Psycholinguistic Consequences of Right-Sided Versus Left-Sided Deafness
Z.M. KURKOWSKI Institute of Physiology and Pathology of Hearing, Warsaw, Poland
4th European Congress of Oto-Rhino-Laryngology, Head and Neck Surgery, Berlin, Germany, May 13-18, 2000
SUMMARY A comparative analysis was conducted to determine the behaviour of people with left-sided and right-sided damage of the hearing organ. Special attention was paid to the recognised cases of peri- and post-lingual damage. The cases of 110 children aged 6-15 years were analysed. Forty-eight children had right-sided and 62 had left-sided deafness. Achievements at school, emotions and linguistic communication were evaluated. The results of lateralisation and dictation were also assessed.
INTRODUCTION In the discussion of functional differences between brain hemispheres, the following terms are associated with left hemisphere: linguistic, analytic, rational, linear, sequential and arbitrary, while right hemisphere is often described with terms: non-linguistic, synthetic (holistic), emotional, spatial, successive and automatic. Some of these terms refer to the features of material dealt with more effectively by a given hemisphere, other words characterise processing procedures. The studies of patients in whom the commissures between both hemispheres were separated (in the case of epilepsy) indicated not only brain functional asymmetry but also the fact that each brain hemisphere is responsible for opposite half of the body. This applies to hearing as well -i.e. a given car is related to the opposite hemisphere more than to the one on the same side of the body. This was confirmed by the studies initiated by D. Kimura, with the use of dichotic listening, which show the superiority of right-ear listening to verbal material, particularly when repeating the sequence of 2-3 words and the superiority of leftear perception of music sounds (fragments of tunes, musical accords, tonal sequences), environmental sounds (dog's barking, train whistle), emotional sounds (laughter, crying). The studies supporting the claim that asymmetry is rather stable after around 4 year of life are also important. Right-sided hearing lateralisation with respect to speech perception and the consequences of its impairment were discussed by numerous authors. A. Tomatis be-
lieves that left-sided hearing lateralisation with dominant left hemisphere with respect to speech functions may result in a number of speech disturbances as well as difficulties in reading and writing.
MATERIAL AND METHOD The cases of 110 children aged 6-15 years were analysed. Forty-eight children had right-sided and 62 had left-sided deafness. In 57 children, the damage of the hearing organ occurred during the peri- and postlingual period. In 43 cases, the damage may have occurred during the pre-and peri-lingual period. A comparative analysis was conducted to determine the behaviour of people with left-sided and right-sided damage of the hearing organ. Special attention was paid to the recognised cases of peri- and post-lingual damage. Achievements at school, emotions and linguistic communication were evaluated. The following instruments were used in the analysis: School Achievements Evaluation Questionnaire, Tree Test, Family Relations Test, Eysenck's Personality Questionnaire, Kostrzewski's Scale of Audi tory Per足ception of Words, and Evaluation Scale of the Motor Activity of Speech Organs. The results of lateralisation and dictation were also assessed.
4th European Congress of Oto-Rhino-Laryngology, Head and Neck Surgery, Berlin, Germany, May 13-18, 2000
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RESULTS Right-sided deafness (58 persons; 27 children diagnosed for the hearing damage during the peri- and post-lingual period) Table 1. Right-sided deafness - linguistic communictation Total Number of persons
Type of disorder
Percentage n=58
Number of persons who have lost hearing ability
Percentage N = 27
Dyslalia, stutter
24
41,4
12
Dyslexia
26
44,8
14
44,4 51,8
Erroneous spelling
18
31,0
7
25,9
Communication problems
27
46,6
18
66,7
Syntagmatic distortion
14
24,1
6
22,2
Table 2. Right-sided deafness - School achievements Type of disorder Sciences preferred Humanities preferred No préférences Difïiculties in sciences Difficulties in humanities Difiiculty not assessed
Total Number of persons 14 14 30 22 24 12
Percentage n=58 24,1 24,1 51,8 37,9 41,4 20,7
Number of persons who have lost hearing ability g 8 11 g 10 9
Percentage N = 27 29,6 29,6 40,8 29,6 37,0 33,4
Emotional behaviour Lack of emotional balance, proneness to anxiety, breakdowns, nervousness and irritability - 28 (48,3%) Lack of symptoms of emotional disorders - 30 (51,7%) Left-sided deafness (62 patients; 30 children diagnosed for the hearing damage during the peri– and post-lingual period) Table 3. Left-sided deafness - linguistic communictation Total Number of persons 14
Type of disorder Dyslalia, stutter
Percentage n=62 22,6
Number of persons who have lost hearing ability 6
Percentage N = 30 20,0
Dyslexia
12
19,4
7
23,3
Erroneous spelling
18
12,9
5
16,7
Communication problems
12
19,4
6
20,0
0
0,0
0
0,0
Syntagmatic distortion
Table 4. Left-sided deafness - School achievements Type of disorder Sciences preferred Humanities preferred
Total Number of persons 56 4
Percentage n=62 90,3 6,4
Number of persons who have lost hearing ability 26 3
Percentage N = 30 86,7 10,0
No préférences
2
3,3
1
3,3
Difficulties in sciences
5
8,1
4
13,3
Difficulties in humanies Difficulty not assessed
54 3
87,1 4,8
25 1
83,4 3,3
Emotional behaviour Lack of emotional balance, proneness to anxiety, breakdowns, nervous-ness and irritability - 54 (87,1%) Lack of symptoms of emotional disorders - 8 (12,9%).
4th European Congress of Oto-Rhino-Laryngology, Head and Neck Surgery, Berlin, Germany, May 13-18, 2000
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CONCLUSIONS The analysis of the research material allows for a comparison of different symptoms of right-sided and left-sided deafness in terms of linguistic and emotional behaviour as well as achievements at school. Right-sided deafness is characterised by more serious problems with linguistic communication - erroneous spelling, dyslexia, and simple communication. School activity is noticeably lower and hence, the results at school are comparatively worse. In the case of left-sided deafness, emotional problems prevail: lack of emotional balance, tendency to nervous breakdowns, nervousness, irritation, lack of selfassertiveness in contact with others, and proneness to crying. At school, science is preferred (because information received by the right car passes more rapidly to the left hemisphere which is more responsible for rational thinking). Problems with Polish may be attributed to inability to perceive a problem as a whole and to discern aesthetic and emotional aspects of things. In certain cases, the perception of music can also be a problem .
REFERENCES 1.
KIMURA D., Cérébral dorninance and thé perception of verbal stimuli. ,,Canadian Journal of Psychology", 15, s.166-171, 1961.
2.
KING F.L., KIMURA D., Left-ear superiority in dichotic perception of vocal nonverbal sounds. ,,Canadian Journal of Psychology, 26, s.111-116, 1972. SOBOTKA S., GRODZICKAJ., Hemispheric diference in evoked potentialis to faces and words, ,,Acta Neurobiologiae Experimentalis". 49, 265-280,1989. TOMATIS A., L'oreille et le langage, Paris, Editions du Seuil, 1978.
3.
4.
4th European Congress of Oto-Rhino-Laryngology, Head and Neck Surgery, Berlin, Germany, May 13-18, 2000
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