Journal of Abnormal Child Psychology, Vol. 20, No. 6, 1992
Social Stimulation and Joint Attention in Young Autistic Children A r t h u r L. Lewy 1,3 and G e r a l d i n e D a w s o n 2
Manusc~pt received in final form June 2, 1992. The present study was designed to examine the effects of social stimulation on the joint attention behavior of 20 autistic children under 6 years of age, 20 receptive language-matched Down syndrome children, and 20 receptive language matched-normally-developing infants. Children's social and non-social engagement states were measured during two experimental play sessions and during free play with parent. For all groups, joint attention was increased when adult play behavior closely followed and was contingent on the behavior of the children; however, the autistic children were significantly less responsive to the experimental manipulation than control subjects. In contrast, the autistic children were no less responsive in terms of other forms of social engagement. Results are interpreted as supporting a model of joint attention deficits in autism that involves factors inherent to the disorder in transaction with social context.
Coordination of attention between object and person is an important developmental accomplishment during the second year of life and periods of coordination appear to be important forums for language and emotional development (Adamson & Bakeman, 1985; Bakeman & Adamson, 1986). Parents' play behaviors appear to facilitate the emergence of joint attention (Bruner, 1982). Bakeman and Adamson (1984) demonstrated that joint attention was enhanced by the activity of a more capable social partner (mother) while it was relatively rare when infants were engaged with a less capable social partner (peers). 1Department of Psychologyand CivitanInternationalResearch Center, Universityof Alabama at Birmingham,Birmingham,Alabama. 2Department of Psychology,Universityof Washington. 3Address all correspondence to Arthur L. Lewy,P.O. Box 313, UAB Station, Birmingham, Alabama 35294. 555 00914)627/92/1200~)555506.50/0 9 1992 Plenum Publishing Corporation
556
Lewy and Dawson
Several studies of young autistic children provide compelling documentation of a deficit in joint attention in autistic children that cannot be accounted for by general developmental delay (e.g., Loveland & Landry, 1986; Mundy, Sigman, Ungerer, & Sherman, 1986; Wetherby & Prutting, 1984). Most interpretations of this research posit that this deficit is due to fundamental and inherent impairments in affective or cognitive understanding of others (e.g., Hobson, 1989; Leslie & Happe, 1989). The effects of social context and the special scaffolding needs of autistic children as contributing factors to their joint attention deficit have not been systematically considered. Previous research has shown that social context can influence social responsiveness of autistic children (Dawson & Adams, 1984; Dawson & Galpert, 1990). Specifically, it was found that, by increasing the predictability and contingency of adult responses, there followed increases in eye contact and creative toy play in the children. To examine the role of type of social context in autistic children's joint attention behavior, in the present study, we systematically varied social stimulation and observed children's joint attention and other social and non-social states of engagement. We predicted that there would be a significant deficit in joint attention in autistic children as compared to receptive language matched groups of mentally retarded and normally developing children. Furthermore, we predicted that experimentally changing social stimulation from non-contingent and unpredictable to contingent and predictable would lead to increases in joint attention, and in other forms of social engagement in all groups of children. Levels of joint attention during free play with parent were expected to fall between these extremes because parent behavior likely ranges between the extremes of the highly contingent and the highly non-contingent experimental conditions.
METHOD
Sample Twenty preschool-aged autistic children and receptive languagematched groups of 20 Down syndrome and 20 normal children participated in the study. The Down syndrome group was included to control for effects of general developmental delay without autism. Receptive language ability was measured with the Sequenced Inventory of Communication Development (SICD, Hedrick, Prather, & Tobin, 1984). Receptive language was chosen as a matching variable because it has been found to be reliably
Social Stimulation and Joint Attention
557
correlated with joint attention skill in normal children (Tomassello & Fartar, 1986). Given that language is typically an area of relative weakness for autistic children compared to visual-spatial skill, a receptive language match is likely to result in an autistic-control comparison that minimizes the possibility that group differences merely reflect differences in another skill known to be correlated with joint attention. All autistic children had been previously diagnosed by physicians or psychologists in the community. Diagnosis of autism was further verified by means of ratings on instruments, a behavior checklist based on the diagnostic criteria for autism in the Diagnostic and Statistical Manual of the American Psychiatric Association (DSM IIIR) and by the Childhood Autism Rating Scale (CARS, Schopler, Reichler, & Renner, 1986). Each autistic child was rated by two clinically-trained raters and disagreements in diagnosis were resolved through review of the videotape of the child made during the study. Sample descriptive statistics are shown in Table I. There were no significant group differences in receptive language age (F(2, 57) = .56, NS). There were significant group differences in chronological age (F(2, 57) = 50.03, p < .001). Follow-up t-tests indicated significant differences in chronological age between all groups. Sixteen randomly-chosen children from the study were reassessed with the receptive language portion of the Vineland Scales of Adaptive Behavior-Revised (Sparrow, Tobin, & Cicchetti, 1986), a parent-interview measure. The correlation (Pearson's r) between the SICD and Vineland was .70 (p = .001), suggesting good external validity of the SICD. The mean CARS score for the autistic children was 37.85 (SD = 2.83, minimum = 33.5, maximum = 41.5). These scores place the sample in the moderate to lower-severe range of autism. The correlation between the independent CARS ratings was .72 (p < .001). There was no significant
Table I. Receptive Language and Chronological Ages of Subjects Group
Mean
SD
Minimum
Maximum
SICD receptive language ages (months) Autistic Down syndrome Normal
20.38 22.50 20.80
7.14 5.61 7.17
12 12 12
40 32 40
Chronological ages (months) Autistic Down syndrome Normal
50.00 37.00 17.80
11.46 13.23 5.50
37 20 12
70 68 28
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Lewy and Dawson
correlation between either the CARS and receptive language age or the CARS and chronological age.
