Мозговые корреляты живости зрительного воображения: фМРТ-исследование.
To date, hampered physiological function after exposure to microgravity has been primarily attributed to deprived peripheral neuro-sensory systems. For the first time, this study elucidates alterations in human brain function after long-duration spaceflight. More specifically, we found significant differences in resting-state functional connectivity between motor cortex and cerebellum, as well as changes within the default mode network. In addition, the cosmonaut showed changes in the supplementary motor areas during a motor imagery task. These results highlight the underlying neural basis for the observed physiological deconditioning due to spaceflight and are relevant for future interplanetary missions and vestibular patients.
Many studies suggest that social punishment is beneficial for cooperation and consequently maintaining the social norms in society. Neuroimaging and brain stimulation studies show that the brain regions which respond to violations of social norms, the understanding of the mind of others and the executive functions, are involved during social punishment. Despite the rising number of studies on social punishment, the concordant map of activations - the set of key regions responsible for the general brain response to social punishment - is still unknown. By using coordinate-based fMRI meta-analysis, the present study examined the concordant map of neural activations associated with various social punishment tasks. A total of 17 articles with 18 contrasts including 383 participants, equalling 191 foci were included in activation likelihood estimation (ALE) analysis. The majority of the studies (61%) employed the widely used neuroeconomic paradigms, such as fairness-related norm tasks (Ultimatum Game, third-party punishment game), while the remaining tasks reported included criminal scenarios evaluation and social rejection tasks. The analysis presented revealed concordant activation in the bilateral claustrum, right interior frontal and left superior frontal gyri. This study provides an integrative view on brain responses to social punishment.
We analyzed brain functional connectivity using data from a task-based fMRI study of explicit categorization of neutral and emotional faces. During the perception of emotional faces, the correlation of BOLD signal in the right posterior superior temporal sulcus (STS) with other regions of the core face system increased, as compared to neutral faces. Conversely, during the perception of neutral faces, we found an increased correlation of STS and other core face system regions with brain areas outside the core system. The functional connectivity of STS shows lateralization due to the presence or absence of emotional expression. The obtained results support the key role of STS in facial expression recognition.
Activation of the limbic structures, and above all the amygdala, is believed to be evidence of a subjective emotional experience. However, a recent paper published by Boubela and colleagues (Boubela et al, 2015) discredits most of the fMRI research concerning BOLD-signal changes in the amygdala region. It was revealed that the BOLD signal increase during perception of affective stimuli might take its origin not from the grey matter itself, but from a large vessel situated near the amygdala: the basal vein of Rothental. In the present research, we attempted to estimate the contribution of veins and venules located near amygdala into BOLD signal changes from the region of interest. We found no systematic increase of BOLD signal in the group of veins within the region of interest in comparison with the BOLD signal in the actual gray matter of the amygdala. At the same time, correlations were found between the BOLD signal in the vessels and the gray matter. The obtained results allow us to interpret the BOLD signal from veins and venules in the region of interest as non systematic noise capable of masking or weakening the observed experimental effects. The method used in this work can be recommended for further fMRI studies of the amygdala.
Neuroimaging research in emotion regulation reveals a decrease of amygdala response to affective stimuli when the stimuli are perceived during the performance of a cognitive task. Two types of tasks are usually used to investigate this effect: one distracts attention from the emotional content of stimuli and another directly addresses the emotional content, such as identification of the emotional facial expression. The present fMRI study tested the effect of a third type of task: a memory task that promotes attraction of one’s attention to the emotional stimuli, but does not directly address the emotional content. A total of 44 volunteers were randomly assigned to one of two groups. In the MRI scanner, participants in the experimental group were asked to memorize emotional and neutral images taken from the IAPS (International Affective Picture System) database. Their recognition memory was subsequently tested after the scanning. Participants in the control group passively viewed the same picture set. The ROI analysis of the BOLD signal change revealed a leftward asymmetry of amygdala activation during the passive viewing of the pictures and a rightward shift of activation induced by the memory task. Results from the control ROIs demonstrated the phenomena of “inattentional deafness” in the auditory cortex and functional asymmetry in the visual cortex. The results are discussed in terms of complex functional connections between the amygdala, sensory cortices, and frontal regions of the brain.
This paper explores in more detail the phenomenon of deactivation of the auditory cortex evoked by the presentation of the affective pictures that we accidentally found in one of our recent studies (Litvinova et al., 2016). Data from two previous studies employing affective pictures (Litvinova et al., 2016 and Rozovskaya et al., 2014, 2016) were re-analyzed and demonstrated a similar pattern of results. Emotionally negative scenes elicited significant deactivation in the auditory cortex in passive viewing and during encoding of pictures into memory. Emotional valence (positive, negative or neutral) significantly affected BOLD signal change in the auditory cortex under conditions of passive viewing (with the most pronounced deactivation evoked by mutilation pictures), but not in the memory task condition. However, mere presentation of an affective picture is not enough to induce deactivation in the auditory cortex. Unlike encoding, retrieval of the affective pictures from working memory evokes a significant positive BOLD response. A pronounced leftward hemispheric asymmetry of this response suggests that it may reflect a role of verbal processes in the retrieval of information from the working memory. Overall, our results suggest that the observed phenomenon may reflect a neural signature of inattentional deafness (ID): a failure to perceive auditory stimuli which manifests under high visual perceptual load. Therefore, we predict that passive viewing and memorization of negative affective pictures, but not their retrieval from WM, would be accompanied by the ID effect at the behavioral level.