Pavlov’s original experiment is an example of Excitatory classical conditioning. Common Pavlovian Excitatory Procedures – Dog salivates to a (CS)tone ; US-food – Pigeon pecks (CS)keylight ; US-food – Rats freeze to a (CS)tone ; US-shock – Rats avoid a (CS)flavour ; US-illness – Rabbit blinks to a (CS)tone ; US-airpuff Two types of Excitatory Conditioning – Appetitive: CS is followed by an appetitive US (i.e., food, water, sex) – Aversive: CS is followed by an aversive US (i.e., mild shock, illness) CS comes to predict the occurrence of the US and as a result the CS elicits responses (CRs) that are related to the US From a procedural point of view, conditioned excitation, or excitatory conditioning occurs when presentation of the CS is followed by a presentation of the US (i.e., CS__US pairings). Excitatory Pavlovian Conditioning

Interstimulus Interval (ISI) - CS-US Interval between start of CS and start of US Intertrial Interval (ITI) – interval between end of one conditioning trial and the start of the next trial Short-delayed – CS proceeds US – US starts before CS ends (they overlap) but have a short ISI – most effective in many situations Trace CS proceeds US – US starts after CS ends (they do not overlap) – almost as effective as short-delay Common Pavlovian Conditioning Procedures and Their Effectiveness

Long-delayed conditioning CS proceeds US – US starts before CS ends (they overlap) but with a long ISI – usually not effective and it can result in inhibition of delay Simultaneous conditioning CS and US start and end at the same time (ISI is zero) – usually ineffective or a failure of performance rather than learning Backward conditioning US proceeds CS – may or may not overlap – complex results and poorly understood, may produce conditioned inhibition (see below) – demonstrates that CS onset before US is not needed for associative learning – cognitively CS predicts US onset in some situations but in others the CS may predict offset or absence of the US Common Pavlovian Conditioning Procedures and Their Effectiveness

The early explanations of the role of CS-US interval in conditioning have more recently been modified because of a complex set of findings. – Under some situations it is possible to get robust conditioning with any of the CS-US procedures. – For example fear conditioning that produces freezing behavior with a short- delay and escape behavior with simultaneous procedure. Trace Conditioning – temporal gap between CS and US – CS offset as a predictor of US – Specialized brain circuits for holding information “working memory” Temporal coding Hypothesis – Learn the temporal CS – US pattern – In addition to forming a CS-US association – For example timing of conditioned eyeblink see figure 3.9 Common Pavlovian Conditioning Procedures and Their Effectiveness

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

Use a test trial (CS without the US) to compare the effectiveness of conditioning procedures Behavior during the CS can be quantified in several ways: – magnitude: number of drops of saliva, value of a suppression ratio or preference ratio – probability of CR occurring to the CS usually with eyeblink conditioning – latency of the CR following CS onset in long delay and trace conditioning the CR can occur before the US is delivered Measuring Conditioned Responses

Need to avoid Pseudoconditioning – increased responding not due to a CS-US association (i.e., presentations of the US alone) Control Group - a comparison group to determine whether changes in behavior are due to conditioning procedures Random Control procedure – present CS and US at random intervals during the experiment which does not always prevent conditioning Explicitly unpaired control – CS and US are presented far apart to prevent their association Control Procedures

Excitatory (CS+) can become conditioned to signal the presence of a US when CS ---> US Inhibitory (CS-) can become conditioned to signal the absence of a US when CS ---> no US (usually an aversive US) common examples of signals that predict no aversive US – No physical punishment including child abuse when abuser is not around – No stress provoking events when taking a break – No panic attacks where warning signals reduce the level of anxiety Unpredicted anxiety attacks increase the level of anxiety Predicted anxiety attacks (there is warning) decreases anxiety See Figure 3.10 Inhibitory Pavlovian Conditioning

