NEUROCOGNITIVE FUNCTIONING IN DRUG-NAIVE PATIENTS WITH FIRST EPISODE OF PSYCHOSIS BEFORE AND AFTER TREATMENT

Cognitive deficit is a core feature of schizophrenia mostly grasping memory, psychomotor processing, attention, thinking, and executive functioning and is already present in the prodromal phase of the illness and is detected at the onset. Recent studies have been focused on the differentiation of cognitive functioning in relation to the diagnostic categories, which reveal cognitive heterogeneity in schizophrenia and schizophrenia spectrum disorders. The study demonstrated that along with changes in the clinical state, specifically, with reduction of psychopathological symptoms, patients with schizoaffective disorders show more positive dynamics with better chances to back up while in schizophrenia the cognitive dysfunction is more defoned and less prone to improvement

NEUROCOGNITIVE FUNCTIONING IN DRUG-NAIVE PATIENTS WITH FIRST EPISODE OF PSYCHOSIS BEFORE AND AFTER TREATMENT

Cognitive deficit is a core feature of schizophrenia mostly grasping memory, psychomotor processing, attention, thinking, and executive functioning and is already present in the prodromal phase of the illness and is detected at the onset. Recent studies have been focused on the differentiation of cognitive functioning in relation to the diagnostic categories, which reveal cognitive heterogeneity in schizophrenia and schizophrenia spectrum disorders. The study demonstrated that along with changes in the clinical state, specifically, with reduction of psychopathological symptoms, patients with schizoaffective disorders show more positive dynamics with better chances to back up while in schizophrenia the cognitive dysfunction is more defoned and less prone to improvement

Orientation Sensitive Properties of Visually Driven Neurons in Extrastriate Area 21a of the Cat\u27s Cortex

Orientation sensitive properties of extrastriate area 21a neurons were investigated. Special attention was paid to the qualitative characteristics of neuron responses to the different orientations of visual stimulus motion across neurons classical receptive field (CRF). The results of experiments have shown that a group of neurons (31%) in area 21a with specialized responses to moving visual stimuli changed their direction selective (DS) characteristics depending on the orientation of the stimulus movement. Some neurons reveal an abrupt drop of the direction sensitivity index (DI) to certain orientation (58%), and some show significant increase of DI at one of the applied orientations (22%). Detailed investigations of the non-directional neurons have revealed qualitative differences in the response to different orientations of the stimulus. There is no correlation between the functional organization of neurons RF\u27s and the qualitative modulations of neuron\u27s response patterns. We suggest that the orientation discrimination is a complex process that includes quantitative as well as qualitative transformations of neuron activity

Orientation Sensitive Properties of Visually Driven Neurons in Extrastriate Area 21a of the Cat\u27s Cortex

Orientation sensitive properties of extrastriate area 21a neurons were investigated. Special attention was paid to the qualitative characteristics of neuron responses to the different orientations of visual stimulus motion across neurons classical receptive field (CRF). The results of experiments have shown that a group of neurons (31%) in area 21a with specialized responses to moving visual stimuli changed their direction selective (DS) characteristics depending on the orientation of the stimulus movement. Some neurons reveal an abrupt drop of the direction sensitivity index (DI) to certain orientation (58%), and some show significant increase of DI at one of the applied orientations (22%). Detailed investigations of the non-directional neurons have revealed qualitative differences in the response to different orientations of the stimulus. There is no correlation between the functional organization of neurons RF\u27s and the qualitative modulations of neuron\u27s response patterns. We suggest that the orientation discrimination is a complex process that includes quantitative as well as qualitative transformations of neuron activity

Spatial Summation Processes in the Receptive Fields of Visually Driven Neurons of the Cat\u27s Cortical Area 21a

The spatial summation in receptive fields (RF) of single neurons in cat\u27s extrastriate area 21a was investigated as a basic neurophysiological substrate for central integration processing of visual information. The results showed that the majority of investigated neurons changed their response patterns with gradual increase of applied stimulus size. In approximately 82% of cases the suppression of neuron discharges was observed when the length of the moving strip exceeded that of the RF. In some neurons the increased size of the moving stimulus leads to the changes in the RF substructure. Receptive fields of neurons recorded at the same microelectrode penetration depth showed a great variety of RF superpositions distributed in a spatially asymmetric manner. As a result, every single RF consists of multiple sub-regions within the RF, differing from each other by the number of superimposed RF-s (density factor). We suggest that such complex spatial organization of the RF provides the neurophysiological basis for central integration processing of the visual information

Spatial Summation Processes in the Receptive Fields of Visually Driven Neurons of the Cat\u27s Cortical Area 21a

The spatial summation in receptive fields (RF) of single neurons in cat\u27s extrastriate area 21a was investigated as a basic neurophysiological substrate for central integration processing of visual information. The results showed that the majority of investigated neurons changed their response patterns with gradual increase of applied stimulus size. In approximately 82% of cases the suppression of neuron discharges was observed when the length of the moving strip exceeded that of the RF. In some neurons the increased size of the moving stimulus leads to the changes in the RF substructure. Receptive fields of neurons recorded at the same microelectrode penetration depth showed a great variety of RF superpositions distributed in a spatially asymmetric manner. As a result, every single RF consists of multiple sub-regions within the RF, differing from each other by the number of superimposed RF-s (density factor). We suggest that such complex spatial organization of the RF provides the neurophysiological basis for central integration processing of the visual information