Perceptual and Motor Skills, 1976,42, 747-750.
Perceptual and Motor Skills 1976
COMPARISON OF DEAF AND HEARING CHILDREN ON BODY-OBJECT LOCALIZATION1 STEPHANIE SCHMIDT PETER E. COMALLI, JR. Temple University Temple University MORTON W. ALTSHULER Veterans Administration Outpatient Clinic Summary.-20 profoundly deaf and 20 normal hearing children from ages 1 0 to 1 3 were compared as to their ability to locate visually the position of apparent vertical and the apparent location o f the longitudinal axis of the body under erect and 30" left and right body-tilt. Both deaf and normal hearing children were able accurately to locate a rod to the apparent visual vertical, but deaf children were significantly more accurate in aligning a rod to their apparent body-position than hearing children. This finding is discussed from both a learning view and from a hypothesis of developmental lag.
The present study represents a preliminary investigation of the effect of profound hearing loss on the development of body -object space localization. The specific localization task chosen was the visual perception of verticality and of body-position under conditions of body-tilt. In a developmental smdy with children ranging from 7 to 17 yr. of age, Wapner (1968) found that with an increase in age the position of apparent vertical shifts from the side of body-tilt to the side-opposite tilt, while the apparent location of the body showed an increasing deviation beyond true body-tilt with advance in age. It was expected that in such a task comparison of deaf and hearing children would permit some assessment of the role of hearing-loss in spatial organization.
METHOD T w o groups of subjects, 2 0 deaf and 20 normal hearing children, were selected. The deaf subjects were students at the Pennsylvania School for the Deaf, Philadelphia, Pa. and were chosen o n the following criteria: ( 1 ) their age ranged from 1 0 to 1 3 yr., ( 2 ) each had been tested by a standard test of intelligence and scored within the normal range. ( 3 ) diagnosis of sensori-neural deafness had been established by an audiologist, ( 4 ) a bilateral hearing loss of 9 0 d B or greater had been present since birth, and ( 5 ) n o evidence of a deviation from the normal range in the musculo-skeletal system. The hearing subjects attended the Holy Child School, Philadelphia. Pa. and were selected on the same criteria as the deaf children except that their hearing was in the normal range ( 1 5 dB H L o r better). In each group were 1 0 males and 1 0 females. A luminous rod, 3 0 in. long and 1% in. wide, part of an apparatus, Model V-1260 M-3DA from Polymetric Co., could be tilted laterally to any degree by remote control, either by the experimenter or by the subject. The rod moved at a constant speed of 1/2 rpm, in either a clockwise or counterclockwise direction, and built-in brakes assured instantaneous stopping. Subjects sat in a specially constructed chair positioned 8 ft. from 'This research was supported in part by Veterans Administration Institutional Research Funds, Veterans Administration Outpatient Clinic, Philadelphia, Pennsylvania.
P. E. COMALLI, JR., ET AL.
748
the rod. The child was held firmly in place by an adjustable head rest, foot rest, and seat belts. Each subject carried out two tasks in a completely darkened room: ( 1 ) Apparent Vertical-the adjustment of a luminous rod in a dark room to a position that appears vertical, i.e., plumbline; and ( 2 ) Apparent Body-Position-the adjustment of a luminous rod to a position that appears parallel to the longirudinal axis of the subject's own body, i.e., lined u p with the body. Each task was carried out under three conditions of bodyposition: erect body-position, 30" left body-tilt, and 30" right body-tilt. For each bodyposition, two starting positions of the rod (initial placement of the rod at the beginning of a trial) were employed: 30" clockwise position and 30" counterclockwise position. For the verticality task, the reference location for starting position was plumbline vertical; for the body-axis task, the reference location was the true position of the bodyaxis. The six conditions for each of the two tasks were presented in a counterbalanced design. Special care was taken to ensure that all subjects understood the nature of both tasks. Deaf subjects were instructed in the tasks via gesture and lip reading by one of their school instructors and by the experimenter. Before each trial, the experimenter placed the luminous rod in its proper starting position with the rod not illuminated. As soon as the rod was illuminated, each subject was permitted to adjust the rod himself by remote control and was allowed to make fine adjustments in either direction until he was satisfied that the rod appeared vertical o r lined u p with his body. Measurements were read to the nearest degree from the experimenter's control console. Each subject received two trials under each of the six test conditions for both apparent vertical and apparent body-axis tasks. The location of apparent vertical was measured with respect to objective-vertical in and counterdegrees with clockwise ( C W ) deviations, as viewed by S, designated by clockwise ( C C W ) deviations designated by - ; the location of apparent body-axis was measured with respect to objective body-axis position, with deviations of apparent bodyand deviations C C W designated position C W of true body-position designated by
