White Matter Integrity in Asperger Syndrome: A Preliminary Diffusion Tensor Magnetic Resonance Imaging Study in Adults
Oswald J.N. Bloemen, Quinton Deeley, Fred Sundram, Eileen M. Daly, Gareth J. Barker, Derek K. Jones, Therese A.M.J. van Amelsvoort, Nicole Schmitz, Dene Robertson, Kieran C. Murphy, and Declan G.M. Murphy
There is a consensus that autism, and Asperger syndrome, is a developmental disorder and has a biological basis. It has been proposed that altered connectivity in the white matter of the brain may be one of the contributing causes of the symptoms of autism. This has not been investigated in Asperger syndrome. We used MRI scans to measure connectivity of whole brain white matter in 13 adults with Asperger syndrome and compared this to 13 healthy controls. The groups did not differ significantly in overall intelligence or age. We found that adults with Asperger syndrome had a significantly lower connectivity than controls in widespread regions of the brain. © 2010 INSAR/Wiley Periodicals, Inc.
Article Citation:Autism Res2010, 3: 203–213. DOI: 10.1002/aur.146
Perception of Emotion in Musical Performance in Adolescents with Autism Spectrum Disorders
Anjali Bhatara, Eve-Marie Quintin, Bianca Levy, Ursula Bellugi, Eric Fombonne, and Daniel J. Levitin
Individuals with autism spectrum disorders (ASD) are impaired in understanding many emotional aspects of speech. Much of the emotion in speech is conveyed through prosody, which consists of the loudness and speed of the voice over and above the words themselves. In music performance, emotion is communicated in a similar fashion, using changes in timing and loudness of the music to convey emotion. Here, we manipulated that timing and loudness variation in musical performances, creating different levels of expressivity. We then asked children and adolescents with ASD, healthy control children and adolescents, and individuals with Williams syndrome to rate how emotional these musical performances sounded. Results showed that the children and adolescents with ASD were less able than the control group or the group with Williams syndrome to judge the difference in emotionality among the levels of expressivity. © 2010 INSAR/Wiley Periodicals, Inc.
Article Citation:Autism Res2010, 3: 214–225. DOI: 10.1002/aur.147
Prototypical Category Learning in High-Functioning Autism
Tony Vladusich, Olufemi Olu-Lafe, Dae-Shik Kim, Helen Tager-Flusberg, and Stephen Grossberg
Do individuals with autism learn object categories in a typical manner? An example of prototypical category learning is the ability to classify coffee cups of varying shape, size and color into a single object-level representation that we know as “cup”. Here we investigate this question with a classical psychological paradigm. In two experiments, we find evidence that a group of young autistic men learn visual prototypes typically, relative to a control group matched for age and IQ. We conclude that high-functioning autistic individuals do not experience severely compromised mechanisms of prototypical category learning. © 2010 INSAR/Wiley Periodicals, Inc.
Article Citation:Autism Res2010, 3: 226–236. DOI: 10.1002/aur.148
Principal Pathogenetic Components and Biological Endophenotypes in Autism Spectrum Disorders
Roberto Sacco, Paolo Curatolo, Barbara Manzi, Roberto Militerni, Carmela Bravaccio, Alessandro Frolli, Carlo Lenti, Monica Saccani, Maurizio Elia, Karl-Ludvig Reichelt, Tiziana Pascucci, Stefano Puglisi-Allegra, and Antonio M. Persico
In this study, Sacco and Colleagues search for basic mechanisms underlying autism spectrum disorder by analyzing several important clinical characteristics, using a complex statistical approach on data collected from 245 Italian patients. The authors identify at least four components that could play a relevant role in this disease: “sensory dysfunction and abnormalities in the sleep-wake rhythm”, “immune system abnormalities” also including maternal complications during pregnancy and/or repeated spontaneous abortions, “cognitive/motor developmental delay” and “repetitive behavior”. Interestingly, at least some of these components appear to be positively associated with one of three biological measures also assessed in this study, namely head circumference, serotonin blood levels and global amounts of peptides present in the urines. In particular, immune abnormalities, repetitive behaviors, and developmental delay appear correlated at least to some extent with greater head size, increased serotonin blood levels, and enhanced excretion of urinary peptides, respectively. In summary, this study suggests the existence of at least four basic processes leading to autism, possibly linked to biological parameters known to be abnormal in subgroups of autistic patients. These results, if replicated, could help clinicians identify subgroups of patients characterized by specific clinical patterns, and to explore possible differences in symptom course and therapeutic response. © 2010 INSAR/Wiley Periodicals, Inc.
Article Citation:Autism Res2010, 3: 237–252. DOI: 10.1002/aur.151
Multisensory Processing in Children with Autism: High-Density Electrical Mapping of Auditory-Somatosensory Integration
Natalie Russo, John J. Foxe, Alice B. Brandwein, Ted Altschuler, Hilary Gomes, and Sophie Molholm
We live in an inherently multisensory world, where we are constantly integrating information from multiple sensory modalities such as sound, vision and touch to make sense of our environments. Typically developing (TD) children make these associations between multisensory stimuli automatically and very early on in development. In contrast, parents and clinicians frequently state that individuals with Autism Spectrum Disorders (ASD) have difficulty integrating sensory inputs. This thesis however has rarely been tested empirically. We sought to test this hypothesis by using measurements of event-related potentials (ERPs) and comparing multisensory integration processes among 17 children with ASD and 17 TD children matched on chronological age and non-verbal IQ. We used a passive task in which children watched a silent movie while they were presented with unrelated sounds and vibrations. The sounds and vibrations could occur separately (yielding two unisensory conditions) or simultaneously (multisensory condition). We then summed the unisensory responses and compared them to the multisensory responses. Significant differences between these responses served to index multisensory integration. Our results provide evidence for the anecdotal and clinical impressions that multisensory inputs are treated differently in persons with ASD. © 2010 INSAR/Wiley Periodicals, Inc.
