Schedules of Reinforcement Lecture 14

Schedules of RFT n Frequency of RFT after response is important n Continuous RFT l RFT after each response l Fast Acquisition l shaping n Partial RFT l RFT after only some responses l Conditions set ~

Partial Schedule of RFT n Do not reinforce every response l Slower acquisition l start CRF  shift to partial n Different patterns of RFT produce different patterns of responding l Cumulative response curves l steeper curve  higher operant strength l e.g., higher motivation ~

number of responses Time higher operant strength lower operant strength Cumulative Response Curve

Typical RFT Patterns n Ratio l RFT after certain number of responses n Interval l RFT after certain time interval n Fixed l Same ratio or interval each time n Variable l Average ratio or interval ~

n patterns of RFT are combined Fixed Variable Ratio Interval FR VR FI VI

Schedules produce different response rates n In general… l Ratio > Interval l Variable > Fixed l VR = highest ~

Ratio patterns of response n Animal controls RFT l faster responses  faster RFT n Fixed Ratio l high ratio (FR 50 )  hi response rate u pause after each RFT u Why? l Low ratio (FR 5 )  lower response rate steady ~

number of responses Time Fixed Ratio Response Patterns FR 5 FR 50

Variable Ratio n RFT after average of X responses n VR 10 = RFT after 7 responses 21 responses 30 responses l 3 RFTs in 30 responses = 10 avg. n High, steady rate of response l why? n Give an example of humans on VR ~

number of responses Time FR 5 VR FR 50

Interval Patterns of Response n RFT when R made after a period of time l Experimenter controls RFT n Fixed Interval l e.g., FI 30 l Scalloping u slower responding after RFT u speeds up as nears time for RFT l Human example? n Why? ~

Interval Patterns of Response n Variable Interval l RFT for response after avg. of X seconds l e.g. VI 30 l Slow, steady responding n Human example? What if they checked on FI schedule? ~

number of responses Time FI VI Variable Interval

Differential Schedules n DRH Differential RFT of high rates of responding l High rate  RFT l Low rate  extinction or punishment l Time limit/deadline n DRL Differential RFT of low rates of responding l Set interval between response l Early B  no RFT, timer reset ~

Differential Schedules n Pacing schedules l too slow/fast  no RFT, punishment n DRO u Differential RFT of Other Behavior l RFT of any B other than target B l Used along with punishment n DRI u Differential RFT of Incompatible Behavior l RFT of prosocial vs. antisocial ~

Schedule Effects n Behavioral contrast l After change in RFT schedule l Positive: lean  rich l Negative: rich  lean l often temporary n Behavioral momentum l Or behavioral persistence l B continues even when RFT changes ~

Partial RFT Effect n Maintains behavior over time l Learn more responses required for RFT n Surprising Reinforcers l Attract greater attention l  deprivation   RFT magnitude n Gradual shift l CRF  Partial RFT ~

Schedule of RFT & Extinction n What if B  no S R ? l Behavior weakens l Extinction n Extinction occurs quickly for CRF l Why? ~

Schedule of RFT & Extinction n CRF l expectation of RFT every time n Partial  resistant to extinction l RFT not expected every time n Variable more resistant than fixed l fixed = expectation of regular RFT ~

Partial RFT Extinction Effect n PREE l Why more resistant to extinction? n Discrimination Hypothesis l May not immediately notice when no longer RFT n Frustration Theory l Learn to respond while frustrated l RFT for responding while frustrated ~