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1.  Attentional Networks in Adolescents with High-functioning Autism: An fMRI Investigation 
The Open Neuroimaging Journal  2016;10:102-110.
Background:
Attentional deficits in Autism spectrum disorder (ASD) are often noted, but their specific nature remains unclear.
Objective:
The present study used the child Attentional Network Task (Child ANT) in combination with functional magnetic resonance imaging (fMRI) to determine if the consistently cited deficits of orienting attention are truly due to dysfunctions of orienting-based networks. We hypothesized that these observations are, in fact, a reflection of executive dysfunctions. As such, we expected that although ASD adolescents would perform worse on the orienting portion of the Child ANT, the strongest differences in activation between them and the neurotypical (NT) control group would be in areas classically associated with executive functioning (e.g., the frontal gyri and anterior cingulate cortex).
Method:
The brain activity of six high-functioning adolescents with ASD and six NT adolescents was recorded while these individuals performed the three subcomponents of the Child ANT.
Results:
ASDs were shown to be more accurate than NTs for the alerting, less accurate for the orienting, and similar in accuracy for the executive portions of the Child ANT. fMRI data showed increased bilateral frontal gyri recruitment, areas conventionally associated with executive control, during the orienting task for the ASD group.
Conclusion:
We submit that the increased activations represent neurocorrelates of signal fixation attributable to the subset of executive control responsible for sustained maintenance signals, not the main components of orienting. Therefore, excessive fixation in ASD adolescents is likely due to dysfunctions of executive control and not the orienting subcomponent of the attention network.
doi:10.2174/1874440001610010102
PMCID: PMC5074002  PMID: 27843514
Adolescents; ASD; Attention; Executive control; FMRI; High-functioning autism
2.  Attentional networks in children and adolescents with autism spectrum disorder 
Background
Individuals diagnosed with autism spectrum disorder (ASD) exhibit lifelong abnormalities in the adaptive allocation of visual attention. The ubiquitous nature of attentional impairments in ASD has led some authors to hypothesize that atypical attentional modulation may be a factor in the development of higher-level sociocommunicative deficits.
Method
Participants were 20 children with ASD and 20 age- and Nonverbal IQ-matched typically developing (TD) children. We used the Attention Network Test (ANT) to investigate the efficiency and independence of three discrete attentional networks: alerting, orienting, and executive control. Additionally, we sought to investigate the relationship between each attentional network and measures of sociocommunicative symptom severity in children with ASD.
Results
Results indicate that the orienting, but not alerting or executive control, networks may be impaired in children with ASD. In contrast to TD children, correlational analyses suggest that the alerting and executive control networks may not function as independently in children with ASD. Additionally, an association was found between the alerting network and social impairment and between the executive control network and IQ in children with ASD.
Conclusions
The results provide further evidence of an impairment in the visuospatial orienting network in ASD and suggest that there may be greater interdependence of alerting and executive control networks in ASD. Furthermore, decreased ability to efficiently modulate levels of alertness was related to increased sociocommunicative deficits, suggesting that domain-general attentional function may be associated with ASD symptomatology.
doi:10.1111/j.1469-7610.2010.02257.x
PMCID: PMC3145814  PMID: 20456535
Autism; reaction time; visual attention; alerting; orienting; executive control
3.  Striatal development in autism: repetitive behaviors and the reward circuitry 
Biological psychiatry  2014;76(5):358-359.
Autism spectrum disorder (ASD) is defined by two essential features – impaired social communication abilities, including deficits with social reciprocity, nonverbal communication and establishing relationships, and by the presence of restricted and repetitive behaviors and interests (RRBIs). Social deficits get the majority of attention both in science and in the popular media, but RRBIs are equally important in understanding autism. Although RRBIs are also seen in typically developing preschoolers, as well as in other psychiatric disorders such as obsessive-compulsive disorder, their impairing and persisting character is a hallmark of ASD1.
Repetitive behaviors are among the first signs of ASD, with significant elevations by the child's first birthday2. Individuals with ASD of all ages and cognitive ability levels display RRBIs to variable degrees, with males usually being more severely affected than females3. Caregivers of individuals with ASD commonly emphasize that RRBIs are among the most challenging facets of the disorder on an everyday basis1. They negatively impact social, cognitive, family functioning and well-being, often leading to increased levels of parental stress and negative parenting styles. While the clinical description and natural history of RRBIs is becoming clear, an understanding of the biological bases of this set of features has only recently begun to emerge4. Better insight into the ontogenesis of RRBIs and their underlying neurobiology is needed not only to inform models of the etiology of ASD, but also to foster the development of new interventions.
In this issue of Biological Psychiatry, Langen et al.5 examine differences in the rate of basal ganglia growth in ASD relative to typically developing children (TDC). Their volumetric analyses focused on developmental trajectories of the ventral striatum (with nucleus accumbens) and dorsal striatum (with caudate nucleus and putamen). These components of the basal ganglia are the major subcortical targets within the frontostriatal behavior control loops that are recognized as likely subserving RRBIs4. This current study is a follow up of this same group's earlier work showing cross sectional differences in growth trajectory. While several labs have previously reported enlargement of the caudate nucleus in ASD, this current study is the first to make repeat morphology measurements, thus overcoming limitations associated with cross sectional analyses. This study involved 86 seven to seventeen year old cases and controls who had 2 MRI anatomical scans approximately 2 and a half years apart on average, allowing a direct test of differential striatal growth. The rate of basal ganglia growth was correlated with the severity of RRBIs as assessed by parent interview at the time of the first MRI scan, corroborating earlier work on the role of the striatum in repetitive behaviors among children with ASD.
Specifically the caudate nucleus showed a growth rate in ASD that was twice as high as the growth rate in TDC (i.e., 4.6% vs. 2.3%). This was independent of overall brain growth, use of psychotropic medications, or other major confounds. Most importantly, more severe RRBIs early in life, particularly insistence on sameness behaviors, such as avoiding trivial changes in routines and environments as well as adhering to compulsions and rituals, were related to faster striatal growth between average ages of about 9 and 12 year old, with large effect sizes (e.g., caudate nucleus: Cohen's d = 0.86). While Langen et al. discuss several complementary explanations for their findings, they conclude that the divergent trajectory of caudate development in relation to RRBIs most likely results from early, and possibly continuing, patterns of repetitive behaviors that shape striatal development – not the other way around.
This new set of data elegantly adds to the notion that the striatum plays a central role in core ASD phenomenology6. However, one question lingers: what cause RRBIs, like insistence on sameness, compulsions and rituals, to become such a force so as to impact the growth trajectory of an evolutionarily ancient brain structure like the caudate nucleus? This question ties in with a long-standing debate among clinicians and scientists concerning the potential functions that the myriad of RRBIs might serve in individuals with ASD. While several plausible ideas have been advanced7, convincing support for any specific one is lacking.
