Chapter 5: Schedules of Reinforcement

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Chapter 5Schedules of Reinforcement
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Schedules of Reinforcement

• A Schedule of Reinforcement is a prescription
  that states how and when discriminative stimuli
  and behavioral consequences will be presented.
• Schedules of reinforcement are common in everyday
  life. A rat pressing a lever for food and a
  person turning on a light seem to have little in
  common. Humans are very complex organisms They
  build cities, write books, go to college, go to
  war, conduct experiments, and do many other
  things that rats cannot do. Nonetheless,
  performance on schedules of reinforcement has
  been found to be remarkably similar for different
  organisms, many types of behavior, and a variety
  of reinforcers.

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Importance of Schedules of Reinforcement

• Rule for the presentation of stimuli that precede
  operants and the consequences that follow them
• Schedules are the fundamental determinants of
  behavior
• Rate and temporal patterns of responding
• Probability of responding

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Terminology

• Partial reinforcement effect
• Discrimination hypothesis
• Generalization decrement hypothesis
• Contingency of reinforcement - features defined
  by the schedule
• Steady-state performance
• Strained performance

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Partial reinforcement effect Resistance to
extinction greater after partial reinforcement
than after continuous reinforcement   Theory Discr
imination hypothesis harder to detect change to
EXT after PRF than CRF, the subject cannot
discriminate that behavior its is on EXT.
Generalization decrement as EXT continues the
situation is more and more different than when
reinforcement was in effect. But the degree of
generalization is much greater from PRF to EXT
than from CRF to EXT. The reinforcement
contingencies in PRF and EXT are more similar
than in CRF and EXT.
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Understanding Cumulative Records

• Plots responses as they occur moment to moment
• A pen records time horizontally. Each response
  moves the pen vertically
• Reinforcers are marked
• Slope of the record indicates response rate
• Steep High
• Flat Low

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Time moves Response moves
low rate
No response
high rate
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Schedules and Patterns of Response

• Patterns of response develop on schedules of
  reinforcement. These patterns come about after
  an animal has experience with the contingency of
  reinforcement defined by a particular schedule.
• Subjects are exposed to a schedule of
  reinforcement and, following an acquisition
  period, behavior typically settles into a
  consistent or steady-state performance.
• It may take many experimental sessions before a
  particular pattern emerges, but once it does, the
  orderliness of behavior is remarkable.

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Schedules and Patterns of Response

• When organisms are reinforced for a fixed number
  of responses, a pause-and-run pattern of behavior
  develops.
• Responses required by the schedule are made
  rapidly and result in reinforcement.
• Following each reinforcement, there is a pause in
  responding, then another quick burst of
  responses.
• This pattern repeats over and over and occurs
  even when the size of the schedule is changed. A
  pause-and-run pattern has been found for horses,
  chickens, vultures, and children.

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Schedules of Reinforcement

• CRF - continuous reinforcement FR 1
• Fixed Ratio- FR an FR schedule
• Postreinforcement pause
• run of responses
• Variable Ratio VR
• Fixed Interval - FI scalloping
• Long term - break and run
• Humans
• Variable Interval - VI

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Reinforcement Schedules

• Response based schedules
• Fixed ratio FR
• Variable ratio VR
• Progressive ratio PR
• Random ratio RR
• Time Based Schedules
• Fixed interval FI
• Variable interval VI
• Fixed and variable time FT/VT

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Other Schedules

• Differential reinforcement of low rates
• IRT gt t
• Differential reinforcement of high rates
• IRT lt t

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Behavior and Schedule Effects

• Schedules of reinforcement affect operant
  behavior because the schedule may interact with
  other independent variables
• When punished after every response during FR
  schedule, the pause length after reinforcement
  increased.
• Although once the animal emitted the first
  response, the rate to finish the run was
  unaffected.
• Punishment reduces the tendency to begin
  responding but once started the behavior is not
  suppressed.

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Behavior and Schedule Effects

• Punishment has different effects when behavior is
  maintained on different schedules of
  reinforcement
• When on a VI (variable interval) and punished
  after each operant, the pattern of behavior is
  the same but the rate of response declines

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Schedules of Positive Reinforcement

• Continuous Reinforcement
• Continuous reinforcement, or CRF, is the
  simplest schedule of reinforcement. On this
  schedule, every operant required by the
  contingency is reinforced.
• CRF and Resistance to Extinction
• Continuous reinforcement generates little
  resistance to extinction. Resistance to
  extinction is a measure of persistence when
  reinforcement is discontinued.

