LETTER

From Big Medical Encyclopedia

LETTER — a special form of the speech at which its elements are fixed on paper or other materials by means of the signs designating the corresponding elements of oral speech. In the majority of modern types of P. as signs letters and only in some — the hieroglyphs expressing not separate sounds of oral speech, and the whole concepts are used.

The item represents the latest type of speech function. The person seizes the letter, as well as reading, as a result of training at sufficient development of oral speech and absence of rough pathology in the intellectual in the no-mnestichesky sphere and system of analyzers (acoustical, visual, motive).

In fiziol, mechanisms P. distinguish three main components: 1) the analysis of a sound complex of the word and its decomposition on phonemes (separate speech sounds); includes reproduction and preservation in memories of the necessary order of sounds and words; 2) a reencryption of phonemes in graphemes (letters or combinations of letters); 3) motive acts, i.e. actually writing for which visual correction and the space analysis are necessary. The mechanism P. changes at various stages of its formation up to turning into the automated act (e.g., the signature).

Methods of a research Items are usually directed to definition of its various elements and levels. Writing off and the letter from dictation of letters, syllables, words, phrases and offers, a reencryption of a printing font and more irregular shapes of a written language is for this purpose carried out. The most widespread research P. comes down to the following scheme: 1) writing of letters; 2) the writing of syllables and words (opened and the closed syllables, syllables with several in a row the going concordants, simple and phonetic compound words, unknown words, folding of syllables and words from the cutting alphabet; 3) writing of a series of words and phrases; 4) irregular shapes of P. (description of the hometown, features of the profession etc.).

Dysgraphias

Distinguish P.'s disturbances on sense and in a form. On sense refer to disturbances the replacements of letters contradicting sense, repetitions of words; to disturbances in a form — spelling errors (if to their disease was not), perversions of the terminations of words, shifts, replacements and perversions of letters, impossibility to adhere to a line, rough changes of handwriting, the sizes of letters and other disturbances. Disturbances of activity of P., the sudden unmotivated termination of P., repeated repetitions of already written are most difficult. The expressed P.'s disturbances caused by preferential focal damages of a brain are considered as agraphia or a dysgraphia. Agraphia is often included as a component into a syndrome of aphasia. At the same time features of disturbance of P. are closely connected with various forms of aphasia, with the nature of disturbance of the speech in general. Agraphia is often combined with disorder of reading — an alexia (a verbal blindness). However also the dissociated frustration are observed. So, at disturbance of understanding of the speech (when function of acoustical perception is broken and there is impossible a differentiation of phonemes) P. from dictation especially suffers, though other types of P. are upset, but to a lesser extent. The patient at partial disturbance of acoustical perception in a varying degree is helped with writing of a letter, syllable or word by their pronunciation; at the same time the large role is played by the arising at activity of organs of articulation, i.e. an articulation, deep muscular afferentation which is important in development of the speech and other highest cortical functions. Perseveration (frequent repetition of the same words in various phrases or from - separate syllables in the pronounced words) and an agrammatism (a mismatch of words on cases, childbirth etc.) in oral speech it is usually shown as well in P. though coincidence happens not always full. To a paraphasia there corresponds in P. the paragraphia (replacement of letters, syllables or words in the letter). At motor aphasia when function of preservation and reproduction of an image of the word suffers preferential, the patient quite often writes or tries to write not dictated word, and similar on sense. E.g., instead of the word «log hut» of the patient writes «huts», trying to write the word «hut». Instead of writing of various dictated letters of the patient writes many times the same letter. Agraphia does not depend on that, the right or left hand writes the text. Only the special form of disturbance of the speech, the so-called mirror letter which mechanism is not quite clear is usually observed only at P. by the left hand and is noted at defeat of the left parencephalon.

Fig. 1. Models of writing of letters B and Zh by the patient with an ataxy.

Agraphia can be result of preferential defeat of the visual analyzer and be combined with visual agnosia (see) and constructive apraxia (see). At the same time in P. the wrong outlines of letters (fig. 1) prevail that is observed also at patients with ataxy (see). In hard cases the handwritten text consists of elements, a little similar to letters. Sometimes elements of the necessary letter are represented correctly, but are incorrectly combined with each other. Similar disturbances need to be distinguished from the wrong correlation of a letter with the corresponding sound when the patient instead of one letter writes Another.

