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8/7/24 Non-Associative Learning; Intro. Classical Conditioning PSYU2236/PSYX2236 Biopsychology & Learning Lecturer: Dr Patrick Nalepka (he/him) 1 Outl...

8/7/24 Non-Associative Learning; Intro. Classical Conditioning PSYU2236/PSYX2236 Biopsychology & Learning Lecturer: Dr Patrick Nalepka (he/him) 1 Outline 1. W hat do w e mean by Learning? 2. Non-Associative Learning Habituation Sensitisation 3. Introduction to Classical Conditioning The key elem ents o f Classical Conditioning 2 1  8/7/24 1. What do we mean by Learning? Hum an m o t o r skill learning (Tutorial 1; Research Report) Operant Conditioning (Week 10; Tutorial 5) R einforcem ent Learning in AI (Tutorial 4) 3 What is learning? HABITUATION AND SENSITISATION Learning is the acquisition of knowledge or skills through experience Typically learning is revealed by a change in behavioural, physiological, and/or neural reactions/responses 4 4 2  8/7/24 How does learning occur? THREE LEVELS Physiological: Riding a bike Behavioural: Neural: Playing the piano Synapses 5 5 Why is learning important? HABITUATION AND SENSITISATION Learning allows an animal to adapt to their environment. ― notice important events and learn to ignore events that occur without consequence (non-associative learning) ― learn what stimuli predict events and what behaviours are associated with certain consequences (reward or punishment) to better predict/prepare for or seek/avoid such consequences (associative learning) 6 6 3  8/7/24 Not all changes are a result of learning HABITUATION AND SENSITISATION Behavioural, physiological, and/or neural changes can occur that are not the result of learning e.g., changes that occur due to: ― fatigue ― illness ― drugs How can you tell if a behavioural change is not related to learning? ― It is NOT a consequence of experience ― Often temporary – learning is typically long-lasting and can only be changed though experience (e.g., through extinction or the learning of an alternative behaviour) 7 7 2. Non-Associative Learning 1. W hat is th e difference betw een n o n - associative and associative learning? 2. Types o f n o n - associative learning H abituation (and dishabituation) W hat purpose does habituation serve? W hat are examples? Sensitisation W hat purpose does sensitisation serve? W hat are examples? 3. When does habituation versus sensitisation occur? 4. H ow does th e dual process theory account fo r habituation and sensitisation? 8 4  8/7/24 Associative Vs Non-associative Learning HABITUATION AND SENSITISATION LECTURE What is the difference between Associative and Non-associative learning? Associative Learning: any learning process in which a new response becomes associated with a particular stimulus. This can occur via the creation of associations between: ― 1) Two stimuli. E.g., a bell and food for Pavlov’s dogs ― 2) A behaviour and its consequence (response). E.g., A dog holding out its paw for a shake and getting a treat Non-associative Learning: Learning that results in a change in the frequency or amplitude of a behaviour/ response after repeated exposures to a single stimulus ― 1) increase in response (sensitisation) ― 2) decrease in the response (habituation) 9 9 Types of Non-associative Learning: Habituation HABITUATION AND SENSITISATION LECTURE People and animals notice novelty from birth When something new happens, we pay attention to it and show an orienting response ― Orienting response: Move toward/attend to new event § Look in the direction of and/or lean toward 10 10 5  8/7/24 Types of Non-associative Learning: Habituation HABITUATION AND SENSITISATION LECTURE However……after repeated exposure to the stimulus we habituate. ― Habituation: A (progressive) decrease in response amplitude or frequency as a consequence of repeated experience with a stimulus ― Habituation is typically stimulus-specific ― Habituation can be short- or long-term, lasting hours, days, or weeks What noise? ― This typically occurs to a stimulus judged to be of little or no importance ― We engage in this type of learning so we can tune out unimportant stimuli and focus on what matters! 