Learning, Chapter 7 , Schedules and Theory of Reinforcement
The typical FR pattern is described a a "_______________" pattern or a short break followed by a steady run of responses.
"Break-and-run"
True or False: The scalloped curve pattern might not appear if we are trying to phone a business during the first 30 minutes of opening
False. you are unlikely to spend time looking at the watch during the start of the interval, but as time progresses you will begin looking more and more frequently. Your behavior will follow the typical scalloped pattern of responding.
Examples of FR schedules
On a Fixed ratio 5 schedule (FR 5) a rat has to press the lever 5 times to obtain a food pellet. On a Fixed ratio 50 schedule (FR 50) a rat has to press the lever 50 times to obtain a food pellet. Earning a dollar every 10 carburetors assembled on an assembly line is an example of a Fixed ratio 10 schedule (FR 10) Earning a dollar every carburetor assembled on an assembly line is an example of a Fixed ratio 1 schedule (FR 1)
True or False: With very low ratios, such as CRF or FR 2, There will be little to no pausing other than the time it takes for the rat to munch down the food pellet.
True: the reinforcer may be so close--only a few lever presses away-- that the rat is tempted to immediately go back to work.
Real world example of variable interval schedule
Waiting on the bus and looking down the street and having no idea when the bus will arrive. Looking is reinforced after varying time (two minutes the first day, 12 minutes the next, 6 minutes the third day and so on). There is an average interval of (VI 10 min) or Contacting your professor with a last minute question about an assignment between her opening hours every few minutes. She will certainly answer upon arrival.
steady-state behaviors
a characteristic response pattern/ stable pattern produced by each intermittent schedule once the organism has had considerable exposure to the schedule.
ratio strain
a disruption in responding due to an overly demanding response requirement
Fixed-ratio (FR) schedule of reinforcement
a schedule where reinforcement is contingent upon a fixed, predictable number of responses.
Ratio strain is often referred to as a _________.
burnout: it can be a big problem for students faced with a heavy workload.
schedule effects
different effects on behavior produced by different response requirements. These are steady state behaviors.
Four Basic Intermittent Schedules
fixed ratio variable ratio fixed interval variable interval
The rat's lever presses result in food sometimes OR asking your mother for a cookie results in getting a cookie sometimes is an example of __________.
Intermittent (partial reinforcement) schedule
Similarities and differences in four basic schedules: Fixed schedules tend to produce _________ where as variable schedules do not.
Post reinforcement pauses. On a variable schedule there is often the possibility of an immediate reinforcer, even if they have just attained the reinforcer, which temps one to immediately resume responding. On a fixed schedule, attaining one reinforcer means that the next reinforcer is some distance away.
fixed ratio graph
Pretty steep because of the high response rate , short breaks because of post-reinforcement pauses
True or False: Hull believed all reinforcers are associated directly or indirectly with some type of drive reduction.
True
True or False: Steady-State behaviors happen in contrast to the more variable patterns of behavior that are evident when the organism is first learning a schedule.
True
Lean schedules
schedules in which the reinforcer is difficult to obtain FR 100 is an example
Intermittent (or partial) reinforcement schedule
A response schedule in which only some responses are reinforced.
each time a rat presses the lever it obtains a food pellet. Each time the dog rolls over on command it gets a treat. Each time Karen turns the ignition in her car, the motor starts. These are examples of
Continuous Reinforcement Schedule
An FR 1 schedule is the same as a ______ schedule in which each response is reinforced. Thus such a schedule can be labeled as either FR 1 or a _______.
Continuous reinforcement (CRF); CRF
If I have just missed the buss when I get to the bus stop, I know that I have to wait 15 minutes for the next one to come along. Given that it is absolutely freeing out, I snuggle into my parka as best I can and grimly wait out the interval. Every one in a while, though, I emerge from my cocoon to take a quick glance down the street to see if the bus is coming. My behavior of looking for the bus is on a(n) ____________ schedule of reinforcement.
FI 15-min I will probably engage in a few glances at the start of the interval, followed by a gradually increasing rate of glancing as time passes.
The first observation of schedule effects were in F______ and S______ experiments with ________.
Fester and skinners experiments with pigeons. This experiment also helped explain human behavior that are attributed to internal traits or desires.
Fixed Ratio (FR) schedule & Post reinforcement pause (PRP)
Fixed ratio schedules produce a high rate of response along with a short pause (post reinforcement pause) following attainment of each reinforcer. Each pause is also followed by a quick return to a high rate response. For example, a rat on an FR 25 schedule will rapidly emit 25 lever presses, munch down the food pellet it receives, and then snoop around the chamber for a few seconds before emitting another 25 lever presses.
