In this study we examined early motor, vocal, and communicative development in a group of younger siblings of children diagnosed with autism (Infant Siblings). Infant Siblings and no-risk comparison later-born infants were videotaped at home with a primary caregiver each month from 5 to 14 months, with follow-up at 18 months. As a group, Infant Siblings were delayed in the onset of early developmental milestones and spent significantly less time in a greater number of postures, suggestive of relative postural instability. In addition, they demonstrated attenuated patterns of change in rhythmic arm activity around the time of reduplicated babble onset; and they were highly likely to exhibit delayed language development at 18 months.

Interests of young children (2.9 to 4.2 years of age) were naturalistically identified through patterns of attention in the preschool classroom. These interests were subsequently related to performance in three experimental tasks assessing (a) the direction of attentional shift to items in the peripheral visual field, (b) the level of recognition of previously encountered pictures, and (c) recall of previously presented objects. Interests were found to be strong, relatively well focused, and individually variable. In addition, a child's particular interests appeared to be a powerful determinant of the direction of attentional shift, level of recognition, and likelihood of recall. Findings are interpreted in terms of a cognitive/affective conceptualization of interest as a central feature of the knowledge and value systems that individuals bring to the task of organizing experience and memory.Recent discussions of attention and memory have begun to focus on subject variables. Craik (1979), for example, suggested that compatibility between information to be stored and subjects' existing knowledge structures may influence elaboration of the information and the distinctiveness with which it is subsequently encoded. In a tetrahedral model specifying variables that affect the child's evolving memory system, Jenkins (1979; see also Bransford, 1979;Brown, 1982) pointed to subject characteristics such as knowledge, purpose, and interest as critical sources of variance in memory.The present research was designed to investigate attention and memory as a function of the last of these subject variables-interest. Individual differences in interest and their effect on the processing of information are a matter of common observation. Two children, for example, can walk through a park and This report is based on portions of a dissertation submitted by the first author to the Department of Education and Child Development, Bryn Mawr College.

Evidence suggests that children and adults diagnosed with autism spectrum disorders (ASD) exhibit difficulties with postural control. Retrospective video studies of infants later diagnosed with ASD indicate that infants who eventually receive an ASD diagnosis exhibit delays in postural development. This study investigates early posture development prospectively and longitudinally in 22 infants at heightened biological risk for ASD (HR) and 18 infants with no such risk (Low Risk; LR). Four HR infants received an autism diagnosis (AD infants) at 36 months. Infants were videotaped at home at 6, 9, 12, and 14 months during everyday activities and play. All infant postures were coded and classified as to whether or not they were infant-initiated. Relative to LR infants, HR infants were slower to develop skill in sitting and standing postures. AD infants exhibited substantial delays in the emergence of more advanced postures and initiated fewer posture changes. Because posture advances create opportunities for infants to interact with objects and people in new and progressively more sophisticated ways, postural delays may have cascading effects on opportunities for infant exploration and learning. These effects may be greater for infants with ASD, for whom posture delays are more significant.

Communication spontaneously initiated by infants at heightened risk (HR; n = 15) for Autism Spectrum Disorders (ASD) is compared to that in low-risk (LR; n = 15) infants at 13 and 18 months of age. Infants were observed longitudinally during naturalistic in-home interaction and semi-structured play with caregivers. At both ages, HR infants spontaneously produced Words, Communicative Non-Word Vocalizations, SHOW and POINT Gestures, and Gesture+Non-Word Vocalization Combinations at lower rates than LR peers. This difference also held for Gesture+Word Combinations at 18 but not 13 months. At 36 months, all HR children were evaluated for ASD and three received a diagnosis of Autistic Disorder (AD). At both 13 and 18 months, these three children had been at or near the bottom of the distribution on all spontaneous communication variables.

This study examined changes in rhythmic arm shaking and laterality biases in infants observed longitudinally at three points: just prior to, at, and just following reduplicated babble onset. Infants (ranging in age from 4 to 9 months at babble onset) were videotaped at home as they played with two visually identical audible and silent rattles presented at midline for 1.5 min each. Rate of rattle shaking increased sharply from the pre-babble to babble onset session; but there was no indication that this increase was specific to the right arm. This finding suggests that the link between babble onset and increased rhythmic arm activity may not be the product of language-specific mechanisms, but is rather part of a broader developmental process that is also perceptual and motor.