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

A signal that predicts the absence of an aversive event (like shock) is a conditioned inhibitory stimulus (CS-) Some recent studies indicate that inhibitory conditioning may also occur with absence of appetitive US. Suppression of the CR – Conditioned inhibition teaches an animal to inhibit or hold back a CR – Inhibitory conditioning requires an excitatory context for the particular US being used i.e. prior experience with the US – For “absence” to be significant, the US has to periodically occur in the situation Inhibitory Pavlovian Conditioning

Conditional (standard) CS+ Procedure used by Pavlov – see Figure 3.11 – 1. Trial type A: CS+(tone) paired with US(shock) trials – 2. Trial type B: combination CS+(tone)/CS-(light) not followed by US(shock) only get the US(shock) when the CS+(tone) occurs Never get the US (shock) when the CS-(light) is present when the CS+(tone) occurs in combination with the CS-(light), no US(shock) is given Switching back and forth between Type A and Type B trials the CS-(light) gradually becomes a signal for the absence of the US (shock) So the CS- can act as a safety signal Procedures for Establishing Conditioned Inhibition

FIGURE 3.11 Pavlov’s procedure for conditioned inhibition. On some trials (Type A), the CS+ is paired with the US. On other trials (Type B), the CS+ is presented with the CS− and the US is omitted. Type A and Type B trials are presented repeatedly in random alternation. The procedure is effective in conditioning inhibitory properties to the CS−.

Negative CS-US contingency “negative correlation” Figure 3.12 Explicit CS+ training is not necessary for inhibitory conditioning Procedure – US (shock) is never paired with a CS- (bell) – US and CS- alternate with long ISI Example – If a child is bullied (US) in a classroom (context) but not when the teacher (CS-) is present – There is no explicit cues (i.e., no CS Tone) – get some conditioning to the classroom (context) so the classroom predicts bullying Can be stated as a probability: If p(US/CS-) < p(US/no CS-) Procedures for Establishing Conditioned Inhibition

FIGURE 3.12 A negative CS–US contingency procedure for conditioning inhibitory properties to the CS. Notice that the CS is always followed by a period without the US.

Bi-directional response systems – Possible to directly observe inhibition with some bi-directional response systems – If baseline responding is above zero, deflections in both directions from baseline (indicative of excitatory and inhibitory learning) can be detected – sign tracking or approach vs avoidance behavior Non-Bidirectional Response Systems – Compound-stimulus (Summation) test Present the CS- in compound with the CS+ CS- should reduce the size of the CR elicited by the CS+ – Retardation-of-acquisition test Try and convert the CS- to a CS+ This should take longer than trying to convert a neutral stimulus into a CS+ Measurement of Conditioned Inhibition

Training: – (1) A+(flashing light) with US (shock) so flashing light becomes a CS+ – (2) A+X- (flashing light/white noise)compound stimulus with no shock, does the white noise becomes a CS- – (3) B+ (Clicker) was presented with US (shock) so clicker becomes a second CS+ Testing: – measurement of behavior using a conditioned suppression procedure thirsty rats are drinking water when the stimuli are presented longer drinking times indicates that drinking behavior was interrupted Compound-stimulus (Summation) test

Testing: see Figure 3.13 – A+ (flashing light) by itself substantially increases time to start drinking (suppression of drinking because of fear) – B+ (Clicker) by itself substantially increases time to start drinking (suppression of drinking because of fear) – A+X- (flashing light/white noise) together increases time to start drinking a little (less suppression of drinking so it produced less fear) – B+X- (Clicker/white noise) together increases time to start drinking a little (less suppression of drinking so it produced less fear) – B+Y (Clicker/buzzer) together increases time to start drinking the most, Y is a control stimulus which was not used during training (the most suppression of drinking so it produced the most fear) – Compare BX to B and AX to A to see if X- (white noise) reduced fear (less suppression of drinking so less fear) – Compare BX to BY to see if X- (white noise) reduced fear (less suppression of drinking so less fear) Also demonstrated in panic attach patients with carbon dioxide induce panic attach with and without a friend to comfort them. Compound-stimulus (Summation) test

