Learning - Chpt. 5 - Schedules of Reinforcement

Schedule of reinforcement

A specific arrangement (or schedule) of consequences (SR+, SP+, etc) for a target response class.

Continuous reinforcement

Every response is reinforced.

Intermittent reinforcement

Most prevalent (the norm); not every operant response is reinforced.

Ratio schedules

Schedules of reinforcement based on the number of emitted responses.

Fixed ratio

The ratio of responses to reinforcers = 1:1; Fixed Ratio 1 = 1 response required per reinforcer.

Variable ratio

A schedule of reinforcement where the number of responses required for reinforcement varies.

Interval schedules

Schedules of reinforcement based on time since the last consequence occurred.

Fixed interval

A schedule where reinforcement is provided after a fixed amount of time has passed.

Variable interval

A schedule where reinforcement is provided after varying amounts of time.

Cumulative record

A graphical representation of the total number of responses over time.

Response patterning

The specific patterns of responses that occur under different reinforcement schedules.

Schedule-like activities

Activities that mimic the structure of reinforcement schedules.

Progressive ratio schedules

A schedule where the requirement for reinforcement increases progressively.

Contingency management

Systematic use of reinforcement (or punishment) to promote desired behavior & the withholding of reinforcement (or punishment) for undesired behavior.

Contingency Management Therapy for Drug Use

A treatment approach where schedules reinforcing abstinence may set up non-drug reinforcers that compete with drug use.

Roll, Higgins, & Badger (1996)

A test of CM (SR+) for abstinence of smoking behavior.

Baseline

$1 → Each meeting while abstinent: +$1; Met while not abstinent: back to baseline.

Fixed monetary reinforcement group

Received the same, consistent reward so long as behavior had stopped.

Control group (non-contingent payment)

Received reward regardless of whether behavior had stopped or not.

Origin of Schedules

In grad school Skinner made his own SR+ pellets. ~8 rats + 100 pellets/day.

Schedule research

758 page book all about different schedules; Nearly all are cumulative records.

The 4 basic schedules

Include Fixed-Interval, Fixed-Ratio, Variable-Interval, and Variable-Ratio.

Cumulative Records

Displays behavior frequency over time response counter in real time

Cumulative Record and Response Rate

Slope of Curve = Response RATE; Y = mX + b(B = 0); m = (responses/time) = (Rise/Run)

Rise

Cumulative Responses

Run

Time (e.g., Minutes)

Slope

m = Responses per sec

Fixed-Ratio (FR) Schedule

Response-based schedule; Fixed amount of effort required; A 'Fixed Ratio' of responses to SR+'s; FR 5: Every 5th response → SR+

Variable-Ratio (VR) Schedule

Response-based schedule; 'Variable-Ratio' of responses to SR+; Every nth response, on average, → SR+; VR 15 (5, 30, 15, & 10); On average, every 15th response is reinforced

Fixed-Interval (FI) Schedule

1st response after a 'fixed interval' of time → SR+; Requires 1 response. 'Response Dependent'; FI 30-s

Variable-Interval (VI) Schedule

Time-based; 1 response required; Time requirement varies between SR+'s; 1st response after n seconds, on average, SR+; VI 15 s (10, 30, 15, & 5 s)

Schedule-Like Things

FR: Piece work (waiting), picking fruit/veggies, assembling something, exercise; VR: Slot machines, asking people out, fishing with a lure; VI: Text messages, hunting from a blind/stand, fishing with bait & bobber; FI: Baking, watching sunsets, mass transit (buses)

VI Schedules Often Used as Baselines

Overall rate of SR+ does not vary much with response rate; Variables studied using VI Schedules: Punishment, Drugs, Deprivation

Complex Schedules of Reinforcement

Multiple Schedules; Stimulus control, ch8; Concurrent Schedules; Choice, ch9; Chained Schedules; Conditioned SR+, ch10; Conjoint Schedules; Adjusting Schedules, ch9

Schedules as a determinant of drug effects

Effects of CNS depressant pentobarbital on rate of responding on either FI or FR schedule with food reinforcer. Note large differences in response suppression under each schedule, particularly at 1 & 2 mg.

Progressive ratio (PR) schedule

Effort (cost/price) required increases after each reinforcer delivery; PR 3: 3, 6, 9, 12, 15...

Break Point

The last ratio requirement completed; The price where consumption stops

Abuse Potential of Ritalin: Assessment w/ PR

Progressive ratio schedule; Self-administration of methylphenidate by rats. Establish small Fixed Ratio; Increase ratio until responding stops. Vary dose. 'Break point' (y axis) indicates abuse potential.

PR Schedules, Drugs, and Reinforcement Efficacy

Ritalin™ (Methelyphenidate) is used to treat ADHD & is related to Adderall (d-Amphetamine). Human drug-abusing volunteers exposed to 1 of 4 doses of methylphenidate or d-amphetamine. Break Points on a PR schedule for drugs.

Response Cost

How much will you pay for this drug? Self-administration of drugs by baboons. 'Break point' (y axis) indicates abuse potential. Vary dose. High abuse potential for cocaine. None for fenfluramine.