One hypothesis that is gaining increased research attention, however, involves the effects of alterations of the balance between social and nonsocial motivation in reward circuitry on RRBIs8. This model suggests that ASD is in part a disorder of “behavioral dependency” to RRBIs because of the rewarding effects they induce1. Indeed, insistence on sameness and preoccupying restricted interests are reported to be quite pleasurable by affected individuals1. The dorsal striatum with caudate nucleus, in particular, is believed to mediate reward value for purposeful actions5. Functional imaging studies show that the brain's reward circuitry in ASD, particularly striatum and ventral prefrontal cortices, selectively over-reacts to objects that may comprise an intense special interest, whereas it under-reacts to more typical desires such as social reward and money6. This may indicate that the brain in ASD cares less for conventional rewards. It is not yet known if an initial lack of social reward motivation opens the door for enhanced rewarding effects of certain circumscribed objects, topics, and routines, or whether the reverse is true – that the dominating reward effects of nonsocial objects, topic and routines diminishes the reward value of social engagement.
The rewarding effects of RRBIs are thought to be fueled by the preference of those with ASD for predictability in their environment, where they can exercise more control; social encounters are in many ways the antithesis of this, as these are often rapid, hard to control and offer much more variable reinforcement contingencies. When RRBIs are rewarding, their pursuit may be strengthened through reinforcement mechanisms that progressively turn them into rigid and strongly desired habits that are performed almost automatically with little conscious oversight. With this heuristic model, RRBIs are self-reinforcing, and they begin to hijack the normal developmental trajectory of entire repertoires of behaviors. The dorsal (associative) striatum with caudate nucleus dominates these processes4. Thus, an accelerated growth rate of the caudate related to RRBIs, as reported by Langen et al.5, could reflect atypical brain specialization in individuals with ASD9. From early in life the caudate nucleus mediates habitual processes for a wide range of different stimuli and contexts. Across development, however, the caudate may become co-opted by the most rewarding aspects of the environment. This interactive and self-sustaining biobehavioral process – in concert with other mesocorticolimbic functions4 – may shape the growth trajectory of the caudate nucleus and strengthens the occurrence of RRBIs in ASD (Figure 1). On a day-to-day basis, RRBIs interfere with social development and functioning as they may absorb resources typically dedicated to other learning opportunities, including social ones6.
The observation that RRBIs in ASD involve plasticity of the caudate nucleus – one major hub within the frontostriatal circuits that control behavior – is a fascinating advance for our field. It brings us closer to the neurobiological roots of how and why affected individuals develop and maintain this set of challenging behaviors. Follow-up research will need to address several issues to improve upon the approach of the Langen et al study. One critical issue is that researchers need to use more precise behavioral measurement tools10. This could involve item rating scales with greater item density around key concepts, as it is clear to all the ADI-R is sorely lacking in this regard. Also, quantitative motion capture tools are now widely available; deploying these in natural environments seems to us to be extremely promising adjuncts to standard rating scales. Repeat behavioral measurement across time, in sync with repeat brain measurement is an important next step that will enable better characterization of the interplay between RRBIs and brain dynamics. In this regard, multimodal imaging in the same sample is called for, as structural imaging will surely only capture portions of the story. The findings by Langen et al.5 call attention to the importance of RRBIs in autism. Because RRBIs may be rooted in the powerful reward circuitries that motivate a great deal of behavior, strategically targeting the role of reward mechanisms promises to improve treatment practices for limiting the life interfering aspects of RRBIs among individuals with ASD and their families.
doi:10.1016/j.biopsych.2014.07.010
PMCID: PMC4780436  PMID: 25103541
4.  In vivo 1H-magnetic resonance spectroscopy study of the attentional networks in autism 
Brain research  2010;1380:198-205.
Attentional dysfunction is one of the most consistent findings in individuals with autism spectrum disorders (ASD). However, the significance of such findings for the pathophysiology of autism is unclear. In this study, we investigated cellular neurochemistry with proton magnetic resonance spectroscopy imaging (1H-MRS) in brain regions associated with networks subserving alerting, orienting, and executive control of attention in patients with ASD. Concentrations of cerebral N-acetyl-aspartate (NAA), creatinine + phosphocreatinine, choline-containing compounds, myo-inositol (Ins) and glutamate + glutamine (Glx) were determined by 3 T 1H-MRS examinations in 14 high-functioning medication-free adults with a diagnosis of ASD and 14 age- and IQ-matched healthy controls (HC) in the anterior cingulate cortex (ACC), thalamus, temporoparietal junction (TPJ), and areas near or along the intraparietal sulcus (IPS). Compared to HC group, the ASD group showed significantly lower Glx concentrations in right ACC and reduced Ins in left TPJ. This study provides evidence of abnormalities in neurotransmission related to networks subserving executive control and alerting of attention, functions which have been previously implicated in ASD pathogenesis.
doi:10.1016/j.brainres.2010.12.057
PMCID: PMC3073642  PMID: 21185269
autism; spectroscopy; glutamate; anterior cingulate cortex; intraparietal sulcus; myo-inositol
5.  Functional and structural connectivity of frontostriatal circuitry in Autism Spectrum Disorder 
Abnormalities in frontostriatal circuitry potentially underlie the two core deficits in Autism Spectrum Disorder (ASD); social interaction and communication difficulties and restricted interests and repetitive behaviors. Whilst a few studies have examined connectivity within this circuitry in ASD, no previous study has examined both functional and structural connectivity within the same population. The present study provides the first exploration of both functional and structural frontostriatal connectivity in ASD. Twenty-eight right-handed Caucasian male ASD (17.28 ± 3.57 years) and 27 right-handed male, age and IQ matched controls (17.15 ± 3.64 years) took part in the study. Resting state functional connectivity was carried out on 21 ASD and control participants, and tractography was carried out on 22 ASD and 24 control participants, after excluding subjects for excessive motion and poor data quality. Functional connectivity analysis was carried out between the frontal cortex and striatum after which tractography was performed between regions that showed significant group differences in functional connectivity. The ASD group showed increased functional connectivity between regions in the frontal cortex [anterior cingulate cortex (ACC), middle frontal gyrus (MFG), paracingulate gyrus (Pcg) and orbitofrontal cortex (OFC)], and striatum [nucleus accumbens (NAcc) and caudate]. Increased functional connectivity between ACC and caudate was associated with deactivation to social rewards in the caudate, as previously reported in the same participants. Greater connectivity between the right MFG and caudate was associated with higher restricted interests and repetitive behaviors and connectivity between the bilateral Pcg and NAcc, and the right OFC and NAcc, was negatively associated with social and communicative deficits. Although tracts were reliably constructed for each subject, there were no group differences in structural connectivity. Results are in keeping with previously reported increased corticostriatal functional connectivity in ASD.
