Schedules of Reinforcement

Lecture 14

Schedules of RFT

Frequency of RFT after response is important

Continuous RFT RFT after each response Fast Acquisition shaping

Partial RFT RFT after only some responses Conditions set ~

Partial Schedule of RFT

Do not reinforce every response Slower acquisition start CRF shift to partial

Different patterns of RFT produce different patterns of responding Cumulative response curves steeper curve higher operant

strength e.g., higher motivation ~

number ofresponses

Time

higher operant strength

lower operant strength

Cumulative Response Curve

Typical RFT Patterns

Ratio RFT after certain number of responses

Interval RFT after certain time interval

Fixed Same ratio or interval each time

Variable Average ratio or interval ~

patterns of RFT are combined

Fixed Variable

Ratio

Interval

FR VR

FI VI

Schedules produce different response rates

In general… Ratio > Interval Variable > Fixed VR = highest ~

Ratio patterns of response Animal controls RFT

faster responses faster RFT Fixed Ratio

high ratio (FR50) hi response rate pause after each RFT Why?

Low ratio (FR5) lower response rate

steady ~

number ofresponses

Time

Fixed Ratio Response Patterns

FR5

FR50

Variable Ratio

RFT after average of X responses VR10 = RFT after 7 responses

21 responses

30 responses 3 RFTs in 30 responses = 10 avg.

High, steady rate of response why?

Give an example of humans on VR ~

number ofresponses

Time

FR5

VRFR50

Interval Patterns of Response

RFT when R made after a period of time Experimenter controls RFT

Fixed Interval e.g., FI30

Scalloping slower responding after RFT speeds up as nears time for RFT

Human example? Why? ~

Interval Patterns of Response

Variable Interval RFT for response after avg. of X

seconds e.g. VI30

Slow, steady responding Human example?

What if they checked on FI schedule? ~

number ofresponses

Time

FI

VI

Variable Interval

Differential Schedules DRH

Differential RFT of high rates of responding High rate RFT Low rate extinction or punishment Time limit/deadline

DRLDifferential RFT of low rates of responding

Set interval between response Early B no RFT, timer reset ~

Differential Schedules Pacing schedules

too slow/fast no RFT, punishment DRO

Differential RFT of Other Behavior RFT of any B other than target B Used along with punishment

DRI Differential RFT of Incompatible Behavior

RFT of prosocial vs. antisocial ~

Schedule Effects Behavioral contrast

After change in RFT schedule Positive: lean rich Negative: rich lean often temporary

Behavioral momentum Or behavioral persistence B continues even when RFT

changes ~

Partial RFT Effect

Maintains behavior over time Learn more responses required for

RFT Surprising Reinforcers

Attract greater attention deprivation RFT magnitude

Gradual shift CRF Partial RFT ~

Schedule of RFT & Extinction

What if B no SR ? Behavior weakens Extinction

Extinction occurs quickly for CRF Why? ~

Schedule of RFT & Extinction

CRF expectation of RFT every time

Partial resistant to extinction RFT not expected every time

Variable more resistant than fixed fixed = expectation of regular RFT ~

Partial RFT Extinction Effect

PREE Why more resistant to extinction?

Discrimination Hypothesis May not immediately notice when

no longer RFT Frustration Theory

Learn to respond while frustrated RFT for responding while

frustrated ~