Inter-hemispherical Investigations on the Functional Connectivity of Autistic Resting State fMRI

2016 ◽  
Vol 10 (2) ◽  
pp. 95-108 ◽  
Author(s):  
Vidhusha S ◽  
Kavitha Anandan
Keyword(s):  
Functional Connectivity ◽  
Granger Causality ◽  
Left Hemisphere ◽  
Right Hemisphere ◽  
Cognitive Task ◽  
Resting State Fmri ◽  
Autism Spectrum ◽  
Control Group ◽  
Adults With Asd ◽  
The Brain

Autism spectrum disorders are connected with disturbances of neural connectivity. Functional connectivity is typically examined during a cognitive task, but also exists in the absence of a task i.e., “rest.” Adults with ASD have been found to show weaker connectivity relative to controls. This work focuses on analyzing the brain activation for autistic subjects, measured by fMRI during rest, relative to the control group using interhemispherical analysis. Though both groups activated similarly in cortical areas, indications of under connectivity were exhibited by the autistic group measured by Granger Causality and Conditional Granger Causality. Results show that as connectivity decreases, GC and CGC values also get decreased. The left hemisphere exhibits depreciation in the connectivity in comparison to that of right hemisphere for the autistic individuals whose GC and CGC values keeps decreasing in the left hemisphere seed regions. Finally, the results provide an approach for analyzing the cortical underconnectivity, in clinical relevance for diagnosing autism in children.

Inter-Hemispherical Investigations on the Functional Connectivity in Controls and Autism Spectrum Using Resting State fMRI

2020 ◽  
pp. 169-186
Author(s):  
S. Vidhusha ◽  
A. Kavitha
Keyword(s):  
Functional Connectivity ◽  
Granger Causality ◽  
Resting State ◽  
Cognitive Task ◽  
Resting State Fmri ◽  
Autism Spectrum ◽  
Control Group ◽  
Neural Connectivity ◽  
Activation Patterns ◽  
The Brain

Autism spectrum disorders are connected with disturbances of neural connectivity. Functional connectivity is typically examined during a cognitive task, but also exists in the absence of a task. While a number of studies have performed functional connectivity analysis to differentiate controls and autism individuals, this work focuses on analyzing the brain activation patterns not only between controls and autistic subjects, but also analyses the brain behaviour present within autism spectrum. This can bring out more intuitive ways to understand that autism individuals differ individually. This has been performed between autism group relative to the control group using inter-hemispherical analysis. Indications of under connectivity were exhibited by the Granger Causality (GC) and Conditional Granger Causality (CGC) in autistic group. Results show that as connectivity decreases, the GC and CGC values also get decreased. Further, to demark the differences present within the spectrum of autistic individuals, GC and CGC values have been calculated.

UNBIASING THE BRAIN: THE EFFECTS OF MEDITATION UPON THE CEREBRAL HEMISPHERES

1983 ◽  
Vol 11 (1) ◽  
pp. 65-76 ◽  
Author(s):  
John Meissner ◽  
Michael Pirot
Keyword(s):  
Reaction Time ◽  
Left Hemisphere ◽  
Right Hemisphere ◽  
Transcendental Meditation ◽  
Hand Preference ◽  
Control Group ◽  
Control Groups ◽  
Clinical Method ◽  
The Right ◽  
The Brain

Twenty males with a strong right hand preference underwent 120 simple reaction time trials to a 500 hz auditory stimulus presented to right, left and both ears. Ten Transcendental Meditators served as their own controls in twenty minute meditation and relaxation conditions and were also compared to a ten Non-Meditator control group who relaxed only in two 20-minute conditions. The reaction time trials were administered after the conditions. When the ears were compared to each other a significant right-ear (left hemisphere) advantage (REA) occurred in all relaxation conditions of the Meditator and Non-Meditator control groups. However, no REA emerged after meditation conditions of the Meditator group. The Meditator group after meditation compared to their own baseline relaxation condition showed a significant suppression of reaction time latencies to stimulation delivered to the left hemisphere and a significant facilitation to stimulation delivered to the right hemisphere. The meaning of these findings suggest Transcendental Meditation is an attentional strategy that disrupts the usual biases of the brain which also has implications as a clinical method. A neuropsychological explanation of the results suggest a comprehensive theory of Transcendental Meditation.

scholarly journals Reduced asymmetry of the hand knob area and decreased sensorimotor u-fiber connectivity in middle-aged adults with autism