doi:10.3389/fnhum.2013.00430
PMCID: PMC3734372  PMID: 23964221
Autism Spectrum Disorder; connectivity; frontostriatal; striatum; fMRI; DTI; social reward
6.  Atypical Attentional Networks and the Emergence of Autism 
The sociocommunicative impairments that define autism spectrum disorder (ASD) are not present at birth but emerge gradually over the first two years of life. In typical development, basic attentional processes may provide a critical foundation for sociocommunicative abilities. Therefore early attentional dysfunction in ASD may result in atypical development of social communication. Prior research has demonstrated that persons with ASD exhibit early and lifelong impairments in attention. The primary aim of this paper is to provide a review of the extant research on attention in ASD using a framework of functionally independent attentional networks as conceptualized by Posner and colleagues: the alerting, orienting and executive control networks (Posner and Petersen, 1990; Petersen & Posner, 2012). The neural substrates and typical development of each attentional network is briefly discussed, a review of the ASD attention literature is presented, and a hypothesis is proposed that links aberrant attentional mechanisms, specifically impaired disengagement of attention, with the emergence of core ASD symptoms.
doi:10.1016/j.neubiorev.2012.11.014
PMCID: PMC3563720  PMID: 23206665
autism; attention; development; alerting; arousal; orienting; disengagement; executive control
7.  Reduced cognitive control of response inhibition by the anterior cingulate cortex in autism spectrum disorders 
NeuroImage  2010;52(1):336-347.
Response inhibition, or the suppression of prepotent, but contextually inappropriate behaviors, is essential to adaptive, flexible responding. In autism spectrum disorders (ASD), difficulty inhibiting prepotent behaviors may contribute to restricted, repetitive behavior (RRB). Individuals with ASD consistently show deficient response inhibition while performing antisaccades, which require one to inhibit the prepotent response of looking towards a suddenly appearing stimulus (i.e., a prosaccade), and to substitute a gaze in the opposite direction. Here, we used fMRI to identify the neural correlates of this deficit. We focused on two regions that are critical for saccadic inhibition: the frontal eye field (FEF), the key cortical region for generating volitional saccades, and the dorsal anterior cingulate cortex (dACC), which is thought to exert top-down control on FEF. We also compared ASD and control groups on the functional connectivity of the dACC and FEF during saccadic performance. In the context of an increased antisaccade error rate, ASD participants showed decreased functional connectivity of the FEF and dACC and decreased inhibition-related activation (based on the contrast of antisaccades and prosaccades) in both regions. Decreased dACC activation correlated with a higher error rate in both groups, consistent with a role in top-down control. Within the ASD group, increased FEF activation and dACC/FEF functional connectivity were associated with more severe RRB. These findings demonstrate functional abnormalities in a circuit critical for volitional ocular motor control in ASD that may contribute to deficient response inhibition and to RRB. More generally, our findings suggest reduced cognitive control over behavior by the dACC in ASD.
doi:10.1016/j.neuroimage.2010.04.010
PMCID: PMC2883672  PMID: 20394829
8.  Decreased Left Caudate Volume Is Associated with Increased Severity of Autistic-Like Symptoms in a Cohort of ADHD Patients and Their Unaffected Siblings 
PLoS ONE  2016;11(11):e0165620.
Autism spectrum disorder (ASD) symptoms frequently occur in individuals with attention-deficit/hyperactivity disorder (ADHD). While there is evidence that both ADHD and ASD have differential structural brain correlates, knowledge of the structural brain profile of individuals with ADHD with raised ASD symptoms is limited. The presence of ASD-like symptoms was measured by the Children's Social Behavior Questionnaire (CSBQ) in a sample of typically developing controls (n = 154), participants with ADHD (n = 239), and their unaffected siblings (n = 144) between the ages of 8 and 29. Structural magnetic resonance imaging (MRI) correlates of ASD ratings were analysed by studying the relationship between ASD ratings and grey matter volumes using mixed effects models which controlled for ADHD symptom count and total brain volume. ASD ratings were significantly elevated in participants with ADHD relative to controls and unaffected siblings. For the entire group (participants with ADHD, unaffected siblings and TD controls), mixed effect models revealed that the left caudate nucleus volume was negatively correlated with ASD ratings (t = 2.83; P = 0.005). The current findings are consistent with the role of the caudate nucleus in executive function, including the selection of goals based on the evaluation of action outcomes and the use of social reward to update reward representations. There is a specific volumetric profile associated with subclinical ASD-like symptoms in participants with ADHD, unaffected siblings and controls with the caudate nucleus and globus pallidus being of critical importance in predicting the level of ASD-like symptoms in all three groups.
doi:10.1371/journal.pone.0165620
PMCID: PMC5091763  PMID: 27806078
9.  Abnormalities of Intrinsic Functional Connectivity in Autism Spectrum Disorders 
NeuroImage  2009;47(2):764-772.
Autism spectrum disorders (ASD) impact social functioning and communication, and individuals with these disorders often have restrictive and repetitive behaviors. Accumulating data indicate that ASD is associated with alterations of neural circuitry. Functional MRI (FMRI) studies have focused on connectivity in the context of psychological tasks. However, even in the absence of a task, the brain exhibits a high degree of functional connectivity, known as intrinsic or resting connectivity. Notably, the default network, which includes the posterior cingulate cortex, retro-splenial, lateral parietal cortex/angular gyrus, medial prefrontal cortex, superior frontal gyrus, temporal lobe, and parahippocampal gyrus, is strongly active when there is no task. Altered intrinsic connectivity within the default network may underlie offline processing that may actuate ASD impairments. Using FMRI, we sought to evaluate intrinsic connectivity within the default network in ASD. Relative to controls, the ASD group showed weaker connectivity between the posterior cingulate cortex and superior frontal gyrus and stronger connectivity between the posterior cingulate cortex and both the right temporal lobe and right parahippocampal gyrus. Moreover, poorer social functioning in the ASD group was correlated with weaker connectivity between the posterior cingulate cortex and the superior frontal gyrus. In addition, more severe restricted and repetitive behaviors in ASD were correlated with stronger connectivity between the posterior cingulate cortex and right parahippocampal gyrus. These findings indicate that ASD subjects show altered intrinsic connectivity within the default network, and connectivity between these structures is associated with specific ASD symptoms.
doi:10.1016/j.neuroimage.2009.04.069
PMCID: PMC2731579  PMID: 19409498
10.  Language comprehension and brain function in individuals with an optimal outcome from autism 
NeuroImage : Clinical  2015;10:182-191.