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Reinforcement and Behavioral Momentum

• Concept of momentum derives from a combination of
  response rate, as generated by schedules of
  reinforcement, and the behavioral dynamic of
  resistance to change, both of which are important
  dimensions of operant behavior and analogous to
  velocity and mass in physics
• Behavioral Momentum refers to behavior persisting
  in the presence of a particular stimulus despite
  disruptive factors

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Schedules of Positive Reinforcement

• When compared to intermittent schedules,
  continuous reinforcement produces less resistance
  to extinction. This is called partial or
  intermittent reinforcement effect.

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Response Stereotypy on CRF

• When on CRF, the topography of response become
  very predictable and have very little
  variability.
• Rats were conditioned to poke their noses
  anywhere along a 50 cm slot on CRF schedule.The
  rats responded to the same point on the slot
  while on CRF
• When placed on extinction, the variability of the
  placement along the slot increased.

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Response Stereotypy on CRF

• As continuous reinforcement persists less and
  less variation occurs of the operant class.
• The variability of response may be inversely
  related to the rate of reinforcement.
• Responses were stereotyped on CRF and became more
  variable when on intermittent or extinction
  schedule.
• It appears that the general principle is when
  things no longer work try new ways of behaving.
• Resurgence increase in topography variability
  during extinction, can contribute to the
  development of creative or original behavior

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Ratio and Interval Schedules of Reinforcement

• On intermittent schedules of reinforcement, some
  rather than all responses are reinforced.
• Ratio schedules are response based that is,
  these schedules are set to deliver reinforcement
  following a number of responses.
• Interval schedules pay off when one response is
  made after some amount of time has passed.
• Interval schedules may be fixed or variable.
• Fixed schedules set up reinforcement after a
  fixed number of responses, or a constant amount
  of time has passed. On variable schedules,
  response and time requirements may vary from one
  reinforcer to the next.

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Ratio Schedules

• A fixed ratio, or FR, schedule is programmed to
  deliver reinforcement after a fixed number of
  responses is made.
• Continuous reinforcement is FR 1
• FR schedules produce a rapid run of responses,
  followed by reinforcement, then a pause in
  responding.
• A cumulative record of behavior on fixed ratio
  looks somewhat like a set of stairs. There is a
  steep period of responding (the run), followed by
  reinforcement, and finally a flat portion. The
  flat part of the cumulative record is called the
  postreinforcement pause, or PRP.

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Schedules of Reinforcement

• Response-based only x responses are required
• Fixed ratio reinforcer is delivered contingent
  on a set number of responses
• FR 5 v FR 15
• Direct contingency X responses must be emitted
• The higher the FR, the higher the response rate
  (side effect) and the longer the pause
• Side effect break and
• run pattern
• Ex piece rate

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FR schedules produce pause-and-run
responding. Pauses occur just after
reinforcement, then responding becomes
steady. Pause length is a function of the
ratio. In what way?
Cumulative responses
Time -----gt
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Analysis of Reinforcement Schedules

• FR postreinforcement pause theories
• Fatigue, a larger ratio produces a longer PRP as
  the subject catches its breath.But why not a
  PRP on VRs with large ratios?
• Satiation, right after consuming reinforcement
  the subject is in a state of relative satiation.
  But PRPs happen after non-consumable reinforcers
• Remaining response, on a multiple schedule, two
  or more schedules alternate each with its own SD
  and its own reinforcement. If a large ratio
  alternates with a shorter ratio, the PRP will be
  longest after the shorter ratio. A PRP might be
  called a PreRatio Pause

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PRP in a Multiple Schedule
On a multiple schedule two or more basic
schedules alternate, each one w\ an SD and
primary reinforcement, as in a blue key light
FR50- SR-red key light-FR5-SR on a MULT schedule
such as this, the PRP is typically longer after
the FR5 than after the FR50. A PRP is more a
function of the upcoming ratio than the
ratio just completed.
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Ratio Schedules

• Variable-ratio, or VR, schedules are similar to
  FRs except that the number of responses required
  for reinforcement changes after each reinforcer
  is presented.
• The average number of responses is used to define
  the schedule.
• Ratio schedules produce a high rate of response.
• When VR and FR schedules are compared, responding
  is typically faster on variable ratio. One
  reason for this is that pausing after
  reinforcement (PRP) is reduced or eliminated when
  the ratio contingency is changed from fixed to
  variable. The provides evidence that the PRP
  does not occur because the animal is consuming
  the reinforcer.