+
+
RESULTS The two trials for each condition were averaged and served as the measure for analysis. The two tasks were treated separately by analysis of variance in an independent groups (deaf vs hearing, subdivided by sex), repeated measurements factorially treated ( 3 body-positions in combination with 2 starting positions) design. Table I presents the means and standard deviations for the deaf and hearing TABLE 1 MEANSAND STANDARD DEVIATIONS(DEGREESPROM PLUMBLINE) FOR DEAF AND HEARING CHILDRENIN ADJUSTINGA ROD TO VERTICALITY UNDERBODY-TILT CONDITIONS Group Body-tilt 30"Left Erect 30" Right Deaf Hearing
M SD
M SD
-0.8 1.4 -1.1 1.G
-0.1
.9 -0.2
.8
+O.G 1.7 -0.G
2.6
BODY-OBJECT LOCALIZATION BY DEAF CHILDREN
749
children when the task is to align a visual rod to plumbline position. Analysis of variance does not show significant differences between the deaf and hearing children in regard to locating the plumbline vertical (Group X Body Tilt: F = 1.24, df = 2/72, p > .05). As can be seen from the means, both normal hearing and deaf children can accurately locate plumbline vertical within 1.2' under conditions of body-tilt and reduced visual cues. Table 2 presents the means and standard deviations when the visual rod was used a an indicator of how the body was oriented. In this task, a statistically significant interaction between groups and body-tilt was found ( F = 12.35, d f = 2/72, p < .001). As can be seen from Table 2, deaf subjects were more accurate in aligning the rod to their apparent body-position than hearing subjects, deviating only -0.6' and +4.2' under 30' left and 30' right tilt as compared with -11.8' and +ll.9' for hearing children. The main effect of body-tilt also was significant ( F = 28.31, df = 2/72, p < .001), indicating that for the groups combined, the location of the apparent body-axis is in the direction beyond the body-tilt. This is in agreement with previous findings for normal children in this age range (Wapner, 1968). In both the apparent vertical and the apparent body-axis task, neither sex nor starting position significantly differentiated between the hearing and deaf children.
*
TABLE 2 MEANS AND STANDARD DEVIATIONS (DEGREES FROMBODY-AXIS)FOR DEAF AND HEARING CHILDREN IN ALIGNING VISUAL ROD TO BODY-POSITION UNDERCONDITIONSOF BODY-TILT -
Group
30" Left Deaf
M SD
Hearing
M SD
-0.6 8.4 -11.8 8.8
Body-tilt Erect
30" Righr
-0.4 1.0 -0.3 1.2
+4.2 7.1 +11.7 8.8
In the present study, deaf children were significantly more accurate in their ability visually to align a rod to their own body-axis than were normal hearing children of the same age. On the other hand, when aligning the rod to physical vertical, no difference in accuracy was found. Thus, the results of this study lend only partial support to the notion that prolonged auditory deprivation affects body-object space localization. Such partial confirmation of differences between deaf and hearing subjects appears consistent with findings from other areas of perception and behavior (Furth, 1961, 1971; Suchman, 1966; Binnie, et al., 1966). That a supersense is developed when one has lost a major sense is of course merely an old adage. However, the probability that the deaf or blind learn to use their remaining senses more efficiently is well substantiated (Myklebust,
750
P. E. COMALLI, JR., ET AL.
1964). The finding in this study that deaf children are more accurate in body localization tends to support this notion by suggesting that the deaf have learned to pay greater attention to the tactual-kinesthetic senses relative to monitoring their body-in-space perception. However, the alternative view that a sensory loss could result primarily in a developmental lag or retardation is also tenable since the finding of greater accuracy is in a direction consistent with developmentally younger ages ( Wapner, 1968). Although the findings here are only suggestive, it would prove interesting to extend this study not only with younger but also older ages since a learning hypothesis would predict a continuing trend toward accuracy, while a develop mental hypothesis would predict a trend away from accuracy for both apparent vertical and apparent body-position. REFERENCES BrNNlE, C., ELKIND, D., & STEWART. J. A comparison of the visual perceptual ability of acoustically impaired and hearing children. International Audiology, 1966, 5. 238-241. FURTH,H.G . Effect of training on the adaptation level of the size weight illusion with normal, deaf, and blind subjects. Perceptual md Motor Skills, 1961, 13, 155-160. FURTH, H.G. Linguistic deficiency and thinking: research with deaf subjects, 1964-1969. Psychological Bulletin, 1971, 76, 58-72. SUCHMAN, R. G. Color-form reference, discriminative accuracy and learning of deaf and hearing children. ~ l i l dDevelopment, 1966. 37, 439-452. WAPNER, S. Age changes in perception of verticality and of the longitudinal body axis under M y tilt. Joiw~aulo f Experimental Child Psychology, 1968, 6, 543-555. Accepted February 3, 1976.
