N.P. Kuzenkov, V.M. Loginov, S.V. Prokopenko, E.Y. Mozheyko
Speech of the person grows out work of the speech apparatus. It is accepted to allocate the central and peripheral departments in a structure of the speech apparatus. The structure of a peripheral department includes all the agencies which are participating during vocalization. The central department includes specific cortical fields of a brain and subcortical structures with system of afferent and efferent paths, innervating a peripheral department of the speech apparatus.
There are various speech pathologies, including examined in work motor aphasias and dysarthrias at organic defeats of the central department of the speech apparatus. These pathologies are the heaviest speech infringements, and are shown in the form of delay and indistinctness of speech, pronunciation distortions, and replacements of sounds and sometimes lead to full loss of speech.
Within the research of examinee it was offered to read through aloud the story «the Malicious boy» of A. P. Chekhov and then to retell it in usual for the examinee rate. At the same time speech of examinees was fixed by means of an electrodynamic microphone and recorded in a file at frequency of digitization 8 kHz. In total the following amount of samples of speech has been written down: reading in norm (absence of a pathology) - 41, a monologue in norm - 79, reading at aphasia (motor, afferent and efferent together) - 26, a monologue at aphasia - 53, reading at dysarthria - 27, a monologue at dysarthria - 33. Then each analyzed sample of speech was represented in the set of durations alternating sounds and pauses that is equivalent to the description of a random telegraph signal by indication of times between fronts of impulses. For reduction of all data sets to one standard kind, all values of some divided on an average of value of some, and then were taken the logarithm.
Then from received of data set with use of a method of time delays the phase portrait in three-dimensional space was reconstructed. The given phase portrait then was broken on 8 clusters, and probabilities of transition of a point between clusters were found. Thus, for each sample of speech the matrix of probabilities of transitions of a point in the size 8×8 was created.
Depending on a kind of infringements in the central nervous system various probabilities of transitions between clusters change. Statistically significant difference of some probabilities of transitions between groups norm, a monologue - aphasia, a monologue, norm, reading - aphasia reading, norm, a monologue - dysarthria, a monologue and norm, reading - dysarthria, reading is revealed.
Thus, use of the given approach allows investigating temporary structure of speech as function of activity of the central nervous system.