Midterm 2: Behaviour Modification pt. B

Question 1

What does shaping behaviour by successive approximation enable us to do?

Answer 1

This technique enables us to modify greatly an existing behaviour OR create an entirely new behaviour.

Question 2

What does shaping behaviour by successive approximation involve? What helps?

Answer 2

• Involves some trial and error learning
• Animal’s natural curiosity helps aid learning

Question 3

How would we shape ‘teaching a dog to stand’ using successive approximation?

Answer 3

1. Begin by monitoring the behaviour you are interested in, and find something you can use as a reinforcer.
2. Watch the dog’s posture, give the dog a bit of food with your arm raised in front of you. Reinforce the dog’s moving upward for the food until the sight of you (or the food) makes the dog raise its head upward
3. Once the dog RELIABLY raises its head, NARROW the range of head raises you reinforce, thus extinguishing lesser head raises.
   - This EXTINCTION process naturally leads to variation in head raisings being tried by the dog, including some in which the forepaws leave the ground.
   - We now have a new class of behaviours, with a higher head raise than a few minutes ago…which we again restrict reinforcement to
   - Through SELECTIVE REINFORCEMENT of higher and higher raises, you could have a dog that leaps into the air

Question 4

Once a behaviour is “shaped” it may be made a member of what?

Answer 4

A CHAIN of behaviours
- behaviour 1 + behaviour 2 + behaviour 3 = chaining

Question 5

In 1937, Skinner trained a rat to pull a string that released a marble from a rack, how?

Answer 5

Shaped the 1st behaviour, reinforcing the rat as it orients toward the string, and then only when it is progressively closer to the string (eg through successive approximation.
- Once we have established string pulling (Behaviour 1), we move to the marble and shape that behaviour (Behaviour 2)

Each desired behaviour is reinforced EVERY time it occurs during the training process (fixed ratio)

Question 6

What is a heterogeneous behaviour chain?

Answer 6

A behaviour chain that involves multiple types of behaviours

Question 7

What is a homogeneous behaviour chain?

Answer 7

A behaviour chain that involves only one type of behaviour
- ex. 1 bar press = blue light, 2 presses = red; behaviour is pushing the bar

Question 8

Animals come with species-specific behaviours which place limits on what animals may be easily trained to do. What can this result in?

Answer 8

Instinctive drift
- you’ve shaped the behaviour but there is a problem with instinctive drift

Question 9

After a conditioned operant response has been learned, it is generally maintained as long as reinforcement is at least occasionally presented. If not, what happens?

Answer 9

Extinction occurs (active process)
- differs from forgetting which is a passive process