Although Autism Spectrum Disorder (ASD) is generally a lifelong disability, a minority of individuals with ASD overcome their symptoms to such a degree that they are generally indistinguishable from their typically-developing peers. That is, they have achieved an Optimal Outcome (OO). The question addressed by the current study is whether this normalized behavior reflects normalized brain functioning, or alternatively, the action of compensatory systems. Either possibility is plausible, as most participants with OO received years of intensive therapy that could alter brain networks to align with typical function or work around ASD-related neural dysfunction. Individuals ages 8 to 21 years with high-functioning ASD (n = 23), OO (n = 16), or typical development (TD; n = 20) completed a functional MRI scan while performing a sentence comprehension task. Results indicated similar activations in frontal and temporal regions (left middle frontal, left supramarginal, and right superior temporal gyri) and posterior cingulate in OO and ASD groups, where both differed from the TD group. Furthermore, the OO group showed heightened “compensatory” activation in numerous left- and right-lateralized regions (left precentral/postcentral gyri, right precentral gyrus, left inferior parietal lobule, right supramarginal gyrus, left superior temporal/parahippocampal gyrus, left middle occipital gyrus) and cerebellum, relative to both ASD and TD groups. Behaviorally normalized language abilities in OO individuals appear to utilize atypical brain networks, with increased recruitment of language-specific as well as right homologue and other systems. Early intensive learning and experience may normalize behavioral language performance in OO, but some brain regions involved in language processing may continue to display characteristics that are more similar to ASD than typical development, while others show characteristics not like ASD or typical development.
Highlights
•fMRI study of "optimal outcome" (OO) youth with no symptoms of autism spectrum disorder.•Results show “compensatory” language activation in some areas in OO.•OO youth also had some “residual ASD” patterns of activation (OO, ASD > TD).•There was no evidence of areas of normalized brain function (OO, TD ≠ ASD).•Early treatment may normalize behavior but not brain in some individuals with ASD.
doi:10.1016/j.nicl.2015.11.014
PMCID: PMC4707189  PMID: 26862477
Autism; Optimal outcomes; Language; fMRI
11.  Mentalizing and motivation neural function during social interactions in autism spectrum disorders☆ 
NeuroImage : Clinical  2013;3:321-331.
Autism Spectrum Disorders (ASDs) are characterized by core deficits in social functions. Two theories have been suggested to explain these deficits: mind-blindness theory posits impaired mentalizing processes (i.e. decreased ability for establishing a representation of others' state of mind), while social motivation theory proposes that diminished reward value for social information leads to reduced social attention, social interactions, and social learning. Mentalizing and motivation are integral to typical social interactions, and neuroimaging evidence points to independent brain networks that support these processes in healthy individuals. However, the simultaneous function of these networks has not been explored in individuals with ASDs. We used a social, interactive fMRI task, the Domino game, to explore mentalizing- and motivation-related brain activation during a well-defined interval where participants respond to rewards or punishments (i.e. motivation) and concurrently process information about their opponent's potential next actions (i.e. mentalizing). Thirteen individuals with high-functioning ASDs, ages 12–24, and 14 healthy controls played fMRI Domino games against a computer-opponent and separately, what they were led to believe was a human-opponent. Results showed that while individuals with ASDs understood the game rules and played similarly to controls, they showed diminished neural activity during the human-opponent runs only (i.e. in a social context) in bilateral middle temporal gyrus (MTG) during mentalizing and right Nucleus Accumbens (NAcc) during reward-related motivation (Pcluster < 0.05 FWE). Importantly, deficits were not observed in these areas when playing against a computer-opponent or in areas related to motor and visual processes. These results demonstrate that while MTG and NAcc, which are critical structures in the mentalizing and motivation networks, respectively, activate normally in a non-social context, they fail to respond in an otherwise identical social context in ASD compared to controls. We discuss implications to both the mind-blindness and social motivation theories of ASD and the importance of social context in research and treatment protocols.
Highlights
•We used an fMRI Domino game to map social networks in high-functioning ASDs.•ASDs did not show MTG increased activation during mentalizing in social context.•ASDs did not show NAcc increased activation for processing reward in social context.•Activation deficits were specific to brain areas involved in social processes.•Results support both the mind-blindness and the social motivation theories of ASDs.
doi:10.1016/j.nicl.2013.09.005
PMCID: PMC3815022  PMID: 24273716
Theory of mind; Reward; Nucleus accumbens; Middle temporal gyrus
12.  Redox metabolism abnormalities in autistic children associated with mitochondrial disease 
Translational Psychiatry  2013;3(6):e273-.
Research studies have uncovered several metabolic abnormalities associated with autism spectrum disorder (ASD), including mitochondrial disease (MD) and abnormal redox metabolism. Despite the close connection between mitochondrial dysfunction and oxidative stress, the relation between MD and oxidative stress in children with ASD has not been studied. Plasma markers of oxidative stress and measures of cognitive and language development and ASD behavior were obtained from 18 children diagnosed with ASD who met criteria for probable or definite MD per the Morava et al. criteria (ASD/MD) and 18 age and gender-matched ASD children without any biological markers or symptoms of MD (ASD/NoMD). Plasma measures of redox metabolism included reduced free glutathione (fGSH), oxidized glutathione (GSSG), the fGSH/GSSG ratio and 3-nitrotyrosine (3NT). In addition, a plasma measure of chronic immune activation, 3-chlorotyrosine (3CT), was also measured. Language was measured using the preschool language scale or the expressive one-word vocabulary test (depending on the age), adaptive behaviour was measured using the Vineland Adaptive Behavior Scale (VABS) and core autism symptoms were measured using the Autism Symptoms Questionnaire and the Social Responsiveness Scale. Children with ASD/MD were found to have lower scores on the communication and daily living skill subscales of the VABS despite having similar language and ASD symptoms. Children with ASD/MD demonstrated significantly higher levels of fGSH/GSSG and lower levels of GSSG as compared with children with ASD/NoMD, suggesting an overall more favourable glutathione redox status in the ASD/MD group. However, compare with controls, both ASD groups demonstrated lower fGSH and fGSH/GSSG, demonstrating that both groups suffer from redox abnormalities. Younger ASD/MD children had higher levels of 3CT than younger ASD/NoMD children because of an age-related effect in the ASD/MD group. Both ASD groups demonstrated significantly higher 3CT levels than control subjects, suggesting that chronic inflammation was present in both groups of children with ASD. Interestingly, 3NT was found to correlate positively with several measures of cognitive function, development and behavior for the ASD/MD group, but not the ASD/NoMD group, such that higher 3NT concentrations were associated with more favourable adaptive behaviour, language and ASD-related behavior. To determine whether difference in receiving medications and/or supplements could account for the differences in redox and inflammatory biomarkers across ASD groups, we examined differences in medication and supplements across groups and their effect of redox and inflammatory biomarkers. Overall, significantly more participants in the ASD/MD group were receiving folate, vitamin B12, carnitine, co-enzyme Q10, B vitamins and antioxidants. We then determined whether folate, carnitine, co-enzyme Q10, B vitamins and/or antioxidants influenced redox or inflammatory biomarkers. Antioxidant supplementation was associated with a significantly lower GSSG, whereas antioxidants, co-enzyme Q10 and B vitamins were associated with a higher fGSH/GSSG ratio. There was no relation between folate, carnitine, co-enzyme Q10, B vitamins and antioxidants with 3NT, 3CT or fGSH. Overall, our findings suggest that ASD/MD children with a more chronic oxidized microenvironment have better development. We interpret this finding in light of the fact that more active mitochondrial can create a greater oxidized microenvironment especially when dysfunctional. Thus, compensatory upregulation of mitochondria which are dysfunctional may both increase activity and function at the expense of a more oxidized microenvironment. Although more ASD/MD children were receiving certain supplements, the use of such supplements were not found to be related to the redox biomarkers that were related to cognitive development or behavior in the ASD/MD group but could possibly account for the difference in glutathione metabolism noted between groups. This study suggests that different subgroups of children with ASD have different redox abnormalities, which may arise from different sources. A better understanding of the relationship between mitochondrial dysfunction in ASD and oxidative stress, along with other factors that may contribute to oxidative stress, will be critical to understanding how to guide treatment and management of ASD children. This study also suggests that it is important to identify ASD/MD children as they may respond differently to specific treatments because of their specific metabolic profile.
