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Background: Visual word recognition is one of the central topics in cognitive psychology and cognitive neuroscience. Genetic factors are known to contribute to the visual word recognition, but no genes associated with this process have been identified so far. We studied the impact of the DRD2 C957T polymorphism on the efficiency of visual word recognition by measuring its neuronal correlates and behavioral parameters. Early (~200 ms) components of event-related potentials (ERP) were recorded during a lexical decision task. The DRD2 C957T polymorphism is thought to be associated with D2 receptor’s availability and binding potential. Earlier studies have demonstrated the influence of this variation on perception and processing of verbal stimuli. The DRD2 C957T is also associated with schizophrenia, with the C allele being the risk allele. Methods: Electroencephalogram, genetic, and behavioral data were collected from 96 healthy individuals (53.1% men). ERPs were recorded for words and pseudowords in implicit and explicit tasks. Two regions of interests in the left ventral temporal cortex, whose role in early visual word processing is well established, were selected for analysis. Results: The results showed the main effect of the DRD2 C957T polymorphism on P200 amplitude. Carriers of the TT genotype had higher P200 amplitudes compared to subjects with schizophrenia risk C allele. Within-group comparisons demonstrated a better ability to adjust attention to orthographic stimuli depending on task demands and lexicality in the TT group. Conclusion: The results of the study suggest that the DRD2 C957T polymorphism modulates early stages of visual word recognition. [ABSTRACT FROM AUTHOR]

The research is based on comparative analysis of 'Hinting Task', 'Faux Pas', and 'Reading the Mind in the Eyes' tests sensitivity in detection of Theory of Mind deficits. The study included 20 subjects with schizophrenia and schizophrenia spectrum disorders with the first episode of psychosis. Every subject performed the three proposed tests. It was shown that success rate of the three tests differed significantly. The non-verbal test 'Reading the Mind in the Eyes' caused the most difficulties. The success rate percentage of this test performance correlated negatively with the severity of psychopathological symptoms evaluated according to the PANSS scale. Thus, 'Reading the Mind in the Eyes' test is the most sensitive out of the three to Theory of Mind deficits detection, which may be used for diagnostic purposes.

It has been repeatedly shown that schizophrenia patients have immense alterations in goal-directed behaviour, social cognition, and social interactions, cognitive abilities that are presumably driven by the mirror neurons system (MNS). However, the neural bases of these deficits still remain unclear. Along with the task-related fMRI and EEG research tapping into the mirror neuron system, the characteristics of the resting state activity in the particular areas that encompass mirror neurons might be of interest as they obviously determine the baseline of the neuronal activity. Using resting state fMRI, we investigated resting state functional connectivity (FC) in four predefined brain structures, ROIs (inferior frontal gyrus, superior parietal lobule, premotor cortex and superior temporal gyrus), known for their mirror neurons activity, in 12 patients with first psychotic episode and 12 matched healthy individuals. As a specific hypothesis, based on the knowledge of the anatomical inputs of thalamus to all preselected ROIs, we have investigated the FC between thalamus and the ROIs. Of all ROIs included, seed-to-voxel connectivity analysis revealed significantly decreased FC only in left posterior superior temporal gyrus (STG) and the areas in visual cortex and cerebellum in patients as compared to controls. Using ROI-to-ROI analysis (thalamus and selected ROIs), we have found an increased FC of STG and bilateral thalamus whereas the FC of these areas was decreased in controls. Our results suggest that: (1) schizophrenia patients exhibit FC of STG which corresponds to the previously reported changes of superior temporal gyrus in schizophrenia and might contribute to the disturbances of specific functions, such as emotional processing or spatial awareness; (2) as the thalamus plays a pivotal role in the sensory gating, providing the filtering of the redundant stimulation, the observed hyperconnectivity between the thalami and the STGs in patients with schizophrenia might explain the sequential overload with sensory inputs that leads to the abnormal cognitive processing.