PSYC 356 Lecture Notes - Lecture 12: Reflex Arc, Reinforcement, Belongingness
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PSYC 356 Chapter 7: Schedules of Reinforcement and Choice Behavior
Instrumental Motivational Mechanisms
Thorndike vs Skinner
●We all display inherent or developed lack of self control
○Can the VDF account for this?
Choice Commitment and Self Control:
In the VDF (V= M/ (1+KD):
●“K” is the decay function
●Small K, shallow function= ↑ self control
●Large K, steep function = ↓ self control
Madden et. al 1997: “Stay off the Horse”
Subjects:
●Controls
●Heroin users
Choice between:
●$1000 at later times (1 week to 25 yrs)
●Users choose smaller amounts right away
“K” large decay steep in heroin users
●Can self control be trained?
●Eisenberger & Adornetto, 1986:
○Subjects: 2nd and 3rd graders
○Pretest: choice
■2¢ immediately
■3¢ at the end of the day
○Training reinforcement with delay
■Group 1: Correct answers: 2¢ immediately
■Group 2: correct answers: 3¢ at day’s end
●At post test, training ↑ choice of 3¢ later
Why does instrumental conditioning work?
We are “motivated” to obtain (or avoid) reinforcement
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Associative Approaches:
Thorndike recognized that instrumental conditioning occurs in the presence of particular stimuli
ie. operant chamber, stick floor texture, new school, etc
Three- Term Contingency: 3 events take part in instrumental conditioning
S-Stimulus (environment, cues)
R- Response (bar press, peck)
O- Outcome (reinforcer, food)
Possible associations:
S-R
S-O
R-O
Associative Approaches: S-R Associations
Stimulus- Response
Law of Effect: The reinforcer (O) is a tool that establishes the association between S-R
●Motivation for R becomes the association of S-R
●Once S-R is learned, the reinforcer (O) is not important
●Fosters reflective behaviors (remember the reflex arc?)
Stimulus- Outcome:
S-O associations are formed implicitly via Classical Conditioning
Stimulus (S)- CS, Outcome (O)- US
Through conditioning, the response (R) is elicited by 2 factors
●S evokes R directly (Instrumental)
●S produces expectancy of O (Classical)
■**Two Process Theory
Two Process Theory: S-O associations activate a central emotional state
(What’s coming?)
Ex 1: Hope:
The Skinner Box (S) may signal the delivery of food (O)
Ex 2: Dread:
The Skinner box (S) may signal the delivery of shock (O)
Implication: the rate of R should be modified by CS (S)
Transfer of Control Experiment: Test of 2 Process Theory
Phase 1 Phase 2 Test (instrumental)
Level (R) → Food Light (CS+)→ Food With CS: #Presses?
Document Summary
Psyc 356 chapter 7: schedules of reinforcement and choice behavior. We all display inherent or developed lack of self control. Small k, shallow function= (cid:515) self control. Large k, steep function = (cid:517) self control. Madden et. al 1997: (cid:483)stay off the horse(cid:484) 1000 at later times (1 week to 25 yrs) Users choose smaller amounts right away (cid:483)k(cid:484) large decay steep in heroin users. 3 at the end of the day. Group 2: correct answers: 3 at day"s end. At post test, training (cid:515) choice of 3 later. We are (cid:483)motivated(cid:484) to obtain (or avoid) reinforcement. Thorndike recognized that instrumental conditioning occurs in the presence of particular stimuli ie. operant chamber, stick floor texture, new school, etc. Three- term contingency : 3 events take part in instrumental conditioning. Law of effect : the reinforcer (o) is a tool that establishes the association between s-r. Motivation for r becomes the association of s-r.