Article Citation:Autism Res2010, 3: 253–267. DOI: 10.1002/aur.152
Is There a Role for Routinely Screening Children with Autism Spectrum Disorder for Creatine Deficiency Syndrome?
Lv Wang, Manya T. Angley, Michael J. Sorich, Robyn L. Young, Ross A. McKinnon, and Jacobus P. Gerber
Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that presents in the first three years of life. Currently, diagnosis of ASD is based on its behavioural manifestations as laboratory diagnostic tests do not exist. Creatine deficiency syndrome (CDS) is one form of inborn error of metabolism where affected individuals have similar clinical features to individuals with ASD. Abnormal urinary creatine (CR) and guanidinoacetate (GAA) levels have reported as biomarkers of CDS. We hypothesized that screening for abnormal levels of urinary CR and GAA in children with ASD may assist in identifying a subgroup of ASD individuals who can be managed with dietary interventions. Morning urine samples were collected from children with and without autism and analyzed for CR and GAA levels. Results showed there was no statistically significant difference in urinary CR: creatinine and GAA: creatinine between the children with ASD and sibling or unrelated controls. In conclusion, routine screening for abnormal urinary CR and GAA could be considered in ASD diagnostic protocols however individuals positive for CDS are likely to be rare in an ASD cohort. © 2010 INSAR/Wiley Periodicals, Inc.
Article Citation:Autism Res2010, 3: 268–272. DOI: 10.1002/aur.145
Cortical Underconnectivity Coupled with Preserved Visuospatial Cognition in Autism: Evidence from an fMRI Study of an Embedded Figures Task
Saudamini Roy Damarla, Timothy A. Keller, Rajesh K. Kana, Vladimir L. Cherkassky, Diane L. Williams, Nancy J. Minshew, and Marcel Adam Just
Individuals with high-functioning autism sometimes exhibit intact or superior performance on visuospatial tasks, in contrast to impaired functioning in other domains such as language comprehension, executive tasks, and social functions. The goal of the current study was to investigate the neural bases of preserved visuospatial processing in high-functioning autism from the perspective of the cortical underconnectivity theory. We used a combination of behavioral, functional magnetic resonance imaging (fMRI), functional connectivity, and white matter morphometry measures. Thirteen participants with high-functioning autism and thirteen controls (age-, IQ-, and gender-matched) were scanned while performing an embedded figures task (EFT). Despite the ability of the autism group to attain behavioral performance comparable to the control group, the brain imaging results revealed several group differences consistent with the cortical underconnectivity account of autism. © 2010 INSAR/Wiley Periodicals, Inc.
Article Citation:Autism Res2010, 3: 273–279. DOI: 10.1002/aur.153
Enhanced Connectivity Between Visual Cortex and Other Regions of the Brain in Autism: A REM Sleep EEG Coherence Study
Cathy Léveillé, Elise B. Barbeau, Christiane Bolduc, Élyse Limoges, Claude Berthiaume, Élyse Chevrier, Laurent Mottron, and Roger Godbout
The brains of autistic people are thought to be characterized by atypical patterns of connectivity which represent atypical communication between brain regions. In this paper, we studied brain connectivity in autistic adults through “EEG coherence,” which is whether brain waves measured from different scalp locations occur at the same time. We chose to measure EEG coherence specifically during rapid eye movement (REM) sleep because during this state the brain both activates itself through internal mechanisms (which permits dreaming for example) and is isolated from influences from the outside world (which normally protects us from awakening too easily). EEG waves during REM sleep are thus relatively uncontaminated and this should help to characterize the true capacity of the different parts of the autistic brain to communicate with one another. Methods: We measured EEG coherence during REM sleep in 9 autistic adults and 13 typical controls. EEG coherence was calculated between EEG recording sites from the same brain hemisphere (intrahemispheric coherence) and between these sites but across both hemispheres (interhemispheric coherence). Results: When the autistic group displayed greater EEG coherence than their controls, it always involved intrahemispheric communication among the left visual cortex (O1) and other regions either close to or distant from the occipital cortex. In contrast, lower coherence values involved frontal electrodes in the right hemisphere. No significant differences between groups were found for interhemispheric EEG coherence. Conclusion: These results could explain why brain-related (cognitive) performance in autistic people is sometimes better and sometimes worse than the performance of nonautistics. More specifically, superior coherence involving visual perceptual areas in autism is consistent with an enhanced role of perception in the functioning of autistic brains. © 2010 INSAR/Wiley Periodicals, Inc.
Article Citation:Autism Res2010, 3: 280–285. DOI: 10.1002/aur.155