Differential Diagnosis of Autism Spectrum Disorder Versus Language Disorder in Children Ages 2 to 5 Years: Contributions of Parent-Reported Development and Behavior.

Early diagnosis of autism spectrum disorder (ASD) has focused on differentiating children with ASD from neurotypical children. However, many children presenting with concern for ASD are ultimately diagnosed with language disorder (LD). This study aimed to identify differences in parent-rated development and behavior among children ages 2 to 5 years presenting with concern for ASD who were diagnosed with either ASD or LD. Children with ASD were rated as more socially withdrawn and more delayed in social development and self-help skills than those with LD. Parent-rated developmental delays were positively correlated with scores on an autism screening measure and with social withdrawal and pervasive developmental problems among children with ASD. Among those with LD, parent-rated social and self-help development were positively correlated with social withdrawal and attention problems. Thus, parent ratings of social withdrawal and development of social and self-help skills may facilitate differential diagnosis of ASD and LD in children ages 2 to 5 years.

Visual Attention and Math Performance in Survivors of Childhood Acute Lymphoblastic Leukemia.

OBJECTIVE: Attentional and academic difficulties, particularly in math, are common in survivors of childhood acute lymphoblastic leukemia (ALL). Of cognitive deficits experienced by survivors of childhood ALL, attention deficits may be particularly responsive to intervention. However, it is unknown whether deficits in particular aspects of attention are associated with deficits in math skills. The current study investigated relationships between math calculation skills, performance on an objective measure of sustained attention, and parent- and teacher-reported attention difficulties. METHOD: Twenty-four survivors of childhood ALL (Mage = 13.5 years, SD = 2.8 years) completed a computerized measure of sustained attention and response control and a written measure of math calculation skills in the context of a comprehensive clinical neuropsychological evaluation. Parent and teacher ratings of inattention and impulsivity were obtained. RESULTS: Visual response control and visual attention accounted for 26.4% of the variance observed among math performance scores after controlling for IQ (p < .05). Teacher-rated, but not parent-rated, inattention was significantly negatively correlated with math calculation scores. CONCLUSIONS: Consistency of responses to visual stimuli on a computerized measure of attention is a unique predictor of variance in math performance among survivors of childhood ALL. Objective testing of visual response control, rather than parent-rated attentional problems, may have clinical utility in identifying ALL survivors at risk for math difficulties.

Patterns of altered neural synchrony in the default mode network in autism spectrum disorder revealed with magnetoencephalography (MEG): Relationship to clinical symptomatology.

Disrupted neural synchrony may be a primary electrophysiological abnormality in autism spectrum disorders (ASD), altering communication between discrete brain regions and contributing to abnormalities in patterns of connectivity within identified neural networks. Studies exploring brain dynamics to comprehensively characterize and link connectivity to large-scale cortical networks and clinical symptoms are lagging considerably. Patterns of neural coherence within the Default Mode Network (DMN) and Salience Network (SN) during resting state were investigated in 12 children with ASD (MAge = 9.2) and 13 age and gender-matched neurotypicals (NT) (MAge = 9.3) with magnetoencephalography. Coherence between 231 brain region pairs within four frequency bands (theta (4-7 Hz), alpha, (8-12 Hz), beta (13-30 Hz), and gamma (30-80 Hz)) was calculated. Relationships between neural coherence and social functioning were examined. ASD was characterized by lower synchronization across all frequencies, reaching clinical significance in the gamma band. Lower gamma synchrony between fronto-temporo-parietal regions was observed, partially consistent with diminished default mode network (DMN) connectivity. Lower gamma coherence in ASD was evident in cross-hemispheric connections between: angular with inferior/middle frontal; middle temporal with middle/inferior frontal; and within right-hemispheric connections between angular, middle temporal, and inferior/middle frontal cortices. Lower gamma coherence between left angular and left superior frontal, right inferior/middle frontal, and right precuneus and between right angular and inferior/middle frontal cortices was related to lower social/social-communication functioning. Results suggest a pattern of lower gamma band coherence in a subset of regions within the DMN in ASD (angular and middle temporal cortical areas) related to lower social/social-communicative functioning. Autism Res 2018, 11: 434-449. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Communication between different areas of the brain was observed in children with ASD and neurotypical children while awake, but not working on a task. Magnetoencephalography was used to measure tiny magnetic fields naturally generated via brain activity. The brains of children with ASD showed less communication between areas that are important for social information processing compared to the brains of neurotypical children. The amount of communication between these areas was associated with social and social communication difficulties.

Magnetoencephalography shows atypical sensitivity to linguistic sound sequences in autism spectrum disorder.

Neuroscientific evidence points toward atypical auditory processing in individuals with autism spectrum disorders (ASD), and yet, the consequences of this for receptive language remain unclear. Using magnetoencephalography and a passive listening task, we test for cascading effects on speech sound processing. Children with ASD and age-matched control participants (8-12 years old) listened to nonce linguistic stimuli that either did or did not conform to the phonological rules that govern consonant sequences in English (e.g. legal 'vimp' vs. illegal 'vimk'). Beamformer source analysis was used to isolate evoked responses (0.1-30 Hz) to these stimuli in the left and the right auditory cortex. Right auditory responses from participants with ASD, but not control participants, showed an attenuated response to illegal sequences relative to legal sequences that emerged around 330 ms after the onset of the critical phoneme. These results suggest that phonological processing is impacted in ASD, perhaps because of cascading effects from disrupted initial acoustic processing.

Visual attention shifting in autism spectrum disorders.

