Operant V – Choice and Behavioural
SLIDE 4 – In concurrent, need 2 manipulanda. 2 keys – one red and green. Side on which key
was located would be randomly changed. Pecking away and once in a while there was a
reinforcers. Pecks on green also produce reinforce on VI1. Makes decision whether to pick on
green or red key. Where choice option comes in
SLIDE 5 – You might accidently reinforce switching. If red and get a reinforcer, might convince
them to switch. To combat that, a changeover delay is used. Switches from red to green and
green to red never followed with reinforcer until the time had passed
SLIDE 6 – Response on one of keys changes colour. Peck on the yellow key to change it to red.
Peck on red to get the reinforcers. Other key is darkened and inactive
SLIDE 7 – have to peck 10 times to change it to red and then red followed with reinforcers.
SLIDE 9 – changes to green and then get keypecks on green to reinforcer. 1 key should go
dark – it’s inactive. If they peck on it, nothing will happen. Pigeons don’t pick on the dark key
anyway. Peck on left = red key. Peck on left = green key.
SLIDE 11 – varied the rate of reinforcement on the 2 keys. Left – got 27 reinforcements per hr.
VI 2 min schedule. 13 per hour – VI 4 min. in which animals getting reinforced 15 rates per hour.
About 2:1 if calculate the amount of reinforcements on each key. Matching law comes in at % of
total responses. Another variation with a different pigeon with 7 and 34. Pigeons matched
response allocation to outcomes of the key
SLIDE 12 – solid line represents perfect matching. 20 and 20, 40 and 40, 60 and 60, etc. Not
data – it is the prediction of the matching law. The actual data are extremely close to that
prediction line. Furthest deviation from the line = 85 data point.
SLIDE 13 – that is the matching law
SLIDE 14 – Big R’s stand for the allocation of responding. Key A being expressed as a
proportion of responses to both keys. Ratio can be as high as 1 and as low as 0. Aren’t
percentages, just proportions.
SLIDE 17 – responses to key A divided by responses to key a and b. Instead of rate of
reinforcers, we have size of reinforcers. Tiny pellets on one key and larger on another. M =
mass. Matching law says the last sentence “if the reinforcers on one key…”
SLIDE 18 – looks at reinforcer immediacy. Sometimes reinforcers delivered immediately,
sometimes there is a delay. Responding on the left. On the right, one over delay. Best thought of
as immediacy. If 1/10 and ½ - the second is more immediate than the first one. SLIDE 19 – Responding on the left. On the right combining previous versions of the matching
law. Manipulate size and delay of the reinforcer. Large immediate and small delay or small
immediate reinforce and large delay reinforcer.
SLIDE 20 – two keys, one red and one green. Single peck on red, turns both keys dark. Get 2
reinforcers followed by a 3 second delay. Key light stay dark for 3.9 secs then they both turn
back to green.
Could have also chosen to peck on green. Dark. Starts 3.9s delay then 4 pelleys, followed by .
Animal choosing between 2 pellets right away or 4 pellets in 4 seconds.
If rationality guided our behavior, then we should pick green
SLIDE 23 – If plug numbers in, the matching law says that contrary to rationalists, you’re going
to pick the immediate 2 pellets most of the time. 95/100 of the times, you will pick 2 pellets over
Maybe you should grab what you can now – what the last sentence means
SLIDE 27 – start out with a pair of yellow keys. Single peck on either starts a timer for 20
seconds. At end of 20 secs, red key produces 2 pellets followed by a 3.9s delay. Don’t get
pellets right away, but in 20 seconds + right away