Similarities and differences in the four basic schedules
Fixed ratio= high response rate & PRP Variable ratio= high response rate and no PRP Fixed interval= Increasing response rate and PRP Variable Interval= Moderate and no PRP
Real world examples of VR schedules
Only some attempts at chasing down prey are successful. Only some residents who are called upon by canvassers will make a contribution Only some tv shows are enjoyable Sports are reinforced largely on a VR schedule. a hit can be on a VR 200 schedule; about 1 in every 200 drives is a good one. The drives are on a leaner schedule in which ratio strain sets in... he rarely hits the ball to where he gives up."
Similarities and differences in four basic schedules: _____ schedules produce higher rates of response than do ______ schedules.
Ratio; Interval reinforcers in ratio schedules are "response contingent" they depend on the number of responses emitted. A rat on a Vr 100 schedule can double the number of food pellets by doubling the rate of lever pressing. This cannot happen in an Interval schedule because reinforcement is time contingent. In an FI 1-minute schedule, no more than 50 reinforcers can be earned in a 50-minute session. responding at a higher rate throughout each interval does not pay off and is a waste of energy. it makes more sense to respond in a way that will maximize the possibility of attaining the reinforcer after it becomes available.
True or False: different response requirements can have different effects on behavior.
True
True or False: it is easier to reach a reinforcer within a dense or rich schedule than it is within a lean schedule
True
True or False: the scalloped curve patten might not appear if we are trying to phone a business that opens in 30 minutes.
True. If we have a watch, we would probably look at our watch to determine when the 30 minutes is over. The indicated time would be a discriminative stimulus S^D for when the reinforcer is available (business is open) and we would wait until the appropriate time before calling.
True or False: Because VI schedules produce steady , predictable response rates, they are often used to investigate other aspects of operant conditioning.
True. They are good for aspects of operant conditioning that involves choice between alternative sources of reinforcement.
True or False: Continuous reinforcement schedules are useful when a behavior is first being shaped or strengthened.
True. When you want to train a subject to do a certain task, reinforcement should be delivered for each approximation to the target behavior.
True or False: Intermittent reinforcement characterizes much of everyday life.
True: Not all concerts we attend are enjoyable, Not everyone we ask on a date accepts our date, Not every date that we go out on leads to an enjoyable evening. We also might not praise a child every time she does her homework, we might only praise out of assumption that such behavior should persist In the absence of praise.
True or False: VR schedules generally produce a high and steady rate of response, with little to no post-reinforcement pause
True: a post reinforcement pause is unlikely to occur within a VR schedule when the minimum response requirement in the schedule is very low. Ex: a post reinforcement pause is less likely to occur within a VR 50 schedule in which the requirement varies between 1 and 100 as opposed to a requirement of 10 and 90 within the same schedule.
True or False: Higher ratio requirements produce longer post-reinforcement pauses
True: you will probably take a longer break after completing a long assignment than a short assignment. A rat will show longer pauses on an FR 100 schedule than on an FR 30 schedule
Real word example of Fixed Interval schedule
Trying to phone a business that opens in exactly 30 minutes will be effective only after the 30 minutes have elapsed. Any phone calls before that is ineffective
You find that by frequently switching stations on your radio, you are able to hear your favorite song on an average of once every 20 minutes. Your behavior of switching stations is thus being reinforced on a ___________.
VI 20 schedule
response deprivation hypothesis
a principle that states a behavior can serve as a reinforcer when the access to the behavior is restricted, and its frequency falls below its preferred level of occurrence. preferred level: the baseline level of occurrence when the animal can freely engage in activity. There are optimum levels/ preferred level of all activities. For example, I like to play the game for 4 hours as my optimum level. When the level is below optimal, organisms will work to restore those levels. Ex: If I only get to run 15 minutes, the wheel becomes the reinforcer because of (deprivation). Rat will work to obtain additional time on the wheel.
variable-ratio schedule
a reinforcement schedule where reinforcement is contingent upon a varying, unpredictable number of responses. For example on a Variable ratio 5 schedule (VR 5), a rat has to emit an average of 5 lever presses for each food pellet, with the number of lever responses on any particular trail between 1 and 10 The required lever presses might be 3 for the first pellet, 6 for the second pellet, 1 for the third pellet, and 7 for the fourth pellet with the overall average being 5 lever presses for each reinforcer. on a Variable ratio 50 schedule (VR 50) the number of required lever presses may vary between 1 and 100, with the average being 50.
Continuous reinforcement schedule (CRF)
a response schedule in which each specified response is reinforced.
Fixed-interval schedule
a schedule where reinforcement is contingent upon the first response after a fixed predictable period of time. Example: A rat on a fixed interval 30 second schedule (FI 30-sec), the first lever press after a 30 second interval has elapsed results in a food pellet. Following that, another 30 seconds must elapse before a lever press will produce must elapse before a lever press will again produce a food pellet. Any lever press during or before the 30 second interval is ineffective.
