Depression impairs learning whereas anticholinergics impair transfer generalization in Parkinson patients tested on dopaminergic medications.
In a study of acquired equivalence in Parkinson disease (PD), in which patients were tested on normal dopaminergic medication, we found that comorbid clinical depression impairs initial acquisition, whereas the use of anticholinergic therapy impairs subsequent transfer generalization. In addition, this study provides a replication of the basic finding of Myers et al (2003) that patients with PD on dopaminergic therapy are impaired at initial acquisition, but normal at subsequent transfer generalization, generalizing these results to an Arabic-speaking population including many participants with no formal education. These results are consistent with our past computational modeling, which argues that acquisition of incrementally acquired, feedback-based learning tasks is dependent on cortico-striatal circuits, whereas transfer generalization is dependent on medial temporal (MT) structures. They are also consistent with prior computational modeling, and with empiric work in humans and animals, suggesting that anticholinergic drugs may particularly impair cognitive abilities that depend on the MT lobe.
Faculty of Medicine, Al Quds University-Abu Dis, Palestinian Territories/West Bank.
Mohammad M
MM
Herzallah
Ahmed A
AA
Moustafa
Adel J
AJ
Misk
Lara H
LH
Al-Dweib
Samer A
SA
Abdelrazeq
Catherine E
CE
Myers
Mark A
MA
Gluck
D000368:Aged; D018680:Cholinergic Antagonists / Q000494:pharmacology* / Q000627:therapeutic use; D003863:Depression / Q000150:complications / Q000188:drug therapy / Q000523:psychology*; D018491:Dopamine Agonists / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007858:Learning / Q000187:drug effects*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000188:drug therapy / Q000523:psychology*; D011597:Psychomotor Performance / Q000187:drug effects; D014163:Transfer, Psychology / Q000187:drug effects*; D014282:Trihexyphenidyl / Q000494:pharmacology* / Q000627:therapeutic use
D018680:Cholinergic Antagonists; D018491:Dopamine Agonists; D014282:Trihexyphenidyl