Accurate age classification of 6 and 12 month-old infants based on resting-state functional connectivity magnetic resonance imaging data

Human large-scale functional brain networks are hypothesized to undergo significant changes over development. Little is known about these functional architectural changes, particularly during the second half of the first year of life. We used multivariate pattern classification of resting-state functional connectivity magnetic resonance imaging (fcMRI) data obtained in an on-going, multi-site, longitudinal study of brain and behavioral development to explore whether fcMRI data contained information sufficient to classify infant age. Analyses carefully account for the effects of fcMRI motion artifact. Support vector machines (SVMs) classified 6 versus 12 month-old infants (128 datasets) above chance based on fcMRI data alone. Results demonstrate significant changes in measures of brain functional organization that coincide with a special period of dramatic change in infant motor, cognitive, and social development. Explorations of the most different correlations used for SVM lead to two different interpretations about functional connections that support 6 versus 12-month age categorization

Impaired eye region search accuracy in children with autistic spectrum disorders.

To explore mechanisms underlying reduced fixation of eyes in autism, children with autistic spectrum disorders (ASD) and typically developing children were tested in five visual search experiments: simple color feature; color-shape conjunction; face in non-face objects; mouth region; and eye region. No group differences were found for reaction time profile shapes in any of the five experiments, suggesting intact basic search mechanics in children with ASD. Contrary to early reports in the literature, but consistent with other more recent findings, we observed no superiority for conjunction search in children with ASD. Importantly, children with ASD did show reduced accuracy for eye region search (p = .005), suggesting that eyes contribute less to high-level face representations in ASD or that there is an eye region-specific disruption to attentional processes engaged by search in ASD

Face in non-face-object search.

<p><i>A:</i> Contrary to our prediction, both groups accurately searched for faces in arrays of non-face objects. <i>B:</i> Both groups showed shallow target-present/steep target-absent RT profiles. ASD children were not slower than typical children. <i>C:</i> Both groups evidenced poor central fixation.</p

Clinical Information for Conjunction.

<p>(Age, WISC, SRS, N = 55; SWAN, CBCL, N = 54).</p>*<p>Positive SWAN scores indicate superior attention and negative scores reflect ADHD symptoms.</p

Eyes-absent search.

<p><i>A:</i> Eye region search accuracy was significantly worse in ASD. <i>B:</i> However, both groups showed similar, shallow target-present/steep target-absent RT functions. <i>C:</i> Fixation was marginally better and not different across groups.</p

Mouth-absent search.

<p>There was no ASD advantage for mouth region search, as measured by <i>A:</i> Accuracy. <i>B:</i> RT. Both groups showed shallow target-present/steep target-absent RT profiles. <i>C:</i> Fixation was poor, with a trend for worse fixation in ASD.</p

Color search.

<p><i>A:</i> Accuracy (% correct) versus array size. <i>B:</i> RT versus array size; Color search was accurate and efficient for both groups. <i>C:</i> Percent of trials fixated, measured with horizontal EOG. ASD children trended for poorer fixation. All plotted Standard Error of the Means (SEMs) are adjusted for repeated measures (error bar = 1 adjusted SEM).</p

Clinical Information for Color, Face, Mouth-Absent, and Eyes-Absent.

<p>(Age, WISC, SRS, N = 60; Swan, CBCL, N = 59).</p>*<p>Positive SWAN scores indicate superior attention and negative scores reflect ADHD symptoms.</p