Percept& and Motor Skills, 1977,45, 1028-1030. @ Perceptual and Motor Skills 1977
DECLINE I N ORAL PERCEPTION FROM 20 TO 70 YEARS ROBERT CANETTA V e t e r m s Administratiom Hospital Danville, Illinois Summary.-120 adults were given a task to determine whether performance on an oral perception task declines with increasing chronological age. Subjects in their 70's performed significantly worse than those in their 60's and younger. This loss of oral perceptual skills is considered relevant to the remediation and training of older individuals with difficulties in speech articulation.
Speech articulation is difficult to maintain, much less acquire, by the individual with reduced or inefficient kinesthetic feedback from the vocal tract. This has been observed in children as young as two years, where oral anesthesia was experimentally induced (Daniloff, Bishop, Ringel, 1977), in a teenager with "highly deficient somesthetic perception" (Rootes & MacNeilage, 1967), and in the adults deprived of full orosensory feedback in various laboratory tests (McCroskey, 1958; Ringel & Steer, 1963; Garnon, Smith, Daniloff, & Kim, 1971). If phonetic precision is facilitated by accurate kinesthetic feedback as servomodels insist (Fairbanks, 1954; Mysak, 1966), it is reasonable to suppose thatshort of nerve-block injections-individuals' variations in kinesthetic sensibility also might be important. They are. Several investigations have found that oral perception declines steadily with capability from a normally speaking population to those with mildly, moderately and severely disordered articulation. This is true both of children and adults (Ringel, Burk, & Scott, 1968; Ringel, House, Burk, Dolinsky, & Scott, 1970). Many of the adults with problems of articulation, the apraxic and dysarthric speakers, have significant oral-sensory deficits (Scott & Ringel, 1971; Rosenbek & Wertz, 1973). Since the course of recovery for these patients frequently is not smooth, impaired oral perception is on logical grounds one of several potentially interfering processes. However, many such patients are elderly, the victims of neurological stroke. Since many sensory capabilities are observed to decline with age, the study reported below sought to determine whether oral perception deteriorates also. If so, it was reasoned, disturbed or reduced kinesthetic feedback might be a significant source of interference in speech remediation.
METHOD Sabjects Subjects were 120 adults, with 10 males and 10 females at each decade from the 20's to the 70's. All had normal speech, oral structures, oral-motor
DECLINING ORAL PERCEPTION OVER YEARS
1029
function, superficial lingual sensation, and manual stereognosis in preliminary screening procedures. No subject reported any history of neurological disturbance. Oral perceptual stimuli were 20 plastic geometric forms, each with an approximate breadth of one-half to three-quarters of an inch and each mounted on 3-in. handle. The forms were those recommended by the National Institute of Dental Research,l described in greater detail elsewhere (Shelton, Arndt, & Hetherington, 1967) . Procedzcre
Subjects first were shown two visual displays containing actual-size contours of the vaious stimulus shapes. The experimenter pointed to the 20 forms individually and each subject was required to find the duplicate in a differently randomized second display. Since all subjects were able to do this without error, each was then presented the oral perception task. Subjects were told that a form would be placed on their tongue-tip and that they were to explore freely the shape of the form with the tip of the tongue. The forms were concealed from the subject's view at all times. There was no time limit placed on the subject's oral exploration, and the subject was able to feel the form while simultaneously examining the 20 choices on the display, which he held at a comfortable viewing distance. When the subject had reached a decision, he merely called out the number below the appropriate pattern. Each form was presented once so the maximum score was 20. RESULTSAND DISCUSSION The mean numbers of correct identifications, of 20 possible, at each decade were 13.7, a = 2.3 (20's); 12.9, u = 2.2 (30's); 13.5, a = 2.9 (40's); 11.7, a = 3.1 (50's); 11.4, a = 2.9 (GO'S), and 7.9, u = 1.9 (70's). There was then a gradual decline up to age 60 and a marked reduction in performance thereafter. Since males did not differ significantly from females (F < 1.00), their data were combined in the formal analysis of age differences. Following = 12.85, p < .01), Keul follow-up tests a significant over-all result (F5,114 (Snidecor, 1956, p. 253) showed a significant decrement between each of the younger age groups (2OYs,30's, 401s, 50's, 60's) and the subjects in their 70's (all ps < .05), but no significant difference between any two age groups between the 20's and GO'S. Consequently there was no appreciable decline in oral perception, as assessed and analyzed here, until the subjects reached their 70's. Since subjects in their 60's did not deviate significantly from the perfor'Our forms were made available by the Wilks Precision Instrument Company, 5706 Frederick Avenue, Rockville, Maryland.
