Fifteen adolescents and young adults with high-functioning autism spectrum disorders (ASD) and 18 age- and IQ-matched adults with typical development (TD) completed a serial reaction time task (SRT) to examine possible motor-linked implicit learning impairments in persons with ASD. Measures were taken to decrease the role of explicit learning in the SRT. Results showed that participants with ASD demonstrated intact motor-linked implicit learning. Furthermore, the motor-linked implicit learning appeared to take place at a similar rate across trials in the group with ASD compared to the group with TD. These results suggest that persons with ASD are successful in implicit learning of motor-linked behavior. The results of this study, coupled with past findings, suggest that people with ASD may be able to learn motor movements without conscious awareness, especially if the individual is older and is learning fine motor sequences.

Decision making plays a key role in daily function, but little is known regarding how individuals with autism spectrum disorder (ASD) make decisions. The present studies examined decision making in persons with ASD using the Iowa Gambling Task (IGT), a computerized card game with the goal of earning money by deciding among decks of cards. To be successful, players need to figure out which decks are associated with winning and which are associated with losing money in the long run. Results of Study 1 indicated that participants with ASD made poorer decisions and showed slower learning of which decks earned more money compared with participants with typical development. Additionally, they made more frequent shifts between decks compared with participants with typical development. In Study 2, undergraduate students with typical development completed the IGT to examine whether instructing them to make frequent shifts between decks early in the IGT would negatively impact their decision making. Results of Study 2 suggested that when participants with typical development were required to make frequent shifts, they exhibited a slower rate of learning and poorer decision making, thus emulating participants with ASD in Study 1. The combined results suggest that the way that persons with ASD explore and attend to their environment may be related to poor decision making. Implications for cognitive learning styles are discussed.

We used survey methodology to assess parent-reported autism symptomology in 758 individuals (639 males; 119 females) with fragile X syndrome (FXS). Caregivers reported whether their child with FXS had been diagnosed with an autism spectrum disorder (ASD) and endorsed symptoms based on a list of observable behaviors related to ASD diagnoses. Symptom counts were categorized based on DSM-IV-TR and DSM-5 criteria. Based on behavioral symptoms endorsed by caregivers, 38.7 % of males and 24.7 % of females met criteria for DSM-IV-TR diagnosis of autistic disorder. Significantly fewer males (27.8 %) and females (11.3 %) met criteria for ASD based on DSM-5 criteria. Although 86.4 % of males and 61.7 % of females met criteria for the restricted and repetitive behavior domain for DSM-5, only 29.4 % of males and 13.0 % of females met criteria for the social communication and interaction (SCI) domain. Relaxing the social communication criteria by one symptom count led to a threefold increase in those meeting criteria for ASD, suggesting the importance of subthreshold SCI symptoms for individuals with FXS in ASD diagnoses. Findings suggest important differences in the way ASD may be conceptualized in FXS based on the new DSM-5 criteria.

Differences in behavioral and cognitive profiles have been suggested to potentially impact the presentation of social and communication symptoms in females with autism spectrum disorder. This study examined gender differences in age of diagnosis, cognitive profiles, social communication symptomatology, and autism spectrum disorder symptom severity in a community-based sample of 566 males and 113 females with autism spectrum disorder ranging in age from 1 year, 9 months to 56 years, 4 months. Results suggest either very small or no gender differences in age at diagnosis, intelligence quotient, cognitive profiles, or autism spectrum disorder symptom severity. This is a departure from clinical lore that females with autism spectrum disorder are more likely to have lower intelligence quotient and more severe impairments. There is a slight difference in symptom severity with females having higher average total Childhood Autism Rating Scale scores, but this difference is likely of minimal clinical significance. In contrast, on the Autism Diagnostic Observation Schedule-Generic, females were found to receive lower scores than males particularly on modules 2 and 3. Across males and females, individuals with stronger verbal problem-solving skills were found to receive lower Autism Diagnostic Observation Schedule-Generic module 3 scores. Given the language demands of this module, additional attention may be warranted when evaluating older children and adolescents for autism spectrum disorder.

The present studies examined implicit contextual cueing in adolescents and adults with Autism Spectrum Disorder (ASD). In Study 1, 16 individuals with ASD and 20 matched individuals with typical development completed a contextual cueing task using stimulus-identity cues. In Study 2, 12 individuals with ASD and 16 individuals with typical development completed a revised version of the contextual cueing task, using both stimulus-identity cues and global spatial-configuration cues. The results suggest that when only stimulus-identity cues were provided, individuals with ASD had difficulty with implicit contextual cueing (Study 1). However, when both stimulus-identity and spatial-configuration contextual cues were provided, individuals with ASD demonstrated successful contextual cueing (Study 2). Nuances in implicit learning and clinical implications are discussed.

Numerous human studies have separately observed the effects of auditory stimuli at brain stem and cortical levels, but little research has focused on possible functional coupling between these diverse brain areas. The present study recorded the cortical C-process [5] evoked by a pitch change between two successive tones, as well as the brain stem frequency-following response (FFR) evoked by each tone. The results replicated expected C-process component waveforms, including a late, negative (N2) component. FFR spectral intensity differences between the two tones were significantly correlated with N2 amplitude. These results suggest that signal processing reflected in long-latency auditory evoked response components is not exclusively a cortical phenomenon, but also depends upon patterns of neural processing occurring in brain stem pathways.

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