11 11 Examples of Habituation HABITUATION AND SENSITISATION LECTURE Long term habituation example… E.g., a novel sound initially makes an eating cat panic, but if the sound is repeated daily, the cat habituates and eats without the slightest reaction 12 12 6  8/7/24 Non-Associative Learning in the Real-World HABITUATION AND SENSITISATION LECTURE What process is going on here? Habituation? Sensory adaptation? Sensitisation? 13 13 Examples of Habituation HABITUATION AND SENSITISATION LECTURE People often habituate to the smell of their own dog in their house or car, or to their own perfume ― Stimulus-specific so people would still notice the pet smell in their friend’s house or someone else’s perfume. 14 14 7  8/7/24 Habituation is NOT sensory adaptation HABITUATION AND SENSITISATION LECTURE Sensory adaptation is the tendency of sensory receptors to fatigue and stop responding to an unchanging stimulus – they change their sensitivity to the stimulus. This is a physical, bottom-up process E.g: Enter dark cinema theatre… …10-15 min later you can see people in seats… 15 15 How can I tell if it’s habituation or sensory adaptation? HABITUATION AND SENSITISATION LECTURE With Sensory Adaptation you can't E.g. if you jump into a pool of cold recapture the initial water, after a few minutes you start to adapt. After about 15 minutes if you stimulus try to get the initial feeling of jumping into the cool water YOU CAN'T (no matter how hard you try!). 16 16 8  8/7/24 How can I tell if it’s habituation or sensory adaptation? HABITUATION AND SENSITISATION LECTURE With Habituation, you can recapture the stimulus E.g., if there is annoying sound, you can eventually tune it out, but if you atten to it, you can hear it again. 17 17 Habituation and Dishabituation HABITUATION AND SENSITISATION LECTURE Dishabituation: Recovery in responsiveness to an already habituated stimulus What noise? Habituation to fridge noise But the addition of a novel stimulus reorients the perceiver to the habituated stimulus… Dishabituation to Oh that noisy fridge fridge noise 18 18 9  8/7/24 Dishabituation HABITUATION AND SENSITISATION LECTURE Dishabituation ―Recovery in responsiveness to an already habituated stimulus Dishabituation – Siren would alert pedestrians to the traffic! 19 19 Why does the first bite always taste the best? HABITUATION AND SENSITISATION LECTURE Why does the first bite always taste the best? (hint: habituation) Why do we tend to over eat at parties? (hint: habituation is slower when there is a variety and different foods can act as dishabituators) Why do we always seem to have room for dessert? (hint: habituation is stimulus-specific) Something called sensory specific satiety also plays a role in these effects… For more information see: Epstein, L. H., Temple, J. L., Roemmich, J. N., & Bouton, M. E. (2009). Habituation as a determinant of human food intake. Psychological review, 116(2), 384–407. https://doi.org/10.1037/a0015074 20 20 10  8/7/24 Types of Non-associative Learning: Sensitisation HABITUATION AND SENSITISATION LECTURE Sensitisation ― An increase in response amplitude or frequency as a consequence of repeated experience with a stimulus ― Sensitisation is typically NOT stimulus-specific ― Often occurs when we are anticipating an important stimulus so that we are prepared for important cues ― Sensitisation (and habituation) are commonly studied using the startle response and orienting response 21 21 Examples of Sensitisation HABITUATION AND SENSITISATION LECTURE Have you ever been in an exam, and the student in the seat next to you has a nervous habit of clicking their pen? In contrast to habituation, sensitisation occurs where the clicking produces increased orienting or attentional responses. 