INTRODUCTION: Abnormal visual attention has been frequently observed in autism spectrum disorders (ASD). Abnormal shifting of visual attention is related to abnormal development of social cognition and has been identified as a key neuropsychological finding in ASD. Better characterizing attention shifting in ASD and its relationship with social functioning may help to identify new targets for intervention and improving social communication in these disorders. Thus, the current study investigated deficits in attention shifting in ASD as well as relationships between attention shifting and social communication in ASD and neurotypicals (NT). METHOD: To investigate deficits in visual attention shifting in ASD, 20 ASD and 20 age- and gender-matched NT completed visual search (VS) and Navon tasks with attention-shifting demands as well as a set-shifting task. VS was a feature search task with targets defined in one of two dimensions; Navon required identification of a target letter presented at the global or local level. Psychomotor and processing speed were entered as covariates. Relationships between visual attention shifting, set shifting, and social functioning were also examined. RESULTS: ASD and NT showed comparable costs of shifting attention. However, psychomotor and processing speed were slower in ASD than in NT, and psychomotor and processing speed were positively correlated with attention-shifting costs on Navon and VS, respectively, for both groups. Attention shifting on VS and Navon were correlated among NT, while attention shifting on Navon was correlated with set shifting among ASD. Attention-shifting costs on Navon were positively correlated with restricted and repetitive behaviors among ASD. CONCLUSIONS: Relationships between attention shifting and psychomotor and processing speed, as well as relationships between measures of different aspects of visual attention shifting, suggest inefficient top-down influences over preattentive visual processing in ASD. Inefficient attention shifting may be related to restricted and repetitive behaviors in these disorders.

Neural synchrony examined with magnetoencephalography (MEG) during eye gaze processing in autism spectrum disorders: preliminary findings.

BACKGROUND: Gaze processing deficits are a seminal, early, and enduring behavioral deficit in autism spectrum disorder (ASD); however, a comprehensive characterization of the neural processes mediating abnormal gaze processing in ASD has yet to be conducted. METHODS: This study investigated whole-brain patterns of neural synchrony during passive viewing of direct and averted eye gaze in ASD adolescents and young adults (M Age = 16.6) compared to neurotypicals (NT) (M Age = 17.5) while undergoing magnetoencephalography. Coherence between each pair of 54 brain regions within each of three frequency bands (low frequency (0 to 15 Hz), beta (15 to 30 Hz), and low gamma (30 to 45 Hz)) was calculated. RESULTS: Significantly higher coherence and synchronization in posterior brain regions (temporo-parietal-occipital) across all frequencies was evident in ASD, particularly within the low 0 to 15 Hz frequency range. Higher coherence in fronto-temporo-parietal regions was noted in NT. A significantly higher number of low frequency cross-hemispheric synchronous connections and a near absence of right intra-hemispheric coherence in the beta frequency band were noted in ASD. Significantly higher low frequency coherent activity in bilateral temporo-parieto-occipital cortical regions and higher gamma band coherence in right temporo-parieto-occipital brain regions during averted gaze was related to more severe symptomology as reported on the Autism Diagnostic Interview-Revised (ADI-R). CONCLUSIONS: The preliminary results suggest a pattern of aberrant connectivity that includes higher low frequency synchronization in posterior cortical regions, lack of long-range right hemispheric beta and gamma coherence, and decreased coherence in fronto-temporo-parietal regions necessary for orienting to shifts in eye gaze in ASD; a critical behavior essential for social communication.

Impaired prefrontal gamma band synchrony in autism spectrum disorders during gaze cueing.

Orienting to eye gaze is a vital social skill that is absent or developmentally delayed in autism spectrum disorders (ASD). Neural synchrony in the gamma frequency band is believed to be involved in perceptual and cognitive functions such as eye-gaze processing, and has been found to be abnormal in ASD. The current study used magnetoencephalography to measure neural synchrony in the gamma frequency band in neurotypicals (n=8) and individuals with ASD (n=10) while performing a directional eye-gaze processing task. Results support impaired generation of neural synchrony in the gamma frequency band during eye-gaze processing in ASD. Impaired gamma oscillatory activity in the prefrontal cortex may be associated with impairments in social cognitive functions such as eye-gaze processing in ASD.

Persistence, diagnostic specificity and genetic liability for context-processing deficits in schizophrenia.

Context-processing deficits have been shown in schizophrenia during first-episode, medication-naïve status, that persist after short-term antipsychotic treatment and also in first-degree relatives of individuals with schizophrenia. To confirm longer term persistence of deficits, we examined schizophrenia patients (n=63) during first-episode, medication-naïve status through to one-year follow-up, compared to healthy control (n=83) and non-schizophrenia psychosis comparison (n=47) groups, as well as unaffected first-degree relatives of individuals with schizophrenia (n=31). Context-processing ability was assessed by performance on the AX-CPT (Continuous Performance Test) at baseline, 8 weeks, 6 months, and 1 year (relatives only at baseline). Reaction time, error rates and signal detection indices (d'-context) of context processing were analyzed. Linear discriminant analyses (LDA) on early timepoints (baseline, 8 weeks) were conducted to predict confirmatory diagnosis (schizophrenia vs. psychosis control) at 6 months. Schizophrenia patients showed evidence of impaired context-processing relative to both the healthy and psychosis comparator groups at baseline and continued through to 1 year. While context-processing impairments persisted in schizophrenia patients through one year, the impairments in psychosis controls, which were more modest at baseline, remitted at follow-up. First-degree relatives showed deficits that were intermediate between the schizophrenia and healthy control groups. LDA showed 67% classification rates for distinguishing schizophrenia from non-schizophrenia psychosis. The persistence, diagnostic specificity and association with genetic liability give support for context processing impairments serving as a cognitive endophenotype for schizophrenia and evaluation of context processing could contribute to diagnostic assessments.