Procedural learning in schizophrenia: reconciling the discrepant findings.
BACKGROUND
Studies of procedural learning in schizophrenia have been inconsistent, sometimes finding it to be preserved and sometimes impaired. This study examined three factors that could account for the variability among findings: type of task, presence of general intellectual impairment, and the extrapyramidal side effects of neuroleptic treatment.


METHODS
Forty-three patients with schizophrenia and 22 normal control subjects were examined with three different paradigms: the pursuit rotor, mirror reading, and probabilistic learning ("weather prediction"). A subgroup of intellectually preserved patients was also examined. Patients with and without tardive dyskinesia and with and without Parkinsonism were also compared.


RESULTS
The schizophrenic patients showed learning comparable to the control subjects on the pursuit rotor and mirror reading but were impaired on the probabilistic learning task. However, this last difference disappeared when the subgroup of intellectually preserved patients was compared with a subgroup of matched control subjects. Patients with and without tardive dyskinesia or Parkinsonism showed similar learning on all three tasks, but patients with tardive dyskinesia showed poorer overall performance than those without.


CONCLUSIONS
Procedural learning tends to be preserved in schizophrenia, and when impairment is found, differences in the overall level of intellectual function might be the determining factor.
Gomar
Jesús J
JJ
Benito Menni Complex Assistencial en Salut Mental, Universitat Autònoma de Barcelona, Barcelona Spain. jgomar@hospitalbenitomenni.org
Pomarol-Clotet
Edith
E
Sarró
Salvador
S
Salvador
Raymond
R
Myers
Catherine E
CE
McKenna
Peter J
PJ
D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000009:adverse effects*; D004409:Dyskinesia, Drug-Induced / Q000523:psychology; D005260:Female; D006801:Humans; D007361:Intelligence Tests; D007858:Learning / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D020734:Parkinsonian Disorders / Q000523:psychology; D011597:Psychomotor Performance / Q000187:drug effects* / Q000502:physiology; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000188:drug therapy* / Q000503:physiopathology*; D012565:Schizophrenic Psychology
D014150:Antipsychotic Agents