Psychology Of Learning PDF

PSYCHOLOGY-OF-LEARNING.pdf user_3057263 Psicología del Aprendizaje 1º Grado en Psicología Facultad de Psicología Universidad Complutense de Madrid Reservados todos los derechos. No se permite la explotación económica ni...

PSYCHOLOGY-OF-LEARNING.pdf user_3057263 Psicología del Aprendizaje 1º Grado en Psicología Facultad de Psicología Universidad Complutense de Madrid Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 PSYCHOLOGY OF LEARNING 1. The purpose of learning - What is learning? - The purpose of learning - Historical Perspective Generals learning processes: · Observed in most species (they have been maintained for millions of years). · Allow the acquisition of very diverse types of information. · Some like non-associative learning are found from protozoa to human beings. · More complex learning (associative) both in vertebrates and invertebrates. · If a learning law or mechanism is discovered in one species, it can be generalized to others (ex: classical conditioning). Specialized learning processes: · Typical of some species. · Quick to acquire, long-lasting effects and bond to sensitive periods. Levels of learning: · Behavioral level: learning as an association between stimuli and responses. · Cognitive level: learning as the acquisition of information and the formation of new mental representations. · Neural level: learning as changes in the nervous system. Learning and cognitive processes: What do we need to learn? · Memory · Perception · Language · Motivation · Attention (be able to focus and concentrate) Historical perspective Several schools of thought influenced the psychology of learning. Some key questions are: Where does the knowledge come from? How do we learn something new? 1. Innatism - innate knowledge (genetics and predetermination) 2. Empiricism - acquired knowledge, potentiality (individuals have the potential of getting knowledge, of learning) Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 The first philosophers: - Plato (427-347 ac) Perceived knowledge as innate, acquired along previous lives of the soul. Innate differences in skills, abilities and talent should determine the individual’s role in society. Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. - Aristotle (384-322 ac) Knowledge emerges from experience, acquired from the environment through the senses. Association forms more complex ideas using simple ones. Sensation -> images -> ideas ❖ Aristotles’ principles of association · Adjacency (time and space) · Frequency · Similarity - Rene Descartes (1596-1650) He proposed the mind-body dualism, which divided the elements between res cogitans and res extensa. These two types should interact with each other. - John Locke (1632-1704) All ideas are acquired directly or indirectly through experience (tabula rasa) Nothing in the mind that was not first in the senses Complex ideas through associations of simpler ideas (sensory experience) The purpose of learning is to bring together the different parts of experience to make a meaningful whole. - Immanuel Kant (1724-1804) All knowledge begins with experience, but not everything comes from it There are a priori intuitions preceding any experience External world is disorganized but it appears to us with an order imposed by our mind. - Ramón y Cajal (1852-1934) He claimed “el hombre tiene más de mono que de ángel y que carece de títulos para envanecerse y engreírse”. - Charles Darwin (1809-1882) He drove comparative psychology, proposed that behavior traits evolve through natural selection, just as physical ones do. For him, learning allows the adaptation of the organism, which gives them a great value for survival. Contents are not transferred just the ability to learn. Abre tu Cuenta NoCuenta con el código WUOLAH10 y llévate 10 € al hacer tu primer pago Psicología del Aprendizaje Banco de apuntes de la a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 - George J. Romanes (1848-1894) Romanes started Comparative Psychology, he had the aim to apply Darwinism to the study of human and animal minds. He created “Animal Intelligence” (1882) was the 1st text on comparative psychology, observing animal behavior to gather general principles. The influence of association is represented in the graph: Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. - Alexander Bain (1818-1903) Bain proposes “trial and error” as a universal mechanism of learning, which will influence the law of effect (Thorndike). For Douglas A. Spalding (1841-1877) behavior must be studied through careful experimentation methods, and it confronts inherited versus learnt behavior. He was the first one to describe the “following reaction”, later described by Lorenz as imprinting. - Douglas Spalding (1841-1877) Behavior must be studied through careful experimentation Inherited vs learnt behavior - Conwy L. Morgan (1852-1936) Morgan criticizes Romane´s anthropocentrism and he created Morgan´s Canon that claimed: “In no case is an animal activity to be interpreted in terms