous, and unlearned bodily response to a stimulus. The relationship between an eliciting stimulus and an elicited response such as the contraction of the pupil of the eye as a result of shining light on it, the jerk of the knee as a result of tapping the patellar tendon, the excretion of sweat as a result of warm air, or the constriction of blood vessels in response to a loud noise. The reflex describes both the behavior of the organism (response) and its environment (stimulus).
Refusal	A lack of response.
Regression	A return to an earlier mental or behavioral level or to an earlier stage of learning. An organism is said to have regressed when its previously conditioned behavior has dropped back to a lower stage of development.
Reinforcement	The strengthening of something by adding to it, or that which strengthens when added. Any condition, or the total circumstances, that strengthen a stimulus-response connection; any circumstances or events that increase the probability that a response will occur again in a situation like that in which the reinforcing condition originally occurred. Generally, any condition strengthening learning.
Reinforcement Schedules	The rule denoting how many or which responses will be reinforced.
Reinforcement Stimulus	Any stimulus which, when presented immediately following a response, tends to increase the frequency of the response.
Reinforcer	The unconditioned stimulus in classical conditioning; any stimulus that increases the probability of a response being emitted in operant conditioning.
Reintroduction	A technique used in conservation biology that uses wild-born and/or captive animals to establish or replenish wild populations in natural habitats from which the species has been extirpated by nature or man, the intent of which is to benefit populations of endangered species in the wild, not individuals of surplus or unwanted captive stocks.
Relational Concept	The idea involving a comparison between two objects.
Relearning	A measure of retention whereby an individual recommits to memory material or a skill already learned but apparently forgotten.
Release	The removal of all physical restraints from an organism.
Reliability	The ability of a test to measure something consistently.
Remote Training	A training situation in which an attempt is made to remove the human element from the picture. No relationship or trust between the animal and the trainer can be developed during this type of training.
Repertoire	The total number of latent performances that an organism may emit under the various conditions present in its environment and as result of its past history. All the possibilities for responses that an organism possesses in a given class.
Repression	The failure of an operant behavior caused by previous aversive consequences. A defense mechanism in which an individual suffering anxiety over his motives seems to banish the thoughts, pushing them into the unconscious.
Respondent Behavior	Behavior that is elicited or automatically controlled by antecedent stimuli. Reflexes are respondents because their performance automatically follows certain stimuli. The connection between unconditioned respondents and antecedent events that control them is unlearned. Respondents may come under the control of otherwise neutral stimuli through classical conditioning. Respondent behavior is not produced willingly.
Response	An identifiable unit of behavior (can be muscular or glandular).
Response Rate	The number of response-instances per unit of time.
Retention	A construct of memory that is measured by various methods such as recall, recognition, and savings.
Retroactive Inhibition	The process whereby the retention of previously learned material is interfered with by new learning. The harmful effect of new learning or other activity on the recall of what previously has been learned.
Reward	A satisfaction-yielding stimulus or stimulus object that is obtained upon the successful performance of a task.
Rods	Elongated elements in the retina of the eye that are sensitive to light, but not color. They function mainly in dim light.

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Satiation	Satiation occurs when a normally positive stimulus is repeatedly offered until it loses its reinforcing properties.
Schedule of Reinforcement	Refers to the conditions under which reinforcement is delivered. Continuous reinforcement and variable reinforcement are the schedules most important to animal training.
Secondary	A quality that an organism responds to because its perception has been conditioned or learned.
Secondary Memory	The storage system in which information is retained for long periods of time, sometimes forever; also called long-term memory.
Secondary Reinforcer	A stimulus which derives its reinforcing value from prior conditioning in which it has been associated with a primary reward. A secondary reinforcer initially has no rewarding properties to an organism but becomes conditioned because of its association with other desired, primary reinforcers. Once conditioning has occurred, the distinction between primary and secondary reinforcers becomes less clearly defined. Also known as a conditioned reinforcer.
Self-Aggression	Behavior aimed at harming oneself.
Semi-Protected Contact	A training situation in which the trainer is partially protected or isolated from the animal. This partial isolation does not provide total protection or freedom to either the animal or trainer. Examples of semi-protected contact are the use of leashes and muzzles that are designed to partially restrict certain activities. Training is still done with complete contact, but the animal is restricted by the leash in its movements or prevented from biting by the muzzle. Also known as semi-free contact.
Sensitization	The intensifying of an organism’s response to stimuli that do not ordinarily produce such strong reactions.
Sensory Capability	The range of sensitivity of those sensory systems that a particular organism may possess.
Sensory Modality	Refers to various modes or ways that information about the environment can be obtained by an organism. Vision is one modality, taste is another.
Shaping	Operant conditioning technique for achieving a final behavior by reinforcing successive approximations of the desired response. The differential reinforcement of successive approximations of some desired behavior in order to increase the probability of the occurrence of a response.
Socialization	The process whereby an organism acquires and participates in the patterns of behavior characteristic of its society.
Species	The lowest grouping in the taxonomic classification scheme developed by Linnaeus.
Spontaneous Recovery	The process whereby a conditioned response reappears after apparent extinction.
Standard Deviation	A mathematical expression of the variability of a distribution.
Station (noun)	An assigned position for an animal, designated by a trainer.
Station (verb)	An animal’s action to remain at an assigned position, usually in a fixed posture, for a period of time as designated by a trainer. Also see Marking Up.
Stereotypic Behavior	A repetitive response that is without variation for extended periods of time. It is usually brought about through a lack of stimulation.
Stimulus	Any environmental condition that impinges on an organism’s sensory perception. An external or internal object or event which occasions an alteration in the behavior of an organism. The organism must be able to perceive the stimulus.
Stimulus Control	A different form or frequency of behavior in the presence of one stimulus (SD) which does not occur in the presence of other stimuli.
Stimulus Delta	See Negative Discriminative Stimulus.
Stress	A physiological condition resulting in mental or emotional pressure. All living organisms are constantly subjected to various stressors.
Successive Approximation	The stair-step process whereby behavior is made to approach a desired act by means of selectively reinforcing those behaviors which lead to the desired act. See Shaping.
Superstitious Behavior	Behaviors offered by an organism that are not required for reinforcement but, nonetheless, become an integral part of the response.
Symbol	Something that stands for something else.
Syntax	The internalized rules by which a language is spoken and understood.
Systematic Desensitization	A procedure by which an organism is allowed to gradually become comfortable with an unusual or frightening stimulus; behavior therapy in which classical conditioning techniques are used to reduce or eliminate anxiety.