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mance level of normal young adults (those in their 20's), there appears to be no reason for unusual concern with kinesthetic feedback as a source of articulatory difficulty in these age groups. However, a large proportion of the routine clinical caseload in hospitals is constituted of individuals in their 70's, many of them evidencing difficulty in recovering or learning articulatory postures. Since that process is facilitated by efficient kinesthetic feedback, a monitoring system observed to fail in the geriatric population studied here, it is suggested that clinicians consider the assessment of oral perception as a potential diagnostic procedure. REFERENCES DANILOFF,R., BISHOP, M., & RINGEL,R. Alteration of children's articulation by application of oral anesthesia. Journal of Phonetics, 1977, 5, 285-298. FAIRBANKS, G. Systematic research in experimental phonetics: I. A theory of the speech mechanism as a servo system. Journal of Speech and Hearing Disorders, 1954, 19, 133-139. GAMMON,S. A., SMITH,P., DANILOFF,R. G., & KIM, C. Articulation and stress/juncture production under oral anesthetization and masking. Journal of Speech and Hearing Research, 1971, 14, 271-282. MCCROSKEY,R. The relative contributions of auditory and tactile cues to certain aspects of speech. Southern Speech Journal, 1958, 24, 84-90. MYSAK,E. D. Speech pathology Mzd feedback theory. Springfield, Ill.: Thomas, 1966. RINGEL,R. L., BURK,K. W., & SCOIT, C. M. Tactile perception: form discrimination i n the mouth. Brkish Journal of Disorders of Communication, 1968, 3, 150-155. RINGEL,R. L., HOUSE,A. S., BURK, K. W., DOLINSKY,S. P., & SCOTT, C. M. Some relations between oral sensory discrimination and articulatory aspects of speech production. Journal of Speech and Hea~ingDisorders, 1970, 35, 3-11. RINGEL,R. L., & STEER,M. D. Some effects of tactile and auditory alterations on speech output. Jownal of Speech and Hearing Research, 1963, 6, 369-378. ROOTES,T. P., & MACNEILAGE,P. F. Some speech perception and production tests of a patient with impairment in somesthetic perception and motor function. In J. F. Bosma (Ed. ) , Symposium on oral sensation and perception. Springfield, Ill. : Thomas, 1967. Pp. 310-317. ROSENBEK,J. C., & WERTZ, R. T. Oral sensation and perception in apraxia of speech and aphasia. JournaZ of Sfieech and Hearing Research, 1973, 16, 22-36. SCOTT, C. M., & RINGEL,R. L. The effects of motor and sensory disruption on speech: a description of articulation. Journal of Speech and Hearing Research, 1971, 14, 819-828. SHELTON,R. L., ARM, W. B., & HETHERINGTON, J. J. Testing oral stereognosis. In J. F. Bosma (Ed.), Symposium on oral sensatiolz and perception. Springfield, Ill.: Thomas, 1967. Pp. 221-243. J. W. Statistical methods. Iowa City, Ia.: Iowa State Univer. Press, 1956. SNIDECOR, Accepted October 20, 1977.
DECLINE I N ORAL PERCEPTION FROM 20 TO 70 YEARS ROBERT CANETTA V e t e r m s Administratiom Hospital Danville, Illinois Summary.-120 adults were given a task to determine whether performance on an oral perception task declines with increasing chronological age. Subjects in their 70's performed significantly worse than those in their 60's and younger. This loss of oral perceptual skills is considered relevant to the remediation and training of older individuals with difficulties in speech articulation.
Speech articulation is difficult to maintain, much less acquire, by the individual with reduced or inefficient kinesthetic feedback from the vocal tract. This has been observed in children as young as two years, where oral anesthesia was experimentally induced (Daniloff, Bishop, Ringel, 1977), in a teenager with "highly deficient somesthetic perception" (Rootes & MacNeilage, 1967), and in the adults deprived of full orosensory feedback in various laboratory tests (McCroskey, 1958; Ringel & Steer, 1963; Garnon, Smith, Daniloff, & Kim, 1971). If phonetic precision is facilitated by accurate kinesthetic feedback as servomodels insist (Fairbanks, 1954; Mysak, 1966), it is reasonable to suppose thatshort of nerve-block injections-individuals' variations in kinesthetic sensibility also might be important. They are. Several investigations have found that oral perception declines steadily with capability from a normally speaking population to those with mildly, moderately and severely disordered articulation. This is true both of children and adults (Ringel, Burk, & Scott, 1968; Ringel, House, Burk, Dolinsky, & Scott, 1970). Many of the adults with problems of articulation, the apraxic and dysarthric speakers, have significant oral-sensory deficits (Scott & Ringel, 1971; Rosenbek & Wertz, 1973). Since the course of recovery for these patients frequently is not smooth, impaired oral perception is on logical grounds one of several potentially interfering processes. However, many such patients are elderly, the victims of neurological stroke. Since many sensory capabilities are observed to decline with age, the study reported below sought to determine whether oral perception deteriorates also. If so, it was reasoned, disturbed or reduced kinesthetic feedback might be a significant source of interference in speech remediation.