22 22 11  8/7/24 Examples of Sensitisation HABITUATION AND SENSITISATION LECTURE While we can often fall asleep to the sound of a loud air conditioning unit or a refrigerator, the presence of a buzz from a mosquito is enough to keep us awake all night! “If you think you’re too small to make a difference… try sleeping with a mosquito.” Dalai Lama 23 23 Types of non-associative learning: Desensitisation HABITUATION AND SENSITISATION LECTURE Desensitisaton ― A decrease in response amplitude or frequency back down to baseline as a consequence of repeated experience with a stimulus. 24 24 12  8/7/24 Habituation vs Sensitisation HABITUATION AND SENSITISATION LECTURE Habituation and sensitisation are both natural responses to repeated events. When will one occur versus the other? Why do different processes occur for similar buzzes? 25 25 Infant study: Habituation and Sensitisation HABITUATION AND SENSITISATION LECTURE Habituation in the human infant Experimental Procedure: Infants were shown either visually complex or simple patterns 8 times for 10 seconds each: Simple: 4 x 4 pattern Complex: 12 x12 pattern Measured: time spent looking at the stimulus. Bashinski HS, Werner JS, Rudy JW. (1985). Determinants of infant visual fixation: evidence for a two-process theory. Journal of Experimental Child Psychology, 39, 580-98. 26 26 13  8/7/24 Infant study: Habituation and Sensitisation HABITUATION AND SENSITISATION LECTURE Habituation and sensitisation affected responding on the same behaviour! 4x4 12 x 12 4 x 4 stimulus 12 x 12 stimulus Results (fixation time over trials) Looking time steadily decreased over trials as the infant habituated to the simpler 4x4 stimulus. Looking time first increased to the complex 12x12 stimulus (sensitisation) before it decreased (habituation) 27 27 Habituation and Sensitisation HABITUATION AND SENSITISATION LECTURE Results show that attention elicited by a novel stimulus changes with familiarity ― Elicited behaviours change over exposures The nature of the change depends on nature of stimulus Simple stimulus: è progressive habituation Complex stimulus: è Sensitisation è habituation 28 28 14  8/7/24 Infant study: Dishabituation HABITUATION AND SENSITISATION LECTURE Visual fixation became habituated to a 4 x 4 chequerboard stimulus presented over 8 trials. After trial 8, a tone was presented as a dishabituating Adapted from Kaplan, P.S., Goldstein, M.H., Huckeby, E.R., Owren, M.J., & Cooper, R.P. (1995). Dishabituation of visual attention by infant- versus stimulus along with the chequerboard pattern causing adult-directed speech: Effects of frequency modulation and spectral recovery of visual fixation to the pattern. composition, Infant Behavior and Development, 18, 209-223 29 29 When does habituation or sensitization occur? HABITUATION AND SENSITISATION LECTURE Intensity of the stimulus: a low intensity stimulus typically results in habituation, while a high intensity stimulus typically results in sensitisation... a stimulus of intermediate intensity often results in a period of sensitisation then habituation. The evolutionary (adaptive) significance of the stimulus: can often override intensity. E.g. essential for mother not to habituate to a baby’s cry ― adaptive to sensitise to them! E.g., Mosquitos carry diseases and cause unpleasant bites 30 30 15  8/7/24 Dual-Process Theory of Habituation & Sensitisation HABITUATION AND SENSITISATION LECTURE Recap: The initial increase in responsiveness to a stimulus is sensitisation. Sensitisation is thought to be a companion process to habituation that opposes the effects of habituation in many, but not all situations. Sensitisation may occur not only during first few presentations of stimulus, but also at the introduction of an unexpected stimulus from another modality (e.g., a dishabituating stimulus) 31 31 Dual-Process Theory of Habituation & Sensitisation HABITUATION AND SENSITISATION LECTURE The underlying processes of habituation and sensitisation can co-occur The observable behaviour is the sum of these two processes The habituation effect is observed when the habituation process is greater than the sensitisation process and vice versa. Groves, P.M., & Thompson, R.F. (1970). Habituation: A dual-process theory. Psychological Review, 77, 419–450. doi:10.1037/h0029810. 