The perception results.

<p>Perceptual discrimination threshold (morph-level difference necessary to perform at 75% correct) for the four categories for children with ASD versus age and IQ-matched typical children. Results indicate deficits in body perception in children with ASD. Error bars denote SEM. *** denotes p<.001.</p

The memory results.

<p>Memory accuracy in percent correct for each of the four stimulus categories for children with ASD versus age and IQ-matched typical children. Results indicate a deficit in face and body memory in children with ASD. Chance was 50% indicated by the horizontal line. Error bars denote SEM. ** denotes p<.01, *** denotes p<.001.</p

Direct comparison between memory and perception data.

<p>Mean across ASD participants of the standardized score for each participant (i.e., the standard deviation of each participant from the typical population) for each stimulus category for memory (left) and perception (right). Values below zero indicate an impairment in ASD. ** denotes p<.01.</p

Amygdala development

<p>The DWI connectivity of 166 individuals ranging from ages 5-30 is provided in this mat file, along with other demographic information (e.g. sex, age, group).  The mean connectivity of each amygdala voxel to each brain region is provided, along with overall connectivity, and connectivity of each individual nucleus group.  Please email the corresponding author for further information as needed.</p

Probabilistic tracts of amygdala connectivity for two example subjects.

<p>Probability maps are thresholded at 0.1 of maximum connection probability for each subject and overlaid on the same subject’s low-b diffusion image. These depict all possible tracts that the tractography algorithm used to connect the left and right amygdalae with all other target regions (i.e. the rest of the brain). Top images are the sagittal sections showing the slice locations for the coronal sections below for the adult subject (left column) and child subject (right column). Coronal slices progress posterior to anteriorly through each subject’s brain. Each slice corresponds to a similar anatomical location in both subjects but the match is not perfect due to differences in head orientation and anatomy. The adult and child subject show the same major pathways that are reconstructed by the tractography algorithm. However, the example child’s map illustrates more widespread connections than the adult participant’s map; e.g. to parietal and temporal regions; see 4^th and 5^th row from the bottom.</p

Magnitude of developmental changes.

<p>Magnitude of developmental changes.</p

Amygdala volume across age.

<p>Amygdala volume is plotted by age. Volume does not correlate with age in either the <b>a.</b> left or <b>b.</b> right amygdala (left: <i>r</i> = 0.13, <i>p</i> = 0.11; right: <i>r</i> = –0.02 <i>p</i> = 0.80).</p

Mean connectivity values with age.

<p>Mean connectivity values per participant are plotted by age and were significantly correlated for the <b>a.</b> left and <b>b.</b> right amygdala (left: <i>r</i> = –0.43, <i>p</i> = 1.41x10^-8; right: <i>r</i> = –0.50, <i>p</i> = 1.59x10^-11). Dashed lines indicate 95% confidence intervals.</p

Correlations of age with mean connectivity for the four amygdala subregions.

<p>A probabilistic atlas of four amygdala subregions (illustrated in the center; coronal slice) was used to extract mean connectivity values from each subregion bilaterally per subject and plotted by age. While connectivity with the basal, lateral, and central subregions were significantly correlated with age, connectivity with the medial amygdala showed no significant change with age.</p

Mean number of ipsilateral target regions that the amygdala connects with in children and adults.

<p>Each amygdala voxel’s connectivity vector to all other target regions is thresholded at 0.1, binarized, and averaged across the amygdala per individual. In children, the amygdala showed connectivity (above 0.1) to a greater number of target regions on average than adults in both left (C: 5.57±0.18, A: 4.50± 0.16) and right (C: 5.81± 0.18, A: 4.48±0.13).</p