[Working memory: neuropsychological and neurobiological issues].
ABSTRACT Working memory denotes an ability to remember information for a short-time and to manipulate it. The memory allows including correct information depending on the situation, to keep the information on present activities for a while and enables changing the reaction according to new criteria. The relation between working memory and efficiency of complex cognitive processes and also with the control of emotional processes, plasticity of behaviour and consciousness was demonstrated. Working memory is connected with the activity of the dorsolateral prefrontal cortex of the brain. Recently, it has been shown, that working memory disturbances play an important role in the aetiopathogenesis of psychiatric disturbances such as schizophrenia, bipolar affective disorder or obsessive-compulsive disorder. Working memory disturbances are also shown in a proportion of healthy first-degree relatives of patients with schizophrenia or bipolar disorders. Working memory disturbances are presently regarded as a cognitive endophenotypic marker of vulnerability to these illnesses. In recent years, an association between working memory abilities and activity of different neurotransmitters, especially with the dopaminergic system in the brain, has been shown. Molecular genetic studies show an association between working memory abilities and polymorphism of the dopaminergic system genes in schizophrenia and polymorphism of BDNF gene in bipolar affective disorders. So far not much data about the genetics of working memory in healthy subjects has been gathered. Currently in Poland such research is carried on in the Clinical Neuropsychology Unit Nicolaus Copernicus University, Collegium Medicum in Bydgoszcz in cooperation with the Department of Adult Psychiatry and Laboratory of Psychiatric Genetics University of Medical Sciences in Poznań.
- European Neuropsychopharmacology 10/2007; 17. DOI:10.1016/S0924-977X(07)70816-7 · 5.40 Impact Factor
- European Neuropsychopharmacology 10/2007; 17. DOI:10.1016/S0924-977X(07)70817-9 · 5.40 Impact Factor
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ABSTRACT: Proton magnetic resonance spectroscopy (1H MRS) allows for examining brain functions in vivo in schizophrenic patients. Correlations between N-acetylaspartate (NAA) level in the frontal lobe and cognitive functions and clinical symptoms have been observed. The aim of the present study was evaluation of relationship between clinical symptoms, cognitive outcomes and brain function in 1H MRS measures in schizophrenic patients. The study included a group of 47 patients with chronic schizophrenia. Patients were assessed by means of PANSS, CGI, and a battery of cognitive tests: WCST, TMT, and verbal fluency test. MRI and MRS procedures were performed. Regions of interest were located in the left frontal lobe, temporal lobe and thalamus. Metabolite (NAA, choline, myoinositol and Glx complex) ratios to creatine were calculated. We observed a significant negative correlation between myoinositol level in the frontal lobe and WSCT test performance. These data were confirmed by further analysis, which showed a significant correlation between WCST outcome, negative symptoms score, education level and myoinositol ratio in the frontal lobe. When analyzing negative symptoms as independent variables, the analysis of regression revealed a significant relationship between negative symptoms score and verbal fluency score, together with choline level in the thalamus. The above data seem to confirm a significant role of the thalamus--a "transmission station" involved in connections with the prefrontal cortex--for psychopathology development (especially negative) in schizophrenia. Moreover, our results suggest that a neurodegenerative process may be involved in schizophrenia pathogenesis.Medical science monitor: international medical journal of experimental and clinical research 06/2012; 18(6):CR390-8. DOI:10.12659/MSM.882909 · 1.22 Impact Factor