Joint attention, developmental level, and symptom ...

Development and Psychopathology, 6 (1994), 389-401 Copyright © 1994 Cambridge University Press Printed in the United States of America

Joint attention, developmental level, and symptom presentation in autism

PETER MUNDY," MARIAN SIGMAN,* AND CONNIE KASARI* "University of Miami; and bUniversity of California at Los Angeles

Abstract Recent data suggest that a disturbance in the development of joint attention skills is a specific characteristic of young autistic children. This observation may have both theoretical and clinical significance. However, many pertinent issues remain to be addressed with regard to the parameters of joint attention disturbance in children with autism. This study attempted to address several of these issues. The study examines the effects of mental age and IQ on the joint attention skills of,children with autism, mental retardation, and normal development. The study also examined the relation of joint attention behaviors to the parent's report of symptoms presented by children with autism. The results suggested that, differences in IQ and mental age may be related to differences in the type of joint attention skill deficits displayed by children with autism. The results also suggested that joint attention disturbance is associated with a circumscribed, but social cluster of symptoms observed among young autistic children by their parents. The implications of these findings for developmental models of autism are discussed.

Recent data suggest that a disturbance in Hogan, & Mundy, 1982). Making eye conthe development of joint attention skills is tact with an adult while pointing to a picture an important characteristic of young autis- in a book is an example of a joint attention tic children (Curcio, 1978; Loveland & behavior. Landry, 1986; Mundy, Sigman, Ungerer, & Observations of joint attention skill disSherman, 1986; Sigman, Mundy, Ungerer, turbance in children with autism may have & Sherman, 1986; Wetherby & Prutting, both theoretical and clinical significance. 1984). Nonverbal joint attention skills refer With regard to theory, it is noteworthy that to the capacity of the young child to use ges- joint attention skills appear to emerge betures and eye contact to coordinate atten- tween 9 and 18 months of age in children tion with another person in order to share with normal development (Bakeman & Adthe experience of an interesting object or amson, 1984; Butterworth & Jarret, 1991; event (Bruner & Sherwood, 1983; Seibert, Hannan, 1987; Jones, Collins, & Hong, 1991). Therefore, it has been suggested that deficits in these skills reflect disturbances in This research was supported by grants NS2S243 from NINCDS and HD17662 from NICHD. We would like relatively basic and early emerging developto acknowledge the indispensable assistance of Alison mental processes (Mundy & Sigman, 1989a, Anson, Mike Espinosa, Stephanie Freeman, Margie 1989b). Attempts to define the nature of Greenwald, Alisa Hoffman, Nicholas Lofthous, Alma these processes have begun to contribute to Lopez, Ellen Ruskin, and Susan Toth in the execution an understanding of how disturbances of of this study. We would also like to thank the anonymous reviewers for their helpful comments on an early affect, attention, and cognition may condraft of this paper. verge in the atypical development of children Address correspondence and reprint requests to: with autism (Capps, Kasari, Yirmiya, & SigPeter Mundy, Director of the Psychological Services man, in press; Kasari, Sigman, Mundy, & Center, Department of Psychology, University of MiYirmiya, 1990; McEvoy, Rogers, & Penami, Coral Gables, FL 33124. 389

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nington, 1993; Mundy, Sigman, & Kasari, 1993; Sigman, Kasari, Kwon, & Yirmiya, 1992). Clinically significant data include the observation that joint attention deficits may be observed in young autistic children relative to controls before disturbances in other domains may be observed, such as deficits in pretense play (Mundy et al., 1993). Thus, observations of joint attention skills may be an especially important behavior domain to consider in the early identification of children with symptoms of autism (cf. BaronCohen, Allen, & Gillberg, 1992). In addition, young autistic children vary in the degree to which they display joint attention skills, and individual differences in these skills have been related to differences in their subsequent language development (Mundy, Sigman, & Kasari, 1990). Thus, the assessment of joint attention skills in young autistic children may contribute to prognostic evaluations or assist in predicting the responsiveness of these children to early intervention efforts. Finally, and perhaps most important, the joint attention skills of young autistic children appear to be affected by environmental manipulations (Lewey & Dawson, 1992). This, in conjunction with the observed association with language development, suggests that joint attention skills may be one of several important targets for early intervention efforts. Conversely, measures of joint attention may also contribute to the assessment of outcome in intervention efforts with young autistic children. The potential clinical and theoretical significance of joint attention deficits suggests that it is important to acquire a detailed understanding of the development of this skill domain in children with autism. However, many pertinent issues remain to be addressed before such a detailed understanding is at hand. In this study we examine three of these issues. First, the reported specificity of nonverbal joint attention deficits in young autistic children needs to be reexamined. Nonverbal joint attention skills refer to a particular type of gestural communication behavior.