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Ratio Schedules

• Many contingencies set by games of chance are
  similar to variable-ratio schedules.
• Gambling is often called addictive, but from a
  behavioral perspective it may be understood as
  persistent high-rate behavior generated by ratio
  contingencies of reinforcement.
• A bird on a standard VR schedule may make
  thousands of responses for a few brief
  presentations of grain

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• Variable ratio a reinforcer is delivered after
  a varied and unpredictable number of responses
• VR 30 means an average number of responses
• Examples
• Casting a line
• Supposedly Gambling
• Random ratio

• Direct contingency mean number of responses
  must occur
• Side effect constant, high rate of responding

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Ratio Schedules

• It is possible to set the average ratio
  requirements so high that an animal will spend
  all of its time working for a small amount of
  food
• Animal will show a net energy loss where effort
  expended exceeds caloric intake, similar to the
  self-defeating response sometimes seen in
  gambling behavior
• Seemingly irrational behavior of gamblers is
  generated by an unfavorable probabilistic
  schedule of reinforcement

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Interval Schedules

• On fixed-interval (FI) schedules, an operant is
  reinforced after a fixed amount of time has
  passed.
• For example, on a fixed-interval 90-second
  schedule, one bar press after 90 seconds results
  in reinforcement.
• When organisms are exposed to interval
  contingencies, they typically produce many more
  responses than the schedule requires.
• Fixed-interval schedules produce a characteristic
  pattern of responding. There is a pause after
  reinforcement (PRP), then a few probe responses,
  followed by more and more rapid responding as the
  interval times out. This pattern of response is
  called scalloping.

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Response-plus-time based schedules

• Arrangement of reinforcer specifies time and
  responses
• Fixed interval reinforcer is delivered after the
  first response occurs after a specific period of
  time
• FI 3 means the first response after three
  minutes elapses gets reinforced
• Contingency one response after 3

• Side effect scallop-shaped pattern
• Little responding at beginning of interval
• Lots of responding at end of interval
• Ex Checking watch while waiting for a bus

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FI schedules produce faster responding at the end
of the interval. Scallops appear in between.
Why?
Time -----gt
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Interval Schedules

• Following considerable experience with FI 5
  minutes, you may get very good at judging the
  time period.
• In this case, you would wait out the interval and
  then emit a burst of responses. Perhaps you
  decide to pace back and forth during the session,
  and you find out that after 250 steps the
  interval has almost elapsed. This kind of
  mediating behavior may develop after experience
  with FI schedules.
• Other animals behave in a similar way and
  occasionally produce a break-and-run pattern of
  responding.

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Generality of Schedule Effects

• Behavior analysts assume that research on
  schedule effects with animals also apply to
  humans.
• The assumption of generality implies that the
  effects of reinforcement extend over species,
  reinforcement, and behavior.
• Humans show similar performances to rats when
  placed on FI schedules.

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Generality of Schedule Effects

• The influence of language may explain why humans
  do not show characteristics of scalloping on FI
  schedules.
• Humans either produce a high rate of response or
  a low rate of response.
• People construct a verbal rule and behave
  according to the rule rather than the
  experimental contingencies.
• Humans who have not developed language skills
  will respond to that of a rat and more like the
  characteristic effects of the schedule

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Interval Schedules

• On a variable-interval, VI, schedule responses
  are reinforced after a variable amount of time
  has passed.
• For example, on a VI 30 second schedule, the time
  to each reinforcement changes but the average
  time is 30 seconds.
• On this schedule rate of response is steady and
  moderate. The pause after reinforcement that
  occurs on FI usually does not appear in the
  variable-interval record. Because rate of
  response is moderate, VI performance is often
  used as a baseline for evaluating other
  independent variables.
• VI contingencies are common in everyday life.

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Schedules of Reinforcement

• Generally, ratio schedules produce shorter IRTs
  and consequently higher rates of response than
  interval schedules.
• Generally, it is well established that the
  postreinforcement pause is a function of the
  interreinforcement interval (IRI).

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PostReinforcement Pause

• PRP as a function of IRI
• FI - ½ interval value.
• FR pause increases as FR is increased, rate of
  response also increases.

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• VR and VI response rates
• VR yoked VI
• Rates are higher on VR schedules even when rate
  of reinforcement is the same
• ?

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• VR and VI response rates
• VR yoked VI
• Rates are higher on VR schedules even when rate
  of reinforcement is the same
• ?

