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Saturday, May 9, 2009
Northwest Hall (Chicago Hilton)
12:00 PM
Background:
Recent research has highlighted the potential overlap between autism spectrum disorders (ASD) and specific language impairment (SLI) populations which note a significant proportion of first-degree relatives of autism probands have language-related learning disabilities, including SLI, and in a large epidemiological sample, siblings of SLI probands found an elevated risk of ASD. Behavioral studies of children with autism have highlighted a subgroup of verbal children with autism who have deficits in language that mirror those seen in SLI. There are also parallels between ASD and SLI at the neurobiological level with similar patterns of reversed asymmetry in inferior frontal cortex of older children as well as increased brain and white matter volumes. Because the few studies that have directly compared ASD and SLI have all been conducted with older children, it is not known whether there is overlap in the earliest manifestations for each of these disorders in specific symptoms or developmental timing.
Objectives:
This project's objective is to investigate the emergence of neural differences in key aspects of language and social-communicative development during the period between 6 and 12 months (a significant developmental window during which a number of critically important changes in language and social engagement emerge in typically developing infants) in infants who later go on to show signs of language impairment or ASD the.
Methods:
In the current longitudinal project we are employing high-density event-related potentials (ERPs) tasks to examine auditory processing at 6, 9 and 12-months of age. This study compares three groups of infants: (1) infants at risk for ASD (HRA), (2) infants at risk for SLI (HRL) and (3) low risk infants (LRC). This paradigm was based on a paradigm developed by Rivera-Glaxiola et al. (2005). It was selected because it can be used to chart developmental changes in speech perception in the first year of life and is sensitive to interesting individual differences that predict later language outcomes.
Results:
On the longitudinal data we have collected to date we conducted statistical analyses that were focused, preliminary analyses on the P1 and N250 components, collected from left and right hemisphere fronto-temporal leads, for the auditory stimuli. At 6 months for both components there were marginally significant group x hemisphere effects (e.g., P1 peak amplitude, (F (1, 23)= 2.19, p=.10). No effects were significant at 12 months, perhaps because of heterogeneity among both groups of infants.
Conclusions:
These pilot data suggest that compared to the LRC in both the HRA and HRL groups there is less asymmetry in response to speech sounds. These findings are consistent with neuroimaging studies of older children with these disorders and their family members. This portion of the larger research program will address more directly the shared and unshared characteristics of these disorders by comparing the early developmental patterns across language and social domains in infants at risk for these disorders using a combination of developmentally sensitive behavioral and neurophysiological measures.
Recent research has highlighted the potential overlap between autism spectrum disorders (ASD) and specific language impairment (SLI) populations which note a significant proportion of first-degree relatives of autism probands have language-related learning disabilities, including SLI, and in a large epidemiological sample, siblings of SLI probands found an elevated risk of ASD. Behavioral studies of children with autism have highlighted a subgroup of verbal children with autism who have deficits in language that mirror those seen in SLI. There are also parallels between ASD and SLI at the neurobiological level with similar patterns of reversed asymmetry in inferior frontal cortex of older children as well as increased brain and white matter volumes. Because the few studies that have directly compared ASD and SLI have all been conducted with older children, it is not known whether there is overlap in the earliest manifestations for each of these disorders in specific symptoms or developmental timing.
Objectives:
This project's objective is to investigate the emergence of neural differences in key aspects of language and social-communicative development during the period between 6 and 12 months (a significant developmental window during which a number of critically important changes in language and social engagement emerge in typically developing infants) in infants who later go on to show signs of language impairment or ASD the.
Methods:
In the current longitudinal project we are employing high-density event-related potentials (ERPs) tasks to examine auditory processing at 6, 9 and 12-months of age. This study compares three groups of infants: (1) infants at risk for ASD (HRA), (2) infants at risk for SLI (HRL) and (3) low risk infants (LRC). This paradigm was based on a paradigm developed by Rivera-Glaxiola et al. (2005). It was selected because it can be used to chart developmental changes in speech perception in the first year of life and is sensitive to interesting individual differences that predict later language outcomes.
Results:
On the longitudinal data we have collected to date we conducted statistical analyses that were focused, preliminary analyses on the P1 and N250 components, collected from left and right hemisphere fronto-temporal leads, for the auditory stimuli. At 6 months for both components there were marginally significant group x hemisphere effects (e.g., P1 peak amplitude, (F (1, 23)= 2.19, p=.10). No effects were significant at 12 months, perhaps because of heterogeneity among both groups of infants.
Conclusions:
These pilot data suggest that compared to the LRC in both the HRA and HRL groups there is less asymmetry in response to speech sounds. These findings are consistent with neuroimaging studies of older children with these disorders and their family members. This portion of the larger research program will address more directly the shared and unshared characteristics of these disorders by comparing the early developmental patterns across language and social domains in infants at risk for these disorders using a combination of developmentally sensitive behavioral and neurophysiological measures.