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Tactile Reinforcer	Any reinforcer discernible by touch.
Target (noun)	A prop that pinpoints a critical location for an animal in training.
Target (verb)	An animal’s action to touch a designated spot. The process of stimulating an animal to touch a particular spot or object.
Team-Based Contingency	A group contingency in which members earn reinforcers on the basis of the performance of the group.
Telepathy	The communication from one mind to another without the intervention of any known sense organ.
Terminal Response	The final pattern of behavior that an organism is expected to demonstrate after the completion of shaping procedures.
Temporal Lobe	A region of the cerebral cortex including auditory information processing, speech and language comprehension, and other complex functions.
Testes	The male reproductive glands, the source of spermatozoa and of the male sex hormones. Also called testicles.
Testosterone	A male sex hormone.
Thermoregulation	The act of maintaining the body temperature within a narrow range.
Thinking	A general term for a group of mental activities including reasoning, discriminating, abstracting, generalizing, and imagining.
Thorax	The chest area of the body.
Threshold	The point at which a stimulus is just strong enough to be perceived or produce a response. The magnitude or strength of a stimulus which is just sufficient to elicit a respondent behavior or emit an operant behavior.
Time Out	A form of punishment in which an organism’s opportunity to gain reinforcement is removed or reduced with the intent of reducing or eliminating the frequency of occurrence of an undesired behavior. Removing the situation in which an organism can get reinforcement; used to suppress incorrect responses correlated with non-reinforcement.
Trace Conditioning	In classical conditioning, the standard sequence whereby the unconditioned stimulus is presented after the conditioned stimulus, with an inter-stimulus interval of about 0.5 seconds.
Trait	A characteristic way of behaving; a predisposition to behave in a certain way.
Transfer of Training	The application of past learning to new learning situations.
Trauma	An injury or wound.
Trial and Error	Type of problem solving in which various ideas are tried until a solution is reached. It may be covert or overt. An approach to problem solving that is based upon continuous attempts at a solution (trials), with each attempt pursued until it ends in failure (error) or success.

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Unconditioned Reflex	A response that is emitted on exposure to a stimulus without previous conditioning.
Unconditioned Reinforcer	See Primary Reinforcer.
Unconditioned Response (UR)	In classical conditioning, an unlearned and innate response to an unconditioned stimulus. A response that is elicited by an unconditioned stimulus without prior learning. Any display of instinct is an unconditioned response.
Unconditioned Stimulus (US)	In classical conditioning, a stimulus that elicits an unlearned and innate response (UR). Any stimulus possessing the capacity to elicit reactions from organisms in the absence of prior conditioning.

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Validity	The degree to which a test measures that for which it was intended.
Variable-Interval Schedule of Reinforcement	A schedule of reinforcement in which the organism is reinforced after a period of time that varies from one reinforcement to the next; reinforcement is independent of correct responses. An irregular schedule in which reinforcement occurs for the first correct response after a variable period of time. A variable interval schedule produces a very uniform rate of responding and is useful in providing a good benchmark against which to test the effects upon behavior of various factors such as reward size. In higher animals, this has been demonstrated as being by far the most motivating schedule of reinforcement.
Variable-Ratio Schedule of Reinforcement	A schedule of reinforcement in which the organism is reinforced after a number of nonreinforced responses; the number varies from reinforcement to reinforcement. A schedule in which reinforcement occurs irregularly after a number of responses. This is similar to reinforcement schedules found in nature. An organism is not usually reinforced 100% of the time in nature even though it may have performed correctly those behaviors that usually lead to reinforcement.
Variance	The spread of scores on a particular test.
Ventral	Pertaining to or situated on or close to the belly; abdominal. The anterior aspect of the human body or the lower surface of the body of an animal.
Vicarious Reinforcement	Reinforcement obtained from watching someone else being rewarded for a particular behavior.
Vicarious Satisfaction	Defense mechanism in which a desire is satisfied by imaginatively participating in the experiences of other organisms.
Viscerotonia	A temperament type that is characterized by a love of comfort, sociability, and a good disposition.
Visual Acuity	The ability to see fine details in the environment; sharpness of vision in daylight.

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Zygote	A fertilized egg.