doi:10.1038/tp.2013.51
PMCID: PMC3693408  PMID: 23778583
autism; inflammation; endophenotypes; mitochondrial disease; oxidative stress
13.  Impaired Error Monitoring and Correction Function in Autism 
Journal of neurotherapy  2010;14(2):79-95.
Introduction
Error monitoring and correction is one of the executive functions and is important for effective goal directed behavior. Deficient executive functioning, including reduced error monitoring ability, is one of the typical features of such neurodevelopmental disorders as autism, probably related to perseverative responding, stereotyped repetitive behaviors, and an inability to accurately monitor ongoing behavior. Our prior studies of behavioral and event-related potential (ERP) measures during performance on visual oddball tasks in high-functioning autistic (HFA) children showed that despite only minor differences in reaction times HFA children committed significantly more errors.
Methods
This study investigated error monitoring in children with autism spectrum disorder (ASD) with response-locked event-related potentials - the Error-related Negativity (ERN) and Error-related Positivity (Pe) recorded at fronto-central sites. The ERN reflects early error detection processes, while the Pe has been associated with later conscious error evaluation and attention re-allocation. Reaction times (RT) in correct trials and post-error slowing in reaction times were measured. In this study fourteen subjects with ASD and 14 age- and IQ- matched controls received a three-category visual oddball task with novel distracters.
Results
ERN had a lower amplitude and longer latency in the ASD group but was localized in the caudal part of anterior cingulate cortex (ACC) in both groups. The Pe component was significantly prolonged in the ASD group but did not reach significance in amplitude differences compared to controls. We found significant post-error slowing in RTs in controls, and post-error acceleration in RTs in the ASD group.
Conclusions
The reduced ERN and altered Pe along with a lack of post-error RT slowing in autism might be interpreted as insensitivity in the detection and monitoring of response errors and a reduced ability of execute corrective actions. This might result in reduced error awareness and failure in adjustment when dealing with situations where erroneous responses may occur. This deficit might be manifested in the perseverative behaviors often seen in individuals with ASD. The results are discussed in terms of a general impairment in self-monitoring and other executive functions underlying behavioral and social disturbances in ASD.
doi:10.1080/10874201003771561
PMCID: PMC2879653  PMID: 20523752
Autism; Executive functions; Error monitoring; Reaction time; Cingulate cortex; oddball task
14.  Brain function and gaze-fixation during facial emotion processing in fragile-X and autism 
This research focuses on the relationship between fragile X syndrome (FXS) and autism spectrum disorders (ASD). Both of these populations have a tendency to avoid looking others in the eye, along with difficulties in communication with others and tend to be socially withdrawn. While it is clear that FXS and ASD share some common abnormal behaviors, the underlying brain mechanisms associated with the social and emotional deficits in these groups remain unclear. We showed pictures of emotional and non-emotional human faces to these groups while in a magnetic resonance scanner (MRI). We collected images of brain function along with measures of where on the faces the individuals were looking (e.g. eyes or mouth). The FXS group showed a similar yet less abnormal pattern of where they were looking on the face compared to the ASD group. The FXS group also showed a similar pattern of decreased brain function in the area of the brain typically used when looking at faces, the fusiform gyrus (FG). The amount of activation in the FG was associated with how much time the FXS and ASD individuals looked at the eyes, the more they looked at the eyes, the greater the FG activation. The FXS group also displayed more brain activation than both the ASD group and a group of typically developing control subjects in brain areas that might suggest increased task difficulty for the FXS group. These group differences in brain activation are important as they suggest there is some overlap in areas of brain function in FXS and ASD when looking at faces, but that these two groups also have unique activation in other brain areas. These findings largely support the idea that ASD characteristics in FXS are associated with partially different patterns of brain activation when looking at human faces compared to individuals with ASD.
Objective:
Fragile X syndrome (FXS) is the most commonly known genetic disorder associated with autism spectrum disorder (ASD). Overlapping features in these populations include gaze aversion, communication deficits, and social withdrawal. Although the association between FXS and ASD has been well documented at the behavioral level, the underlying neural mechanisms associated with the social/emotional deficits in these groups remain unclear.
Method:
We collected functional brain images and eye-gaze fixations from 9 individuals with FXS and 14 individuals with idiopathic ASD, as well as 15 typically developing (TD) individuals, while they performed a facial-emotion discrimination task.
Results:
The FXS group showed a similar yet less aberrant pattern of gaze-fixations compared to the ASD group. The FXS group also showed fusiform gyrus (FG) hypoactivation compared to the TD control group. Activation in FG was strongly and positively associated with average eye fixation and negatively associated with ASD characteristics in the FXS group. The FXS group displayed significantly greater activation than both the TD control and ASD groups in the left hippocampus (HIPP), left superior temporal gyrus (STG), right insula (INS), and left post-central gyrus (PCG).