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VR VI maintain steady rates of responding FR
FI produce predictable post reinforcement
pauses Ratio schedules produce higher
response rates than interval schedules
Why? -         Feedback function Ratio
schedules selectively reinforce high response
rates because increased response rate means more
reinforcement. The faster the subject responds,
the sooner the next reinforcement is
obtained. Interval schedules preferentially
reinforce long Inter Response Times (IRTs)
because the longer you pause, the more likely the
first response after the pause will be
reinforced. Rate of responding is irrelevant to
obtaining the next reinforcement any sooner.
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Variable schedules produce more consistent
responding (no pauses or scallops) than fixed
schedules. Why? VR schedules produce faster
response rates than VI. Why?
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Rates of Response
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Schedules and IRTs
FRs and VRs differentially reinforce short IRTS,
the shorter the time interval between consecutive
responses, the more frequent and rapid
reinforcement will be obtained. Ratio schedules
reinforce bursts of responding like a machine
gun. Interval schedules, whether fixed or
variable, tend to reinforce longer IRTS such as
respond-wait-respond-wait since responding faster
will not produce more frequent or rapid
reinforcement. On such schedules, only a single
response is required as long as that single
response occurs after the interval has elapsed.
As a result, a paced response rate with delays
between consecutive responses is likely to
produce reinforcement. These are molecular
accounts of response rate.
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Rate of Response on Schedules

• Dynamic interactions between
• Molecular aspects - moment-to-moment
  relationships
• Molar aspects- length of session

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Molecular Account of Rate of Response

• The time between any two responses, or what is
  called the interresponse time (IRT) may be
  treated as an operant.
• Generally, ratio schedules produce shorter IRTs
  and consequently higher rates of response than
  interval schedules.
• To understand this, consider the definition of an
  operant class. It is a class of behavior that may
  either increase or decrease in frequency on the
  basis of contingencies of reinforcement. In other
  words, if it could be shown that the time between
  responses changes as a function of selective
  reinforcement, then the IRT is by definition an
  operant in its own right.

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Molecular Account of Rate of Response

• Several experiments have shown that the
  distribution of IRTs may in fact be changed by
  selectively reinforcing interresponse times of a
  particular duration.
• When compared to ratio schedules, interval
  contingencies generate longer IRTs and
  consequently a lower rate of response.
• Interval schedules may pay off after some amount
  of time has passed and a response is made. As
  IRTs become longer, more and more of the time
  requirement on the schedule elapses. This means
  that the probability of reinforcement for a
  response increases with longer IRTs.

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Molar Accounts of Rate Differences

• There are several problems with the IRT account
  of rate differences on ratio and interval
  schedules.
• A logical objection is that showing that the
  reinforcement of IRTs can change behavior does
  not mean that this is what is happening on other
  schedules. In other words, demonstrating that
  IRTs can be selectively reinforced does not prove
  that this occurs on either interval or ratio
  schedules.

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Molar Accounts of Rate Differences

• Molar explanations of rate differences are
  concerned with the global relationship between
  responses and reinforcement.
• In general terms, the correlation between
  responses and reinforcement produces the
  difference in the rate on interval and ratio
  schedules.
• Generally, if a high rate of response is
  associated with a higher frequency of
  reinforcement, then subjects will respond
  rapidly. When the increased rate of response does
  not affect the rate of reinforcement, organisms
  do not respond faster.

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Molar Accounts of Response Rate
Consider a subject responding on a VR 100
schedule for a 50 minute session. If this subject
responds leisurely at .8 responses per second,
in the 50 minutes, 48 responses per minute,
about 2 minutes per VR 100 or about 30
reinforcers obtained in the 50 minutes. If on
the same VR 100, the subject responded at 2
responses per sec., or 120 responses/minute or
about 48 seconds per VR 100 many more
reinforcers are obtained in the same 50 minutes.
Here, increases in response rate are correlated
with more frequent reinforcement. Increases in
response rate on interval schedules are not
correlated with increases in response
rate. Ratio schedules produce higher response
rates not due to timing on the order of IRT
length but in terms of timing over entire
sessions.
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Molar Accounts of Rate Differences

• According to supporters of the molar view, this
  correlation between increasing the rate of
  response and the increased frequency of
  reinforcement is responsible for rapid responding
  on ratio schedules.
• A different correlation between the rate of
  response and the frequency of reinforcement is
  set up on interval schedules.