Procedure Following language testing, each child participated in a free play (FP) interaction with his or her parent. This occurred in a carpeted playroom which was equipped with toys consisting of a book, ball, telephone, bowl and spoon, rolling toys, rings, bucket and blocks, and a pinwheel. Following free play, two experimental play conditions occurred in counterbalanced order across subjects. In the experimental conditions the child interacted with a single unfamiliar experimenter. All play interactions were videotaped from behind a one-way mirror for later coding. The experimental conditions are described below. Adult-Centered Play (ACP, 7 min). A set of four toys was placed on a table between the child and the experimenter. The experimenter then proceeded to perform familiar but noncontingent schemes with the toys along with simple verbalizations describing these actions. The schemes used by the experimenter were those used by the child during the free play interaction with the parent. The experimenter alternated gaze between the child and the toy that the experimenter was using, and maintained a positive affective facial expression. In order to simulate normal play interactions, one time per minute the experimenter attempted to direct the child's attention to an object that the child was not attending to. This attention-direction lasted for 5 sec. During attention-direction the experimenter held the toy about 12 inches from the child's face, shook it gently and stated "look at the (toy name)." Child-Centered Play (CCP, 7 rain). Two identical sets of four toys, which were functionally similar to the toys used during adult-centered play, were placed between the child and the experimenter. The experimenter proceeded to imitate all of the child's verbalizations, vocalizations, and hand or body movements, and either imitated the child's toy play or engaged in actions that were small elaborations of the child's actions with a toy identical to the one that the child was using. This procedure was used instead of the constant direct imitation used by Dawson and Adams (1984) because many normal children became distressed by constant imitation during pilot testing. The experimenter also used brief verbal statements that described what the child was doing. The experimenter engaged in attention-directing behaviors that attempted to direct the child to the
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Table II. Engagement States Coding Scheme Categories
Unengagement. Child has no clear attentional focus. Onlooking. Child passively watches adult or activity of adult. Object engagement. Child is actively engaged solely with toy (e.g., manipulates toy with sustained visual regard). Person engagement. Child is actively engaged solely with adult (e.g., sustained gaze with laughter). Supported joint engagement (SJE). Child is actively involved with toy that adult manipulates in such a way as to alter child's experience with that object (e.g., child laughs at adult toy demonstration and reaches for toy). Coordinated joint engagement (CJE). Child is actively involved with person and toy (e.g., child holds toy toward adult and manually activates toy with alternating periods of sustained gaze to adult).
toy identical to the one that the child was using. The form, rate, and duration of attention-direction were the same as those used during adultcentered play. The toys used during the experimental conditions consisted of a squeaking toy, telephone, pinwheel, and bucket and block. Different toys were used in each condition. Adult-centered play and child-centered play were designed as dramatic contrasts on the stimulation dimensions of predictability and childcontrol; both, however, involved action schemes that were within the children's developmental capabilities.
Dependent Variable Joint attention and other social behaviors were coded using the Engagement States Coding Scheme (Bakeman & Adamson, 1984). Six mutually exclusive and exhaustive engagement states were coded, as described in Table II. Fifteen minutes of play time, 5 min in each condition, were coded for each child.
Data Coding and Reliability Engagement states were coded by trained undergraduates who were blind to the hypotheses of the study. Twenty percent of all play episodes were re-coded for reliability. Reliability was estimated with Cohen's kappa (Cohen, 1960), a statistic that computes percentage agreement correcting for chance agreement thus yielding a conservative measure of inter-rater
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reliability. Kappa for the engagement states was .78 (84% raw percent agreement).
RESULTS
Group Differences in Engagement States Percentages of time spent in each engagement state by each group during each condition are shown in Table III. Repeated measures group(3) x condition(3) analyses of variance (ANOVAs) revealed significant main effects of group for CJE, object engagement, unengagement, and onlooking (CJE F(2, 57) = 10.15, p < .001; object (F (2, 57) = 9.06, p < .001; unengaged F(2, 57) = 3.45, p = .039; onlooking F(2, 57) = 7.75, p = .001). Planned autistic-control a priori t-tests indicated that these effects were accounted for by the relatively lower levels of CJE and onlooking and relatively higher levels of object engagement and unengagement in the autistic children compared to the combined control group children across all conTable Ill. Engagement States During Each Condition by Group a
Autistic ACP
FP CCP Down syndrome ACP
FP CCP Normal ACP
FP CCP
UN
ON
OB
PE
SJ
CJ
11.9 (12.9) 18.4 (17.9) 9.8 (7.3)
10.2 (11.4) 4.8 (3.6) 4.7 (4.9)
74.7 (19.4) 55.2 (21.9) 52.1 (16.0)
.03 (.00) 3.7 (8.2) 2.7 (4.8)
.8 (1.4) 13.5 (12.1) 19.6 (16.1)
2.2 (6.4) 4.0 (5.3) 10.8 (11.2)
8.3 (7.9) 8.4 (9.0) 5.6 (5.7)
20.6 (14.5) 8.2 (8.2) 6.0 (7.2)
60.3 (13.8) 52.0 (17.3) 23.8 (13.2)
.9 (2.0) 4.4 (4.5) 3.9 (6.6)
2.8 (3.4) 7.4 (7.3) 19.7 (14.3)
7,1 (7,3) 19,5 (18,3) 41.0 (23.3)
8.6 (6.5) 13.1 (9.0) 8,5 (8,2)
20.2 (10.2) 13.5 (9.8) 9.2 (7.0)
64.6 (14.4) 54.1 (17.3) 28.1 (15.1)
.6 (1.4) 1.4 (2.5) 2.2 (3,3)
1.5 (2.2) 6.5 (8.5) 17.2 (16.9)
4.5 (5.3) 11.5 (10.2) 34.7 (24.6)
aAll means are in percents, and SDs are in parentheses. UN-unengaged; ON-onlooking; OB-object engaged; PE-person engaged; SJ-supported joint engagement; CJ-coordinated joint engagement.