Conclusions:
These group differences in brain activation are important as they suggest unique underlying face-processing neural circuitry in FXS versus idiopathic ASD, largely supporting the hypothesis that ASD characteristics in FXS and idiopathic ASD reflect partially divergent impairments at the neural level, at least in FXS individuals without a co-morbid diagnosis of ASD.
doi:10.1002/aur.32
PMCID: PMC2679695  PMID: 19360673
fragile X syndrome; autism; face processing; brain function; fMRI
15.  Neural selectivity for communicative auditory signals in Phelan-McDermid syndrome 
Background
Phelan-McDermid syndrome (PMS), a neurodevelopmental disorder caused by deletion or mutation in the SHANK3 gene, is one of the more common single-locus causes of autism spectrum disorder (ASD). PMS is characterized by global developmental delay, hypotonia, delayed or absent speech, increased risk of seizures, and minor dysmorphic features. Impairments in language and communication are one of the most consistent characteristics of PMS. Although there is considerable overlap in the social communicative deficits associated with PMS and ASD, there is a dearth of data on underlying abnormalities at the level of neural systems in PMS. No controlled neuroimaging studies of PMS have been reported to date. The goal of this study was to examine the neural circuitry supporting the perception of auditory communicative signals in children with PMS as compared to idiopathic ASD (iASD).
Methods
Eleven children with PMS and nine comparison children with iASD were scanned using functional magnetic resonance imaging (fMRI) under light sedation. The fMRI paradigm was a previously validated passive auditory task, which presented communicative (e.g., speech, sounds of agreement, disgust) and non-communicative vocalizations (e.g., sneezing, coughing, yawning).
Results
Previous research has shown that the superior temporal gyrus (STG) responds selectively to communicative vocal signals in typically developing children and adults. Here, selective activity for communicative relative to non-communicative vocalizations was detected in the right STG in the PMS group, but not in the iASD group. The PMS group also showed preferential activity for communicative vocalizations in a range of other brain regions associated with social cognition, such as the medial prefrontal cortex (MPFC), insula, and inferior frontal gyrus. Interestingly, better orienting toward social sounds was positively correlated with selective activity in the STG and other “social brain” regions, including the MPFC, in the PMS group. Finally, selective MPFC activity for communicative sounds was associated with receptive language level in the PMS group and expressive language in the iASD group.
Conclusions
Despite shared behavioral features, children with PMS differed from children with iASD in their neural response to communicative vocal sounds and showed relative strengths in this area. Furthermore, the relationship between clinical characteristics and neural selectivity also differed between the two groups, suggesting that shared ASD features may partially reflect different neurofunctional abnormalities due to differing etiologies.
Electronic supplementary material
The online version of this article (doi:10.1186/s11689-016-9138-9) contains supplementary material, which is available to authorized users.
doi:10.1186/s11689-016-9138-9
PMCID: PMC4763436  PMID: 26909118
16.  The Neural Substrates of Cognitive Control Deficits in Autism Spectrum Disorders 
Neuropsychologia  2009;47(12):2515-2526.
Executive functions deficits are among the most frequently reported symptoms of autism spectrum disorders (ASDs), however, there have been few functional magnetic resonance imaging (fMRI) studies that investigate the neural substrates of executive functions deficits in ASDs, and only one in adolescents. The current study examined cognitive control –the ability to maintain task context online to support adaptive functioning in the face of response competition—in 22 adolescents aged 12–18 with autism spectrum disorders and 23 age, gender, and IQ matched typically developing subjects. During the cue phase of the task, where subjects must maintain information online to overcome a prepotent response tendency, typically developing subjects recruited significantly more anterior frontal (BA 10), parietal (BA 7, 40), and occipital regions (BA 18) for high control trials (25% of trials) versus low control trials (75% of trials). Both groups showed similar activation for low control cues, however the ASD group exhibited significantly less activation for high control cues. Functional connectivity analysis using time series correlation, factor analysis, and beta series correlation methods provided convergent evidence that the ASD group exhibited lower levels of functional connectivity and less network integration between frontal, parietal, and occipital regions. In the typically developing group, fronto-parietal connectivity was related to lower error rates on high control trials. In the autism group, reduced fronto-parietal connectivity was related to attention deficit hyperactivity disorder symptoms.
doi:10.1016/j.neuropsychologia.2009.04.019
PMCID: PMC2766616  PMID: 19410583
autism spectrum disorders; cognitive control; executive functions; fMRI; functional connectivity; attention deficit disorder
17.  Alterations of Resting State Functional Connectivity in the Default Network in Adolescents with Autism Spectrum Disorders 
Brain research  2009;1313:202.
Autism spectrum disorders (ASD) are associated with disturbances of neural connectivity. Functional connectivity between neural structures is typically examined within the context of a cognitive task, but also exists in the absence of a task (i.e., “rest”). Connectivity during rest is particularly active in a set of structures called the default network, which includes the posterior cingulate cortex (PCC), retrosplenial cortex, lateral parietal cortex/angular gyrus, medial prefrontal cortex, superior frontal gyrus, temporal lobe, and parahippocampal gyrus. We previously reported that adults with ASD relative to controls show areas of stronger and weaker connectivity within the default network. The objective of the present study was to examine the default network in adolescents with ASD. Sixteen adolescents with ASD and 15 controls participated in a functional MRI study. Functional connectivity was examined between a PCC seed and other areas of the default network. Both groups showed connectivity in the default network. Relative to controls, adolescents with ASD showed widespread weaker connectivity in nine of the eleven areas of the default network. Moreover, an analysis of symptom severity indicated that poorer social skills and increases in restricted and repetitive behaviors and interests correlated with weaker connectivity, whereas poorer verbal and non-verbal communication correlated with stronger connectivity in multiple areas of the default network. These findings indicate that adolescents with ASD show weaker connectivity in the default network than previously reported in adults with ASD. The findings also show that weaker connectivity within the default network is associated with specific impairments in ASD.
doi:10.1016/j.brainres.2009.11.057
PMCID: PMC2818723  PMID: 20004180
Functional Magnetic Resonance Imaging; development; symptom severity; Asperger’s syndrome; pervasive developmental disorder not otherwise specified
18.  Atypical Neural Networks for Social Orienting in Autism Spectrum Disorders 
NeuroImage  2011;56(1):354-362.