32 32 16  8/7/24 Dual-Process Theory of Habituation & Sensitisation HABITUATION AND SENSITISATION LECTURE Key assumption: Response to repeated presentations of a stimulus reflect the operation of two separate processes, habituation and sensitisation Habituation produces a stimulus-specific decline in responding to repeated stimulation, and grows stronger as the number of repetitions increases The sensitisation process produces increases in responsiveness on early trials, which decay spontaneously over time These two processes are thought to sum to determine overt responding 33 33 Dual-Process theory of Habituation & Sensitisation HABITUATION AND SENSITISATION LECTURE Habituation effect Sensitisation effect 34 34 17  8/7/24 Brief Summary: Non-associative Learning HABITUATION AND SENSITISATION LECTURE Habituation Repeated exposure to a stimuli can result in a decrease in the response elicited (habituation) The weaker the stimulus the more rapid/likely the habituation This response decrement (habituation) shows stimulus specificity Sensitisation Repeated exposure to a stimuli can result in an increase in the response elicited (sensitisation) The stronger the stimulus the more rapid/likely the sensitisation The response increase (sensitization) generalizes to other stimuli in the domain 35 35 Brief Summary: Non-associative Learning HABITUATION AND SENSITISATION LECTURE Relationship between habituation and sensitisation Habituation and sensitization can co-occur Measurable, outward behaviour is a result of the combined habituation and sensitisation effects The habituation effect is observed when the habituation process is greater than the sensitisation process and vice versa. 36 36 18  8/7/24 Break Break Time 37 3. Introduction to Classical Conditioning 1. W hat is Classical Conditioning? H ow does i t d iffe r f r o m n o n - associative learning? 2. Key elem ents o f classical conditioning N eutral S tim ulus (NS) Unconditioned S tim ulus (US) U nconditioned Response (UR) Conditioned S tim ulus (CS) Conditioned Response (CR) 3. Examples o f classical conditioning 4. Types o f U nconditioned S tim u li (US) Appetitive Aversive 5. Accounts o f classical conditioning S tim ulus S u b stitu tio n Hypothesis Preparatory Response Theory Compensatory Response Model 6. S tim ulus generalisation and discrim ination processes 38 19  8/7/24 Associative Learning INTRODUCTION TO CLASSICAL CONDITIONING LECTURE Learning to associate one stimulus with another 39 39 What is Classical Conditioning? INTRODUCTION TO CLASSICAL CONDITIONING LECTURE Classical Conditioning: The procedure of repeatedly pairing an initially neutral stimulus (NS) and an Unconditioned Stimulus (US) – a stimulus that reliably elicits a (Unconditioned) Response (UR) After conditioning the neutral stimulus, it becomes established as a Conditioned Stimulus (CS) with the capacity to elicit a (Conditioned) Response (CR) that usually resembles the Unconditioned Response (UR) 40 40 20  8/7/24 What is Classical Conditioning? INTRODUCTION TO CLASSICAL CONDITIONING LECTURE The difference between classical and operant conditioning 41 - Peggy Andover - YouTube 41 Key element of Classical Conditioning INTRODUCTION TO CLASSICAL CONDITIONING LECTURE Key elements of classical conditioning ― Neutral Stimulus (NS) ― Unconditioned Stimulus (US) ― Unconditioned Response (UR) ― Conditioned Stimulus (CS) ― Conditioned Response (CR) Make sure you are comfortable with this terminology! 42 42 21  8/7/24 Classical Conditioning Terminology INTRODUCTION TO CLASSICAL CONDITIONING LECTURE In the beginning… Then the NS is paired with US… And voilà an association forms! CS è CR 43 43 Examples of Classical Conditioning INTRODUCTION TO CLASSICAL CONDITIONING LECTURE e.g. Separation anxiety in dogs Jingle of keys Oh No – she’s leaving me Classical conditioning imbues the previously neutral sound of jingling keys with the capacity to elicit separation anxiety 44 44 22  8/7/24 Classical Conditioning of Separation Anxiety INTRODUCTION TO CLASSICAL CONDITIONING LECTURE Happy dog jingle Owner goes to work Sad/anxious dog ♬ ♪ ♫ Neutral Unconditioned Unconditioned Stimulus Stimulus Response CR of