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561
ditions (CJE t(58) = 4.16, p < .001; object t(58) = 3.87, p = .001). No significant differences between the two control groups on these or any other engagement state measure were found. Repeated measures A N O V A s also revealed significant group x condition effects for CJE and object engagement (CJE F(4, 114) = 4.74, p = .001; object F(4, 114) = 4.64, p = .002). To examine these interactions, a series of follow-up one-way A N O V A s were conducted. For CJE and object engagement the greatest autistic-control differences emerged during CCP (CJE F(2, 57) = 11.95, p < .001; object F(2, 57) = 20.94, p < .001). Less significant autistic-control differences in CJE were found in the other conditions (p = .01-.04). There were no significant autistic-control differences in object engagement during FP, and the autistic children showed higher levels of object engagement than controls during ACP (p = .02). The repeated measures group(3) x condition(3) A N O V A s for supported joint engagement and person engagement failed to show significant main effects of group or group x condition interactions. Discriminant function analyses showed that measures of CJE over all three conditions correctly classified all but three (85%) of the autistic children and 65% of controls (22 = 22.35, p < .0001). Measures of object engagement correctly classified 75% of the autistic children and 90% of controls (~2 = 34.27, p < .0001). The only other statistically significant predictor of group membership was onlooking which correctly classified 80% of the autistic children and 60% of controls (Z 2 = 12.78, p = .004).
Effects of the Experimental Manipulation on Engagement States Repeated measures group(3) • condition(2) A N O V A s for levels of each engagement state during ACP and CCP showed significant main effects of condition for CJE, SJE, person engagement, object engagement, and onlooking (CJE F(1, 57) = 79.15, p < .001; SJE F(1, 57) -- 80.05, p < .001; person F(1, 57) = 13.63, p = .001; object F(1, 57) = 158.69, p < .001; onlooking F(1, 57) = 42.48, p < .001). Paired t-tests revealed that during CCP each group showed significant increases in CJE (autistic t(19) = 2.33, p < .03; Down syndrome t(19) = 6.51, p < .001; normal t(19) = 5.89, p < .001), and in supported joint engagement. Significant increases in person engagement were found for the autistic children; nonsignificant trends in person engagement were found for the control groups (autistic supported joint t(19) = 5.34, p < .001, person t(19) = 2.60,p = .017; Down syndrome supported joint t(19) = 5.90, p < .001, person t(19) = 2.00, p = .06; normal supported joint t(19) = 4.51, p < .001, person t(19) = 1.88, p = .075). All groups showed significant decreases in object engagement and
Lewy and Dawson
562
% time 80% Autistic
70%
~
Down syndrome
60%
~
Normal
50% 40% 30%
10%~1~ 0% .
.
I~ .
ON-AON-C
.
. _
.
OB-AOB-C
B~
PE-A PE-C
,
..~
SJ-A SJ'C
CJ-A CJ-C
ON-onlooking; OB-object engaged SJ-supported joint; CJ-coordinated joint A-ACP; C-CCP
Fig. 1. Significant effects of experimental manipulation on engagement states.
onlooking during CCP (autistic object t(19) = 4.14, p = .001, onlooking t(19) = 2.49, p = .02; Down syndrome object t(19) = 9.74, p < .001, onlooking t(19) = 3.92, p = .001; normal object t(19) = 9.47, p < .001, onlooking t(19) = 5.15,p < ,001). Figure 1 graphically depicts these significant effects. These repeated measures ANOVAs also revealed significant group x condition interactions for CJE and object engagement (CJE F(2, 57) = 8.53, p = .001; object F(1,57) = 3.84, p = .027). These effects were accounted for by the autistic children showing far less of an increase in CJE and far less of a decrease in object engagement during CCP compared to controls. This was determined through additional analyses of covariance (ANCOVAs) by group on the levels of CJE and object engagement during CCP that controlled for levels of each engagement state shown by the children during FP and ACP, thereby controlling for the autistic children's tendency to generally show lower levels of CJE and higher levels of object engagement. These ANCOVAs still found a significant main effect of group on CJE and object engagement during CCP (CJE F(2, 57) = 7.58, p = .001; object F(2, 57) = 17.59, p < .001). These findings suggest that the
Social Stimulation and Joint Attention
563
autistic children were significantly less responsive than controls to the CCP condition in terms of coordinated joint engagement but were equally responsive for the less mature socially-oriented engagement states, person engagement, and SJE. As can be seen from Table III, levels of CJE, SJE, person engagement, object engagement, and onlooking during FP fell between the extremes seen during ACP and CCP. The combined measure of the two least social engagement states (object engagement and unengagement) during FP also fell between levels seen during ACP and CCP. However, not all ACP-FP and FP-CCP comparisons were significant for all groups.
