Definition: The learning of a contingency between behaviour and consequence.
• Studied the behaviours of cats in a puzzle box over several trials and recorded
their escape time
• His hypothesis was that on trials following his discovery of the correct solution,
the cat would then escape immediately when placed in the same puzzle box; long
escape times during initial trials would be followed by a dramatic step down in
time to escape in later trials. He was wrong.
• The frequency of the random behaviours gradually decreased over time
o Suggests that animals follow a simple stimulus response type process with
little credit for consciousness
• Stamping In or Stamping Out of behaviour leads to refinement and eventually a
The Law of Effect: Behaviours with positive consequences are stamped in while those
with negative consequences are stamped out.
Four different types
1. Presenting a positive reinforcer
a. Reward training à leads to increase of behaviour
2. Removing a positive reinforcer
a. Omission training à leads to decrease of behaviour
3. Presenting a negative reinforcer
a. Punishment training à leads
to decrease of behaviour
4. Removing a negative reinforcer
a. Escape training à leads to
increase of behaviour
All types of instrumental conditioning ben-
efit from the immediate presentation of the
consequence after the response.
SuccessiveApproximation: a type of
shaping where complex behaviour is organized into smaller steps which gradually build
up to the full response that is meant to be conditioned. E.g. training pigeons to play ping
pong by teaching them to 1. Peck Ping-Pong table, 2. Peck stationary ball 3. Peck moving
ball and 4. Peck ball all across the table.
Instrumental Conditioning Module Notes PSYCH 1X03
The Discriminative Stimulus (SD or S+): when the contingency between a response
and a reinforcer is on.
Sδ: when the contingency between a response and a reinforcer is off.
Generalization occurs for instrumental conditioning as well.
CS vs SD
• CS à automatically elicits the response. The response is involuntary and reflexive
• SD à sets the occasion for a response. Signals when the response-reinforcer rela-
tionship is valid. Response is voluntary and not reflexive
Schedules of Reinforcement