Drive Reduction Theory Hull 1943
an event is reinforcing to the extent that it is associated with a reduction in a physiological drive. Why is this a reinforcer? Food deprivation (primary reinforcer) produces a hunger drive , which then encourages the animal to seek out food (increases in behavior) to reduce the physiological hunger drive. The association between the primary reinforcer and the behavior is strengthened because of the reduction or increase in physiological drives. a secondary reinforcer is one that has been associated directly or indirectly with a primary reinforcer. problem sometimes organisms will work to obtain things not directly related to physiological needs. They will engage in some things because of Incentive Motivation like Watching Tv, music, video games, things they like. Therefore it must be something motivating about the reinforcer.
Continues reinforcement schedule is very useful when behavior is ________.
first being shaped or strengthened. so during shaping procedures there should be reinforcement delivered for each approximation to the target behavior. if we wish to encourage a child to always brush her teeth before bed, we would do well to initially praise her each time she does so.
A subject within an FI schedule should respond at a ___________ rate as the interval draws to a close. A subject within an VI schedule should respond at a ___________ pace throughout the interval.
gradually increasing; moderate, steady
Variable ratio schedules help to account for the persistence with which some people display certain _________________.
maladaptive behaviors. For example -gambling: the unpredictable nature of these activities results in a high rate of behavior. - Men using cute, flippant remarks to introduce themselves to women (even though women view these negatively): some women respond favorably which reinforces the use of such remarks.
VI schedules usually produce a _____ and _____ rate of response, often with little or no post-reinforcement pause
moderate; steady by responding at a relatively steady rate throughout the interval, the rat on a VI 30 sec schedule will attain the reinforcer almost as soon as it becomes available.
"Stretching the Ratio"
moving from a low ratio requirement (a dense schedule) to a high ratio requirement (a lean schedule). This should be done gradually. Once lever pressing is established on a CRF schedule then it can be gradually increased to FR 2, FR 5, FR 10 and so on. if it is increased too quickly the rat may become erratic and die out too quickly. CRF to FR2 to a sudden FR 20 may result in the rat becoming erratic.
Intermittent Schedule of reinforcement is also called a _____.
partial reinforcement schedule
Premack Principle
principle that states a high probability behavior (reinforcer) can be used to reinforce a low probability behavior. Ex: going to sleep has a higher likelihood of occurrence than going on a run. This means going to sleep is the high probability behavior (HPB), can be used to reinforce the target behavior or Low probability behavior (LPB) going on a run. In other words, you have to go on a run in order to go to sleep. only a high can reinforce a low, so focus on the relative probabilities of behaviors to quickly identify reinforcers.
variable-interval schedule
reinforcement is contingent upon the first response after a varying, unpredictable period of time. a rat on a variable interval 30 second (VI 30-sec) schedule, the first lever press after an average interval of 30 seconds will result in a food pellet with the actual interval varying between 1 and 60 seconds. The number of seconds that must pass before a lever press will produce a food pellet could be 8 seconds for the 1st pellet, 55 seconds for the 2nd pellet, 24 seconds for the third, and so on. As long as the average is 30 seconds.
Fixed Interval Schedules often produce a "___________" (upwardly curved pattern of responding, consisting of a post-reinforcement pause followed by a gradual increasing rate of response as the interval draws to a close.
scalloped A rat on an FI 30-sec schedule will likely emit no lever presses at the start of the 30 second interval. There will probably be a few lever presses midway through the interval, with a gradually increase rate of response. By the time the interval draws to a close and the reinforcer is imminent, the rate will emit a high rate of response and the reinforcer will be attained as soon as it is available.
Responding on an FI schedule is often characterized by a ___ pattern of responding consisting of a ___ ___ followed by a gradually (increasing/decreasing) _____ rate of behavior as the interval draws to a close
scalloped; post reinforcement pause; increasing
'Dense' or 'rich' schedules
schedules in which the reinforcer is easily obtained FR 5 is an example
On an FR schedule there is usually a _____ post reinforcement pause before grinding out another set of responses. On an FI schedule the post reinforcement pause is followed by a __________ rate of response as the interval draws close and the reinforcer become imminent.
short ; gradually increasing
schedule of reinforcement
the response requirement that must be met to obtain reinforcement. a schedule indicates what exactly has to be done for the reinforcer to be delivered
Behavioral Bliss Point Approach
the theory that states an organism with free access to alternative activities will distribute its behavior in such a way as to maximize overall reinforcement Example: a rat who can freely chose between running in a wheel and exploring a maze might spend 1 hour running in the wheel and 2 hours exploring the maze. optimal reinforcement= behavioral bliss point