DISCUSSION These findings replicate previous research in documenting a distinct deficit in joint attention in autistic children. It is notable here that a different measure of joint attention was used than in previous research with autistic children, suggesting that the joint attention deficit extends beyond discrete acts of showing, pointing, etc., to the more organizational-level and socially interactive conceptualization of joint attention as active coordination of attention, used here. Autistic-control differences in joint attention were most marked during the child-centered play condition in which the experimenter's actions were highly contingent upon the child's. The autistic children were more socially unengaged and spent more time directing their attention to objects compared to controls. They also spent less time watching their social partner than controls. All groups responded positively to the child-centered play condition by showing increases in coordinated joint engagement; however, the autistic children were significantly less responsive and showed only a modest increase. All groups also showed increases in the amount of time spent socially engaged with the experimenter and in supported joint engagement in the child-centered condition; the autistic children were no less responsive than controls in terms of these less mature forms of social behavior. These results support the notion that social context can have an important influence on the expression of autistic symptoms, even on a relatively complex skill such as coordinated joint engagement. The autistic children's relative lack of immediate responsiveness to the child-centered manipulation in terms of coordinated joint engagement, however, suggests that this skill, at the age measured here, is only partially responsive to environmental manipulations, however, the effects of a facilitating social context on joint attention when used for a longer period of time have yet to be assessed. The present findings suggest that joint attention deficits in
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Lewy and Dawson
autism may be a function of factors inherent to autism in transaction with social context. At least three possible inherent factors may play a role in autistic children's joint attention deficit. First, periods of joint attention are important forums for sharing of positive affect (Adamson & Bakeman, 1985); it may be that autistic children's deficit in coordinated joint attention reflects impaired capacity for affect sharing, a prerequisite to intersubjectivity (Kasari, Mundy, & Sigman, 1990). A second possible contributor to a deficit in joint attention is difficulty sustaining attention to social stimulation, stimulation which is often unpredictable and novel (Ferrara & Hill, 1980). Dawson and Lewy (1989) have suggested that autistic children's difficulty processing unpredictable stimuli may be related to a deficit in arousal regulation, an idea first offered by Hutt, Hutt, Lee, and Ounstead (1964). Here, the autistic children's preponderance of engagement to entirely predictable stimulation (object engagement) is consistent with this hypothesis. A third possibility is that autistic children are unable to attend simultaneously to, or switch attention between, the two sources of information (person and object) necessary to successfully show coordinated joint engagement. Problems with attention switching in autistic individuals have been noted by Courchesne (Courchesne, Townsend, Akashoomoff, Yeung-Courchesne, Press, & Murakami, in press). Here, that the autistic children were as frequently person-engaged and as frequently involved in supported joint engagement as control children, hut lacking in the engagement state that was a coordinated alternation of the two is consistent with this notion. At this juncture, developmental studies of joint attention are needed. Hopefully, these studies will illuminate the attentional, cognitive, and social prerequisites for this skill and lead the way toward the assessment of early developmental competencies that contribute to joint attention deficits in autism. Finally, this study adds to a growing literature on a promising therapeutic strategy for young autistic children (e.g., Dawson & Adams, 1984; Dawson & Galpert, 1990; Grofer-Klinger & Dawson, 1992). The results of these studies suggest that child-directed intervention may be able to increase levels of social and cognitive skills such as complexity of toy play, turn taking, and symbolic play, in addition to joint attention.
ACKNOWLEDGMENTS This research is based on the doctoral dissertation of the first author. This research was supported by the American Psychological Association, Sigma Xi---The Scientific Research Society, the Washington Association
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for Retarded Citizens Research Trust, and a University of Washington Social Sciences Dissertation Award to the first author. We thank Lauren Adamson, Roger Bakeman, Susan Landry, and Peter Mundy for their helpful comments during the course of this study. Appreciation is extended to the coders. Special appreciation is extended to the parents and children who took part in the study. Portions of this research were presented at the Biennial Meeting of the Society for Research in Child Development, Seattle, March 1991.
REFERENCES Adamson, L., & Bakeman, R. (1985). Affect and attention, infants observed with mothers and peers. Child Development, 56, 582-593. Bakeman, R., & Adamson, L. (1984). Coordinating attention to people and objects in mother-infant and peer-infant interactions. Child Development, 55, 1278-1289. Bakeman, R., & Adamson, L. (1986). Infants' conventionalized acts: Gestures and words with mothers and peers. Infant Behavior and Development, 9, 215-230. Bruner, J. (1982). The organization of action and the nature of adult-infant transaction. In E. Tronick (Ed.), Social interchange in infancy: Affect, cognition, and communication. Baltimore: University Park Press. Cohen, J. (1960). A coefficient of agreement for nominal scales. Education and Psychological Measurement, 20, 37-46. Courchesne, E., Townsend, J., Akashoomoff, N., Yeung-Courchesne, R., Press, G., & Murakami, J. (in press). A new finding in autism: Impairment in shifting attention. In S. Broman & J. Grafman (Eds.), Impairment in shifting attention in autistic and cerebellar patients. Hillsdale, N J: Erlbaum. Dawson, G., & Adams, A. (1984). Imitation and social responsiveness in autistic children. Journal of Abnormal Child Psychology, 12, 209-225. Dawson, G., & Galpert, L. (1990). Mothers' use of imitative play for facilitating social responsiveness in young autistic children. Development and Psychopathology, 2, 151-162. Dawson, G., & Lewy, A. (1989). Arousal, attention, and the socio-emotional impairments of individuals with autism. In G. Dawson (Ed.), Autism: Perspectives on nature, diagnosis, and treatment. New York: Plenum. Ferrara, C., & Hill, S. (1980). The responsiveness of autistic children to the predictability of social and nonsocial toys. Journal of Autism and Developmental Disorders, 10, 51-57. Grofer-Klinger, L., & Dawson, G. (1992). Facilitating social and communicative development in children with autism. In S. Warren & J. Richle (Eds.), Perspectives on communication and language intervention. Baltimore: Brooks. Hedrick, D., Prather, E., & Tobin, A. (1984). Sequenced Inventory of Communication Development-Revised. Seattle: University of Washington Press. Hobson, R. (1989). On sharing experiences. Development and Psychopathology, 1, 197-204. Hurt, S., Hutt, C., Lee, D., & Ounsted, C. (1964). Arousal and childhood autism. Nature, 204, 908-909. Kasari, C., Mundy, P., & Sigman, M. (1990). Affect sharing in the context of joint attention interactions of normal, autistic, and mentally retarded children. Journal of Autism and Developmental Disorders, 20, 87-100. Leslie, A., & Happe, F. (1989). Autism and ostensive communication: The role of metarepresentation. Development and Psychopathology, 1, 205-212. Loveland, K., & Landry, S. (1986). Joint attention and language in autism and developmental language delay. Journal of Autism and Developmental Disorders, 16, 335-348.
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Mundy, P., Sigman, M., Ungerer, J., & Sherman, T. (1986). Defining the social deficits of autism: The contribution of non-verbal communication measures. Journal of Child Psychology and Psychiatry, 27, 657-669. Schopler, E., Reichler, R., & Renner, B. (1986). Childhood Autism Rating Scale. New York: Irvington. Sparrow, S., Tobin, D., & Cicchetti, D. (1986). Vineland Adaptive Behavior Scale. Circle Pines, MN: American Guidance Service. Tomassello, M., & Farrar, M. (1986). Joint attention and early language. Child Development, 57, 1454-1463. Wetherby, A., & Prutting, C. (1984). Profiles of communicative and cognitive-social abilities in autistic children. Journal of Speech and Hearing Research, 27, 364-377.
