Evidence of a role for multiple memory systems in behavioral extinction

Area of Science:

• Neuroscience
• Behavioral Psychology
• Cognitive Science

Background:

• Learned behavior acquisition involves multiple memory systems.
• Hippocampal damage impairs cognitive learning but spares habit learning.
• Extinction of learned behaviors also involves new learning processes.

Purpose of the Study:

• To investigate if multiple memory systems theory applies to the neural basis of extinction.
• To determine the role of the dorsal hippocampus in different types of extinction learning.

Main Methods:

• Adult Long-Evans rats were trained in a straight-alley maze for food reward.
• Extinction training involved either a response-extinction (habit learning) or latent extinction (cognitive learning) condition.
• The dorsal hippocampus was reversibly inactivated using bupivacaine infusions before extinction training.

Main Results:

• Rats with hippocampal inactivation showed normal extinction in the response condition.
• Rats with hippocampal inactivation failed to exhibit latent extinction.
• Extinction learning can be neuroanatomically dissociated based on training procedures.

Conclusions:

• Extinction learning can occur with or without performing the previously acquired response.
• The dorsal hippocampus is critical for cognitive extinction learning but not for habit-based extinction.
• Similar to initial learning, the hippocampus mediates extinction requiring cognitive processes.