of higher psychological processes if it can be fairly interpreted in terms of processes which stand lower in the scale of psychological evolution and development”. In this study he explained that if animals learn from their experience, then they are not conscious automata. Animals learn because their behavior is modified by immediate consequences, so they learn by trial and error. Russian reflexology - Ivan M. Sechenov (1829-1905) Explained mental phenomena as reflexes but with a physiological base. - Ivan P. Pavlov (1849-1936) Nobel prize in Physiology or medicine in 1904 for his work on the digestive system In “Conditioned reflexes” (1927), he proposed the innate and unconditioned reflexes vs the learnt and conditioned reflexes. · Elements of conditioned reflexes: - US: unconditioned stimulus - UR: unconditioned response - CS: conditioned stimulus - CR: conditioned response New neural connections between CS and US sensory senses All behavior can be explained by reflexes · Requirements of the conditioned reflexes: - Health - Hunger Abre tu Cuenta NoCuenta con el código WUOLAH10 y llévate 10 € al hacer tu primer pago a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 - Arousal - Temporal succession - Absence of other stimuli · Described basic learning phenomena: - Extinction - Spontaneous recovery - High order conditioning - Generalization Study of learning by rigorous experimental methods results in the development of explanatory theories, which also results in a linkage between behavior and nervous system - Vladimir M. Bechterev (1857-1927) Studied conditioning in the motor system, creating the methodological bases for the study of aversive conditioning. His experiment consisted in giving a shock to the leg of a dog while producing a sound, this will create a reflexive response. When the sound is reproduced the reflexive response is recreated. Pavlov —> appetitive conditioning Bechterev —> aversive conditioning Functionalism - Edward L. Thorndike (1874-1949) Claimed that the purpose (function) of behavior is adaptation of the individual Influenced by evolutionism. Controlled animal experiments (puzzle boxes): · Learning by trial error -> gradual · Mechanical relations established between a pattern of stimuli and response -> subject doesn’t think · Phylogenetic level and learning are related -> biological limitations Proposals: · Law of effect (1911): Behavior change as a function if its consequences (Spencer-Bain’s principle of pleasure pain) · Law of exercise: The strength of connection increases as the response occurs -> practice is needed, cannot learn by watching · Law of readiness: Some S-R bonds are easier to happen than others (biological predisposition) Behaviorism Arises in the 1920s in the US as a reaction to structuralism (which required introspection) Influenced by: Pavlov and Thorndike Subject of study: Observable behavior Behaviorist manifesto: Psychological Review (1913) - J.B. Watson Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 · Psychology as the behaviorist views it is a purely objective experimental branch of natural science. (…) Introspection forms no essential part of its methods, (…) recognises no dividing line between man and brute. - John B. Watson (1878-1958) “Give me a dozen healthy infants, well-formed, and my own specified world to bring Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. them up in and I’l guarantee to take any one at random and train him to become any type of specialist I might select- doctor, lawyer, artist, merchant-chief, and, yes, even beggar-man and thief, regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors.” · Educated in the empiricist and evolutionist tradition · S->R paradigm explains all psychological phenomena · Rejects introspection as a method, as well as the study of (unobservable) mental processes. · Replace the object (awareness/behavior) and the method (introspection /experimental) of Psychology. Gestalt - Wolfgang Köhler (1887-1927) Studies learning and problem solving in chimpanzees Köhler’s experiments: - Solution is not straight, it requires observation of the global scene - Learning not by trial and error - Learning full comprehension —> insight Chimpanzees learn emergent relations among stimuli (means-goals relations) —> cognitive learning based on perceptive processes GESTALT: configuration, shape or entirety Opposite to associationist explanations of Learning (S->R) GLOBAL VIEW OF BEHAVIOR: analysis of behavior as a whole, “chunks”, not discrete units (Ss and Rs) Emphasizes cognitive processes (perception) · Max Wertheimer (1880-1943) · Wolfgang Köhler (1887-1967) Kurt Koffka (1886-1941) Perceptive organization and learning laws and principles: Law of Prägnanz (good shape): the perceptual organization of any set of stimuli will form as good a Gestalt as the prevailing conditions allow. Principle of proximity ; Principle of similarity ; Principle of figure-ground ; Principle of continuity ; Principle of closure ; Principle of symmetry Explained in the