Psych - 1x03 Instrumental Conditioning PDF

Preview

Summary

kim...

Description

Continuous reinforcement: a response leads to a reinforcer on every single trial. This schedule of reinforcement is called continuous reinforcement PARTIAL REINFORCEMENT SCHEDULES - A ratio schedule of reinforcement is based on the number of responses made by a subject, which determines when reinforcement is given. Reward is given every certain number responses - A pigeon is rewarded with food for every tenth pecking response - FR-6 pecks - An interval schedule of reinforcement is based on the time since the last response that was reinforced. - Pigeon oon FI-1 minute schedule is rewarded with food every 1 minute period Both ratio and interval schedules can be either fixed or variable - Following are example of fixed schedules - On an FR 10 schedule, the pigeon must peck exactly 10 times to get the food reward. - On the FI-10 minute schedule the pigeons first peck response after exactly 10 minutes is rewarded with food In both cases, these conditions were held constant across trials. Lets now consider the variable schedule twist. In contrast to a fixed schedule, rewards on variable ratio and interval scaled are provided following a variable amount of work or length of time -

Example: on a VR 10 schedule, the pigeon must peck an average of 10 times to get food reward but the exact number of pecks that yields a rewards changes across trials - When you look at the overall rate of reinforcement, it works out that on average 10 pecks were necessary on any given trial. On a VI-10 min schedule, the first response following an average of 10 min will be reinforced, but the exact length of time between rewards changes across trials

There is a limit to how stingy an FR-fixed ratio schedule can be. - A schedule that is too stingy will lead to ratio strain and the subject will stop responding - Pause and run pattern on the graph for a FR-fixed ratio schedule - Variable ratio schedule is capable of supporting very constant and high exposure rate on graph - A cumulative record of responses reinforced on a variable ratio schedule may almost look like a diagonal line with no pauses between - The slope of a variable ratio schedule’s cumulative record reflects the average number of responses required before reinforcement is delivered. - Variable schedules that deliver more frequent reinforcement will support higher response rates - A VR-10 schedule will have a steeper slope than a VR-40 schedule -

Fixed ratio schedule: pause and run pattern Variable ratio schedule: diagonal line with no pauses between Fixed interval schedule: scallop pattern Variable interval schedule: diagonal line. Increases at a steady rate. Straight line on the cumulative record - reinforcement can be received at any time...