An anamnestic form of agraphia call frustration of P. at which the patient cannot write the necessary letter at once, referring to the fact that forgot it, and through a nek-swarm time nevertheless writes it. Sometimes the patient correctly writes a letter, and then cannot call it. In some cases replacements of the necessary letters similar on writing (— «x») or standing close alphabetically («I» — «Ф»), writing bigger are observed, than it is required, quantities of elements (instead of «п» — «ш») or smaller (instead of «m» — «n»). Quite often P.'s disturbance accepts the nature of decrease of the activity, and sometimes and total failure from the Item.

The condition of the motive sphere and a muscle tone affects P.'s character. Existence of hyperkinesias affects handwriting (distortion of letters, fluctuations of a line). At a tremor of a letter they carry a print of trembling of a hand, sometimes very small (micrography), or, on the contrary, excessively large (a makrografiya, or a megalografiya). Changes of handwriting can have funkts, and to reflect character excited or depression of a nervous system.

Fig. 2. Samples of the letter from dictation of the patient with touch aphasia (after wound to the left temporal area).
Fig. 3. Samples of the letter of patients with efferent motor aphasia after wound: 1 — 2 — to the left frontotemporal area, 3 — to the front speech area, 4 — to the area of the left frontal crinkle (samples are written: and — without pronunciation — with pronunciation of words aloud), 5 — to the area of the right frontal crinkle of the lefthander (samples are written: and — without pronunciation — with pronunciation of words aloud).
Fig. 4. A sample of the letter of the patient with efferent motor aphasia with signs of violent movements: the sites of the text caused by the violent movements are emphasized.

The analysis of disturbances of P. is important for topical diagnosis of damages of a brain. So, in case of defeats of the cortical site of the acoustic analyzer localized preferential in upper parts of a temporal share (an upper temporal crinkle, the field 22), difficulties in P. arise owing to disturbance of the sound analysis and synthesis. Especially also spontaneous P. at relative safety of writing off (fig. 2) suffers therefore from P. from dictation. Defeats of operkulyarny departments of the left precentral and postcentral crinkles with existence of motor aphasia and preferential disturbance of a kinestatichesky basis of the speech act (afferent impulses of deep muscle sense from speech bodies) are followed by P.'s disturbance in the form of difficulty or utter impossibility of writing of letters, syllables, according to the heard sounds. Also characteristic artikulyatorny replacements of letters (e.g., «N» or «l» instead of «д» is written, to «m») are observed, also other and graphic disturbances are noted. At the defeat of the lower frontal crinkle of a dominant hemisphere (field 44, 45) which is followed by motor aphasia of efferent type (efferent motor aphasia) into the forefront changes of an order of letters, syllables, perseverations (fig. 3) act. At defeat of premotorny area of disturbance of P. can be shown only by perseverations and the violent movements (fig. 4). Defeats of occipital, occipitoparietal and occipitotemporal areas in a dominant hemisphere (usually left) are characterized by optical agraphia at which because of loss of a visual object of a letter it is difficult for patient to find the grapheme corresponding to a sound, letters are distorted sometimes to full unrecognizability. Complicates the act of the letter or even makes it completely impossible writer's cramp (see). P.'s disturbances are observed also at the torsion dystonia (see), parkinsonism (see), multiple sclerosis (see), a chorea of Gentington (see. Gentington chorea ), diseases of Peak, Alzheimer (see. Peak disease , Alzheimer disease ), etc.

P.'s disturbance can be recovered and compensated if P. which is the cornerstone of disturbances patol, process has no the progressing character. At involution patol, process there can be a spontaneous recovery of P. and other highest cortical functions that is observed, e.g., after operational removal of benign tumors of a brain or in the recovery period at focal vascular damages of a brain. Use of various methods of special logopedic training does process of recovery of P. by more effective.

