Adolescents with Autism Spectrum Disorders (ASD) and typically developing (TD) controls underwent a rigorous psychophysical assessment that measured contrast sensitivity to seven spatial frequencies (0.5 to 20 cycles/degree). A contrast sensitivity function (CSF) was then fitted for each participant, from which four measures were obtained: visual acuity, peak spatial frequency, peak contrast sensitivity, and contrast sensitivity at a low spatial frequency. There were no group differences on any of the four CSF measures, indicating no differential spatial frequency processing in ASD.Although it has been suggested that detail-oriented visual perception in individuals with ASD may be a result of differential sensitivities to low vs. high spatial frequencies, the current study finds no evidence to support this hypothesis.

The modified checklist for autism in toddlers (M-CHAT) is a tool developed for 16-30 month old children to screen for autism spectrum disorders (ASD). It is a well-researched tool, but little is known about its utility with Singaporean toddlers and with older children referred for developmental concerns. This study investigated the M-CHAT's performance with 18-30 month old (N = 173) and >30-48 month old (N = 407) developmentally at-risk Singaporean children, when used with three recommended scoring methods i.e., the total, critical and Best7 scoring methods. The results indicate that the critical and Best7 scoring methods detected most true cases of ASD without inflating the false positive rates in toddlers, and that only the total scoring method performed acceptably for the older children.

The magnocellular (M) pathway hypothesis proposes that impaired visual motion perception observed in individuals with Autism Spectrum Disorders (ASD) might be mediated by atypical functioning of the subcortical M pathway, as this pathway provides the bulk of visual input to cortical motion detectors. To test this hypothesis, we measured luminance and chromatic contrast sensitivity, thought to tap M and Parvocellular (P) pathway processing respectively. We also tested the hypothesis that motion processing is impaired in ASD using a novel paradigm that measures motion processing while controlling for detectabilty. Specifically, this paradigm compares contrast sensitivity for detection of a moving grating with contrast sensitivity for direction-of-motion discrimination of that same moving grating. Contrast sensitivities from adolescents with ASD were compared to typically-developing adolescents, and also unaffected siblings of individuals with ASD (SIBS). The results revealed significant group differences on P, but not M, pathway processing, with SIBS showing higher chromatic contrast sensitivity than both participants with ASD and TD participants. This atypicality, unique to SIBS, suggests the possible existence of a protective factor in these individuals against developing ASD. The results also revealed impairments in motion perception in both participants with ASD and SIBS, which may be an endophenotype of ASD. This impairment may be driven by impairments in motion detectors and/or by reduced input from neural areas that project to motion detectors, the latter possibility being consistent with the notion of reduced connectivity between neural areas in ASD.

Further revisions to the checklists can include simplifying the words and sentences and providing relevant pictures to aid understanding. If the checklists are to be used for screening, standardization of how the checklists are to be completed and how children at risk of developmental delays can be identified on the checklists need to be provided. Parents' awareness of the importance of evaluating their child's development at 9 months, 18 months, and particularly at 2.5 years, needs to be raised. Developmental screening for children at these critical ages can be made mandatory. An electronic version of the health booklet is likely to facilitate implementation of developmental screening in the health care system.

Field-independence, or weak central coherence, is a recognised phenotype of autism spectrum disorder (ASD). There is also evidence of cultural variation in this perceptual style, as neurotypical individuals from Western nations are more field-independent than neurotypical individuals from East-Asian nations. The majority of research on perceptual style in those with ASD has been carried out in Western nations therefore it is unclear whether increased field-independence in ASD is a culturally universal phenotype. Here, we assessed perceptual style in children with and without ASD from England and Singapore using the Children's Embedded Figures Test and the Framed-Line Test. We found increased field-independence in the English participants with ASD only, suggesting that weak central coherence in ASD is not culturally universal.