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Background. Ideas about relationships between "I", egocentric spatial orientation and the sense of bodily "Self " date back to work by classics of philosophy and psychology. Cognitive neuroscience has provided knowledge about brain areas involved in self-referential processing, such as the rostral prefrontal, temporal and parietal cortices, often active as part of the default mode network (DMN).objective and method. Little is known about the contribution of inferior parietal areas to self-referential processing. Therefore, we collected observations of everyday behavior, social communication and problem solving in patients with brain lesions localized either in the left inferior parietal cortex (LIPC group, n = 45) or the right inferior parietal cortex (RIPC group, n = 58).Results. A key characteristic of the LIPC group was an overestimation of task complexity. This led to a prolonged phase of redundant and disruptive contemplations preceding task solution. In the RIPC group, we observed disorders in reflective control and voluntary regulation of behavior. Abilities for experiencing emotions, understanding mental states, and social communication were to a great extent lost. Results are interpreted within a multilevel framework of cognitive-affective organization (velichkovsky, 2002). In particular, we highlight the role of right-hemisphere mechanisms in self-referential cognition, emotional and corporeal awareness. This is consistent with recent data on a profound asymmetry in connectivity of left and right hippocampi within the DMN (Ushakov et al., 2016).

Introduction: It is believed that hippocampal exposure plays a major role in the development of memory disorders after cranial irradiation. This effect is evident in whole-brain irradiation and is less certain in local irradiation of intracranial targets. The present study aims to clarify the dosimetric features and dynamics of memory functions after local irradiation of the hippocampus when treating cavernous sinus meningiomas.Methods: The study included 28 patients (24 females and 4 males) with cavernous sinus meningiomas diagnosed according to typical clinical and radiological findings. The mean age was 52 years (30-65 years). Stereotactic radiotherapy in standard fractionation regimen (54 Gy total dose) was the primary treatment in all patients. Patients underwent memory testing (ability to reproduce and recognize) using a previously developed and validated methodology at standard time points: before the start of radiotherapy, at the end of the course, and 6 and 12 months after treatment. Hippocampal dose, dynamics of memory function, and their possible relationship were evaluated.Results: In total, 28 cavernous sinus meningiomas (15 left-sided and 13 right-sided) were treated. The mean target volume was 24.0 ccm (8.2 ccm to 53.8 ccm). Twelve months after radiotherapy, there was an increase in the median total number of recognition errors from 6.5 [4;11] to 9.5 [5;12], p=0.025, the median number of "old-similar" errors from 2 [1;3.25] to 3 [1.75;5], p=0.021, and the median number of "similar-old" errors from 3 [1;5] to 5.5 [3;7], p<0.001. The number of reproduction errors did not increase. A moderate correlation (p = 0.03, correlation coefficient = 0.41) was found between the dose to 10% of the ipsilateral hippocampus and the total number of reproduction errors at the end of the course. No other significant correlations were found at the end of radiotherapy and six and 12 months after it. Conclusion: Thus, even partial lateralized exposure of the hippocampus during irradiation of the cavernous sinus meningiomas affects its function in the form of specific pattern separation type disturbances, which are detected as early as 12 months after the impact. The hippocampus in this treatment should be considered as a critical structure whose sensitivity to irradiation requires additional assessment.

In recent years, distinguishing between similar short-term memory traces (pattern separation) in humans and animals has become an important part of neurophysiological research aimed to localize these functions in the brain. The aim of this study was to assess the spatial gaze distribution in healthy subjects with a specific pattern separation error detected in visual attention and memory tests using the eye tracking technology. Materials and Methods. The 45 healthy volunteers were enrolled in the study and divided into two independent groups. In group 1 (28 subjects aged from 19 to 78 years old), the age-related features of visual fixations distribution were studied in the task of distinguishing similar objects. In group 2 (17 subjects aged 19 to 25), the distribution of visual attention in specific areas of the object was investigated. An original neuropsychological method was used: visual stimuli, eye tracking and subsequent assessment of stimuli recall and recognition. Results. We found significant differences in the distribution of visual fixations between the younger and older groups (p<0.05), as well as in the occurrence of pattern separation errors (p<0.05). The obtained data support the hypothesis of different physiological mechanisms that control the spatial distribution of visual attention in subjects of different ages.