context of perception and problem solving Reinforcement acts just on attention Abre tu Cuenta NoCuenta con el código WUOLAH10 y llévate 10 € al hacer tu primer pago a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 Neobehaviorism Behaviorism consolidates from 1930 Methodological objectivism Internal mental events are rejected as they are unobservable and poorly defined Animal experimentation using simple tasks (mazes, puzzle-boxes, etc.) · Edwin R. Guthrie (1886-1959) Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. · Edward C. Tolman (1887-1967) · Clark L. Hull (1884-1952) · Burrhus F. Skinner (1904-1990) - Edward C. Tolman (1887-1967) “Behavior reeks of purpose” Cognitive and intentional nature of behavior Intermediate variables in the S-R relationship, for example, purpose, expectation or cognition. Subjects establish relations between events —> causal Structure of the world —> cognitive maps Rejects consciousness but studies the behavioral act (whole) —> behaviorism and gestaltic. Learning by acquiring environmental knowledge —> rejects S-R connections Latent learning: possible to learn with no behavioral signs Forefather of cognitive learning view - Burrhus F. Skinner (1904-1990) Radical behaviorism Operant behavior: an organism's action on the environment leads to a consequence —> reinforcement needed. Functional analyses of behavior: Sd -> OR -> Sr OR and Sr: stimulus happens in a concrete situation (Sd) Responding response (response to a previous S) vs Operant response (previous S is not required) Learning laws are the same for any organism. Develops reinforcement schedules: continuous, intermittent, radio, etc. Designs the “Skinner’s box” Influenced Clinical and Educational Psychology “Beyond Freedom and Dignity” (1971): consciousness and free are illusions —> we behave through pre-programmed (learnt) responses. Behaviorism and psychology of learning · Associationist view of learning: all knowledge acquired through associative mechanisms —> simple and arbitrary laboratory tasks · General processes of learning do exist · Environmentalism: behavior is controlled by environmental contingencies Passive conception of organism Abre tu Cuenta NoCuenta con el código WUOLAH10 y llévate 10 € al hacer tu primer pago a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 · Reductionism: behavior can be split up into simpler elements - S and R. The cognitive approach Middle 1950s behaviorist paradigm went into crisis Internal factors: theoretical and empirical anomalies challenge basic assumptions Blocking phenomenon questions the principle of contiguity (CSB should also provide new and valuable information) · Can't explain Tolman’s cognitive maps · Can't explain acquisition of complex facets of language (Chomsky, 1959) · Can't explain key component of cognition: reasoning, memory or perception Factors external to Psychology Information T and computational science come into scene Notion of “information processing” penetrates Psychology Computer metaphor: mind completes mental representations, which are transformed, in its passage through different structures and processors Hardware —> cognitive processes (binary code) —> observable level: behavior (screen) New objectives and principles Understand the nature and operation of the human mind Observable behavior (and private subjective experiences) depend on unobservable mental events (mechanisms and processes). Mental representation Contents in mind about the meaning of objects, events or (external or internal) environmental states Change of paradigm Assumptions · Mentalism: mental constructs are precedents of behavior · Functionalism: mind results from brain organization (not the same, not different) · Computational: mental processes (learning) explained as computation processes Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 · Restrictive: limited capacity at the structural and resources level (depends on neurological layer) - Replace reductionism with causal structures and processes (memory structures, attention processes, etc.) - Replace environmentalism for subject-variables and task-variable interactions - Greater interest in memory processes—> how is information represented? Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. - Subject as an active (searches and re-elaborates) vs passive (just receives) processor Connectionism The simultaneous activation of two units (neurons) increases the connecting force between both. “Neurons that fire together, wire together” The relationship between the presynaptic neuron and postsynaptic neuron will be modified if the presynaptic neuron is repeatedly part of postsynaptic neuron excitation. -Donald Hebb, 1949 - Information is represented in a distributed network made up of many simple but densely interconnected units - Each unit has a degree of activation that excites or inhibits the others —> dynamic system that reaches stable/ modifiable patterns · Learning based on a series of changes in the associative weights/ strengths. What do we