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The VR-VI difference

• IRT reinforcement
• IRTs are conditionable
• Synthetic schedules, merely by making
  reinforcement contingent upon IRTs of specific
  lengths, a VI like performance can be obtained.
• Response-reinforcer correlation

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Analysis of Reinforcement Schedules

• FR postreinforcement pause theories
• Fatigue, a larger ratio produces a longer PRP as
  the subject catches its breath.But why not a
  PRP on VRs with large ratios?
• Satiation, right after consuming reinforcement
  the subject is in a state of relative satiation.
  But PRPs happen after non-consumable reinforcers
• Remaining response, on a mixed schedule, two or
  more schedules alternate each with its own SD and
  its own reinforcement. If a large ratio
  alternates with a shorter ratio, the PRP will be
  longest after the shorter ratio. A PRP might be
  called a PreRatio Pause

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Postreinforcement Pause on Fixed Schedules

• Molecular accounts of pausing are concerned with
  the moment-to-moment relationships that
  immediately precede reinforcement. Such accounts
  are concerned with the relationship between the
  number of bar presses that produce reinforcement
  and the subsequent postreinforcement pause.
• In contrast, molar accounts of pausing focus on
  the overall rate of reinforcement for a session
  and the average pause length.

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Postreinforcement Pause on Fixed Schedules

• Generally, it is well established that the
  postreinforcement pause is a function of the
  interreinforcement interval (IRI).
• As the time between reinforcements becomes
  longer, the PRP increases.

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Postreinforcement Pause on Fixed Schedules

• On fixed-interval schedules, in which the time
  between reinforcement is controlled by the
  experimenter, the postreinforcement pause is
  approximately one-half the interreinforcement
  interval.
• For example, on a FI 300-s schedule (in which the
  time between reinforcements is 300 s), the
  average PRP will be 150 s.
• On fixed ratio, the evidence suggests similar
  control by the IRIas the ratio requirement
  increases, the PRP becomes longer.

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Postreinforcement Pause on Fixed Schedules

• There is, however, a difficulty with analyzing
  the postreinforcement pause on FR schedules.
• On ratio schedules, the time between
  reinforcements is partly determined by what the
  animal does. That is, the animals rate of
  pressing the lever affects the time between
  reinforcements.
• Another problem with ratio schedules, for an
  analysis of pausing, is that the rate of response
  goes up as the size of the ratio is increased.
  Unless the rate of response exactly coincides
  with changes in the size of the ratio,
  adjustments in ratio size alter the
  interreinforcement interval.
• Thus, changes in postreinforcement pause as ratio
  size is increased may be caused by the ratio
  size, the interreinforcement interval, or both.

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A Molar Interpretation of Pausing

• We have noted that the average PRP is one half of
  the interreinforcement interval.
• Another finding is that the postreinforcement
  pauses are normally distributed over the time
  between reinforcements.
• An animal that was sensitive to the overall rate
  of reinforcement (maximization) should come to
  emit pauses that are on average one half of the
  FI interval, assuming a normal distribution.
  Thus, maximization of reinforcement provides a
  molar account of the postreinforcement pause.

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Molecular Interpretations of Pausing

• There are two molecular interpretations of
  pausing on fixed schedules that have some amount
  of research support.
• One account is based on the observation that
  animals often emit other behavior during the
  postreinforcement pause.
• For example, rats may engage in grooming,
  sniffing, scratching, and stretching after the
  presentation of a food pellet.
• Because this behavior reliably follows
  reinforcement, it is said to be induced by the
  schedule. Schedule-induced behaviors may be
  viewed as operants that automatically produce
  reinforcement.

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Molecular Interpretations of Pausing

• One interpretation is that pausing occurs because
  the animal is maximizing local rates of
  reinforcement.
• That is, the rat gets food for bar pressing as
  well as the automatic reinforcement from the
  induced activities.
• The average pause should therefore reflect the
  allocation of time to induced behavior and to the
  operant that produces scheduled reinforcement
  (e.g., food).
• At present, experiments have not ruled out or
  clearly demonstrated the induced-behavior
  interpretation of pausing.

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Molecular Interpretations of Pausing

• A second molecular account of pausing is based on
  the run of responses or the amount of work that
  precedes reinforcement.
• This work-time interpretation hold that the
  previously experienced run of responses regulates
  the length of the postreinforcement pause.
• Work time affects the PRP by altering the value
  of the next scheduled reinforcement.
• In other words, the more effort or time expended
  for the previous reinforcer, the lower the value
  of the next reinforcer and the longer it takes
  for the animal to initiate responding (i.e.,
  pause length).