P. Mundy, M. Sigman, and C. Kasari

However, other types of gestural communication skills also exist. The young child may use eye contact and gestures to regulate social interaction and turn-taking episodes or they may also be used to request assistance in obtaining objects or events (Bates, 1979; Bruner & Sherwood, 1983; Seibert et al., 1982). Early research suggested that joint attention deficits, as apposed to nonverbal requesting or nonverbal social interaction and turn-taking deficits, were a specific characteristic of young autistic children (e.g., Baron-Cohen, 1989a; Mundy et al., 1986). However, a recent study (McEvoy et al., 1993) reported that young autistic children may also display a clear deficit in nonverbal social interaction and turn-taking skills, but this deficit was reportedly less robust than the joint attention deficit that was also observed in this study (McEvoy et al., 1993). It may be that less pronounced deficits in other nonverbal communication skills are also characteristic of young autistic children. However, the small sample sizes and associated relatively low power of earlier studies (Mundy et al., 1986; Sigman, et al.) may have been insufficient to observe these deficits clearly. The present study addresses this possibility by examining nonverbal communication skills in a relatively large sample of autistic and comparison children. A second issue concerns whether the type or expression of the joint attention skill deficits vary with the developmental status of the child. The social and cognitive skills deficits of children with autism may differ with the developmental status of the child as reflected by mental age (MA) and IQ (Rutter & Garmezy, 1983; Volkmar, Cohen, Bregman, Hooks, & Stevenson, 1989). Moreover, the types of behaviors used in nonverbal communication skills, including joint attention skills, vary with the developmental status of children (Seibert et al., 1982). For example, younger children may only use eye contact to establish joint attention, whereas older children may use conventional gestures such as pointing and showing (Seibert et al., 1982; Seibert, Hogan, & Mundy, 1984). Together, these observations suggest that the type of nonver-

Symptom presentation in autism

bal social behavior disturbance displayed by children with autism, such as eye contact versus conventional gestures, may vary as a function of their developmental status. To examine this possibility, the children with autism in this study were divided into subsamples according to developmental status, defined in terms of MA or IQ, and compared to control children on eye contact versus conventional gesture measures of nonverbal joint attention, requesting, and social interaction and turn-taking skills. The third issue concerns the degree to which joint attention deficits are associated with other features of the autistic syndrome. Young children with autism often display an array of behavior disturbances including problems with attention regulation, sensory responsiveness, perseverative behaviors, and self-abusive behaviors (Volkmar & Cohen, 1988). However, it is not clear how joint attention deficits fit into the larger symptom picture. It may be that joint attention deficits are a general marker of autistic pathology. If so, individual differences in joint attention skills may be expected to be associated with differences in a wide variety of autistic symptoms. Alternatively, joint attention deficits may be a marker of a relatively circumscribed aspect of this syndrome. In such a case, it would be expected that individual differences in joint attention would be associated with a limited set of autistic symptoms. To our knowledge, no studies have addressed this issue. To begin to deal with this issue, this study also examined the relation between joint attention deficits and parents' reports of symptoms in young autistic children.

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score equal to or greater than 32 on an abbreviated version of the Childhood Autism Rating Scale (CARS; Schopler, Reichler, & Renner, 1986), which was completed for all children in this study by a blind rater using videotaped samples of behavior; and (c) a score of 70 or above on the Autism Behavior Checklist (ABC; Krug, Arick, & Almond, 1979) based on parental interview conducted by an independent rater. Two control samples also participated in this study. One group comprised 30 children (17 boys and 13 girls) with developmental delays. These children did not meet any of the preceding diagnostic criteria and were matched individually with the autistic children on chronological ( ± 3 months) and mental age ( ± 3 months). The third group comprised 30 children (27 boys and 3 girls) with normal development who were matched individually with the autistic children on mental age ( ± 3 months). Because a goal of this study was to consider the effect of developmental level on the expression of nonverbal communication in children with autism, the samples were divided into two MA subgroups. Those children with MAs above 19 months comprised the higher MA subgroup and those with MAs below 20 months were in the lower MA subgroup. These discrete groupings were based on theory and data that suggest that an important development shift in cognitive, social, and communication skills is often manifest in children with normal and atypical development at about 20 months MA (McCall, Eichorn, & Horgarty, 1977; Seibert et al., 1984). The chronological age, MA, and IQ characteristics of these subsamples can be seen in Table 1.

Method Procedures Subjects Thirty preschool, autistic children (27 boys and 3 girls) participated in this study. Diagnoses of autism were based on confirmation of at least two of the following criteria: (a) a referring clinician's diagnosis made according to DSM-III-R guidelines (American Psychiatric Association [APA1,1987); (b)a

Each child was seen with one or more of his or her parents in a university-based laboratory. To estimate MA and obtain an estimate of IQ, the children were either administered the Cattell Developmental Scales (Cattell, 1960) or the Stanford-Binet Intelligence Test, Form L-M (Thorndike, 1972). This combination of tests was used because

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Table 1. Sample characteristics of high and low mental age (MA) subsamples: The three diagnostic groups"

MA Low MA High MA Chronological age Low MA High MA IQ Low MA High MA

Autism

Mental Retardation

Normal

16.8 (2.3) N = 13 30.8 (11.5) N= 17

17.2 (2.7) N =U 27.9 (9.6) N= 19

16.5 (2.4) AT = 15 30.1 (U.4) N= 15

38.4 (7.3) 47.6 (13.4)

37.1 (8.7) 44.3 (H.l)

14.3 (2.3) 25.4 (8.2)

