Chapter 6 - Schedules of Reinforcement and Choice Behaviour Flashcards
What is a schedule of reinforcement?
It is the rule that determines how and when a response will be reinforced
What are the two types of reinforcement rates?
- continuous reinforcement
2. partial reinforcement
What is continuous reinforcement?
Reinforcing every correct response
- most efficient way to condition a new response
- rare in real life
What is partial reinforcement?
Reinforcing some, but not all responses
- more effective at maintaining or increasing the rate of response (and produces long lasting responses)
What is the consequence of having different schedules?
There are distinct rates and patterns of responses with varying degrees of resistance to extinction
What are the two basic types of partial reinforcement schedules?
- ratio
2. interval
What do ratio types require?
A certain number of responses to be made before one is reinforced
What do interval types require?
A certain amount of time to elapse before a reinforcer is given
What are the two basic categories within ratio and interval partial reinforcement schedules?
- fixed
2. variable
Describe fixed ratio (FR) schedules
FR schedules
- reinforcement is given if the subject completes a pre-set number of responses (ex. FR5 = after 5 responses, the subject is rewarded)
- continuous reinforcement (CRF) is the same as FR1
What do we observe with fixed ratio schedules?
- ratio run: when the subject exhibits the same response again and again - shows that learning has occurres
- post-reinforcement pause: taking a break in performing after reward has been given
- ratio strain: a pause during the ratio run, following a sudden, significant increase in ratio requirement (they stop performing because of an increase in requirement)
Describe variable ratio (VR) schedules
- the number of responses required to get each reinforcer is not fixed (it is random around a particular number - usually the average)
- numerical value of the ratio indicates the average number of responses required per reinforcer (ex. VR7 means that on average, 7 responses are required before a reinforcer is introduced)
- the reinforcer is less predictable, therefore there is less likelihood of pausing between responses (due to the fact that the very next response could be reinforced)
When are interval schedules reinforced?
Only if they occur after a certain amount of time has passed
- time is the factor, but a response is still required to obtain a reinforcer
Describe a fixed interval (FI) schedule?
- a response is only reinforced if a constant or fixed amount of time has elapsed from the previous delivery of a reinforcer (ex. FI5 = five minutes have to elapse)
What is a fixed interval scallop?
Time towards the end of the interval will increase the rate of responding
- more responses closer to the time and fewer immediately after
Describe a variable interval (VI) schedule?
- a response is reinforced only if it occurs more than a variable amount of time after the delivery of an earlier reinforcer
- because VI are less predictable, just like VR, there is a steady rate of response with little break in between
Which two reinforcement schedules have the strongest response rate?
- Fixed ratio
- variable ratio
- the organism learns that it is causing the reward with its behaviour
What is the distinguishing characteristic of a fixed interval schedule?
The scallops
Which schedule produces the highest rate of responding, and is the most resistant to extinction?
variable ratio schedules, because the organism doesn’t know when the response will be reinforced
What are the similarities between ratio and interval schedules?
- in both FR and FI schedules there is a typical pause after each reinforcer, and an increased rate of response just before the delivery of the next reinforcer
- in both VR and VI schedules the response rate is steady without predictable pauses
What is the difference between ratio and interval schedules?
Different rate of response even when reinforcement frequency is similar
Why would different schedules with similar rates of reinforcement produce different rates of behaviour?
- reinforcement of inter-response times (IRT):
- the faster you respond, the more likely you are to receive reinforcement (probabilistic)
- variable ratio schedules reinforce shorter IRTs
- interval schedules favour long IRTs - feedback function:
- higher responding is reinforced more (only in ratio schedules)
Define choice behaviour
The voluntary act of selecting or separating from two or more things that which is preferred
What factors are our everyday choices influenced by?
- reinforcer: quality and quantity
- behaviour: type of response, schedule of reinforcement
- available alternatives
- delay in reinforcement