What determines the nature of the CR? When a neutral CS is paired with a US what determines the specific characteristics of the CR? Look at why particular responses become conditioned – salivary : UR is release of saliva, CR is release of saliva – eyeblink: UR is eyeblink, CR is eyeblink – fear: UR is vocalization, jumping, pooping, freezing, CR is freezing, pooping – tolerance to drugs: UR can be decreased arousal, CR can be increased arousal The first explanation for the nature of the CR is the Stimulus Substitution model used by Pavlov

The Stimulus Substitution Model Explained by Pavlov as CS substitutes for the US see Figure 4.7 The association of the CS-US turns the CS into a ‘surrogate’ US Each US has unique brain center connected to a unique UR center – This is the reflex system The CS activates reflex neural circuits previously activated by US – So CS only elicits responses “CR” similar to the US With pairings of the CS and US – a new connection develops between the neural circuits previously activated by the CS and the neural circuits previously activated only by the US Reasonable model for simple reflexes, simple consummatory behavior at the end of a behavior sequence but can not explain the variety of classical conditioning procedures

The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

The US as a determining factor for the CR The form of the CR is determined by and usually resembles the form of the UR The quality or nature of the US affects the type of CR because different USs elicit different URs – US Food elicits salivation so a light CS would produce a CR salivation – US Shock elicits fear response so a light CS would produce a CR fear response Sometimes there are subtle differences in CR depending on the US Jenkins & Moore (1973) using a Sign tracking procedure – when the US was water it produced slow pecks with a closed beak at the Key Light – when the US was grain it produced rapid peaks with an open beak at the Key Light – Photograph of pigeons pecking at key light Photograph – Pigeons peck at the Key Light in both cases but the pecking response is different – Thus, the form of the CR resembles the form of the UR However, in some conditioning situations, the CRs and URs are very different (see next section for details)

The CS as a determinant of the form of the CR The quality or nature of the CS affects CR, even though the CS is supposed to be innocuous or neutral Experiment by Holland with rat subjects – Tone ---> Food Tone elicits head jerk behavior (rapid back and forth movements of the head) – Light ---> Food Light elicits rearing and investigation of the food cup Timberlake and Grant (1975) see Figure 4.8 – Investigated classical conditioning in rats with food as the US – CS was a presentation of another rat – Instead of gnawing and biting as stimulus substitution model might predict – the CR was orientation, approach, sniffing and social contact

The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

The CS – US Interval as a Determining Factor for the CS-US interval (ISI) in fear conditioning – Short intervals for quick responding related to fear and panic – Long intervals for slower responding related to anxiety CR Sexual Behaviour System: Atkins (2000) – CS Light paired with US Female quail – CS-US interval determines where the CS becomes incorporated in the sequence 1 minute -> CS elicited focal search (male searched in area of light) 20 minute -> CS elicited general search (male searched all of chamber) – See Figure 4.9 General Search Behaviour -> Focal Search Behaviour -> Courtship and Consummatory Behaviour (copulation)

The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved. FIGURE 4.9 Effects of the CS-US interval in the sexual conditioning of male quail. CS approach (left panel) and general locomotor behavior (right panel) were measured in response to the CS in groups that received paired or unpaired CS-US presentations (based on Akins, 2000).

Conditioned Behavior and Behavior Systems Various behavioral systems (feeding, defense, reproduction, etc.,) each with a series of response modules The US activate behavioral systems that are relevant to the US – food activates foraging/feeding system – mate activates sexual behavior system – rivals activate aggressive behavior So behavioral systems approach can explain – US as a determining factor – CS as a determining factor CS becomes associated with US, it becomes integrated into that behavior system – CS-US interval as a determining factor determines where the CS becomes incorporated into the behavior sequence – As seen in figure 4.10 – Short CS-US produces approach behavior – Long CS-US produces general search behavior

The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

S-S versus S-R Learning: How does a CS produce responding? S-S Learning Interpretation States that the CS enters into an association with the US (or US representation) The CS triggers a memory of the US which in turn elicits a response Link to example in PPT An association begins to develop between the CS center and the US center Support from US-devaluation experiments

US-Devaluation Procedure Logic of US Devaluation Experiments see Figure 4.11 Conventional classical conditioning is followed by US devaluation by either – unlimited access to the US (satiation) – US is associated with illness Subsequently, the CS in presented alone and the CR is measured Changing the US representation Holland & Rescorla (1975) – Phase 1: Tone CS -> Food US (association) – Phase 2: US devaluation via food satiation – Phase3: Test Tone CS for CR strength (activity) – Result: reduced CR to Tone CS following US devaluation treatment in phase 2 S-S versus S-R Learning: How does a CS produce responding?