Perceptual and Motor Skills 1976
COMPARISON OF DEAF AND HEARING CHILDREN ON BODY-OBJECT LOCALIZATION1 STEPHANIE SCHMIDT PETER E. COMALLI, JR. Temple University Temple University MORTON W. ALTSHULER Veterans Administration Outpatient Clinic Summary.-20 profoundly deaf and 20 normal hearing children from ages 1 0 to 1 3 were compared as to their ability to locate visually the position of apparent vertical and the apparent location o f the longitudinal axis of the body under erect and 30" left and right body-tilt. Both deaf and normal hearing children were able accurately to locate a rod to the apparent visual vertical, but deaf children were significantly more accurate in aligning a rod to their apparent body-position than hearing children. This finding is discussed from both a learning view and from a hypothesis of developmental lag.
The present study represents a preliminary investigation of the effect of profound hearing loss on the development of body -object space localization. The specific localization task chosen was the visual perception of verticality and of body-position under conditions of body-tilt. In a developmental smdy with children ranging from 7 to 17 yr. of age, Wapner (1968) found that with an increase in age the position of apparent vertical shifts from the side of body-tilt to the side-opposite tilt, while the apparent location of the body showed an increasing deviation beyond true body-tilt with advance in age. It was expected that in such a task comparison of deaf and hearing children would permit some assessment of the role of hearing-loss in spatial organization.
METHOD T w o groups of subjects, 2 0 deaf and 20 normal hearing children, were selected. The deaf subjects were students at the Pennsylvania School for the Deaf, Philadelphia, Pa. and were chosen o n the following criteria: ( 1 ) their age ranged from 1 0 to 1 3 yr., ( 2 ) each had been tested by a standard test of intelligence and scored within the normal range. ( 3 ) diagnosis of sensori-neural deafness had been established by an audiologist, ( 4 ) a bilateral hearing loss of 9 0 d B or greater had been present since birth, and ( 5 ) n o evidence of a deviation from the normal range in the musculo-skeletal system. The hearing subjects attended the Holy Child School, Philadelphia. Pa. and were selected on the same criteria as the deaf children except that their hearing was in the normal range ( 1 5 dB H L o r better). In each group were 1 0 males and 1 0 females. A luminous rod, 3 0 in. long and 1% in. wide, part of an apparatus, Model V-1260 M-3DA from Polymetric Co., could be tilted laterally to any degree by remote control, either by the experimenter or by the subject. The rod moved at a constant speed of 1/2 rpm, in either a clockwise or counterclockwise direction, and built-in brakes assured instantaneous stopping. Subjects sat in a specially constructed chair positioned 8 ft. from 'This research was supported in part by Veterans Administration Institutional Research Funds, Veterans Administration Outpatient Clinic, Philadelphia, Pennsylvania.
P. E. COMALLI, JR., ET AL.
748
the rod. The child was held firmly in place by an adjustable head rest, foot rest, and seat belts. Each subject carried out two tasks in a completely darkened room: ( 1 ) Apparent Vertical-the adjustment of a luminous rod in a dark room to a position that appears vertical, i.e., plumbline; and ( 2 ) Apparent Body-Position-the adjustment of a luminous rod to a position that appears parallel to the longirudinal axis of the subject's own body, i.e., lined u p with the body. Each task was carried out under three conditions of bodyposition: erect body-position, 30" left body-tilt, and 30" right body-tilt. For each bodyposition, two starting positions of the rod (initial placement of the rod at the beginning of a trial) were employed: 30" clockwise position and 30" counterclockwise position. For the verticality task, the reference location for starting position was plumbline vertical; for the body-axis task, the reference location was the true position of the bodyaxis. The six conditions for each of the two tasks were presented in a counterbalanced design. Special care was taken to ensure that all subjects understood the nature of both tasks. Deaf subjects were instructed in the tasks via gesture and lip reading by one of their school instructors and by the experimenter. Before each trial, the experimenter placed the luminous rod in its proper starting position with the rod not illuminated. As soon as the rod was illuminated, each subject was permitted to adjust the rod himself by remote control and was allowed to make fine adjustments in either direction until he was satisfied that the rod appeared vertical o r lined u p with his body. Measurements were read to the nearest degree from the experimenter's control console. Each subject received two trials under each of the six test conditions for both apparent vertical and apparent body-axis tasks. The location of apparent vertical was measured with respect to objective-vertical in and counterdegrees with clockwise ( C W ) deviations, as viewed by S, designated by clockwise ( C C W ) deviations designated by - ; the location of apparent body-axis was measured with respect to objective body-axis position, with deviations of apparent bodyand deviations C C W designated position C W of true body-position designated by
