class 13

learned helplessness

a state that occurs after a person has experienced a stressful situation repeatedly

continuous reinforcement (crf)

every response delivers reinforcer

partial/intermittent reinforcement

responding reinforcement only happens sometimes; post-reinforcement pauses (inter-trial interval) are long and prominent

ratio schedule

reinforcement depends only on number of responses subject has to
perform in order to receive reinforcement (i.e., the O, aka “US”)
• ”Fixed” Ratio (FR)
• “Variable” Ratio (VR)

interval schedule

reinforcement depends only on amount of time passed after which subject can perform in order to receive reinforcement (i.e., the O,
aka “US”)
• ”Fixed” Interval (FI)
• “Variable” Interval (VI)

fixed ratio

reinforcement given after action completed a fixed amount of times

variable ratio

reinforcement given after action completed a varying amount of times

fixed ratio schedule

number of responses and reinforcers it got; ex: 10 responses per reinforcer is FR10

cumulative record

total number of responses that have occurred up to a particular point in time

post reinforcement pause

zero rate of responding that typically occurs just after reinforcement on fixed ratio

ratio run

high and steady rate of responding that completes each ratio requirement

ratio strain

if ratio requirement is suddenly increased, animal likely to pause periodically before completion of ratio

variable ratio schedule

different number of responses required to obtain successive reinforcers

fixed interval schedule

amount of time that has to pass before a response is reinforced is constant from one trial to the next; interval determines only when reinforcer becomes available, not when it is delivered

fixed interval scallop

increase in response rate, evident toward end of each fixed interval; an acceleration in cumulative record before “time’s up” ; reflects subjects accuracy in telling time; subjects still have to actually make the instrumental response after the time passes

variable interval schedule

required time to set up reinforcer varies from one trial to the next; subject still has to respond to obtain the set-up time; maintain steady and stable rates of responding without regular pauses (same as with variable ratio schedules)

fr and fi

post reinforcement pauses after each reinforcer; high rates of responding just before next reinforcer delivery

vr and vi schedule

steady rates of responding without predictable pauses

vr schedule

motivates vigorous instrumental behavior due to shorter inter-response times, tight relationship between response rates and reinforcement rates; the higher the response rate, the more likely the reinforcer

vi schedule

doesn’t promote as strong instrumental behavior due to; reinforcer doesn’t rely on effort, reinforcer is unpredictable; more responses doesn’t mean more reinforcer necessarily