The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved. FIGURE 3.13 Compound-stimulus test of inhibition in a lick-suppression experiment. Stimuli A and B were conditioned as excitatory stimuli by being presented alone with shock (A+ and B+). Stimulus X was conditioned as an inhibitor by being presented with stimulus A without shock (AX–). Stimulus Y was a control stimulus that had not participated in either excitatory or inhibitory conditioning. A was a flashing light; B, X, and Y were auditory cues (a clicker, white noise, and a buzzer, counterbalanced across participants.) A and AX were tested in the original training context. B, BX, and BY were tested in a different context. (Based on Cole, R. P., Barner, R. C., & Miller, R. R. (1997). An evaluation of conditioned inhibition as defined by Rescorla’s two-testing strategy in Learning and Motivation, Volume 28, 333, copyright 1997, Elsevier Science (USA).)

Training: – (1) A+(flashing light) with US (shock) – (2) A+X- (flashing light/white noise) with no shock – (3) Pair Stimulus X (white noise) with US (shock) three times – (4) Pair Stimulus Y (buzzer) with US (shock) three times Retardation-of-acquisition test

Testing: measurement of behavior see Figure 3.14 – using a conditioned suppression procedure – thirsty rats are drinking water when the stimuli are presented – longer drinking times indicates that drinking behavior was interrupted X (white noise) by itself increases drinking time a little (a little suppression so a little fear) Y (buzzer) by itself substantially increases drinking time (a lot of suppression so a lot fear to buzzer), Y is a control stimulus which was not used during training compare X(white noise) to Y(buzzer) to see if X(white noise) produces less fear (less suppression of drinking) – X(white noise) produces very little fear because of its prior use as a compound stimulus with flashing light, it is not a good predictor of shock – Y(buzzer) produces much fear because it was a novel stimulus when paired with the shock, it is a good predictor of shock. Retardation-of-acquisition test

The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved. FIGURE 3.14 Effects of a retardation of acquisition test of inhibition in a lick-suppression experiment after the same kind of inhibitory conditioning as was conducted to produce the results presented in Figure Stimulus X was previously conditioned as an inhibitory stimulus, and stimulus Y previously received no training. (Based on Cole, R. P., Barner, R. C., & Miller, R. R. (1997). An evaluation of conditioned inhibition as defined by Rescorla’s two- testing strategy in Learning and Motivation, Volume 28, 333, copyright 1997, Elsevier Science (USA).)

Globe and Mail Thursday, September 12, 2002 – "Bright, beautiful fall days bother me," says Laurel Nickson, who is watching the ceremony from her office window, five floors above ground zero. "It angers me that they've spoiled those days for us." – Human Causal Judgements: how we judge one event as the cause of another eventCausal Judgements – Learning of anxiety disorders, phobias, and panic disordersphobias – Drug tolerance and addiction Drug tolerance and addiction – Infant and maternal responses in nursing Infant and maternal responses in nursing – Sexual conditioning and increases in reproductive fitness (i.e., number of offspring in fish and perhaps quail) Sexual conditioning Prevalence of Classical Conditioning

Contemporary Research on Pavlovian Conditioning Mechanistic perspective: How and under what circumstances does the conditioning occur? – the association of CS and US – mechanisms in the brain for processing CS and US Ecological perspective: What does conditioning contribute to the animals’ ability to survive and reproduce? – environmental cues reliably precede biologically important events – such as finding and eating food – learning to associate cues for presence of food sight, smell, vibration with eating the food – even in insects vibration cues can be associated with catching food – see Specialized Learning in AntlionsSpecialized Learning in Antlions defeating rivals – male-male competition such as aggression between two males over territory – cues that signal the presence of a rival improve the odds of winning – absence of the cues of a rival enhance survivability by reducing overall aggression avoiding predators locating mates Prevalence of Classical Conditioning

Cognitive Perspective: – What are the underlying cognitive processes that support conditioning? – predictability of the US based on the occurrence of the CS Biological Constraints: – An animals biology and the environment they inhabit limits conditioning – defensive behaviors such as freezing, fighting and fleeing are part of an animal's modal action patterns – these built-in behavioral response systems constrain the type of response in animal will make when threatened Prevalence of Classical Conditioning