Autism spectrum disorders (ASD) are characterized by significant social impairments, including deficits in orienting attention following social cues. Behavioral studies investigating social orienting in ASD, however, have yielded mixed results, as the use of naturalistic paradigms typically reveals clear deficits whereas computerized laboratory experiments often report normative behavior. The present study is the first to examine the neural mechanisms underlying social orienting in ASD in order to provide new insight into the social attention impairments that characterize this disorder. Using fMRI, we examined the neural correlates of social orienting in children and adolescents with ASD and in a matched sample of typically developing (TD) controls while they performed a spatial cueing paradigm with social (eye gaze) and nonsocial (arrow) cues. Cues were either directional (indicating left or right) or neutral (indicating no direction), and directional cues were uninformative of the upcoming target location in order to engage automatic processes by minimizing expectations. Behavioral results demonstrated intact orienting effects for social and nonsocial cues, with no differences between groups. The imaging results, however, revealed clear group differences in brain activity. When attention was directed by social cues compared to nonsocial cues, the TD group showed increased activity in frontoparietal attention networks, visual processing regions, and the striatum, whereas the ASD group only showed increased activity in the superior parietal lobule. Significant group × cue type interactions confirmed greater responsivity in task-relevant networks for social cues than nonsocial cues in TD as compared to ASD, despite similar behavioral performance. These results indicate that, in the autistic brain, social cues are not assigned the same privileged status as they are in the typically developing brain. These findings provide the first empirical evidence that the neural circuitry involved in social orienting is disrupted in ASD and highlight that normative behavioral performance in a laboratory setting may reflect compensatory mechanisms rather than intact social attention.
doi:10.1016/j.neuroimage.2011.02.031
PMCID: PMC3091391  PMID: 21334443
autism; attention; functional magnetic resonance imaging; gaze; social cue
19.  NTRK2 expression levels are reduced in laser captured pyramidal neurons from the anterior cingulate cortex in males with autism spectrum disorder 
Molecular Autism  2015;6:28.
Background
The anterior cingulate cortex (ACC) is a brain area involved in modulating behavior associated with social interaction, disruption of which is a core feature of autism spectrum disorder (ASD). Functional brain imaging studies demonstrate abnormalities of the ACC in ASD as compared to typically developing control patients. However, little is known regarding the cellular basis of these functional deficits in ASD. Pyramidal neurons in the ACC are excitatory glutamatergic neurons and key cellular mediators of the neural output of the ACC. This study was designed to investigate the potential role of ACC pyramidal neurons in ASD brain pathology.
Methods
Postmortem ACC tissue from carefully matched ASD and typically developing control donors was obtained from two national brain collections. Pyramidal neurons and surrounding astrocytes were separately collected from layer III of the ACC by laser capture microdissection. Isolated RNA was subjected to reverse transcription and endpoint PCR to determine gene expression levels for 16 synaptic genes relevant to glutamatergic neurotransmission. Cells were also collected from the prefrontal cortex (Brodmann area 10) to examine those genes demonstrating differences in expression in the ACC comparing typically developing and ASD donors.
Results
The level of NTRK2 expression was robustly and significantly lower in pyramidal neurons from ASD donors as compared to typically developing donors. Levels of expression of GRIN1, GRM8, SLC1A1, and GRIP1 were modestly lower in pyramidal neurons from ASD donors, but statistical significance for these latter genes did not survive correction for multiple comparisons. No significant expression differences of any genes were found in astrocytes laser captured from the same neocortical area. In addition, expression levels of NTRK2 and other synaptic genes were normal in pyramidal neurons laser captured from the prefrontal cortex.
Conclusions
These studies demonstrate a unique pathology of neocortical pyramidal neurons of the ACC in ASD. NTRK2 encodes the tropomyosin receptor kinase B (TrkB), transmission through which neurotrophic factors modify differentiation, plasticity, and synaptic transmission. Reduced pyramidal neuron NTRK2 expression in the ACC could thereby contribute to abnormal neuronal activity and disrupt social behavior mediated by this brain region.
Electronic supplementary material
The online version of this article (doi:10.1186/s13229-015-0023-2) contains supplementary material, which is available to authorized users.
doi:10.1186/s13229-015-0023-2
PMCID: PMC4440594  PMID: 26000162
Pyramidal neurons; Astrocytes; Cingulate; Autism; Glutamate receptors
20.  Working memory deficits in high-functioning adolescents with autism spectrum disorders: neuropsychological and neuroimaging correlates 
Working memory is a temporary storage system under attentional control. It is believed to play a central role in online processing of complex cognitive information and may also play a role in social cognition and interpersonal interactions. Adolescents with a disorder on the autism spectrum display problems in precisely these domains. Social impairments, communication difficulties, and repetitive interests and activities are core domains of autism spectrum disorders (ASD), and executive function problems are often seen throughout the spectrum. As the main cognitive theories of ASD, including the theory of mind deficit hypotheses, weak central coherence account, and the executive dysfunction theory, still fail to explain the broad spectrum of symptoms, a new perspective on the etiology of ASD is needed. Deficits in working memory are central to many theories of psychopathology, and are generally linked to frontal-lobe dysfunction. This article will review neuropsychological and (functional) brain imaging studies on working memory in adolescents with ASD. Although still disputed, it is concluded that within the working memory system specific problems of spatial working memory are often seen in adolescents with ASD. These problems increase when information is more complex and greater demands on working memory are made. Neuroimaging studies indicate a more global working memory processing or connectivity deficiency, rather than a focused deficit in the prefrontal cortex. More research is needed to relate these working memory difficulties and neuroimaging results in ASD to the behavioral difficulties as seen in individuals with a disorder on the autism spectrum.
doi:10.1186/1866-1955-5-14
PMCID: PMC3674927  PMID: 23731472
Working memory; Adolescents; Autism; Neuropsychology; Neuroimaging
21.  The brains of high functioning autistic individuals do not synchronize with those of others☆ 
NeuroImage : Clinical  2013;3:489-497.
Multifaceted and idiosyncratic aberrancies in social cognition characterize autism spectrum disorders (ASDs). To advance understanding of underlying neural mechanisms, we measured brain hemodynamic activity with functional magnetic resonance imaging (fMRI) in individuals with ASD and matched-pair neurotypical (NT) controls while they were viewing a feature film portraying social interactions. Pearson's correlation coefficient was used as a measure of voxelwise similarity of brain activity (InterSubject Correlations—ISCs). Individuals with ASD showed lower ISC than NT controls in brain regions implicated in processing social information including the insula, posterior and anterior cingulate cortex, caudate nucleus, precuneus, lateral occipital cortex, and supramarginal gyrus. Curiously, also within NT group, autism-quotient scores predicted ISC in overlapping areas, including, e.g., supramarginal gyrus and precuneus. In ASD participants, functional connectivity was decreased between the frontal pole and the superior frontal gyrus, angular gyrus, superior parietal lobule, precentral gyrus, precuneus, and anterior/posterior cingulate gyrus. Taken together these results suggest that ISC and functional connectivity measure distinct features of atypical brain function in high-functioning autistic individuals during free viewing of acted social interactions. Our ISC results suggest that the minds of ASD individuals do not ‘tick together’ with others while perceiving identical dynamic social interactions.
Highlights
•We studied brain function in autism during free viewing of social interactions.•The brains of individuals with autism do not ‘tick together’ with others.•Long-range functional connectivity is altered in individuals with autism.•Link between autistic traits and social brain synchrony extends to normal population.
doi:10.1016/j.nicl.2013.10.011
PMCID: PMC3830058  PMID: 24273731
Asperger syndrome; fMRI; Intersubject correlation; Movie; Social brain
22.  Caudate Nucleus Volume and Cognitive Performance: Are they related in Childhood Psychopathology?1 
Biological psychiatry  2006;60(9):942-950.