anxiety CS Several trips to ♬ ♪ work later… ♫ 45 45 Classical Conditioning Overview INTRODUCTION TO CLASSICAL CONDITIONING LECTURE Acquisition Extinction Spontaneous Recovery 46 46 23  8/7/24 Acquisition of Learning INTRODUCTION TO CLASSICAL CONDITIONING LECTURE Learning follows a negatively accelerating curve You can only respond so much 47 47 Types of Unconditioned Stimuli (US) INTRODUCTION TO CLASSICAL CONDITIONING LECTURE The US used in classical conditioning studies are typically of two types: 1. Appetitive US automatically elicits approach responses, such as eating, drinking, caressing, etc. These responses give satisfaction and pleasure. 2. Aversive US such as noise, bitter taste, electric shock, painful injections, etc. are painful, harmful, and elicit avoidance and escape responses. Appetitive classical conditioning is slower and requires greater number of acquisition trials, but aversive classical conditioning is established in one, two or three trials depending on the intensity of the aversive US. 48 48 24  8/7/24 What form does the Conditioned Response (CR) take? INTRODUCTION TO CLASSICAL CONDITIONING LECTURE Stimulus Substitution Theory That bell is looking very tasty Pavlov thought that the CS became a substitute for the US Innate US-UR reflex pathway ― CS substitutes for the US in evoking the same response ― CR and UR produced by same neural region ― Food è salivation ― CS è salivation If so, the CR should always be the same as the UR! 49 49 Evidence FOR stimulus substitution hypothesis INTRODUCTION TO CLASSICAL CONDITIONING LECTURE Jenkins and Moore (1973) study: Sign tracking (aka Autoshaping) in pigeons ― One group had CS (light) è US (grain) § Pigeons tried to “eat” the lit key (open beak & closed eyes) when they pecked Photographs showing pigeons pecking keys when receiving water reward (left) or food (right). ― Another group had CS (light) è US (water) Pecks to the water-related key included drinking § Pigeons tried to “drink” the lit key (closed beak & like movements such as licking. Pecks to the open eyes) when they pecked food-related key were made with the beak slightly open, as if to seize a piece of grain. CR is sometimes directed at the CS Jenkins, H. M. & Moore, B. R. (1973). The form of the auto-shaped response with food or water reinforcers, Journal of the Experimental Analysis of Behavior, 20, 163–181. doi: 10.1901/jeab.1973.20-163 This shows that the nature of the US determines the form of the CR 50 50 25  8/7/24 Sign-tracking and individual differences INTRODUCTION TO CLASSICAL CONDITIONING LECTURE Some animals are sign-trackers and some are goal trackers Sign trackers direct their behaviour at the CS (i.e., the sign) (e.g., light) even at the expense of the US (reward/goal). Goal trackers’ behaviour is directed to the US. 51 51 Sign-tracking and individual differences INTRODUCTION TO CLASSICAL CONDITIONING LECTURE Both sign and goal trackers are learning that the CS predicts the food outcome, but only sign trackers ascribe incentive to the cue (CS). Rats who display sign tracking towards a CS predictive of food are more likely to develop compulsive cocaine self-administration (Tunstall & Kearns, 2015). 52 52 26  8/7/24 Sign tracking and addiction in humans INTRODUCTION TO CLASSICAL CONDITIONING LECTURE Research from animals on sign tracking is frequently applied to looking at whether people who over eat or who are susceptible to addiction are overly sensitive to cues associated with food, alcohol, or drugs! Conditioned stimuli that signal reward can become motivational magnets that capture attention, even when individuals are motived to ignore them. Sign-tracking offers an account of how impulsive and involuntary behaviour begins and is triggered by cues. It offers a theory of how addiction gets started, while, at the same time, explaining why the erosion of self-control induced by sign-tracking goes largely unnoticed. Tomie, A. (1995). CAM: An animal learning model of excessive and compulsive implement-assisted drug-taking in humans, Clinical Psychology Review, 15, 145-167. (CAM= Cue and Manipilandum) 