The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved. Allowed to eat until not hungry Reduced responding to the CS

S-R Learning Interpretation States that because the CS occurs close in time to the UR, it comes to trigger the response directly An association forms between the CS and the response link to example in PPT There is also support for S-R Learning – studies with operant conditioning in chapter 7 S-S versus S-R Learning: How does a CS produce responding?

Pavlovian Conditioning as Modification of Responses to the Unconditioned Stimulus When CS is Associated with US the CR can interact with US – Conditioned eyeblink reduces eyeblink to US airpuff – Conditioned analgesia reduces pain from US shock – Conditioned drug tolerance – These are examples of conditioned diminution of the CR Two experimental procedures – Common testing design A – US paired compared to A US unpaired Test with A -- US – Common Training design A – US paired compared to B US unpaired Test A-US and B-US

The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved. FIGURE 4.12 Experimental designs used to demonstrate conditioned modification of the unconditioned response.

Classical Conditioning in Homeostatic Systems Homeostasis introduced by Water Cannon –physiological responses are maintained at acceptable levels –body temperature, heart rate, blood pressure "compensatory" responses return the system to baseline levels –for example low body temperature is compensated by feedback signals that help retain or produce body temperature Classical conditioning can be beneficial to anticipate the challenges to homeostasis and start compensatory mechanisms earlier –cues that signal exposure to cold temperatures can activate compensatory adjustments in anticipation of the cold i.e. start retaining heat before exposure to the cold –anticipation of exercise can produce heart rate increases before exercise starts –But only with experience, classical conditioning of compensatory systems

Conditioned Compensatory Response (CCR) the compensatory system can become conditioned to the CS in which case the CR should be called a conditioned compensatory response "CCR" a drug (morphine) "US" produces increased body temperature "UR" that activates the compensatory decreased body temperature environmental cues "CS" at the time of drug administration can condition the compensatory response decreased body temperature CCRs mediate the development of tolerance by counteracting the drug effect can be tested by presenting the CS (drug cues) without the US (drug)

Conditioning model of drug tolerance Tolerance - effect of a drug decreasing with repeated administrations – classical conditioning contributes to tolerance – drug is taken repeatedly in the same way in the same context "situation" – CS drug taking cues signal the availability of the drug specific environmental stimuli context - the overall situation self-administration cues – With repeated conditioning the CS elicit a CCR that attenuates the drug effect with repeated experience CS drug -- US getting high is attenuated by CCR i.e. produces “drug tolerance” Testing situational-specificity of tolerance – drug is administered in an unfamiliar environment (lack of CS) – tolerance is attenuated (get more drug effect) – can increases the lethality of some drugs such as morphine or heroine which suppress breathing

The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved. FIGURE 4.13 Illustration of the conditioning model of drug tolerance. The magnitude of a drug reaction is illustrated by deviation from the horizontal level. (A) Primary reaction to the drug before conditioning, illustrating the initial effects of the drug (without any homeostatic adjustments). (B) The homeostatic compensatory drug reaction that becomes conditioned to the drug- predictive CS after repeated drug administrations. (C) The net attenuated drug response that is observed when the drug is administered with the drug- conditioned CS. This net attenuated drug response illustrates the phenomenon of drug tolerance.

Conditioned Reproduction and Fertility Appetitive conditioning – tone ---signals --- food – light --- signals --- opportunity for mating Hollis (1997) – Blue Gourani males – 18 trials of CS light ---signals---- appearance of female behind the barrier – On final CS barrier is removed and the male and female can interact – Over six days courting, nest building and copulation – Male conditioned with light where Less aggressive Better nest builders Higher clasp frequency Produced more offspring

The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved. FIGURE 4.14 Interactions between male and female gourami following exposure to a Pavlovian CS for males that previously had the CS paired or unpaired with visual access to a female (based on Hollis et al., 1997).