Background
Impaired neuropsychological test performance, especially on tests of executive function and attention, is often seen in children diagnosed with autism spectrum disorders (ASD). Structures involved in fronto-striatal circuitry, such as the caudate nucleus, may support these cognitive abilities. However, few studies have examined caudate volumes specifically in children with ASD, or correlated caudate volumes to cognitive ability.
Methods
Neuropsychological test scores and caudate volumes of children with ASD were compared to those of children with bipolar disorder (BD) and of typically developing (TD) children. The relationship between test performance and caudate volumes was analyzed.
Results
The ASD group displayed larger right and left caudate volumes, and modest executive deficits, compared to TD controls. While caudate volume inversely predicted performance on the Wisconsin Card Sorting Test in all participants, it differentially predicted performance on measures of attention across the ASD, BD and TD groups.
Conclusions
Larger caudate volumes were related to impaired problem solving. On a test of attention, larger left caudate volumes predicted increased impulsivity and more omission errors in the ASD group as compared to the TD group, however smaller volume predicted poorer discriminant responding as compared to the BD group.
doi:10.1016/j.biopsych.2006.03.071
PMCID: PMC2947855  PMID: 16950212
executive function; attention; bipolar disorder; autism spectrum disorders; caudate volume; neuroimaging
23.  EVENT-RELATED POTENTIAL STUDY OF ATTENTION REGULATION DURING ILLUSORY FIGURE CATEGORIZATION TASK IN ADHD, AUTISM SPECTRUM DISORDER, AND TYPICAL CHILDREN 
Journal of neurotherapy  2012;16(1):12-31.
Autism spectrum disorders (ASD) and attention deficit/hyperactivity disorder (ADHD) are very common developmental disorders which share some similar symptoms of social, emotional, and attentional deficits. This study is aimed to help understand the differences and similarities of these deficits using analysis of dense-array event-related potentials (ERP) during an illusory figure recognition task. Although ADHD and ASD seem very distinct, they have been shown to share some similarities in their symptoms. Our hypothesis was that children with ASD will show less pronounced differences in ERP responses to target and non-target stimuli as compared to typical children, and to a lesser extent, ADHD. Participants were children with ASD (N=16), ADHD (N=16), and controls (N=16). EEG was collected using a 128 channel EEG system. The task involved the recognition of a specific illusory shape, in this case a square or triangle, created by three or four inducer disks. There were no between group differences in reaction time (RT) to target stimuli, but both ASD and ADHD committed more errors, specifically the ASD group had statistically higher commission error rate than controls. Post-error RT in ASD group was exhibited in a post-error speeding rather than corrective RT slowing typical for the controls. The ASD group also demonstrated an attenuated error-related negativity (ERN) as compared to ADHD and controls. The fronto-central P200, N200, and P300 were enhanced and less differentiated in response to target and non-target figures in the ASD group. The same ERP components were marked by more prolonged latencies in the ADHD group as compared to both ASD and typical controls. The findings are interpreted according to the “minicolumnar” hypothesis proposing existence of neuropathological differences in ASD and ADHD, specifically minicolumnar number/width morphometry spectrum differences. In autism, a model of local hyperconnectivity and long-range hypoconnectivity explains many of the behavioral and cognitive deficits present in the condition, while the inverse arrangement of local hypoconnectivity and long-range hyperconnectivity in ADHD explains some deficits typical for this disorder. The current ERP study supports the proposed suggestion that some between group differences could be manifested in the frontal ERP indices of executive functions during performance on an illusory figure categorization task.
doi:10.1080/10874208.2012.650119
PMCID: PMC3544080  PMID: 23329879
Autism Spectrum Disorder; ADHD; Event-related Potential; Attention
24.  fMRI evidence of neural abnormalities in the subcortical face processing system in ASD 
NeuroImage  2010;54(1):697-704.
Recent evidence suggests that a rapid, automatic face-detection system is supported by subcortical structures including the amygdala, pulvinar, and superior colliculus. Early emerging abnormalities in these structures may be related to reduced social orienting in children with autism, and subsequently, to aberrant development of cortical circuits involved in face processing. Our objective was to determine whether functional abnormalities in the subcortical face processing system are present in adults with autism spectrum disorders (ASD) during supraliminal fearful face processing. Participants included twenty-eight individuals with ASD and 25 controls group-matched on age, IQ, and behavioral performance. The ASD group met diagnostic criteria on the ADI-R, ADOS-G, and DSM-IV. Both the ASD and control groups showed significant activation in bilateral fusiform gyri. The control group exhibited additional significant responses in the right amygdala, right pulvinar, and bilateral superior colliculi. In the direct group comparison, the controls showed significantly greater activation in the left amygdala, bilateral fusiform gyrus, right pulvinar, and bilateral superior colliculi. No brain region showed significantly greater activation in the ASD group compared to the controls. Thus, basic rapid face identification mechanisms appear to be functional in ASD. However, individuals with ASD failed to engage the subcortical brain regions involved in face detection and automatic emotional face processing, suggesting a core mechanism for impaired socioemotional processing in ASD. Neural abnormalities in this system may contribute to early emerging deficits in social orienting and attention, the putative precursors to abnormalities in social cognition and cortical face processing specialization.
doi:10.1016/j.neuroimage.2010.07.037
PMCID: PMC3426450  PMID: 20656041
25.  Autism is characterized by dorsal anterior cingulate hyperactivation during social target detection 
Though the functional neural correlates of impaired cognitive control and social dysfunction in autism spectrum disorders (ASD) have been delineated, brain regions implicated in poor cognitive control of social information is a novel area of autism research. We recently reported in a non-clinical sample that detection of ‘social oddball’ targets activated a portion of the dorsal anterior cingulate gyrus and the supracalcarine cortex (Dichter, Felder, Bodfish, Sikich, and Belger, 2009). In the present investigation, we report functional magnetic resonance imaging results from individuals with ASD who completed the same social oddball task. Between-group comparisons revealed generally greater activation in the ASD group to both social and non-social targets. When responses to social and non-social targets were contrasted, the ASD group showed relatively greater activation in the right and middle inferior frontal gyri and a region in dorsomedial prefrontal cortex that abuts the dorsal anterior cingulate (Brodmann's Area 32). Further, dorsal anterior cingulate activation to social targets predicted the severity of social impairments in a subset of the ASD sample. These data suggest that the dorsal anterior cingulate mediates social target detection in neurotypical individuals and is implicated in deficits of cognitive control of social information in ASD.
doi:10.1093/scan/nsp017
PMCID: PMC2728636  PMID: 19574440
autism; fMRI; target detection; face processing; cingulate gyrus

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