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The impairment in tasks requiring intact frontal lobe functions has been repeatedly shown in schizophrenics. However, the relative roles of confounding factors, like duration of the disease, social withdrawal, or antidopaminergic medication, are not clearly demonstrated. We studied the performance of 12 young active patients, with chronic residual schizophrenia that had recent onset, and 12 control subjects, with frontal lobe tests and with a battery designed to explore working memory. The results show normal performance in schizophrenia. The small number of patients does not allow definitive conclusions, but this study suggests that a frontal dysfunction may not be present early in the evolution of schizophrenia in active patients.

A dysfunction of dorsolateral prefrontal cortex (DLPF) in major depression is suggested by functional imagery and comparative neuropsychology. However, assessment of frontal lobe syndrome with DLPF-dependent tests led to controversial results. To clarify these findings, we administered 5 of these tests (Wisconsin Card Sorting Test, Stroop Test, Trail Making Test, Tower of Toronto, verbal fluency) to 16 major depressive subjects and their 16 controls, before and after 21 days of treatment. Furthermore, we tried to assess the prognostic value of frontal lobe dysfunction, and its relation with the endogenous or exogenous nature of the depression on the one hand, the severity of the depression on the other hand. Our results suggest that the presence of a frontal lobe syndrome (defined by impaired performances at 3 tests or more) is only noted in endogenous depression; after treatment, no impairment is detected. No correlation is found with the severity of the depression. Frontal lobe syndrome does not seem to indicate poorer prognosis for current depressive episode.

Objective: To test the verbal subsystem of Baddeley's working memory model (the phonological loop) in patients with Parkinson's disease.Methods: Fifteen patients with idiopathic Parkinson's disease and 15 controls were tested with a span paradigm to assess the effects reflecting the functioning of the phonological loop: the phonological similarity effect (in verbal and visual presentation), and the word length effect (in visual presentation).Results and Conclusions: The patients did not show any dysfunction of the phonological loop, reflected by the presence of phonological similarity and word length effects, but had lower spans than controls. The implications of these results for the working memory model are discussed. [ABSTRACT FROM AUTHOR]