The letter in the medicolegal relation

In investigative practice of P. is used for identifications of the personality (see) on handwriting that makes the content of judicial handwriting examination. During conducting such examination decides as well some other the tasks connected with establishment of the unusual conditions of writing of the manuscript exerting impact on properties of handwriting (a condition of contagious excitation, alcoholic intoxication, a mental disease, etc.). During the conducting examination in the manuscript distinguish semantic aspect (written language) and handwriting — system of usual peculiar interdependent and steady movements at reproduction of written signs. Style of a statement, verbal structure of language, the general level of literacy of writing belong to the signs characterizing a written language. As signs of handwriting features of movements at the Item are considered. They are divided into the general and private. The general signs reflect the general system of movements at P.: clarity, speed, complexity, the prevailing form, extent and the direction, efforts, connectivity of the fixed movements, and also dimensional orientation. Private signs of handwriting are its separate features during the writing and binding of written signs and elements in them: form, relative direction, extent and type of connection of movements, quantity and sequence of movements.

At purpose of judicial handwriting examination submit to the expert the studied manuscript (which performer is required to be established) and the samples written by the person suspected of their writing. The technique of conducting examination provides a number of consecutive stages: preliminary studying of the sent materials, a separate research of signs of P. in the studied manuscript and in P.'s samples, a comparative research of the revealed signs.

During the preliminary research the expert gets acquainted with the facts of the case, estimates the volume and quality of graphic material. The essence of a separate research consists in identification in the manuscript and examples of handwriting of the general and its private signs and their assessment. At the same time idea of features and properties of handwriting is created.

In a stage of a comparative research the signs revealed during the separate research of manuscripts are compared. At the same time coincidence and distinctions of signs and their value for the solution of a problem of identification is defined. At a research of the general signs the expert makes descriptive developments, private signs — graphic developments. There are techniques allowing to make objective assessment of the compared signs taking into account the frequency of their repetition in handwritings of different persons.

In the course of the comparative research of manuscripts the expert shall estimate the received results and come to a conclusion about writing of the compared manuscripts by the same person or different persons. The matching or differing signs established at a comparative research can be put (taking into account their quantity and quality) in a basis positive (categorical or probable) or negative (categorical or probable) conclusions. In all cases assessment both the coincident, and differing signs is obligatory. Only steady signs integrally inherent in the letter of the particular person can be the basis for a conclusion about the performer. A categorical positive conclusion is possible at coincidence of enough the resistant, rather seldom found features of handwriting, to-rye only P. of a certain person are in total inherent and cannot meet in P. of other persons. The available distinctions in such cases can be explained with various conditions of writing of the compared manuscripts. The categorical negative conclusion is drawn at establishment of distinctions in steady signs of handwriting, to-rye cannot be explained with various conditions of writing of the compared manuscripts. The probable positive conclusion about writing of the compared manuscripts by the same person is drawn when steady distinctions it is not established, but quality and quantity of coinciding signs do not allow to exclude practically a possibility of accidental coincidence of handwriting of different persons. Probable negative conclusion is possible in cases when it is not possible to track stability of the revealed distinctions of handwriting, napr, at the small volume of the studied manuscript. Results of the carried-out judicial handwriting examination are made out in the form of the expert opinion.

See also Pocherkovedeniye .


Bibliogr: Levina R. E. Disturbances of the letter at children with an underdevelopment of the speech, M., 1961; Luriya A. R. Sketches of psychophysiology of the letter, M., 1950; it she, the Highest cortical functions of the person, page 421, M., 1969; P at c about and and with K. G., P and with and l and d and from F. K. and Pappus P. K. To a question of the mirror letter and reading, Zhurn, a neuropath, and psikhiat., t. 78, No. 12, page 1806, 1978; Judicial handwriting examination, under the editorship of E. D. Dobrovolskaya, etc., M., 1971; Tom ying V. V. l. Bases of forensic medical examination of the letter, M., 1974; Leonhard K. Rechriert-und zeitliche Orientierungssto-rung bei Agraphie und kostructiver Apra-xie, Arch. Psychiat. Nervenkr., Bd 188, S. 504, 1952; Spiel W. Beitrag zur congenitalen Lese-und Schreibstorungen, Wien. Z. Nervenkr., Bd 7, S. 20, 1953; Warrington E. K. a. S h a 1 1 i-c e T. Semantic access dislexia, Brain, v. 102, p. 43, 1979.


L. A. Kukuyev; V. V. Tomilin (court.).

Яндекс.Метрика