[Event-related brain potentials when Russian verbs being conjugated: to the problem of language processing modularity].

In the light of alternative conceptions of "two-system" and "single-system" models of language processing the efforts have been undertaken to study brain mechanisnis for generation of regular and irregular forms of Russian verbs. The 19 EEG channels of evoked activity were registered along with casual alternations of speech morphology operations to be compared. Verbs of imperfective aspect in the form of an infinitive, belonging either to a group of productive verbs (default, conventionally regular class), or toan unproductive group of verbs (conventionally irregular class) were presented to healthy subjects. The subjects were requested to produce first person present time forms of these verbs. Results of analysis of event related potentials (ERP) for a group of 22 persons are presented. Statistically reliable ERP amplitude distinctions between the verb groups are found onlyin the latencies 600-850 ms in central and parietal zones of the cortex. In these latencies ERP values associated with a presentation of irregular verbs are negative in relation to ERP values associated with the presentation of regular verbs. The received results are interpreted as a consequence of various complexity of mental work with verbs of these different groups and presumably don't support a hypothesis of universality of the "two-system" brain mechanism for processing of the regular and irregular language forms.

[Effect of acoustic stimulation parameters on human appreciation of changes in distance from a sound source]. / Vliianie parametrov akusticheskoi atimuliatsii na otsenku chelovekom izmeneniia rasstoianiia ot istochnika zvuka.

Minimal time necessary for appearance of sensation of approaching or withdrawing of the amplitude-impulse-modulated sound was 0.3--0.4 sec at changing the intensity from minimal to maximal within the range of 30--60 dB over the threshold of rhythmic series determination (10--50 Hz). The number of short lengths of tones or noises in the series within this time epoch should be not less than three. The effect of the value of carrying frequency of the series lengths upon the sensation of approaching or withdrawing is only evident within the range of those temporal parameters of the signal which accompanied change of criterion of estimation of the sound quality. Further shortening of the signal leads to substitution of the criterion for estimation of stimulus position for the criterion of sound accentuation at a tonal carrier and for the criterion of consonant-likeness at a noise carrier. The downward frequency modulation from the initial frequency at a growing amplitude enhances the sensation of "approaching", the upward modulation enhances the sensation of source "withdrawing", as compared with the constant frequency or the frequency modulation of opposite sign.

[Relationship between perception of low-frequency amplitude modulation, age and training in man]. / Zavisimost' vospriiatiia nizkochastotnoi amplitudnoi moduliatsii ot vozrasta i trenirovki u cheloveka

As it was shown earlier, normal hearing in man is characterized by selective sensitivity to amplitude modulation (AM) of sound within the frequency region of 4--8 cps, which corresponds to the most probably AM frequency of the speech signal. Since this phenomenon is presumably due to a constant training for speech perception, it has been investigated in ontogenesis, i.e. starting from 7--8-year children, in whom the process of speech learning is especially intensive. The results obtained indicate that the auditory threshold in children at the age of 7--8, 9--10 and 13--14 years exhibits evident preferable sensitivity in the region of 4--8 cps. Besides, it was found that although the thresholds to 1--2 and 32--64 cps frequencies decrease with ageing, no decrease of the sensitivity takes place within the region of 4--8 cps. Similar data were obtained during special or professional (musical) training of the subjects.

[Selective sensitivity of hearing to amplitude modulation of speech in man]. / Ob izbiratel'noi chuvstvitel'nosti slukha cheloveka ka amplitudnoi moduliatlsii rechi

Studies on the sensitivity of man's hearing to the reception of amplitude modulation (AM) of the sound reveal statistically reliable threshold minimum in the region of 4-6 c. p. s. It is suggested that this phenomenon is evolutionary conditioned by tuning of human auditory system on the perception of speech, in which AM results from articulation of the syllables. The acoustical analysis of several speech extracts demonstrated statistically reliable maximum of AM of the sound flow just within 4-6 c. p. s. Therefore, the selective sensitivity of hearing to perception of these AM frequencies increases the safety and interference resistance of the system "speech-hearing".

[From animal communication to the human language and cognition: evolution or revolution?].

The paper discusses the problem of language and cognitive specificity in humans as compared to other species. The main hypotheses of human evolution and the emergence of language seem to be well researched on genetic basis of higher functions. Cognitive abilities of other animals and their communication signals and the main views on basic principles of brain underlying these functions are described.

[Mirror brain systems, concepts and language: the price for anthropogenesis].

The paper discusses the problem of cognitive evolution and the basis for the origin of language and mind, genetic history of Homo sapiens and whether the basic concepts are inborn or effected by experience, sensory or cognitive per se. The problem of localization of higher functions and Theory of Mind in norm and pathology is analyzed.