METHOD Sabjects Subjects were 120 adults, with 10 males and 10 females at each decade from the 20's to the 70's. All had normal speech, oral structures, oral-motor
DECLINING ORAL PERCEPTION OVER YEARS
1029
function, superficial lingual sensation, and manual stereognosis in preliminary screening procedures. No subject reported any history of neurological disturbance. Oral perceptual stimuli were 20 plastic geometric forms, each with an approximate breadth of one-half to three-quarters of an inch and each mounted on 3-in. handle. The forms were those recommended by the National Institute of Dental Research,l described in greater detail elsewhere (Shelton, Arndt, & Hetherington, 1967) . Procedzcre
Subjects first were shown two visual displays containing actual-size contours of the vaious stimulus shapes. The experimenter pointed to the 20 forms individually and each subject was required to find the duplicate in a differently randomized second display. Since all subjects were able to do this without error, each was then presented the oral perception task. Subjects were told that a form would be placed on their tongue-tip and that they were to explore freely the shape of the form with the tip of the tongue. The forms were concealed from the subject's view at all times. There was no time limit placed on the subject's oral exploration, and the subject was able to feel the form while simultaneously examining the 20 choices on the display, which he held at a comfortable viewing distance. When the subject had reached a decision, he merely called out the number below the appropriate pattern. Each form was presented once so the maximum score was 20. RESULTSAND DISCUSSION The mean numbers of correct identifications, of 20 possible, at each decade were 13.7, a = 2.3 (20's); 12.9, u = 2.2 (30's); 13.5, a = 2.9 (40's); 11.7, a = 3.1 (50's); 11.4, a = 2.9 (GO'S), and 7.9, u = 1.9 (70's). There was then a gradual decline up to age 60 and a marked reduction in performance thereafter. Since males did not differ significantly from females (F < 1.00), their data were combined in the formal analysis of age differences. Following = 12.85, p < .01), Keul follow-up tests a significant over-all result (F5,114 (Snidecor, 1956, p. 253) showed a significant decrement between each of the younger age groups (2OYs,30's, 401s, 50's, 60's) and the subjects in their 70's (all ps < .05), but no significant difference between any two age groups between the 20's and GO'S. Consequently there was no appreciable decline in oral perception, as assessed and analyzed here, until the subjects reached their 70's. Since subjects in their 60's did not deviate significantly from the perfor'Our forms were made available by the Wilks Precision Instrument Company, 5706 Frederick Avenue, Rockville, Maryland.
1030
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mance level of normal young adults (those in their 20's), there appears to be no reason for unusual concern with kinesthetic feedback as a source of articulatory difficulty in these age groups. However, a large proportion of the routine clinical caseload in hospitals is constituted of individuals in their 70's, many of them evidencing difficulty in recovering or learning articulatory postures. Since that process is facilitated by efficient kinesthetic feedback, a monitoring system observed to fail in the geriatric population studied here, it is suggested that clinicians consider the assessment of oral perception as a potential diagnostic procedure. REFERENCES DANILOFF,R., BISHOP, M., & RINGEL,R. Alteration of children's articulation by application of oral anesthesia. Journal of Phonetics, 1977, 5, 285-298. FAIRBANKS, G. Systematic research in experimental phonetics: I. A theory of the speech mechanism as a servo system. Journal of Speech and Hearing Disorders, 1954, 19, 133-139. GAMMON,S. A., SMITH,P., DANILOFF,R. G., & KIM, C. Articulation and stress/juncture production under oral anesthetization and masking. Journal of Speech and Hearing Research, 1971, 14, 271-282. MCCROSKEY,R. The relative contributions of auditory and tactile cues to certain aspects of speech. Southern Speech Journal, 1958, 24, 84-90. MYSAK,E. D. Speech pathology Mzd feedback theory. Springfield, Ill.: Thomas, 1966. RINGEL,R. L., BURK,K. W., & SCOIT, C. M. Tactile perception: form discrimination i n the mouth. Brkish Journal of Disorders of Communication, 1968, 3, 150-155. RINGEL,R. L., HOUSE,A. S., BURK, K. W., DOLINSKY,S. P., & SCOTT, C. M. Some relations between oral sensory discrimination and articulatory aspects of speech production. Journal of Speech and Hea~ingDisorders, 1970, 35, 3-11. RINGEL,R. L., & STEER,M. D. Some effects of tactile and auditory alterations on speech output. Jownal of Speech and Hearing Research, 1963, 6, 369-378. ROOTES,T. P., & MACNEILAGE,P. F. Some speech perception and production tests of a patient with impairment in somesthetic perception and motor function. In J. F. Bosma (Ed. ) , Symposium on oral sensation and perception. Springfield, Ill. : Thomas, 1967. Pp. 310-317. ROSENBEK,J. C., & WERTZ, R. T. Oral sensation and perception in apraxia of speech and aphasia. JournaZ of Sfieech and Hearing Research, 1973, 16, 22-36. SCOTT, C. M., & RINGEL,R. L. The effects of motor and sensory disruption on speech: a description of articulation. Journal of Speech and Hearing Research, 1971, 14, 819-828. SHELTON,R. L., ARM, W. B., & HETHERINGTON, J. J. Testing oral stereognosis. In J. F. Bosma (Ed.), Symposium on oral sensatiolz and perception. Springfield, Ill.: Thomas, 1967. Pp. 221-243. J. W. Statistical methods. Iowa City, Ia.: Iowa State Univer. Press, 1956. SNIDECOR, Accepted October 20, 1977.
