Исследовали параметры вербального и сенсомоторного ответа на иллюзии Мюллер-Лайера и Понзо в двух группах, пребывающих в условиях 5-суточной опорной разгрузки, которую воспроизводили методом «сухой» иммерсии.
Differences in the parameters of memory-guided saccades and saccades to visual stimuli were demonstrated. Increases in the latent periods of memory-guided saccades as compared with saccades to visual stimuli provided evidence of slowing of saccade programming based on the extraction of information from working memory. Differently directed lateral differences were seen in the latent periods and durations of saccades to visual targets and memory-guided saccades, reflecting the leading role of the left hemisphere in the programming of saccades to visual stimuli and the right hemisphere in the programming of memory- guided saccades. Comparison of parameters of the temporospatial dynamics of initiation potentials P-1 and N-1, which develop in the last 100 msec of the latent periods of saccades, suggest that there are different mechanisms for the final step of programming saccades to visual stimuli and memory-guided saccades. Decreases in the latent period of the P-1 and N-1 peak potentials before memory-guided saccades may be evidence showing acceleration of the initiation processes for memory-guided saccades as compared with visually evoked saccades. This provides grounds for suggesting that the slowing of the programming of memory-guided saccades occurs at steps preceding saccade initiation.
В обзоре рассматриваются современные данные о возможных механизмах формирования синергий в норме, особенно на корковом уровне. Обсуждаются механизмы формирования патологических синергий с учетом анатомо-физиологических характеристик руки и гипотезы трансформирования синергетических паттернов у пациентов со спастическими геми-парезами. Приводится анализ современных представлений о патофизиологических основах формирования патологических синергий на основе данных нейровизуализационных и нейрофизиологических методов исследования, а также методик неинвазивной стимуляции головного мозга. Обсуждается проблема коррекции и трансформации патологических синергий в реабилитационной практике. Особое внимание уделено клинической и инструментальной оценке синергий с использованием апробированных клинических шкал и таких инструментальных методик как видеоанализ движений, электромиография, магнитные и бесконтактные трэкинговые системы и технологии виртуальной реальности.
A community of hamadryas baboons (Papio hamadryas) consists of a unique organization with four structural levels and marked hierarchical relationships between males and females. This makes it an ideal system for testing the hypothesis that relationship quality influences reconciliation between individuals. Post-conflict reconciliation was studied in hamadryas baboons. The behavior of 436 conflicting pairs was studied. Reconciliation was found to be characteristic of pairs of different composition, including: 1) pairs consisting of a male and a female from his harem; 2) pairs consisting of two females from the same harem; 3) pairs consisting of two related animals; 4) pairs consisting of two males; 5) pairs including a female and a young (almost adult) male. Significant differences in reconciliatory tendencies were seen in different pair categories, along with a high level of selectivity of the interactions between former antagonists, evidencing that the probability of reconciliation between hamadryas baboon individuals depends on the quality of the relationships between th
Experiments were performed on four European rabbits (Oryctolagus cuniculus). Rabbits underwent implantation of silver-plated electrodes into the bone over the primary visual cortex to record evoked potentials. Evoked potentials to substitution of threshold visual stimuli of intensity 0.28 and 0.31 cd/m2 were initially recorded, after which these stimuli were supplemented by sounds (2000 Hz, 84 dB, 40 msec). Sounds presented alone did not induce responses. Measurement of the amplitude of the N1 wave (85–110 msec) showed that the magnitudes of the response to substitution of sound + light complexes were significantly greater, by a factor of 1.6, than responses to substitution of light stimuli. Paired substitutions of light stimuli of eight intensities over the range 0.28–20.2 cd/m2 were then performed, and factor analysis was used to reconstruct the intensity sensory space. This was compared with a similarly obtained sensory space constructed with light stimuli accompanied by sounds. Analysis of the distances between the ends of the vectors representing the stimuli showed that addition of sounds led to enlargement of the space occupied by low-intensity light (0.28, 1.02, 3.05, and 6.35 cd/m2) by an average factor of 1.4 and ordered the positions of light in the space – strictly from the less to the more intense. At the same time, sounds shrank the space delimited by stimuli of greater intensities (8.48, 13.7, 16.8, 20.2 cd/m2) by a mean factor of 1.33. It is suggested that addition of sounds leads to improvements in the discrimination of lowintensity lights and leads to some degree of restriction to the discrimination of high intensities. The sensory spaces constructed from these substitutions of complex sound + light stimuli, as in the case of light stimuli, were two-dimensional, providing evidence supporting the suggestion that these stimuli are integrated into the single complexes when delivered simultaneously.
In recent years, possible therapeutic effects of transcranial direct current stimulation (tDCS) have been widely investigated in studies dealing with different types of neural pathologies. Initially, tDCS was applied for treatment of patients with motor stroke; later on, it was introduced into studies of patients with Alzheimer’s disease, multiple sclerosis, Parkinson’s disease, schizophrenia, and post-stroke aphasia. Recent reviews of tDCS application in patients with post-stroke aphasia did not provide coherent evidence on the tDCS efficiency. There were no uniform protocols of stimulation used, patients’ selection criteria were highly divergent, and the reports of treatment outcomes varied dramatically. In this review, we will focus on the reported heterogeneity of tDCS effects, trying to disentangle its putative underpinnings rooted in the diversity of lesion types, aphasia severity, and recovery stages. Given the current theoretical models suggesting the qualitatively different patterns of brain activity to accompany post-stroke aphasia recovery, a number of physiological factors should be taken into account to choose optimal tDCS parameters. With this in mind, we assess results of ten studies applying tDCS in post-stroke aphasia treatment, and, based on this analysis, suggest directions for further research in this rapidly developing field.