Devan & White (1999)

Question 1

What are the links between P+M and D+W?

Answer 1

• They both investigated animal learning by looking at similar brain systems
• Devan and White used a similar but different task, swimming pool instead of a maze was used
• Place learning in the water maze also impaired by hippocampal damage, as well as in T maze

Question 2

Introduction?

Answer 2

• Inactivated the dorsilateral caudate nucleus, the dorsomedial caudate nucleus and the fornix/fimbria (hippocampus)
• there was no fixed route to the platform

Question 3

Methods?

Answer 3

• 90 rats assigned to 4 bilateral lesion groups
• Rats trained to swim to a platform in a swimming pool that was sometimes visible or hidden
• At the end of training they conduct a conflict trial where the platform was moved to the opposite side of the pool

Question 4

Results?

Answer 4

• All animals found it very difficult to get to the platform when it was hidden, but some got quicker as time went on
• The fornix/ fimbria animals always stay slow
  -> They are supposed to use cues outside the pool (place learning) when the platform is hidden and the fornix/fimbria lesions impair place learning
• Those with lateral caudate nucleus lesions go primarily to the right place
• Rats with fornix/fimbria lesions don’t know where the place is and follow the cue instead

Question 5

Summary?

Answer 5

• When platform was hidden, rats had to rely on external landmarks to find the platform’s position
• Rats with fimbria/fornix lesions did not improve with repeated training to find the hidden platform
• All other groups improved over sessions
• Place learning in the water maze also impaired by hippocampal damage, as well as in T maze