Social Stimulation and Joint Attention in Young Autistic Children A r t h u r L. Lewy 1,3 and G e r a l d i n e D a w s o n 2
Manusc~pt received in final form June 2, 1992. The present study was designed to examine the effects of social stimulation on the joint attention behavior of 20 autistic children under 6 years of age, 20 receptive language-matched Down syndrome children, and 20 receptive language matched-normally-developing infants. Children's social and non-social engagement states were measured during two experimental play sessions and during free play with parent. For all groups, joint attention was increased when adult play behavior closely followed and was contingent on the behavior of the children; however, the autistic children were significantly less responsive to the experimental manipulation than control subjects. In contrast, the autistic children were no less responsive in terms of other forms of social engagement. Results are interpreted as supporting a model of joint attention deficits in autism that involves factors inherent to the disorder in transaction with social context.
Coordination of attention between object and person is an important developmental accomplishment during the second year of life and periods of coordination appear to be important forums for language and emotional development (Adamson & Bakeman, 1985; Bakeman & Adamson, 1986). Parents' play behaviors appear to facilitate the emergence of joint attention (Bruner, 1982). Bakeman and Adamson (1984) demonstrated that joint attention was enhanced by the activity of a more capable social partner (mother) while it was relatively rare when infants were engaged with a less capable social partner (peers). 1Department of Psychologyand CivitanInternationalResearch Center, Universityof Alabama at Birmingham,Birmingham,Alabama. 2Department of Psychology,Universityof Washington. 3Address all correspondence to Arthur L. Lewy,P.O. Box 313, UAB Station, Birmingham, Alabama 35294. 555 00914)627/92/1200~)555506.50/0 9 1992 Plenum Publishing Corporation
556
Lewy and Dawson
Several studies of young autistic children provide compelling documentation of a deficit in joint attention in autistic children that cannot be accounted for by general developmental delay (e.g., Loveland & Landry, 1986; Mundy, Sigman, Ungerer, & Sherman, 1986; Wetherby & Prutting, 1984). Most interpretations of this research posit that this deficit is due to fundamental and inherent impairments in affective or cognitive understanding of others (e.g., Hobson, 1989; Leslie & Happe, 1989). The effects of social context and the special scaffolding needs of autistic children as contributing factors to their joint attention deficit have not been systematically considered. Previous research has shown that social context can influence social responsiveness of autistic children (Dawson & Adams, 1984; Dawson & Galpert, 1990). Specifically, it was found that, by increasing the predictability and contingency of adult responses, there followed increases in eye contact and creative toy play in the children. To examine the role of type of social context in autistic children's joint attention behavior, in the present study, we systematically varied social stimulation and observed children's joint attention and other social and non-social states of engagement. We predicted that there would be a significant deficit in joint attention in autistic children as compared to receptive language matched groups of mentally retarded and normally developing children. Furthermore, we predicted that experimentally changing social stimulation from non-contingent and unpredictable to contingent and predictable would lead to increases in joint attention, and in other forms of social engagement in all groups of children. Levels of joint attention during free play with parent were expected to fall between these extremes because parent behavior likely ranges between the extremes of the highly contingent and the highly non-contingent experimental conditions.
METHOD
Sample Twenty preschool-aged autistic children and receptive languagematched groups of 20 Down syndrome and 20 normal children participated in the study. The Down syndrome group was included to control for effects of general developmental delay without autism. Receptive language ability was measured with the Sequenced Inventory of Communication Development (SICD, Hedrick, Prather, & Tobin, 1984). Receptive language was chosen as a matching variable because it has been found to be reliably
Social Stimulation and Joint Attention
557
correlated with joint attention skill in normal children (Tomassello & Fartar, 1986). Given that language is typically an area of relative weakness for autistic children compared to visual-spatial skill, a receptive language match is likely to result in an autistic-control comparison that minimizes the possibility that group differences merely reflect differences in another skill known to be correlated with joint attention. All autistic children had been previously diagnosed by physicians or psychologists in the community. Diagnosis of autism was further verified by means of ratings on instruments, a behavior checklist based on the diagnostic criteria for autism in the Diagnostic and Statistical Manual of the American Psychiatric Association (DSM IIIR) and by the Childhood Autism Rating Scale (CARS, Schopler, Reichler, & Renner, 1986). Each autistic child was rated by two clinically-trained raters and disagreements in diagnosis were resolved through review of the videotape of the child made during the study. Sample descriptive statistics are shown in Table I. There were no significant group differences in receptive language age (F(2, 57) = .56, NS). There were significant group differences in chronological age (F(2, 57) = 50.03, p < .001). Follow-up t-tests indicated significant differences in chronological age between all groups. Sixteen randomly-chosen children from the study were reassessed with the receptive language portion of the Vineland Scales of Adaptive Behavior-Revised (Sparrow, Tobin, & Cicchetti, 1986), a parent-interview measure. The correlation (Pearson's r) between the SICD and Vineland was .70 (p = .001), suggesting good external validity of the SICD. The mean CARS score for the autistic children was 37.85 (SD = 2.83, minimum = 33.5, maximum = 41.5). These scores place the sample in the moderate to lower-severe range of autism. The correlation between the independent CARS ratings was .72 (p < .001). There was no significant
Table I. Receptive Language and Chronological Ages of Subjects Group
Mean
SD
Minimum
Maximum
SICD receptive language ages (months) Autistic Down syndrome Normal
20.38 22.50 20.80
7.14 5.61 7.17
12 12 12
40 32 40
Chronological ages (months) Autistic Down syndrome Normal
50.00 37.00 17.80
11.46 13.23 5.50
37 20 12
70 68 28
558
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correlation between either the CARS and receptive language age or the CARS and chronological age.
