Digit Ratio 2D:4D in Relation to Autism Spectrum Disorders, Empathizing, and Systemizing: A Quantitative Review
During fetal development, testosterone has effects that persist throughout life. It has been proposed that prenatal testosterone increases systemizing (the drive to understand lawful input–output relationships), that it decreases empathizing (the drive to understand others), and that it causes autism via hypermasculinization of the brain. Digit ratio 2D:4D, i.e. the length of the second (index) finger divided by the length of the fourth (ring) finger, appears to be a marker of prenatal testosterone levels. An online study with 1896 participants into the relationship between empathizing and 2D:4D is reported. This did not find evidence for a link between empathizing and 2D:4D in either females or males. Further, three quantitative reviews of relevant studies are presented that look into the relationships of 2D:4D with autism spectrum disorder (ASD), systemizing, and empathizing. 2D:4D was substantially lower (more masculine) in people affected by ASD than in normal controls. However, 2D:4D was found to be virtually unrelated to systemizing and empathizing in normal adults. The results support the idea that high prenatal testosterone is a risk factor for autism, but they challenge the view that prenatal testosterone substantially contributes to sex differences in systemizing and empathizing. Possibly, this pattern reflects that prenatal testosterone drives ASD characteristic changes only in brains that have been damaged otherwise. © 2012 INSAR/Wiley Periodicals, Inc.
Article citation: Autism Res 2012, 5: 221–230. DOI: 10.1002/aur.1230
Perceptual and Neural Response to Affective Tactile Texture Stimulation in Adults with Autism Spectrum Disorders
Carissa J. Cascio, Estephan J. Moana-Filho, Steve Guest, Mary Beth Nebel, Jonathan Weisner, Grace T. Baranek, Gregory K. Essick
People with autism spectrum disorders (ASD) often show differences in sensory sensitivity and emotional responses to their five senses. The sense of touch, although a frequent example of this, has been studied much less than vision and hearing in people with ASD. In early infancy, the sense of touch is more developed than vision or hearing; and touch is an important way that parents and babies communicate and bond, which in turn affects later development of social skills. Thus, it is important to understand more about how people with ASD perceive touch. We asked a group of adults with ASD and a comparison group of adults without ASD to rate three textures for how rough/smooth and how pleasant/unpleasant they felt. We also used brain imaging to look at how the brain responded to these three textures. The ratings of adults with ASD were similar to those of the comparison group. Even though the groups gave similar ratings, the brain response differed greatly between the groups. The ASD group showed much less response to all three textures than the comparison group in many brain areas that are known to respond to touch. For the most unpleasant texture, some brain regions were more responsive in the ASD group; these regions are important for evaluating emotional significance. These differences in brain response to touch might result in social touch feeling less enjoyable for people with ASD, which could contribute to social withdrawal. © 2012 INSAR/Wiley Periodicals, Inc.
Article citation: Autism Res 2012, 5: 231–244. DOI: 10.1002/aur.1224
Changes in the Sulcal Size Associated with Autism Spectrum Disorder Revealed by Sulcal Morphometry
Mahsa Shokouhi, Justin H. G. Williams, Gordon D. Waiter, Barrie Condon
Finding structural changes (biomarkers) in the brain of subjects with autism have been the subject of a number of magnetic resonance imaging studies. Investigating such structural changes can provide useful information about autism, and therefore, it is desirable to find new biomarkers. However, because of the complexity of this disorder, finding the appropriate biomarkers is a challenging task. In this study, the size of the cerebral sulci (the folds on the human cortex) has been estimated for a group of adolescents with autism and compared with those for healthy adolescents. This was done using the software package Brainvisa that automatically detects the cortical folds and identifies each sulcus (each specific fold). The properties of each sulcus, such as length and surface area, can then be calculated. We showed that either length or surface area of the sulci in the brain areas already known to be affected by the autism disorder are larger in subjects with autism compared with healthy individuals. Our findings therefore suggest that sulcal length and surface can reflect cortical abnormality associated with this disorder. © 2012 INSAR/Wiley Periodicals, Inc.