53 53 Evidence AGAINST stimulus substitution hypothesis Any study in which the elicited CR is different from the UR ― This is often the case with aversive US § e.g., when a tone is paired with shock, rats will jump to the US (shock), but the CR is typically freezing § Freezing is a preparatory defense response 54 54 27  8/7/24 Alternative Accounts: Preparatory Response Theory INTRODUCTION TO CLASSICAL CONDITIONING LECTURE Kimble’s (1961, 1967) theory proposed that the CR is a response that serves to prepare the organism for the upcoming US Better warm-up my jaws and get the e.g., following acquisition of CRs in eye-blink saliva flowing…food is on its way conditioning, the CR eye-blink may actually prepare the person for the upcoming air-puff such that the eye would be partially closed when the air-puff occurs Kimble, G.A. (1961). Hilgard and Marquis’ conditioning and Learning (2nd ed.) New York, NY: Appleton Century Crofts. Kimble, G. A. (1967). The definition of learning and some useful distinctions. In G.A. Kimble (ed) Foundations of conditioning and learning. 55 New York, NY: Appleton-Century-Crofts. 55 Alternative Accounts: Compensatory Response Theory INTRODUCTION TO CLASSICAL CONDITIONING LECTURE The compensatory-response model is one version of preparatory-response theory Better get that saliva flowing to off-set In this model of classical conditioning, my dry mouth when eating the compensatory after-effects to a US are what come to be elicited by the CS Based on the opponent-process theory of emotion / motivation Central goal is to maintain a state of homeostasis 56 56 28  8/7/24 Generalisation, transfer, and discrimination INTRODUCTION TO CLASSICAL CONDITIONING LECTURE Stimulus Generalisation: A tendency to respond to stimuli that are similar, but not identical to, a conditioned stimulus ― Transfer of Training: Being able to apply knowledge gained in one situation to that of a similar one. Stimulus Discrimination: The learned ability to respond differently to similar stimuli – to pick the ‘real deal’ from the look-alikes! 57 Image generated using ChatGPT 4o 57 Classical Conditioning & Generalisation INTRODUCTION TO CLASSICAL CONDITIONING LECTURE Pavlov found that conditioning resulted in salivation not only to the CS presented during training, but also to other stimuli that were similar to it In one experiment, he conditioned salivation to a tone of 1000 Hz… ― after conditioning the dogs also salivated to 1100 Hz and 1200 Hz, among other ― the greatest salivation occurred to the tones most similar to the training stimulus. 58 58 29  8/7/24 Discrimination INTRODUCTION TO CLASSICAL CONDITIONING LECTURE No, but why not? 59 59 Discrimination INTRODUCTION TO CLASSICAL CONDITIONING LECTURE Pug is discriminating between different sounds Telephone ringing is not a good predictor of owner leaving house Picking up her bag might cause some concern as it’s a better predictor of leaving. 60 60 30  8/7/24 Brief Summary: Introduction to Classical Conditioning INTRODUCTION TO CLASSICAL CONDITIONING LECTURE Classical conditioning is a type of associative learning – it involves the formation of a relationship between two stimuli Key elements of classical conditioning are: ― Neutral stimulus (NS), Unconditioned stimulus (US), (UR)unconditioned response, (CS) conditioned stimulus, and (CR) conditioned response Unconditioned stimuli can be appetitive (positive) or aversive (negative) There are a number of accounts of classical conditioning ― Stimulus Substitution Hypothesis ― Preparatory Response Theory ― Compensatory Response Model Generalisation (transfer of training) and discrimination of the CS occurs 61 61 Next Time The le ctu re to p ic next w eek is “The Neuron” Reading: The Kalat chapter t it le d “Nerve Cells and Nerve Im pulses” Tutorials begin next week. In - person: Find o u t w here is your classroom! (12SW Room 317) Online: Find your associated tu to ria l channel on teams. Make use o f our PSYUX2236-2 0 2 4 -S2 Team fo r u n it discussions, ask questions, or help answer questions f r o m your peers! Have a good day! 62 31