Auditory spatial attention to speech and complex non-speech sounds in children with autism spectrum disorder.

One of the earliest observable impairments in autism spectrum disorder (ASD) is a failure to orient to speech and other social stimuli. Auditory spatial attention, a key component of orienting to sounds in the environment, has been shown to be impaired in adults with ASD. Additionally, specific deficits in orienting to social sounds could be related to increased acoustic complexity of speech. We aimed to characterize auditory spatial attention in children with ASD and neurotypical controls, and to determine the effect of auditory stimulus complexity on spatial attention. In a spatial attention task, target and distractor sounds were played randomly in rapid succession from speakers in a free-field array. Participants attended to a central or peripheral location, and were instructed to respond to target sounds at the attended location while ignoring nearby sounds. Stimulus-specific blocks evaluated spatial attention for simple non-speech tones, speech sounds (vowels), and complex non-speech sounds matched to vowels on key acoustic properties. Children with ASD had significantly more diffuse auditory spatial attention than neurotypical children when attending front, indicated by increased responding to sounds at adjacent non-target locations. No significant differences in spatial attention emerged based on stimulus complexity. Additionally, in the ASD group, more diffuse spatial attention was associated with more severe ASD symptoms but not with general inattention symptoms. Spatial attention deficits have important implications for understanding social orienting deficits and atypical attentional processes that contribute to core deficits of ASD. Autism Res 2017, 10: 1405-1416. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

Language effects in second-language learners: A longitudinal electrophysiological study of spanish classroom learning.

How do the neural mechanisms involved in word recognition evolve over the course of word learning in adult learners of a new second language? The current study sought to closely track language effects, which are differences in electrophysiological indices of word processing between one's native and second languages, in beginning university learners over the course of a single semester of learning. Monolingual L1 English-speakers enrolled in introductory Spanish were first trained on a list of 228 Spanish words chosen from the vocabulary to be learned in class. Behavioral data from the training session and the following experimental sessions spaced over the course of the semester showed expected learning effects. In the three laboratory sessions participants read words in three lists (English, Spanish and mixed) while performing a go/no-go lexical decision task in which event-related potentials (ERPs) were recorded. As observed in previous studies there were ERP language effects with larger N400s to native than second language words. Importantly, this difference declined over the course of L2 learning with N400 amplitude increasing for new second language words. These results suggest that even over a single semester of learning that new second language words are rapidly incorporated into the word recognition system and begin to take on lexical and semantic properties similar to native language words. Moreover, the results suggest that electrophysiological measures can be used as sensitive measures for tracking the acquisition of new linguistic knowledge.

CSF concentrations of 5-methyltetrahydrofolate in a cohort of young children with autism.

OBJECTIVE: To examine the association between cerebral folate deficiency and autism, this study examined CSF 5-methyltetrahydrofolate (5-MTHF) concentrations in a group of young children with autism, investigated the natural variation in CSF 5-MTHF over time, and assessed the relationship between CSF 5-MTHF and symptoms. METHODS: CSF was collected from 67 children with a diagnosis of DSM-IV-TR autistic disorder (age, mean ± SD 43 ± 11 months), with a second CSF sample obtained 1-3 years later on 31 of these subjects (time to follow-up, 30 ± 8 months). RESULTS: At time 1, 7% (5/67) of participants had 5-MTHF <40 nmol/L. At follow-up, 23% (7/31) of participants had 5-MTHF <40 nmol/L (only one of whom had been low at time 1). A moderate correlation with a very wide confidence interval (CI) was observed between time 1 and time 2 CSF 5-MTHF measurements (Pearson r[p] = 0.38 [0.04]; 95% CI 0.02-0.64). Neither the CSF 5-MTHF levels nor changes over time correlated with the clinical features of autism. CONCLUSIONS: CSF 5-MTHF levels vary significantly over time in an unpredictable fashion and do not show a significant relationship to typical clinical features of autism. Reduced CSF 5-MTHF levels are a nonspecific finding in autism. Our data do not support the use of lumbar puncture for assessment of CSF 5-MTHF in autism.

Dietary adequacy of children with autism compared with controls and the impact of restricted diet.

OBJECTIVE: Children with autism (AUT) may consume a restricted diet relative to typical peers, whether due to therapeutic measures or sensory sensitivities. The objective of this study was to compare children with AUT with both typically developing (TYP) and developmentally delayed children on nutrient and food group intake and overall diet quality and to evaluate the impact of diet restriction. METHODS: Three-day food records and interview information were analyzed from 69 children with AUT, 14 children with developmental delay, and 37 TYP children, drawn from a larger longitudinal study. RESULTS: Children with AUT did not differ significantly from children with other developmental delays on any dietary measures. Although there were differences in the average intake of some nutrients between AUT and typical controls, only calcium and dairy were also less likely to be consumed in adequate amounts by the AUT group. Intentional diet restriction accounted for most of the differences between AUT and typical controls. On average, all groups had inadequate fiber, vitamin D, and vegetable intake. Inadequate intake of folate, grains, and dairy was noted for the AUT subgroup with intentional diet restrictions. Children in the AUT group not following a restricted diet received significantly worse Healthy Eating Index-2005 scores than those following a restricted diet and typical controls. These differences were not nutritionally significant. CONCLUSIONS: When evaluating nutritional adequacy of children with AUT, special consideration should be given to calcium, folate, dairy, and grains. Diets of all children with AUT should be evaluated for idiosyncratic deficiencies because of unique dietary patterns.