The action observation networks (AON) (or the mirror neuron system) are the neural underpinnings of visuomotor integration and play an important role in motor control. Besides, one of the main functions of the human mirror neuron system is recognition of observed actions and the prediction of its outcome through the comparison with the internal mental motor representation. Previous studies focused on the human mirror neurons (MNs) activation during object-oriented movements observation, therefore intransitive movements observation effects on MNs activity remains relatively (...) little-studied. Moreover, the dependence of MNs activation on the biomechanical characteristics of observed movement and their biological plausibility remained highly underexplored. In this study we proposed that naturalness of observed intransitive movement can modulate the MNs activity. Event-related desynchronization (ERD) of sensorimotor electroencephalography (EEG) rhythms, N400 event-related potentials (ERPs) component and corticospinal excitability were investigated in twenty healthy volunteers during observation of simple non-transitive finger flexion that might be either biomechanically natural or unnatural when finger wriggled out toward the dorsal side of palm. We showed that both natural and unnatural movements caused mu/beta-desynchronization, which gradually increased during the flexion phase and returned to baseline while observation of extension. Desynchronization of the mu-rhythm was significantly higher during observation of the natural movements. At the same time, beta-rhythm was not found to be sensitive to the action naturalness. Also, observation of unnatural movements caused an increased amplitude of the N400 component registered in the centro-parietal regions. We suggest that the sensitivity of N400 to intransitive action observation with no explicit semantic context might imply the broader role of N400 sources within AON. Surprisingly, no changes in corticospinal excitability were found. This lack of excitability modulation by action observation could be related with dependence of the M1 activity on the observed movement phase. (shrink)

The author elucidates the ontological basis of elementary mathematical theories and thereby assesses their certainty as a foundation for the more complex theories of modern mathematics, such as mathematical analysis and set theory. He adduces arguments in favor of the position of Frege, who held that geometry can provide a sufficiently broad and certain foundation for mathematics.

t. 1. Problemy vospitanii︠a︡ vsestoronne razvitoĭ lichnosti. Dukhovnyĭ mir shkolʹnika. Metodika vospitanii︠a︡ kollektiva.--t. 2. Formirovanie Kommunisticheskikh ubezhdeniĭ molodogo pokolenii︠a︡. Kak vospitat nastoi︠a︡shchego cheloveka. Sto sovetov uchiteli︠u︡.--t. 3. Serdt︠s︡e otdai︠u︡ deti︠a︡m. Rozhdenie grazhdanina. Pisʹma k synu.--t. 4. Pavlyshskai︠a︡ sredni︠a︡i︠a︡ shkola. Razgovor s molodym direktorom shkoly.--t. 5. Statʹi.

t. 1. Serdt︠s︡e otdai︠u︡ deti︠a︡m. Rozhdenie grazhdanina.--t. 2. Pavlyshskai︠a︡ sredni︠a︡i︠a︡ shkola.

t. 1. Problemy vykhovanni︠a︡ vsebichno rozvynenoï osobystosti. Dukhovnyĭ svit shkoli︠a︡ra. Metodika vykhovanni︠a︡ kolektyvu -- t. 2. Formuvanni︠a︡ komunistychnykh perekonanʹ molodoho pokolinni︠a︡. I︠A︡k vykhovaty spravz︠h︡ni︠u︡ li︠u︡dynu. Sto porad uchytelevi -- t. 3. Sert︠s︡e viddai︠u︡ diti︠a︡m. Narodz︠h︡enni︠a︡ hromadi︠a︡nyna. Lysty do syna -- t. 4. Pavlysʹka seredni︠a︡ shkola. Rozmova z molodym dyrektorom -- t. 5. Statti.