Presentation on theme: "Operant Conditioning: Sniffy the Rat"— Presentation transcript:
1 Operant Conditioning: Sniffy the Rat 210 Lab Assignment #2 – 2014Due: Friday April 4th (last day of classes)
2 TodayBrief background: Operant conditioning and the reinforcement schedules we’ll useUsing the Sniffy ProgramSteps to completing the assignmentWalkthrough of CRF training (and brief explanation of how to start PRF training)Assignment Outline – lab report
3 PurposeThe Sniffy program will help you understand operant conditioning and give you first-hand experience with these concepts:Magazine trainingShaping behaviorPartial Reinforcement (PRF) schedulesContinuous Reinforcement (CRF)Fixed Ratio (FR)Variable Ratio Schedule (VRF)Fixed Interval (FI)Variable Interval (VI)AcquisitionExtinction
4 Operant ConditioningIncreases the rate of a desired behavior by reinforcing that behavior when it occursIn our case, we want Sniffy to bar-pressWe will reinforce him with food pellets
5 Schedules of Reinforcement – Main Types: Continuous Reinforcement (CRF)Partial Reinforcement (PRF)Rewarded some times when behavior occurs; not every timee.g. Sniffy might press the bar 5 times and only get rewarded once.Rewarded every time the desired behavior occursEvery time Sniffy presses the bar, he will get a food pellet
6 PRF Schedules – 4 Types: Fixed Variable Ratio Fixed Ratio (FR) - Reward happens after a set number of responses or timeVariable- Reward happens around a certain averageRatio- Bar-pressing is the determinant for rewardFixed Ratio (FR)- Pellet is delivered after a set number of bar-pressesVariable Ratio (VR)- Pellet is delivered after an average number of bar-pressesInterval- Amount of time is the determinant for rewardFixed Interval (FI)- Pellet is delivered after a set amount of time passesVariable Interval (VI)- Pellet is delivered after an average amount of time passes1234
7 Materials neededThe lab manual (on Moodle) read this before you startSniffy ProgramOn any campus lab computer:Click My Computer Apps on Caesar (‘S:’ drive) Sniffy folder double click the Sniffy icon to open the programStop watch, or stop watch app on your phonePaper & pen
8 Project components Shaping an Operant Response: PRF Schedules: Observe Sniffy’s base-line behavior for 10 minsMagazine TrainingShaping Bar-Pressing by Successive ApproximationExtinctionSpontaneous RecoveryPRF Schedules:Fixed Ratio 20 extinctionVariable Ratio 20 extinctionFixed Interval 20 extinctionVariable Interval 20 extinction
9 Observing baseline behavior For 10 minutes, observe Sniffy’s behaviorPay attention to what he does and get an idea of what kind of behaviors you’ll be reinforcing later onPlanning ahead a bit will help with the next partRecord how many times Sniffy bar-presses on his own in the 10 minutesDO NOT reinforce him
10 barwatermagazine/hopperThe cumulative record (CR) will show you how Sniffy’s training is progressingThese dotted lines show you 5-minute increments
11 The ticks on the cumulative record show when Sniffy bar-presses The ticks on the cumulative record show when Sniffy bar-presses. The line also moves up when he presses the bar, allowing you to track training progress. Sniffy may bar press a few. My Sniffy bar-pressed twice during the 10 min observation time.
12 Magazine TrainingUsing the spacebar or your mouse, drop a pellet from the hopperWhen Sniffy approaches and eats it, give him another pelletConsider Sniffy magazine-trained when he approaches the hopper as soon as you drop a pellet (10-15 reinforcements)You can test his training by waiting until he is far away from the hopper (nearest to you) and dropping a pellet: if he goes to eat it, he’s magazine-trained
13 Training Sniffy to bar-press Training by successive approximationReinforce behavior that is closer and closer to the desired behaviorReinforce: drinking, rearing on the rear wall, going near the food hopper, passing in front of itFixationIf you reinforce one behavior too frequently (e.g. reinforcing rearing on the rear wall too many times in a row), Sniffy will fixate on that behavior, rather than what you are trying to shapeNoteI cannot stress enough how important it is to devote your FULL attention to this part of the assignment.Training Sniffy to bar-press takes about 30 to 45 mins if you pay attention and reinforce him appropriately. It can take several hours if you aren’t giving it your full attention.