think nowadays? Learning involves the association of ideas or concepts, although we still discuss how these associations are formed and used We recognise the influence of genetics on learning, although heredity is just a basic design, modulated by experience. Only the scientific method and experimental analysis allow us to advance our knowledge about Learning (and Psychology) Cognition is a continuum where some animals (rats or pigeons) have limited capacity while others are capable of a greater degree of reasoning and symbolic thinking (cetaceans and primates). Abre tu Cuenta NoCuenta con el código WUOLAH10 y llévate 10 € al hacer tu primer pago a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 2. Non-associative learning - Repetition-based learning: Habituation Sensitization Theories - Exposure-based learning: Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. Priming Perceptual learning Spatial learning Learn by exposure to a stimulus Learning on a single stimulus —> pre-associative learning Most common instance of learning goes across species. It is not really simple, but low species, such as bacteria, use it to learn. Repetition Based Learning - Habituation - Sensitization (kind of opposite to habituation in behavioral/observable level) - Theories Exposure Based Learning - Priming - Perceptual learning - Spatial learning Brain Substrates - Invertebrate models - Perceptual learning & cortical plasticity - Spatial learning & the hippocampus’ role (particularly in rats) 1. Repetition based learning - Habituation Reduction is the effectiveness of a stimulus in eliciting a response, following repeated exposure to the stimulus In the laboratory - Acoustic startle reflex: Defensive response to unexpected loud noises Repeated presentation of the same noise decreases the response habituation - Orienting response: Innate reaction to a novel stimulus Fixation time decreases with repeated presentations Advantages - Avoids wasting time and energy on unnecessary responses to single repetitions of same event - Releases resources for other processes → adaptive value Abre tu Cuenta NoCuenta con el código WUOLAH10 y llévate 10 € al hacer tu primer pago a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 Risks - Reduces the response to relevant stimuli Functional properties of habituation - Stimulus specificity Habituation to one event doesn’t cause habituation to every other stimulus in the same sensory modality (Thompson and Spencer, 1966) Coolidge effect Peeke and Veno (1983): → Session A 4 groups same treatment Habituation → Session B Varies fish and place Response depends on familiarity High arousing events also habituate (Thompson and Spencer, 1966) → Male rats’ mating behavior habituates with the same female → Response recovers with a new female (Dewsbury 1981) rules out fatigue Also in human males → Habituation to sexually explicit images → Presentation of new images induced a recovery of the response → Physiological measures show more habituation than participant’s reports Females seem to show lower habituation Dishabituation Habituated response can be renewed if the old stimulus is presented along with a new one A flash presented along with acoustic stimulus recovers the habituated startle response in rats (Groves and Thompson, 1970) In humans, new drink recovers habituated salivary response to lemon juice (in following trials) (Epstein et al, 1992) Reappearance of response is temporary and easily habituates Generalization Acquired learning can be transferred to a similar stimulus Stimuli and context are seldom constant Spontaneous recovery Reappearance (or increase in strength) of a previously habituated response after a short period of no stimulus presentation Depends on: - Intersession interval Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 - Stimulus intensity - Number of trials of habituation Reappears with lower strength Fast re-habituation Stimulus intensity Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. The lower (arousal) the faster the habituation Greater reduction over the first trials (when becomes familiar) · Thompson et al (1973) Withdrawal response in spinal cats Stimulation frequency Repeated stimuli induce faster habituation (Thompson and Spencer, 1966) - Massive exposure Fast habituation Temporary effects (spontaneous recovery) Short-term habituation - Spaced exposure Slow habituation Enduring effects Long-term habituation Cumulative effects with repeated sessions of habituation Response appears below zero habituation latent learning - Sensitization Temporary increase in the strength or occurrence of response following repeated exposure to an intense stimulus. - As habituation, sensitization happens in a wide range of species. - Very transitory effect (on first repetitions) though can induce long-lasting effects. - Requires fewer presentations - No stimulus specificity —> generalization —> adaptive value - Fast & intense response to potentially harmful stimuli (and those that look like them). - In case they