Dissociating medial temporal and basal ganglia memory systems with a latent learning task.
The medial temporal (MT) lobes and basal ganglia have both been implicated as brain substrates of associative learning. Here, we show a dissociation between medial temporal and basal ganglia damage using a latent learning task, in which prior exposure to cues, uncorrelated with each other, slows subsequent learning of an association between them. Consistent with prior work, we found a robust exposure effect in healthy controls, with exposed controls learning more slowly than non-exposed controls. This effect was abolished in medial temporal amnesia: both exposed and non-exposed amnesic patients learned at the same speed. A group of patients with basal ganglia damage due to Parkinson's disease showed a reversal of the effect: exposed subjects learned faster than non-exposed subjects. Our findings point to distinct and dissociable contributions of medial temporal lobe and basal ganglia structures to learning and memory.
Memory Disorders Project, Department of Psychology, Rutgers University-Newark, 101 Warren Street, Newark, NJ 07102, USA. myers@pavlov.rutgers.edu
Catherine E
CE
Myers
Daphna
D
Shohamy
Mark A
MA
Gluck
Steven
S
Grossman
Somporn
S
Onlaor
Narinder
N
Kapur
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001245:Association Learning / Q000502:physiology*; D001479:Basal Ganglia / Q000503:physiopathology*; D016022:Case-Control Studies; D003463:Cues; D005260:Female; D005794:Generalization, Response; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000503:physiopathology; D011930:Reaction Time; D013702:Temporal Lobe / Q000503:physiopathology*