17 Immediately save Sniffy to your H: drive, USB drive, etc. Bar-pressing cont.Slowly wean reinforcement down to only when he is rearing near the bar, or in front of the magazineSniffy will start to bar-press by himself more and more frequently stop reinforcing him manually and let him continue to bar press until the CR resets two times. Time him to make sure he’s bar-pressing at a frequency of 4-5 presses per minute. If he is, your training was successful!Go to File Save As Name him something appropriate (SniffyCRF.sdf, etc.). You’ll be working from this saved Sniffy file several more times, so saving is vital. You don’t want to have to train a new Sniffy later.Immediately save Sniffy to your H: drive, USB drive, etc.
20 My CR has resent by going back to the bottom twice. At this point he’s bar-pressing 4-5 times per minute.
21 Extinction TrialsClick Parameters menu Training Schedules Extinction Click OKSniffy will no longer be on a CRF schedule – He won’t get a pellet when he presses the barTime and Record:Number of non-reinforced bar presses in the first 2 minutes of extinctionTime to complete extinction(if he presses 3 times or less in 5 minutes we’ll consider that extinction)
23 Spontaneous RecoveryNext we’re going to test spontaneous recovery after a ‘time out’ (think of this as an overnight break from the chamber)Click Parameters Remove Sniffy for Time-Out OKAfter Sniffy is placed back in the chamber, time and record:Number of bar presses in first 2 minutesAmount of time required for Sniffy to completely extinguish a second timeSave this Sniffy (e.g. SniffyEXT.sdf) and print your resultsYou’re finished with CRF training!
26 Note on Cumulative Records You will print a copy of CRF, extinction, and spontaneous recovery cumulative records to turn in with your reportLabel the printout (in pen):When was acquisition complete?When was extinction instituted?When was extinction complete?When was spontaneous recovery instituted?When was extinction complete the second time?Print and make notes as you go through the steps, not after you’re finished everything – it might be hard to remember later.Check the manual for more info on what you’ll need to print as you move through the steps, and what you’ll need to label on the printout for each training schedule
27 PRF Training I’ll show you how to do the one PRF training schedule Fixed Ratio (FR) 20Teach Sniffy to bar-press 20 times for a food pelletThe procedure to carry out this training schedule applies to all the othersFirst, open your original CRF SniffyWe can’t start out with FR20, we have to start out with a lower ratioRemember how fast extinction occurred? If we start out at FR20, or FR15, or FR10, it’s likely that he won’t learn the new schedule
28 Use for interval schedules Use for fixed schedulesWhat I’ve selected means Sniffy will get a pellet after 4 bar-presses (FR4)
33 TipsGive yourself lots of time to complete training – start as early as you canI can give you rough estimates of how long each part will take:Observing behaviour and magazine training: 30 minsCRF – from 30 mins to an hourAssuming you’re paying attention! I’ve been told it can take several hours if you’re not.The PRF schedules (+ extinction) take about an hour eachIf you forget to start your stopwatch, you can tell 2 minutes (or whatever time you need) using the CR and a rulerPrint the CR and label it before moving on to a new step.Read the instructions fully before starting – it’s hard to do it as you’re working on trainingSaved full labs from last term
34 Lab Assignment #2 Due April 4th (in class) After you’ve trained Sniffy and printed your CRs, write a lab report detailing your findingsMore info on lab report requirements are in the manualComponents:Title pagePartial IntroOutline hypotheses for each training schedule (how do you think they will they compare to one another?)MethodResultsReport your observations made during steps outlined in the manual (acq/ext times, behavioural observations, etc.)DiscussionAddress questions listed in the manualRefs (textbook, chapter 5)CR printouts (labelled and with required notes)