Operant conditioning after temporal lobe lesions in man: conditional and simple discrimination learning

Area of Science:

• Neuroscience
• Cognitive Psychology
• Behavioral Neuroscience

Background:

• Temporal lobe lesions are known to affect classical conditioning, specifically impairing conditional discrimination learning while sparing simple conditioning.
• Previous research indicates a role for the temporal lobe in complex learning paradigms.

Purpose of the Study:

• To investigate the impact of left or right temporal lobe resections on operant conditioning tasks involving simple and conditional discrimination.
• To compare the performance of subjects with temporal lobe lesions to frontal lobe and control subjects.

Main Methods:

• Subjects with left or right temporal resections and control subjects performed two operant conditioning tasks: a conditional discrimination and a simple discrimination.
• The tasks were designed to be analogous to previously studied classical conditioning paradigms.

Main Results:

• Subjects with right temporal lesions, and to a lesser extent left temporal lesions, showed significant impairment in acquiring the conditional discrimination task.
• Both left and right temporal lobe subjects performed comparably to controls on the simple operant discrimination task.

Conclusions:

• Temporal lobe lesions, particularly on the right side, impair the acquisition of conditional discrimination in operant conditioning.
• The findings support theories linking hippocampal function to the learning of complex if-then rules, as demonstrated by the spared simple discrimination.
• These results highlight the specific role of the temporal lobe in higher-order associative learning.