Procedure Following language testing, each child participated in a free play (FP) interaction with his or her parent. This occurred in a carpeted playroom which was equipped with toys consisting of a book, ball, telephone, bowl and spoon, rolling toys, rings, bucket and blocks, and a pinwheel. Following free play, two experimental play conditions occurred in counterbalanced order across subjects. In the experimental conditions the child interacted with a single unfamiliar experimenter. All play interactions were videotaped from behind a one-way mirror for later coding. The experimental conditions are described below. Adult-Centered Play (ACP, 7 min). A set of four toys was placed on a table between the child and the experimenter. The experimenter then proceeded to perform familiar but noncontingent schemes with the toys along with simple verbalizations describing these actions. The schemes used by the experimenter were those used by the child during the free play interaction with the parent. The experimenter alternated gaze between the child and the toy that the experimenter was using, and maintained a positive affective facial expression. In order to simulate normal play interactions, one time per minute the experimenter attempted to direct the child's attention to an object that the child was not attending to. This attention-direction lasted for 5 sec. During attention-direction the experimenter held the toy about 12 inches from the child's face, shook it gently and stated "look at the (toy name)." Child-Centered Play (CCP, 7 rain). Two identical sets of four toys, which were functionally similar to the toys used during adult-centered play, were placed between the child and the experimenter. The experimenter proceeded to imitate all of the child's verbalizations, vocalizations, and hand or body movements, and either imitated the child's toy play or engaged in actions that were small elaborations of the child's actions with a toy identical to the one that the child was using. This procedure was used instead of the constant direct imitation used by Dawson and Adams (1984) because many normal children became distressed by constant imitation during pilot testing. The experimenter also used brief verbal statements that described what the child was doing. The experimenter engaged in attention-directing behaviors that attempted to direct the child to the
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Table II. Engagement States Coding Scheme Categories
Unengagement. Child has no clear attentional focus. Onlooking. Child passively watches adult or activity of adult. Object engagement. Child is actively engaged solely with toy (e.g., manipulates toy with sustained visual regard). Person engagement. Child is actively engaged solely with adult (e.g., sustained gaze with laughter). Supported joint engagement (SJE). Child is actively involved with toy that adult manipulates in such a way as to alter child's experience with that object (e.g., child laughs at adult toy demonstration and reaches for toy). Coordinated joint engagement (CJE). Child is actively involved with person and toy (e.g., child holds toy toward adult and manually activates toy with alternating periods of sustained gaze to adult).
toy identical to the one that the child was using. The form, rate, and duration of attention-direction were the same as those used during adultcentered play. The toys used during the experimental conditions consisted of a squeaking toy, telephone, pinwheel, and bucket and block. Different toys were used in each condition. Adult-centered play and child-centered play were designed as dramatic contrasts on the stimulation dimensions of predictability and childcontrol; both, however, involved action schemes that were within the children's developmental capabilities.
Dependent Variable Joint attention and other social behaviors were coded using the Engagement States Coding Scheme (Bakeman & Adamson, 1984). Six mutually exclusive and exhaustive engagement states were coded, as described in Table II. Fifteen minutes of play time, 5 min in each condition, were coded for each child.
Data Coding and Reliability Engagement states were coded by trained undergraduates who were blind to the hypotheses of the study. Twenty percent of all play episodes were re-coded for reliability. Reliability was estimated with Cohen's kappa (Cohen, 1960), a statistic that computes percentage agreement correcting for chance agreement thus yielding a conservative measure of inter-rater
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reliability. Kappa for the engagement states was .78 (84% raw percent agreement).
RESULTS
Group Differences in Engagement States Percentages of time spent in each engagement state by each group during each condition are shown in Table III. Repeated measures group(3) x condition(3) analyses of variance (ANOVAs) revealed significant main effects of group for CJE, object engagement, unengagement, and onlooking (CJE F(2, 57) = 10.15, p < .001; object (F (2, 57) = 9.06, p < .001; unengaged F(2, 57) = 3.45, p = .039; onlooking F(2, 57) = 7.75, p = .001). Planned autistic-control a priori t-tests indicated that these effects were accounted for by the relatively lower levels of CJE and onlooking and relatively higher levels of object engagement and unengagement in the autistic children compared to the combined control group children across all conTable Ill. Engagement States During Each Condition by Group a
Autistic ACP
FP CCP Down syndrome ACP
FP CCP Normal ACP
FP CCP
UN
ON
OB
PE
SJ
CJ
11.9 (12.9) 18.4 (17.9) 9.8 (7.3)
10.2 (11.4) 4.8 (3.6) 4.7 (4.9)
74.7 (19.4) 55.2 (21.9) 52.1 (16.0)
.03 (.00) 3.7 (8.2) 2.7 (4.8)
.8 (1.4) 13.5 (12.1) 19.6 (16.1)
2.2 (6.4) 4.0 (5.3) 10.8 (11.2)
8.3 (7.9) 8.4 (9.0) 5.6 (5.7)
20.6 (14.5) 8.2 (8.2) 6.0 (7.2)
60.3 (13.8) 52.0 (17.3) 23.8 (13.2)
.9 (2.0) 4.4 (4.5) 3.9 (6.6)
2.8 (3.4) 7.4 (7.3) 19.7 (14.3)
7,1 (7,3) 19,5 (18,3) 41.0 (23.3)
8.6 (6.5) 13.1 (9.0) 8,5 (8,2)
20.2 (10.2) 13.5 (9.8) 9.2 (7.0)
64.6 (14.4) 54.1 (17.3) 28.1 (15.1)
.6 (1.4) 1.4 (2.5) 2.2 (3,3)
1.5 (2.2) 6.5 (8.5) 17.2 (16.9)
4.5 (5.3) 11.5 (10.2) 34.7 (24.6)
aAll means are in percents, and SDs are in parentheses. UN-unengaged; ON-onlooking; OB-object engaged; PE-person engaged; SJ-supported joint engagement; CJ-coordinated joint engagement.