62
Factors affecting performance on a schedule

• Quality of reinforcer
• Rate of reinforcement
• Delay of reinforcement
• Amount of reinforcement
• Level of motivation

63
Schedule Performance in Transition

• Steady State occurs when behavior show little
  change from day to day. Ex. Break and run
  behavior.
• Transition State are periods between steady
  states. Ex. When initially place on any
  reinforcement schedule
• Most learning takes place when behavior is in
  transition.

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Schedule Performance in Transition

• After steady-state performance is established on
  CRF, you are faced with the problem of how to
  program the steps from CRF to FR 100.
• Notice that there is a large shift in the rate of
  reinforcement for bar pressing.
• If you simply move from CRF to large-ratio value,
  the animal will show ratio strain in the sense
  that it produces longer and longer pauses after
  reinforcement.

65

Schedule Performance in Transition

• Large and sudden increases in schedules may
  produce extinction and is why a slow progression
  to a higher schedule is implemented
• Transitions in schedules occur in major life
  events. Ex. Divorce
• Following a divorce a shift in contingencies of
  reinforcement take place.
• Feelings of depression and loneliness may be
  produced by ratio strain and extinction.

66
Schedules used to condition response rate 1)
Differential reinforcement of low rates of
responding (DRL) Reinforcers only follow
responses that occur after a minimum amount of
time has passed has elapsed between two
consecutive responses. Ex) DRL 10
sec Response--10 sec delay --gt Response --gt
Reinf If a response occurs during the delay, a
reinforcer is not given, DRLs reinforce
very long IRTs.
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2) Differential reinforcement of high rates of
responding (DRH) Reinforcers only follow
responses that occur before a minimum amount of
time has passed. Ex) DRH 10 Response-? 10 sec
delay --gt Response -gt No reinf Two consecutive
responses must occur before the 10 secs to be
reinforced. The IRT between two consecutive
responses must be less than some specified value.
A DRH reinforces very short IRTs.
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Sanford (IQ 65) a prisoner in GA prison
system The incentive value of the reinforcer
(points) was higher if Sanford learned faster. 1
grade level in 90 days (DRH 90) ---gt 120
pts (DRH 4) ----gt 900 pts
(DRH 1) -----gt 4700 pts With points exchangeable
for tangible privileges and goods, studying hard
became so reinforcing that Sanford started
skipping recreation time to study. Studying
Sanford completed 5 years of high school in 5
months! He was being differentially reinforced
for learning fast (high rate).
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Intelligence and IQ
Some students may be questioning whether the
subject Sanford actually had an IQ of 65. What is
the IQ test measuring, intelligence or the
subjects ability to do well on such tests?
Cognitive psychologists would of course argue
that some partially innate intellectual or
information processing capability is being
assessed. Hence, the notorious bell curve
data showing different races have different
IQs. But what if the IQ test is just measuring
ability to take such tests which could be
affected by variables such as motivation to work
hard??? African American students who took IQ
tests and were given affirmative feedback for
each correct score produced IQ test scores 10 15
points higher than for African Americans tested
without this feedback. The use of feedback had no
real effect on white students taking IQ tests.
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Applying Schedules to Smoking

• The use of drugs is operant behavior maintained
  by the reinforcing effects of the drug.
• A population of smokers (N60) were assigned to
  one of three groups Progressive reinforcement
  (N20), fixed rate reinforcement (N20), and
  control (N20). Carbon monoxide testing detected
  the abstinence from smoking
• Money was the reinforcement for the experiment to
  implement response cost.

71
Applying Schedules to Smoking

• The progressive reinforcement group was given
  3.00 for passing initial carbon monoxide test
  and .50 for second and third consecutive
  passings. On the third consecutive passing a
  bonus of 10 was given. This schedule was
  repeated. Failing a CO test would not be
  reinforced and the payment was returned to 3.00.

72
Applying Schedules to Smoking

• The fixed reinforcement group were paid 9.80 for
  passing each test. No bonuses or resets for
  failing.
• The control group was paid the same as the
  average payment to the progressive reinforcement
  group unconditional to their CO levels.

73
Applying Schedules to Smoking

• Smokers in both experimental groups passed 80 of
  CO tests while the control group passed 40 of
  the tests
• 22 of the progressive group resumed smoking
  while 60 of the fixed and 82 of the control
  group resumed smoking.
• Progressive reinforcement schedule appears
  effective in the short run of abstinence of
  smoking. Further research is needed to indicate
  if this schedule is effective for long run
  abstinence.