Article citation: Autism Res 2012, 5: 245–252. DOI: 10.1002/aur.1232
Same but Different: 9-Month-Old Infants at Average and High Risk for Autism Look at the Same Facial Features but Process Them Using Different Brain Mechanisms
Alexandra P. F. Key, Wendy L. Stone
Reduced attention to the eyes and/or increased focus on the mouth have been described as features of atypical face processing in individuals with autism spectrum disorders (ASD). In this study, we examined whether 9-month-old infants at average vs. high risk for ASD differ in their detection of changes in individual facial features (eyes vs. mouth) and whether this ability is related to infants' social and communicative skills. Eye-tracking data and electrical brain activity were recorded while infants viewed repeated presentations of a smiling unfamiliar female face. Occasionally, the eyes or the mouth of that face were replaced with corresponding parts from a different face. There were no group differences in the number or duration of fixations on the eye or mouth regions for any of the face stimuli. Brain activity data revealed that all infants detected both eye and mouth changes, and that these changes were associated with changes in activity of the face-specific perception mechanisms for average-risk infants only. For all infants, the size and speed of brain responses correlated with parental reports of communication use and understanding, suggesting that differences in brain processing of faces and their features in infants are associated with individual differences in early communication skills. © 2012 INSAR/Wiley Periodicals, Inc.
Article citation: Autism Res 2012, 5: 253–266. DOI: 10.1002/aur.1231
The ADOS Calibrated Severity Score: Relationship to Phenotypic Variables and Stability over Time
Stacy Shumway, Cristan Farmer, Audrey Thurm, Lisa Joseph, David Black, Christine Golden
Measuring the severity of autism is a challenge for researchers and clinicians. Recently, Gotham, Pickles, & Lord (2009) addressed this issue by creating calibrated severity scores (CSS) based on raw total scores of the Autism Diagnostic Observation Schedule (ADOS), a standardized measure commonly used in autism diagnosis. We tested the utility of the CSS by comparing its scores to raw scores from the ADOS in a sample of 368 children aged 2 to 12 years with autism, pervasive developmental disorder-not otherwise specified (PDD-NOS), non-spectrum delay, or typical development. As expected, we found that the CSS were more uniformly distributed within diagnostic categories and across ADOS modules than were raw scores. In particular, CSS were useful in controlling for differences in verbal development. Follow-up evaluations showed good temporal stability of the CSS over 12 to 24 months in children with autism. The results of this study support the use of the CSS to measure the severity of the core symptoms of autism. Further research is needed to determine if the CSS can also be used to measure changes in symptom severity and serve as a tool for clinical research. © 2012 INSAR/Wiley Periodicals, Inc.
Article citation: Autism Res 2012, 5: 267–276. DOI: 10.1002/aur.1238
Haploinsufficiency of CMIP in a Girl With Autism Spectrum Disorder and Developmental Delay due to a De Novo Deletion on Chromosome 16q23.2
Nathalie Van der Aa, Geert Vandeweyer, Edwin Reyniers, Sandra Kenis, Lina Dom, Geert Mortier, Liesbeth Rooms, R. Frank Kooy
In a patient with autism spectrum disorder (ASD), we identified a deletion of a single gene on chromosome 16. This gene, called CMIP, was found by others to be involved in speech disorders. It is not uncommon that a single gene disturbs multiple pathways in the brain, and we hypothesize that the deletion in this patient contributes to the autism in our patient. Thus, we present CMIP as a novel candidate gene for ASD. © 2012 INSAR/Wiley Periodicals, Inc.
Article citation: Autism Res 2012, 5: 277–281. DOI: 10.1002/aur.1240
Selective Attention to Facial Emotion and Identity in Children With Autism: Evidence for Global Identity and Local Emotion
Yongning Song, Yuji Hakoda
Determining whether faces are recognized on the basis of their individual features, or whether the identity of faces is determined more holistically, on the basis of their overall shape, is an important issue in face recognition research. The present study sought to test the global-identity and local-emotion processing hypothesis in face perception, by examining emotional interference in face perception in children with high-functioning autism who are thought to be weak in global-oriented processing. We compared the performance on a classical selective attention tasks in study of face (Garner paradigm) between a group of children diagnosed with autism spectrum disorder (ASD) (n = 15) and a paired non-ASD group (n = 18). The emotional interference rather than identity interference revealed in ASD suggested that emotion judgment mainly depends on local processing, while identity judgment mainly depends on global processing. The traits of processing to facial emotion were also discussed in this study. © 2012 INSAR/Wiley Periodicals, Inc.
Article citation: Autism Res 2012, 5: 282–285. DOI: 10.1002/aur.1242