Classical vs. Operant Conditioning Operant conditioning (R  SRF) • A voluntary response (R) is followed by a reinforcing stimulus (SRF) • The voluntary response is more likely to be emitted by the organism. • A reinforcer is any stimulus that increases the frequency of a behavior • To be a reinforcer stimuli must immediately follow the response and must be perceived as contingent upon the response Classical conditioning (S  R) • An involuntary response (UCR) is preceded by a stimuli (UCS), or • A stimulus (UCS) automatically triggers an involuntary response (UCR) • A neutral stimulus (NS) associated with UCS automatically triggers a conditioned response. • The NS becomes a conditioned stimulus (CS). A teacher reported that she had been giving her students points on the chalkboard whenever their group was the most quiet and attentive. Eventually, her students learned to become quiet and attentive whenever the teacher approached the chalkboard. What type of conditioning is at work here? What is the role of the teacher by the chalkboard? Even though there is a S  R connection between the teacher standing by the chalkboard and students becoming quiet and attentive, this stimulus is an antecedent (or discriminative) stimulus (not a CS). This is an example of stimulus control in operant conditioning. In operant conditioning, the antecedent stimulus does not directly elicit the response, as it does in classical conditioning. Instead, the stimulus sets the occasion for a response to be reinforced. When an antecedent stimulus influences the likelihood that a response will occur, we call that stimulus a discriminative stimulus ... and say that the response is under stimulus control (Ormrod, 1999, pp. 56-57). The teacher by the chalkboard does not directly elicit an involuntary response. Rather, a voluntary response (being quite and attentive) is strengthened by a reinforcing stimulus. The teacher by the chalkboard (S+) is a cue, a signal, or a signpost telling students that if they behave (R) in a certain way, a specific consequence is likely to follow (SRF). [ (S+) R  SRF] Discriminative Stimulus (S+) Response (R) Reinforcing Stimulus (SRF) Antecedent Behavior Consequence Teacher by the chalkboard Being quiet and attentive Points on chalkboard Teacher by the chalkboard is an antecedent telling students if they are quiet and attentive there is a probability that they will earn points on board. This type of stimulus is a cue or a reminder, not an automatic trigger. Also, note that similar stimuli (e.g., teacher standing anywhere in the classroom) may also cue (S+) behavior (R). This is known as stimulus generalization. The more similar the stimulus is (e.g., teacher standing close to the chalkboard vs. standing away from the chalkboard) the more likely it is to generalize (generalization gradient). Conversely, students can learn that a certain response may be reinforced in one situation (S+), but not in another (S-). For example, students may learn that they only are reinforced (R) when the teacher is out of her seat (S+) and not when she is sitting at her desk (S-). This is known as stimulus discrimination: [(S-) R  (nothing)]. However, classical conditioning may be playing a role here. The teacher by the chalkboard, because of its association with a reward, may begin to elicit a conditioned response (a happy feeling). This "feeling" may help to remind children to behave in a certain way. It may help to make the antecedent a more powerful (or automatic) behavioral cue. Stimulus Response Stimulus Response Antecedent Behavior Consequence Teacher by the chalkboard Being quiet and attentive Reward Pleasure NS  UCS  UCR   CS   CRBehavioral Explanations of PTSD Symptoms Manifestations of Acute Distress Symptoms Type of Reaction Re-experience Avoidance and Numbing Increased Arousal Somatic • Reactivity to reminders (e.g., sweating, rapid heart beat, nausea, dizziness, dry mouth, difficulty breathing) • Sensory numbing • Abdominal distress • Hot flashes or chills • Frequent urination • Trouble swallowing Behavioral • Insomnia • Increased activity • Aggression • Act as if trauma were recurring • Avoidance of trauma reminders (e.g., activities, locations, conversations, people, things) • Decrease interest in significant activities • social withdrawal • Insomnia • Exaggerated startle Cognitive • Intrusive recall • Flashbacks • Trauma nightmares. • Amnesia • Poor concentration • Hypervigilance Emotional • Psychological distress with exposure to reminders (e.g., anxiety, anger, guilt, shame, hopelessness) • Emotional numbing • Irritability • Outburst of anger Classical conditioning = Symptoms of Reexperiencing NS + UCS = UCR (e.g., a setting) (a trauma) (acute distress) NS>CS = CR (e.g., a setting) (acute distress) Operant conditioning = Symptoms of Escape and Avoidance Voluntary Response = Reinforcing Stimuli (Escape/Avoidance) = (Negative Reinforcement) Classical conditioning = Symptoms of Arousal NS + UCS = UCR (e.g., a setting) (a trauma) (fight or flight) NS>CS = CR (e.g., a setting) (acute distress)Basic Concepts in Operant Conditioning Concept Definition Free Operant Level Natural level of behavior (or baseline). Terminal Behavior Desired frequency of a behavior at the end of a planned reinforcement. Extinction Reinforcing stimulus no longer follows a response and the response is less frequent. Superstitious Behavior “Guesses” as to how one can to obtain reinforcement. Shaping When the free operant level of a behavior is very low (or absent), reinforcement is offered for successive approximations of the target behaviorTypes of Reinforcers Reinforcers increase the frequency of a response Primary Satisfies basic needs. Secondary Becomes reinforcing via learned associations (classical conditioning) with primary reinforcers. Positive Presentation of something desired (e.g., tangibles, attention, control, internal good feeling without external contingency). Negative Termination of something that is undesired. Stopping an aversive stimuli (escape). Learning to stay away from an aversive stimuli (avoidance). Primary Automatic reinforcers Secondary Learned reinforcers Positive Obtaining desired stimuli • Physical