According to dual process theories, depletion of executive resources may amplify decision-making biases. Psychological studies investigating the influence of executive control on risky decision mak- ing typically employ dual task paradigms, e.g. a risky decision-making task in parallel with an exec- utive task. However, these paradigms often reveal relatively weak to null effects. In this study, we designed a novel task to determine the influence of executive control on risky decision making di- rectly, and simultaneously separating gains and losses using a block design. Contrary to other tasks, risk taking, and executive control occurred during the same decision. When risky decisions were conditioned on high executive control, participants demonstrated a reflection effect: higher risk taking for loss blocks, compared to gain blocks. Further exploration revealed that the gain-domain specific influence of executive control on risky decisions occurred due to the influence of trial-by- trial decision-making strategies.
Working memory (WM) capacity is well known to influence mathematical abilities. This effect is more profound for volume of visual-spatial domain of WM, while volume of WM phonological loop, associated with processing of auditory and phonological information has no or little effect on mathematical abilities in adults. However the role of the brain language network at mathematical cognition is still under discussion. We examined the effect of WM in phonological loop using a simple forward digital span test at the speed and correctness of solving different mathematical versus verbal tasks in healthy right handed young volunteers with higher education or students in math and humanities. The correctness (С) and time of the task solving (TS) was significantly better in Math group (N=10), than in Humanitarian group of subjects (N=10). The WM volume did not differ between the groups, but affected differently C and TS of tasks in mathematicians and humanitarians. Spearman’ correlation analysis for separate groups showed that WM affected the C of solving the mathematical tasks in Math group but not TS, while in Humanitarian group we observed the opposite tendency. Remarkably, the WM correlated negatively with TS of logical task for arithmetical sequences in Math group. Our results imply that WM in verbal domain may influence mathematical abilities especially when they require involvement of logical thinking.
In this article, the problems of neurophysiological mechanisms of social behavior perception are considered. The concept of the human brain mirror neuron system, its connection with the mu-rhythm and its role in the social version is disclosed. An original three-block technique for presenting the experimental material has been developed and tested. This technique allows an electroencephalographic study of the brain mirror system with a simple, purposeful and emotionally colored motor act. It was shown that this execution accompanies the mu-rhythm desynchronization and the human brain mirror neuron system activation. There were identified Brodman fields, corresponding to the maximum activity areas and brain mirror system activation.
Brain-computer interfaces find application in a number of different areas and have the potential to be used for research as well as for practical purposes. The clinical use of BCI includes current studies on neurorehabilitation ([Frolov et al., 2013; Ang et al., 2010]), and there is the prospect of using BCI to restore movement and communication capabilities, providing alternative effective pathways to those that may be lost due to injury or illness. The processing of electrophysiological data requires analysis of high-dimensional, nonstationary, noisy signals reflecting complex underlying processes and structures. We have shown that for non-invasive neuroimaging methods such as EEG the potential improvement lies in the field of machine learning and involves designing data analysis algorithms that can model physiological and psychoemotional variability of the user. The development of such algorithms can be conducted in different ways, including the classical Bayesian paradigm as well as modern deep learning architectures. The interpretation of nonlinear decision rules implemented by multilayer structures would enable automatic and objective knowledge extraction from the neurocognitive experiments data. Despite the advantages of non-invasive neuroimaging methods, a radical increase in the bandwidth of the BCI communication channel and the use of this technology for the prosthesis control is possible only through invasive technologies. Electrocorticogram (ECoG) is the least invasive of such technologies, and in the final part of this work we demonstrate the possibility of using ECoG to decode the kinematic characteristics of the finger movement.
According to psychological research erotic images are evaluated in the context of positive emotions as the most intense, most associated with emotional arousal, among the variety of pleasant and unpleasant stimuli. However it is difficult to separate areas of the brain that are related to the general emotional process from the activity of the brain areas involved in neuronal representations of reward system. The purpose of this study was to determine differences in the brain activity using functional magnetic resonance imaging (fMRI) in male subjects in evaluating an intensity of pleasant images, including erotic, or unpleasant and neutral pictures. When comparing the condition with evaluation of the pleasant erotic images with conditions containing neutral or unpleasant stimuli, a significant activation was observed in the posterior cingulate cortex, the prefrontal cortex and the right globus pallidus. An increased activity of the right anterior central gyrus was observed in the conditions related to evaluation of pleasant and neutral stimuli. Thus, in the process of evaluating the intensity of emotional images of an erotic nature the active brain areas were related not only to neuronal representations of emotions, but also to motivations and control system of emotional arousal, which should be taken into account while using erotic pictures as intensive positive emotional stimuli.
The aim of the present work was to assess long-lasting effects of acute prenatal stress in white rats. Forced swimming in cold water on the 7th or the 14th gestational day was used as a prenatal stressor. The prenatal stress led to low birthweight of offspring and their delayed growth rate during the second month of life. Prenatally stressed animals showed abnormalities in exploratory behavior and anxiety, increased emotionality and impaired learning capabilities at the age of 1—2 month. Consequently, acute stress on the 7th and at the 14th day of pregnancy induced long-lasting negative behavioral changes in offspring of stressed white rats.
Modern neuroimaging studies begin to explore neurobiological mechanisms of social norms enforcement. Several regions of frontal lobes and temporo-parieto-occipital cortex play a key role in decision making of social punishment of fairness’ norm violation. The cutting–edge methods of brain stimulation allow to change a frequency and intensity of social punishment in different economic tasks (games). The analysis of modern studies show that brain mechanisms of decision making to punish non–cooperative individual requires further investigation with brain stimulation methods to differentiate a role of frontal and temporo-parieto-occipital regions and clarify its interaction.
The paper presents the results of complex ischemia study using background (resting) EEG, blood flow rates in major head arteries and cognitive tests. The examined subjects were: patients with severe atrophy of cerebral hemisphere (N = 35), patients after left (N = 34) and right (N = 32) stroke and healthy volunteers (N = 42). Resting state clusters having specific frequency pattern, topography and time of presence were discriminated from EEG for each group. Clusters observed in healthy subjects were almost or even completely absent in patients with ischemia. Their time of presence correlated directly with blood flow rates in head arteries and inversely with stenosis level in internal carotid artery. Further, there were clusters specific to patients groups, also being correlated with stenosis level. “Ischemic” clusters proved to be quite similar for patients with SACH and after right stroke, but they were completely different in patients after left stroke. Time of presence of these clusters correlated with cognitive tests scores. The results prove the resting EEG analysis to be applicable for ischemia diagnosis as an additional instrument.
In the review there are given current data of theories and neurophysiological aspects of motor control and pathological motor synergies. Attention has been focused on the discussion of certain mechanisms of pathological synergies based on anatomical and physiological upper limb characteristics. Synergistic pattern transformation hypothesis in patients with spastic hemiparesis are described and highlighted. The analysis of modern theories of pathophysiologic backgrounds of pathological synergies formation is based on neuroimaging and non-invasive brain stimulation research data. The problem of pathological synergies correction and transformation in rehabilitation practice has been reviewed. Special attention is paid to clinical and instrumental evaluation of synergies. Data has been proved by clinical scales and instrumental techniques such as movement video analysis, electromyography, magnetic and wireless tracking systems and virtual reality technology.