are safe, response decreases. Intensity & duration Greater intensity —> faster sensitization Davis (1974) Short & tone intense successive presentation in rats. Group A —> weak environmental noise Group B —> intense environmental noise Abre tu Cuenta NoCuenta con el código WUOLAH10 y llévate 10 € al hacer tu primer pago a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. Interval Shorter interval —> greater sensitization Sensitization and pseudo-conditioning Intense response to a neutral stimulus due to previous exposure to and intense and aversive stimulus. Requires the presentation of 2 stimulus Intense S —> response —> neutral S Sensitization to neutral stimuli Neutral-S and startle response Never paired —> pseudo-conditioning Horror film at cinema —> scared jump —> bf touches leg —> scared jump Dual process theory (Groves & Thompson, 1970) Repeated events always lead to the processes underlying both, sensitization and habituation. Two systems: · Stimulus-response system - Activated by any stimulus able to induce a response - Underlies habituation · State system - Activated by intense to significant stimuli - Modulates S-R (stimulus-response) system - Underlies sensitization Abre tu Cuenta NoCuenta con el código WUOLAH10 y llévate 10 € al hacer tu primer pago a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 Both happen in parallel and influence response in opposite directions. Behavioral outcome depends on the interaction of the strength of both systems. Neuropsychological evidence from spinal cats A —> weak, low frequency stimuli —> fast habituation B & C —> increase intensity, enhance state system arousal —> longer habituation D —> high intensity stimulation, greater enhancement of state system arousal —> stimuli response Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 Opponent process theory (Solomon y Corbit, 1974) An experience event leads to two independent (emotional) processes. · Initial phase: - While stimulus is present - Emotion of given valence (joy, horror,...) · ‘Rebound’: Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. - When stimulus is over - Emotion of opposed valence from the initial one (sadness, excitation, …) a mechanism to guarantee emotional stability Standard pattern of affective dynamics · Emotional reaction depends on stimulus’ sensory and affective features · Always the same temporal pattern Stimulation leads to process A and process B · Process A (primary) - Induces the initial emotional response - Fast onset and stays with the stimulus · Process B (opponent) - Emotional response opposite to the former - Slow onset and development Observable affective response results from the addition of both processes Process A does not change with repeated presentations Process B strengthens with repeated presentations · Increases with higher intensity, frequency and duration · Scarce physiological evidence · Temporal dynamics are very different across species · Highly ecological from the homeostasis view 2. Exposure based learning Animals hardly sit and wait for stimulation Exploratory behaviors determine: · Type of situation you get Abre tu Cuenta NoCuenta con el código WUOLAH10 y llévate 10 € al hacer tu primer pago a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 · Frequency of stimulation –Priming Mere exposure to a stimulus induces familiarity Animals spend less time exploring objects that have already been presented Some species show avoidance behaviors or neophobia Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. Familiarity is inferred from absence of avoidance Priming: Improved ability to recognize a stimulus that has been previously presented · Familiarity, even being not conscious, can affect the individuals response Animals do show priming · Ex: Trained blue jays better detect moths on a background if they have already been detected recently Experience with a set of stimuli make sit easier to distinguish those stimuli Subject recognized differences bere¡ween stimuli that they could bnot perceive before exposure Gibson y Walk (1956) · Mere exposure phase (1 month) · Training phase (approach just one of the shapes) - Exposed rats learn faster → they better distinguish Gibson y Gibson (1955) · A target is shown for later recognition · First trials, can distinguish dissimilar but not similar lures · Several trials later (no feedback), better discrimination of target among similar lures explanation from dual process theory · Circles and triangles share characteristics: size, color, … · Differ in others: edges, … - Exposure to shared features is twice that of distinctive features (they appear for triangles) –Perceptual learning Explanation from dual process theory - Circles and triangles share characteristics: size, color, placement… - Differ in others: straight or round edges… Exposure to shared features is twice that of distinctive features (they appear for triangles but also for circles) Exposed rats habituate more to common features Distinct features are easier when we are habituated Learn