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ditions (CJE t(58) = 4.16, p < .001; object t(58) = 3.87, p = .001). No significant differences between the two control groups on these or any other engagement state measure were found. Repeated measures A N O V A s also revealed significant group x condition effects for CJE and object engagement (CJE F(4, 114) = 4.74, p = .001; object F(4, 114) = 4.64, p = .002). To examine these interactions, a series of follow-up one-way A N O V A s were conducted. For CJE and object engagement the greatest autistic-control differences emerged during CCP (CJE F(2, 57) = 11.95, p < .001; object F(2, 57) = 20.94, p < .001). Less significant autistic-control differences in CJE were found in the other conditions (p = .01-.04). There were no significant autistic-control differences in object engagement during FP, and the autistic children showed higher levels of object engagement than controls during ACP (p = .02). The repeated measures group(3) x condition(3) A N O V A s for supported joint engagement and person engagement failed to show significant main effects of group or group x condition interactions. Discriminant function analyses showed that measures of CJE over all three conditions correctly classified all but three (85%) of the autistic children and 65% of controls (22 = 22.35, p < .0001). Measures of object engagement correctly classified 75% of the autistic children and 90% of controls (~2 = 34.27, p < .0001). The only other statistically significant predictor of group membership was onlooking which correctly classified 80% of the autistic children and 60% of controls (Z 2 = 12.78, p = .004).
Effects of the Experimental Manipulation on Engagement States Repeated measures group(3) • condition(2) A N O V A s for levels of each engagement state during ACP and CCP showed significant main effects of condition for CJE, SJE, person engagement, object engagement, and onlooking (CJE F(1, 57) = 79.15, p < .001; SJE F(1, 57) -- 80.05, p < .001; person F(1, 57) = 13.63, p = .001; object F(1, 57) = 158.69, p < .001; onlooking F(1, 57) = 42.48, p < .001). Paired t-tests revealed that during CCP each group showed significant increases in CJE (autistic t(19) = 2.33, p < .03; Down syndrome t(19) = 6.51, p < .001; normal t(19) = 5.89, p < .001), and in supported joint engagement. Significant increases in person engagement were found for the autistic children; nonsignificant trends in person engagement were found for the control groups (autistic supported joint t(19) = 5.34, p < .001, person t(19) = 2.60,p = .017; Down syndrome supported joint t(19) = 5.90, p < .001, person t(19) = 2.00, p = .06; normal supported joint t(19) = 4.51, p < .001, person t(19) = 1.88, p = .075). All groups showed significant decreases in object engagement and
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% time 80% Autistic
70%
~
Down syndrome
60%
~
Normal
50% 40% 30%
10%~1~ 0% .
.
I~ .
ON-AON-C
.
. _
.
OB-AOB-C
B~
PE-A PE-C
,
..~
SJ-A SJ'C
CJ-A CJ-C
ON-onlooking; OB-object engaged SJ-supported joint; CJ-coordinated joint A-ACP; C-CCP
Fig. 1. Significant effects of experimental manipulation on engagement states.
onlooking during CCP (autistic object t(19) = 4.14, p = .001, onlooking t(19) = 2.49, p = .02; Down syndrome object t(19) = 9.74, p < .001, onlooking t(19) = 3.92, p = .001; normal object t(19) = 9.47, p < .001, onlooking t(19) = 5.15,p < ,001). Figure 1 graphically depicts these significant effects. These repeated measures ANOVAs also revealed significant group x condition interactions for CJE and object engagement (CJE F(2, 57) = 8.53, p = .001; object F(1,57) = 3.84, p = .027). These effects were accounted for by the autistic children showing far less of an increase in CJE and far less of a decrease in object engagement during CCP compared to controls. This was determined through additional analyses of covariance (ANCOVAs) by group on the levels of CJE and object engagement during CCP that controlled for levels of each engagement state shown by the children during FP and ACP, thereby controlling for the autistic children's tendency to generally show lower levels of CJE and higher levels of object engagement. These ANCOVAs still found a significant main effect of group on CJE and object engagement during CCP (CJE F(2, 57) = 7.58, p = .001; object F(2, 57) = 17.59, p < .001). These findings suggest that the
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autistic children were significantly less responsive than controls to the CCP condition in terms of coordinated joint engagement but were equally responsive for the less mature socially-oriented engagement states, person engagement, and SJE. As can be seen from Table III, levels of CJE, SJE, person engagement, object engagement, and onlooking during FP fell between the extremes seen during ACP and CCP. The combined measure of the two least social engagement states (object engagement and unengagement) during FP also fell between levels seen during ACP and CCP. However, not all ACP-FP and FP-CCP comparisons were significant for all groups.
