Spence

1
Spences Theory of Discrimination and
Generalization in an animated graph
2
Spences Theory of Discrimination Learning

• Excitatory Strength is increased when a
  response to a specific stimulus is reinforced
• Inhibitory Strength is increased when a
  response to a specific stimulus is not
  reinforced
• Excitatory and Inhibitory Strength generalize to
  surrounding stimuli
• The tendency to respond to any stimulus is based
  upon its Net Excitatory Strength

3
The next slide animates Spences Theory. You
should read the account of his theory in the
textbook before viewing the next slide. Sit back
and enjoy an elegant explanation of an important
issue in the scientific study of learning. (Turn
on your speakers to maximize your enjoyment)
4
Spences Theory of Discrimination and
Generalization
70(-33)37
65(-37)28
60(-12)48
Peak Shift
52(-45)7
45(-5)40
40(-36)4
32(-25)7
27(-2)25
15(-15)0
5(-8)-3
12012
S
3(-2)1
S-
505
540
500
5
Summary of the animals behavior as explained by
Spences Net Excitatory Strength
Peak Shift
S
S-
540
500
Note that the peak of the resultant gradient is
shifted away from S .