+
+
RESULTS The two trials for each condition were averaged and served as the measure for analysis. The two tasks were treated separately by analysis of variance in an independent groups (deaf vs hearing, subdivided by sex), repeated measurements factorially treated ( 3 body-positions in combination with 2 starting positions) design. Table I presents the means and standard deviations for the deaf and hearing TABLE 1 MEANSAND STANDARD DEVIATIONS(DEGREESPROM PLUMBLINE) FOR DEAF AND HEARING CHILDRENIN ADJUSTINGA ROD TO VERTICALITY UNDERBODY-TILT CONDITIONS Group Body-tilt 30"Left Erect 30" Right Deaf Hearing
M SD
M SD
-0.8 1.4 -1.1 1.G
-0.1
.9 -0.2
.8
+O.G 1.7 -0.G
2.6
BODY-OBJECT LOCALIZATION BY DEAF CHILDREN
749
children when the task is to align a visual rod to plumbline position. Analysis of variance does not show significant differences between the deaf and hearing children in regard to locating the plumbline vertical (Group X Body Tilt: F = 1.24, df = 2/72, p > .05). As can be seen from the means, both normal hearing and deaf children can accurately locate plumbline vertical within 1.2' under conditions of body-tilt and reduced visual cues. Table 2 presents the means and standard deviations when the visual rod was used a an indicator of how the body was oriented. In this task, a statistically significant interaction between groups and body-tilt was found ( F = 12.35, d f = 2/72, p < .001). As can be seen from Table 2, deaf subjects were more accurate in aligning the rod to their apparent body-position than hearing subjects, deviating only -0.6' and +4.2' under 30' left and 30' right tilt as compared with -11.8' and +ll.9' for hearing children. The main effect of body-tilt also was significant ( F = 28.31, df = 2/72, p < .001), indicating that for the groups combined, the location of the apparent body-axis is in the direction beyond the body-tilt. This is in agreement with previous findings for normal children in this age range (Wapner, 1968). In both the apparent vertical and the apparent body-axis task, neither sex nor starting position significantly differentiated between the hearing and deaf children.
*
TABLE 2 MEANS AND STANDARD DEVIATIONS (DEGREES FROMBODY-AXIS)FOR DEAF AND HEARING CHILDREN IN ALIGNING VISUAL ROD TO BODY-POSITION UNDERCONDITIONSOF BODY-TILT -
Group
30" Left Deaf
M SD
Hearing
M SD
-0.6 8.4 -11.8 8.8
Body-tilt Erect
30" Righr
-0.4 1.0 -0.3 1.2
+4.2 7.1 +11.7 8.8
In the present study, deaf children were significantly more accurate in their ability visually to align a rod to their own body-axis than were normal hearing children of the same age. On the other hand, when aligning the rod to physical vertical, no difference in accuracy was found. Thus, the results of this study lend only partial support to the notion that prolonged auditory deprivation affects body-object space localization. Such partial confirmation of differences between deaf and hearing subjects appears consistent with findings from other areas of perception and behavior (Furth, 1961, 1971; Suchman, 1966; Binnie, et al., 1966). That a supersense is developed when one has lost a major sense is of course merely an old adage. However, the probability that the deaf or blind learn to use their remaining senses more efficiently is well substantiated (Myklebust,
750
P. E. COMALLI, JR., ET AL.
1964). The finding in this study that deaf children are more accurate in body localization tends to support this notion by suggesting that the deaf have learned to pay greater attention to the tactual-kinesthetic senses relative to monitoring their body-in-space perception. However, the alternative view that a sensory loss could result primarily in a developmental lag or retardation is also tenable since the finding of greater accuracy is in a direction consistent with developmentally younger ages ( Wapner, 1968). Although the findings here are only suggestive, it would prove interesting to extend this study not only with younger but also older ages since a learning hypothesis would predict a continuing trend toward accuracy, while a develop mental hypothesis would predict a trend away from accuracy for both apparent vertical and apparent body-position. REFERENCES BrNNlE, C., ELKIND, D., & STEWART. J. A comparison of the visual perceptual ability of acoustically impaired and hearing children. International Audiology, 1966, 5. 238-241. FURTH,H.G . Effect of training on the adaptation level of the size weight illusion with normal, deaf, and blind subjects. Perceptual md Motor Skills, 1961, 13, 155-160. FURTH, H.G. Linguistic deficiency and thinking: research with deaf subjects, 1964-1969. Psychological Bulletin, 1971, 76, 58-72. SUCHMAN, R. G. Color-form reference, discriminative accuracy and learning of deaf and hearing children. ~ l i l dDevelopment, 1966. 37, 439-452. WAPNER, S. Age changes in perception of verticality and of the longitudinal body axis under M y tilt. Joiw~aulo f Experimental Child Psychology, 1968, 6, 543-555. Accepted February 3, 1976.