DISCUSSION These findings replicate previous research in documenting a distinct deficit in joint attention in autistic children. It is notable here that a different measure of joint attention was used than in previous research with autistic children, suggesting that the joint attention deficit extends beyond discrete acts of showing, pointing, etc., to the more organizational-level and socially interactive conceptualization of joint attention as active coordination of attention, used here. Autistic-control differences in joint attention were most marked during the child-centered play condition in which the experimenter's actions were highly contingent upon the child's. The autistic children were more socially unengaged and spent more time directing their attention to objects compared to controls. They also spent less time watching their social partner than controls. All groups responded positively to the child-centered play condition by showing increases in coordinated joint engagement; however, the autistic children were significantly less responsive and showed only a modest increase. All groups also showed increases in the amount of time spent socially engaged with the experimenter and in supported joint engagement in the child-centered condition; the autistic children were no less responsive than controls in terms of these less mature forms of social behavior. These results support the notion that social context can have an important influence on the expression of autistic symptoms, even on a relatively complex skill such as coordinated joint engagement. The autistic children's relative lack of immediate responsiveness to the child-centered manipulation in terms of coordinated joint engagement, however, suggests that this skill, at the age measured here, is only partially responsive to environmental manipulations, however, the effects of a facilitating social context on joint attention when used for a longer period of time have yet to be assessed. The present findings suggest that joint attention deficits in
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autism may be a function of factors inherent to autism in transaction with social context. At least three possible inherent factors may play a role in autistic children's joint attention deficit. First, periods of joint attention are important forums for sharing of positive affect (Adamson & Bakeman, 1985); it may be that autistic children's deficit in coordinated joint attention reflects impaired capacity for affect sharing, a prerequisite to intersubjectivity (Kasari, Mundy, & Sigman, 1990). A second possible contributor to a deficit in joint attention is difficulty sustaining attention to social stimulation, stimulation which is often unpredictable and novel (Ferrara & Hill, 1980). Dawson and Lewy (1989) have suggested that autistic children's difficulty processing unpredictable stimuli may be related to a deficit in arousal regulation, an idea first offered by Hutt, Hutt, Lee, and Ounstead (1964). Here, the autistic children's preponderance of engagement to entirely predictable stimulation (object engagement) is consistent with this hypothesis. A third possibility is that autistic children are unable to attend simultaneously to, or switch attention between, the two sources of information (person and object) necessary to successfully show coordinated joint engagement. Problems with attention switching in autistic individuals have been noted by Courchesne (Courchesne, Townsend, Akashoomoff, Yeung-Courchesne, Press, & Murakami, in press). Here, that the autistic children were as frequently person-engaged and as frequently involved in supported joint engagement as control children, hut lacking in the engagement state that was a coordinated alternation of the two is consistent with this notion. At this juncture, developmental studies of joint attention are needed. Hopefully, these studies will illuminate the attentional, cognitive, and social prerequisites for this skill and lead the way toward the assessment of early developmental competencies that contribute to joint attention deficits in autism. Finally, this study adds to a growing literature on a promising therapeutic strategy for young autistic children (e.g., Dawson & Adams, 1984; Dawson & Galpert, 1990; Grofer-Klinger & Dawson, 1992). The results of these studies suggest that child-directed intervention may be able to increase levels of social and cognitive skills such as complexity of toy play, turn taking, and symbolic play, in addition to joint attention.
ACKNOWLEDGMENTS This research is based on the doctoral dissertation of the first author. This research was supported by the American Psychological Association, Sigma Xi---The Scientific Research Society, the Washington Association
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for Retarded Citizens Research Trust, and a University of Washington Social Sciences Dissertation Award to the first author. We thank Lauren Adamson, Roger Bakeman, Susan Landry, and Peter Mundy for their helpful comments during the course of this study. Appreciation is extended to the coders. Special appreciation is extended to the parents and children who took part in the study. Portions of this research were presented at the Biennial Meeting of the Society for Research in Child Development, Seattle, March 1991.
REFERENCES Adamson, L., & Bakeman, R. (1985). Affect and attention, infants observed with mothers and peers. Child Development, 56, 582-593. Bakeman, R., & Adamson, L. (1984). Coordinating attention to people and objects in mother-infant and peer-infant interactions. Child Development, 55, 1278-1289. Bakeman, R., & Adamson, L. (1986). Infants' conventionalized acts: Gestures and words with mothers and peers. Infant Behavior and Development, 9, 215-230. Bruner, J. (1982). The organization of action and the nature of adult-infant transaction. In E. Tronick (Ed.), Social interchange in infancy: Affect, cognition, and communication. Baltimore: University Park Press. Cohen, J. (1960). A coefficient of agreement for nominal scales. Education and Psychological Measurement, 20, 37-46. Courchesne, E., Townsend, J., Akashoomoff, N., Yeung-Courchesne, R., Press, G., & Murakami, J. (in press). A new finding in autism: Impairment in shifting attention. In S. Broman & J. Grafman (Eds.), Impairment in shifting attention in autistic and cerebellar patients. Hillsdale, N J: Erlbaum. Dawson, G., & Adams, A. (1984). Imitation and social responsiveness in autistic children. Journal of Abnormal Child Psychology, 12, 209-225. Dawson, G., & Galpert, L. (1990). Mothers' use of imitative play for facilitating social responsiveness in young autistic children. Development and Psychopathology, 2, 151-162. Dawson, G., & Lewy, A. (1989). Arousal, attention, and the socio-emotional impairments of individuals with autism. In G. Dawson (Ed.), Autism: Perspectives on nature, diagnosis, and treatment. New York: Plenum. Ferrara, C., & Hill, S. (1980). The responsiveness of autistic children to the predictability of social and nonsocial toys. Journal of Autism and Developmental Disorders, 10, 51-57. Grofer-Klinger, L., & Dawson, G. (1992). Facilitating social and communicative development in children with autism. In S. Warren & J. Richle (Eds.), Perspectives on communication and language intervention. Baltimore: Brooks. Hedrick, D., Prather, E., & Tobin, A. (1984). Sequenced Inventory of Communication Development-Revised. Seattle: University of Washington Press. Hobson, R. (1989). On sharing experiences. Development and Psychopathology, 1, 197-204. Hurt, S., Hutt, C., Lee, D., & Ounsted, C. (1964). Arousal and childhood autism. Nature, 204, 908-909. Kasari, C., Mundy, P., & Sigman, M. (1990). Affect sharing in the context of joint attention interactions of normal, autistic, and mentally retarded children. Journal of Autism and Developmental Disorders, 20, 87-100. Leslie, A., & Happe, F. (1989). Autism and ostensive communication: The role of metarepresentation. Development and Psychopathology, 1, 205-212. Loveland, K., & Landry, S. (1986). Joint attention and language in autism and developmental language delay. Journal of Autism and Developmental Disorders, 16, 335-348.
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Mundy, P., Sigman, M., Ungerer, J., & Sherman, T. (1986). Defining the social deficits of autism: The contribution of non-verbal communication measures. Journal of Child Psychology and Psychiatry, 27, 657-669. Schopler, E., Reichler, R., & Renner, B. (1986). Childhood Autism Rating Scale. New York: Irvington. Sparrow, S., Tobin, D., & Cicchetti, D. (1986). Vineland Adaptive Behavior Scale. Circle Pines, MN: American Guidance Service. Tomassello, M., & Farrar, M. (1986). Joint attention and early language. Child Development, 57, 1454-1463. Wetherby, A., & Prutting, C. (1984). Profiles of communicative and cognitive-social abilities in autistic children. Journal of Speech and Hearing Research, 27, 364-377.