without feedback on our performance → so it is not trial and error it is learning based on an exposure to the stimulus. It is known to play a role in the development of stereotypes. –-Spatial learning Abre tu Cuenta NoCuenta con el código WUOLAH10 y llévate 10 € al hacer tu primer pago a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 Acquisition of information about one’s surroundings Mere exploration increases our knowledge of the environment Tolman and Honzik (1930) A. Trained rats: days 1-10, trained to find the exit B. Exploration first-rats: days 1-10, freely explore, no food if they find the exit - Day 11, started to get food if they found the exit → both groups learnt → Latent learning Tinbergen and Kruyt (1972) Bee’s ability to return to the nest - A circle of pineapples around the nest - When leaving, they flew around the nest - Moving the circle of pineapples while they were out confused them visual clues Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 3. Classical conditioning - What is classical conditioning? - Appetitive and aversive conditioning - Basic phenomena in classical conditioning - Determinants of classical conditioning - Explanatory models of classical conditioning Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. What is associative learning? We study the relationship with events in the environment 1. Classical conditioning: Relationship among between 2. Instrumental conditioning: Relationship between behavior/consequences Concept of CC Type of associative learning in which organisms relate two or more events to predict and prepare for the occurrence of one of them → Adaptive learning Part of our emotional behavior is acquired by CC. Affects both automatic and voluntary responses. Basic elements It was first described by Pavlov. Elements in the conditioned reflex (what he first described): - US (unconditioned stimulus): biologically relevant (food, noise) elicits a response - UR (unconditioned response): unconditional response to US (salivation, startle) - NS (neutral stimulus): arbitrary, it elicits an orienting response that is quickly extinguished - Training: NS and US repeatedly paired - CS (conditioned stimulus): the NS acquires the property of predicting US and triggers an anticipated response. - CR (conditioned response): similar to UR, but without US, just as a response to CS. Which event can be USs or CSs? → US: biologically relevant, pleasant or unpleasant → CS: any environmental trait, even an US Abre tu Cuenta NoCuenta con el código WUOLAH10 y llévate 10 € al hacer tu primer pago a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 Terminology in CC In an experimental session, we have a trial (repeated instances that the experimenter wants to study in a specific sequence). The interval of time between the CS and the US is called the interstimulus interval (ISI). It is important modulating the CC, as well as the intertrial interval (ITI), timing between one trial and another one. All the elements take place in an experimental session. Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. Measuring the CR - Probability: % of trials with CR. Ex: blinking. It is not easy to measure it in terms of magnitude so we measure it in percentages. - Magnitude of the CR: Intensity of the response. Ex: it is easy in the case of the salivary response → mL of saliva - Latency: between the appearance of the CS and the appearance of the CR. If the CS-US interval is very short it is difficult to distinguish CR from UR → Test trials (no US). Types of CC Contingency CS-US Motivational value Positive Relation Excitatory: appetitive Excitatory: aversive CS+ → US (CS+ signals US appearance) Negative Relation Inhibitory: appetitive Inhibitory: aversive CS → No US (CS signals US absence) Eye blink condition Excitatory CC: the best known or most studied form for this kind of CC in mammals is the eyeblink response. It is a reflex response in which the CR looks identical to the UR. Rabbits are usually used in these experiments because they stay still. Eye blinking differs in time of appearance: → CR appears before the air puff CS (tone) predicts the air puff - CR protects the eye - Adaptive learning Conditioned taste aversion Another type of excitatory CC is conditioned taste aversion. We develop aversion to a taste by thinking it is harmful. → Learn a single trial → Long ISI Ex: Chemotherapy patients dislike previously eaten food (Limebeer and Parker). Avoidance of potentially harmful foods - Adaptive learning Abre tu Cuenta NoCuenta con el código WUOLAH10 y llévate 10 € al hacer tu primer pago a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 Autoshaping CC not only in reflexive RS but also in voluntary motor RS. In the Brown and Jenkins experiment they used pigeons and the Skinners box. Experimental group Control group CS → US CS / US light food light food → Some animals react to songs of food and to the food itself in a similar manner → Key lights predict food availability · UR: food-peck · CR: key-peck Conditioned