The consortium seeks to achieve the following specific aims:
Aim 1: Compare whether laboratory based (LB) measures versus clinician and caregiver assessments of specific domains of social impairment are more sensitive indicators of (i.e., more strongly correlated with) clinical status. Correlations among the LB measures and clinician and caregiver assessments will also be examined at each time point and across time points.
Aim 2: Evaluate whether a well-justified set of ET and EEG measures, individually or in combination, has potential utility as stratification biomarkers and/or sensitive and reliable measures of change in clinical trials. Specifically, we will assess the technical and biological variability of the biomarkers and their relationship with measures of social impairment in order to evaluate the viability of biomarkers in terms of:
a. Construct validity demonstrated by task-specific brain activation and signal strength (i.e., modulation of EEG spectral power and event-related potential (ERP) latency/amplitude in accordance with experimental manipulation). b. Test-retest reliability, consistency, and stability in the sample overall and separately by site and diagnostic group; this will demonstrate that measurements of the potential biomarkers are replicable within subjects, are robust to practice effects, remain stable when underlying clinical status is unchanged, and can be consistently measured across experimental locations and time points, making them suitable for use in multi-site longitudinal clinical trials.
c. Discriminant validity reflected in sensitivity to detect differences between ASD and TD subjects’ performance on the measures at each time point and across time points. d. Convergent validity shown by reliable correlation (i.e., consistent patterns of inter-subject variability) of EEG and ET measures with social-communicative impairment (as assessed by LB and clinician/caregiver assessments) and clinical status (as assessed by independent rater) at each time point.
e. Sensitivity to change, assessed in terms of how change in EEG and ET measures corresponds to intra-subject natural course variability in social-communicative impairment and clinical status across time points.
Aim 3: Collect blood (DNA) samples from all subjects, including parents of ASD subjects, for future genomic analyses and share raw, processed, and analyzed data via the NDAR and NIH/NIMH Data Repositories to create a community resource accessible for use by all qualified investigators.