45.2 (10.7) 62.1 (17.4)

48.1 (12.4) 60.2 (12.9)

115.7 (6.5) 111.3 (10.3)

'Chronological age and MA estimates in months. Standard deviations appear below means in parentheses.

it provides a continuous measurement system across the developmental range of the children in this study. An independent tester presented each child with an abbreviated version of the Early Social-Communication Scales (ESCS; Seibert et al., 1982). This version of the ESCS contains fewer items and yields frequency scores for the nonverbal behaviors observed rather than developmental level scores (Mundy, Sigman, Ungerer, & Yirmiya, 1988; Mundy et al., 1986). In this procedure, the child and a tester sat facing each other at a small table. A set of toys including a hat, a comb, a picture book, a ball, a car, three small wind-up mechanical toys, and three hand-operated mechanical toys including balloons were in view, but out of reach of the child. Colorful postures adorned the walls of the room and the child's caregiver sat approximately 3 ft directly behind the child. Throughout the course of the ESCS, the tester presented each of the six mechanical toys. During a presentation the toy was activated on the table at least three times. The

tester presented other types of situations between toy presentation trials. In two separate trials the tested clapped, sang a brief song, and then gently tickled the child. In each of these trials the tester tickled the child three times with pauses between each tickle episode. The tester also presented two pointing trials. In each of these trials the tester pointed to the left, to the right, and behind the child while emphatically stating the child's name. In addition, the tester offered the child several object turn-taking opportunities. These included presenting the child once with the opportunity to roll a ball back and forth with the tester and once with the opportunity to roll a car back and forth with a tester. Opportunities to take turns using a comb, hat, or glasses in a functionally appropriate fashion were also provided. This procedure was videotaped to record the front-upper body profile of the tester and a full-face and upper body view of the child. The period of interaction with each child was approximately 20 min. Frequencies of behaviors were recorded from the videotapes by trained observers who were

Symptom presentation in autism

blind to the hypotheses of this study. Observations were grouped into three mutually exclusive categories: requesting, joint attention (indicating), and social interaction (turn-taking). Within each category behaviors were also classified according to developmental levels established in previous research (Seibert et al., 1984; Seibert, Hogan, & Mundy, 1986). Behaviors only involving eye contact or nonconventional gestures, such as reaching, were classified as low level behaviors. Those behaviors that involved the use of conventional gestures, such as pointing, were classified as high level behaviors. The requesting category included behaviors that were used to direct attention to objects or events in order to request aid in obtaining the object or repetition of an event (e.g., reactivation of a mechanical toy). Behaviors.rated here included Low Level, (1) reaching to toys out of reach; and (2) eye contact and reaching to toys out of reach; and High Level, (3) giving a toy to the tester, defined as extending a toy toward the experimenter's hand, and (4) pointing (extends index finger) to toys that were out of reach. The joint attention category also involved the coordination of the child's and tester's attention to objects or events. However, the instrumental function of these behaviors was less apparent because the object was within reach or the event was ongoing. These behaviors included Low Level, (1) eye contact while holding a toy; and (2) alternating eye gaze between the tester's face and an active toy; and High Level, (3) pointing to toys within reach, and (4) showing toys or extending toys toward the tester's face. The social interaction behaviors involved eliciting attention or physical contact from the tester and engaging in turn-taking with objects. Behaviors observed within this category included Low Level, (1) responding to a pause in being tickled with eye contact and a gesture (e.g., reach or bang table), and (2) rolling a ball or car back and forth with the tester three or more times; and High Level, (3) placing the hat, comb, and/

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or glasses to the tester's head after the tester leans forward and says "Can I play"; and (4) engaging in a prohibited activity while smiling and making eye contact with the tester (i.e., teases). A separate index of the child's capacity to respond appropriately to the tester's pointing was also scored. Termed "responding to joint attention," this measure was scored dichotomously across six trials according to whether or not a child turned his or her head (at least 45 °) and eyes in the correct direction when the tester pointed to the left, to the right, and behind the child. To assess the interrater reliability of the ESCS in this study, seven children were randomly selected and rated by three independent observers to assess multiple rater agreement with generalizability analyses. Generalizability coefficients above .50 indicate adequate reliability (Mitchell, 1979). The generalizability coefficients for the high and low level scores used in this study ranged from .66 (low level social interaction) to 1.0 (responding to joint attention). The mean of the generalizability coefficients was .81. Similarly, high levels of interrater reliability have previously been reported for summary measures derived from the ESCS (McEvoy et al., 1993; Mundy et al., 1988). Results To consider the effects of diagnostic group and developmental level on nonverbal communication skills a sequence of 3 (Group) x 2 (MA) ANOVAs were conducted for the high and low ESCS scores. Significant group effects were followed by pairwise comparisons using Tuckey's Studentized Range Test to specify whether the autistic children significantly differed from the mental retardation or normal control samples in this study. The results of these analyses are presented in Table 2. Analyses revealed both significant group (F = 8.56, p < .001) and MA effects (F = 4.66, p < .05) for the low level joint attention behaviors, and group (F - 8.90, p < .001) and MA effects (F = 17.7, p