suppression Another kind of excitatory CC is conditioned suppression in which certain events can suppress the behavior that the individual is carrying out. CS predicts the appearance of that US → associated fear to CS paralyze behavior Suppression ratio: Behavior disturbance is an indirect measure of the strength of CS SR = A /(A+B) = nº Rs following CS / (nº Rs following CS + nº Rs before CS) Values closer to 0 mean strong conditioning and higher values mean lower or weaker conditioning Temporal relation CS-US Forward procedures: delay conditioned Subject learns that the US takes time to appear - CR is delayed Each species and response system has an optima ISI Trace conditioning - Requires that the animal keeps in memory a footprint of the CS until the US arrives - The longer the ISI the lower the likelihood of conditioning - Less effective than delay conditioning Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 Inhibitory CC From a CS-, the individual learns to predict the absence of the US. → Requires from an excitatory context (vending - buy chips) → CR opposed to excitatory CR (don’t insert coin) Standard procedure (Pavlov) Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. There are two types of trials: - Trials type A: CS+ matched with US, acquires predictive value → excitatory context - Trials type B: CS+ matched with CS-, followed by the absence of US CS- acquires inhibitory properties - Signals the absence of US even in face of CS+ Differential inhibitions - Trials type A: CS+ matched with US, acquires predictive value - Trials type B: CS- alone followed by the absence of US CS- acquires inhibitory properties → signals the absence without presence of CS+. Which is the excitatory context environment (Skinner box) acquired excitatory nature Negative contingency Just one type of trial, within an excitatory context. CS- presented in negative contingency with US which does not predict US so there is no response in the presence of CS-. EX: A victim of bullying can reduce anxiety in the presence of a teacher (CS-). Measuring conditioned inhibition Bidirectional response systems: heart or respiratory rate (increase or decrease with respect to baseline). Indirect measures: - Summation (or compound stimulus) test: joint presentation of CS+ and CS-. If the response is smaller than in presence of CS+ alone, CS- is truly inhibitory. Ex: Victims of bullying further reduce their anxiety if the teacher (CS-) is close to the bullies (CS+) in the playground. - Retardation of acquisition test: turn CS- into CS+. If acquisition is slower than in a control group, CS- was truly inhibitory. Ex: Victims of bullying take longer to feel anxiety if the teacher (CS-) starts harassing them (CS-), with respect to the other adults (NS). Basic phenomena in classical conditioning: – Acquisition Graducal increase in CR after repeated paired presentations of CS-US - First, only UR - With training CR appears before US - Amount of trials to achieve the cc varies from some response systems to others Abre tu Cuenta NoCuenta con el código WUOLAH10 y llévate 10 € al hacer tu primer pago a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 · Negatively accelerated increase in the learning slope, with marked increases in the first tests until reaching asymptotic level – Extinction Repeated presentation of CS in absence of US reduces the strength of association Different from habituation: Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. · Procedure: - Habituation (non-associative): presenting US - Extinction (associative): presenting CS · Response: - Habituation (non-associative) of UR - Extinction (associative) of CR – Recovery of the extinct CR 1. Spontaneous recovery: Reappearance of extinct CR after a period of rest or change of context Phase 1 Phase 2 Phase 3 Extinction Rest Test CS CS · CR comes back with lower intensity · Evidence that CR does not disappear → CS associated to a new meaning 2. Reinstatement: US presented alone, following extinction, induces CR recovery when CS is presented again. Phase 1 Phase 2 Phase 3 Extinction US Test CS CS 3. Renewal: Extinct CR comes back if CS presented in a context different from than in acquisition ABA DESIGN Phase 1 Phase 2 Phase 3 Acquisition Extinction Test CS → US CS CS Abre tu Cuenta NoCuenta con el código WUOLAH10 y llévate 10 € al hacer tu primer pago a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 ABC DESIGN Phase 1 Phase 2 Phase 3 Acquisition Extinction Test CS → US CS CS · CR hardly comes back with AAB design Renewal, retrieval of information model (Bouton, 1997) · Acquisition creates an excitatory association CS → US · Extinction does not break that association → new inhibitory CS-US association CS → US context - Inhibitory effect of extinction is linked to the context - When CS and context representations are active, inhibition weakens US representation → extinction - No inhibition if context representation is not active → renewal – Generalization Old learning is transferred to new events or situations Stimuli similar to CS (white light vs yellow light) can trigger a CR (more likely the ore similar they are) – Discrimination Various stimuli but just one paired with US, association restricted to that stimulus · Individual distinguishes which stimulus predicts consequence → adaptive Hanson (1959) Pigeons trained to peck yellow key-light (550nm) to later: · S+ group: same training · S- group: discrimination, same training + trials using similar light (555nm) unpaired with US · Test phase: - S+ generalization - S- do not respond over 550nm Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 Other phenomena in CC: – Conditioning without US · Sensory preconditioning: EXPERIMENTAL CONTROL Preconditioning NS → NS NS / NS Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. 2 NS presented in tone light tone light association (not contingent in control group) Conditioning CS → US CS → US CC on one of NS light food light food Test CS CS Untrained NS triggers CR tone tone in experimental groups · High-order conditioning: EXPERIMENTAL CONTROL 1st order conditioning CS → US CS → US CC on a NS light food light food 2nd order conditioning CS → CS CS / CS Previous CS used as US tone light tone light following a second CS Test CS CS Second CS (never paired tone tone with a real US) triggers CR in experimental group – Counterconditioning CS can be re-conditioned Phase 1 CS → US → UR Phase 2 CS → US → UR CR triggered by CS can change if the latter is paired with a US of opposing sign (ex: mistreated animals getting scared when we move our hands suddenly) – Compound conditioning What if ECs jointly paired with a US? EC1 + EC2 → US tone light food · ECs ‘compete’ for the association with the US Abre tu Cuenta NoCuenta con el código WUOLAH10 y llévate 10 € al hacer tu primer pago a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 · Intrinsic CS variables modulate their ‘individual’ conditioning Overshadowing (Mackintosh, 1976) EXPERIMENTAL 1 EXPERIMENTAL 2 CONTROL CONTROL CONTROL 3 n 1L 2N Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. CC CS CS → US CS CS → US CS → US CS → US CS → US light noise shock light weak noise shock light shock noise shock weak noise shock Test CS , CS CS , CS CS CS CS light noise light weak noise light noise weak noise · Light CC in experiment 2 and control 1 but weak in experiment 1 → loud noise overshadows light · Noise CC: in experiment 1 and control 2 but weak in experiment 2 → light overshadows weak noise Blocking effect (Kamin, 1969) EXPERIMENTAL CONTROL Phase 1 CS → US Rats into box light tone No training Phase 2 CS CS → US CS CS → US light tone shock light tone shock Test CS CS , CS tone light tone · Control got moderately conditioned to light and tone · Experimental almost null conditioning to tone → Previous conditioning blocks out second CS in the compound conditioning → ECs muse provide new predictive information about U – Pre-exposure to CS Latent inhibition (Lubow, 1965) EXPERIMENTAL CONTROL Pre-exposure CS Conditioning CS → US CS → US Test CS CS · Delays conditioning in experimental group → Latent inhibition - Specific of pre-exposed CS Abre tu Cuenta NoCuenta con el código WUOLAH10 y llévate 10 € al hacer tu primer pago a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 - Depends on nº and length of exposures, and ISI · Can it be explained by inhibitory conditioning? No, according to the summation test - If we present CS along with another excitatory CS, CR is not different from the one to excitatory CS alone → No inhibition · More likely a decrease in attention to CS (Lubow et al, 1981; Schmajuk, 2002) - Pre-exposition reduces CS novelty - Attention to CS is reduced during conditioning – Pre-exposure to the US Pre-exposition to US delays subsequent conditioning EXPERIMENTAL CONTROL Pre-exposure US Conditioning CS → US CS → US Test CS CS · Explained by blocking effect (Kamin, 1969) · During pre-exposition, context works as CS predis¡cting US · During conditioning, context blocks our¡t subsequent CS (which does not provide new information) Pre-exposure CS → US context. Conditioning CS CS → US context light. – Pre-exposure to uncorrelated CS and US Learned irrelevance EXPERIMENTAL CONTROL Pre-exposure CS / US Conditioning CS → US CS → US Test CS CS · Delays subsequent conditioning · Not an addition of CS and US pre-exposure Joint effect greater than the sum of independent effects → Active learning about CS and US mutual independency before conditioning Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. a64b0469ff35958ef4ab887a898bd50bdfbbe91a-7173394 Determinants of classical conditioning – Owing to the CS CS intensity · The greater the intensity/relevance, the easier the descrimination of CS in the context CS → US → CR Reservados todos los derechos. No se permite la explotación económica ni la transformación de esta obra. Queda permitida la impresión en su totalidad. water + saccharine stomach ache sweet water intake reduction CS nature · Ecological stimuli better work as CSs → evolutionary meaning