2021 ◽  
Author(s):  
Janice Hau ◽  
Ashley Baker ◽  
Chantal Chaaban ◽  
Jiwandeep S Kohli ◽  
R Joanne Jao Keehn ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Motor Skills ◽  
Right Hemisphere ◽  
Autism Spectrum ◽  
Middle Aged ◽  
Hand Knob ◽  
The Right ◽  
Middle Aged Adults ◽  
Adults With Asd ◽  
Fiber Connectivity

Individuals with autism spectrum disorder (ASD) frequently present with impairments in motor skills (e.g., limb coordination, handwriting and balance), which are observed across the lifespan but remain largely untreated. Many adults with ASD may thus experience adverse motor outcomes in aging, when physical decline naturally occurs. The 'hand knob' of the sensorimotor cortex is an area that is critical for motor control of the fingers and hands. However, this region has received little attention in ASD research, especially in adults after midlife. The hand knob area of the precentral (PrChand) and postcentral (PoChand) gyri was semi-manually delineated in 49 right-handed adults (25 ASD, 24 typical comparison [TC] participants, aged 41-70 years). Using multimodal (T1-weighted, diffusion-weighted, and resting-state functional) MRI, we examined the morphology, ipsilateral connectivity and laterality of these regions. Correlations between hand knob measures with motor skills and autism symptoms, and between structural and functional connectivity measures were also investigated. The right PrChand volume was greater, and typical leftward laterality of PrChand and PoChand volume was lower in the ASD than the TC group. Furthermore, we observed increased mean diffusivity of the right PoC-PrChand u-fibers in the ASD group. In the ASD group, right PoC-PrChand u-fiber volume was negatively associated with current autism severity, and positively associated with right PoC-PrChand functional connectivity (FC). Correlations of hand knob measures were observed with manual dexterity and coordination skills but did not survive multiple comparisons correction. Our findings suggest decreased morphological laterality and u-fiber connectivity of the sensorimotor network involved in hand function in middle-aged adults with ASD. The altered morphology may relate to atypical functional asymmetries found in ASD earlier in life, but additionally, could reflect an overreliance on right hemisphere motor circuits over time. The right PoC-PrChand u-fibers may underlie compensatory self-regulation of unwanted core motor behaviors seen in ASD.

scholarly journals Analysis of population functional connectivity data via multilayer network embeddings

2020 ◽  
pp. 1-24
Author(s):  
James D. Wilson ◽  
Melanie Baybay ◽  
Rishi Sankar ◽  
Paul Stillman ◽  
Abbie M. Popa
Keyword(s):  
Functional Connectivity ◽  
Cognitive Task ◽  
Resting State Fmri ◽  
Population Connectivity ◽  
Multilayer Networks ◽  
Multilayer Network ◽  
Feature Representations ◽  
Population Analyses ◽  
Functional Regions ◽  
The Brain

Abstract Population analyses of functional connectivity have provided a rich understanding of how brain function differs across time, individual, and cognitive task. An important but challenging task in such population analyses is the identification of reliable features that describe the function of the brain, while accounting for individual heterogeneity. Our work is motivated by two particularly important challenges in this area: first, how can one analyze functional connectivity data over populations of individuals, and second, how can one use these analyses to infer group similarities and differences. Motivated by these challenges, we model population connectivity data as a multilayer network and develop the multi-node2vec algorithm, an efficient and scalable embedding method that automatically learns continuous node feature representations from multilayer networks. We use multi-node2vec to analyze resting state fMRI scans over a group of 74 healthy individuals and 60 patients with schizophrenia. We demonstrate how multilayer network embeddings can be used to visualize, cluster, and classify functional regions of the brain for these individuals. We furthermore compare the multilayer network embeddings of the two groups. We identify significant differences between the groups in the default mode network and salience network—findings that are supported by the triple network model theory of cognitive organization. Our findings reveal that multi-node2vec is a powerful and reliable method for analyzing multilayer networks. Data and publicly available code are available at https://github.com/jdwilson4/multi-node2vec.

scholarly journals Effects of Dog-Assisted Therapy on the Physical Function and Communication Skills of Adults with Autism: A Study Protocol for a Controlled Study

2021 ◽  
Vol 11 (22) ◽  
pp. 10650
Author(s):  
Isabel Gómez-Calcerrada ◽  
Ana Myriam Lavín-Pérez ◽  
Santos Villafaina ◽  
Juan Carlos Rueda-Rubio ◽  
Beatriz Rivera-Martín ◽  
...  
Keyword(s):  
Communication Skills ◽  
Controlled Trial ◽  
Autism Spectrum ◽  
Controlled Study ◽  
Control Group ◽  
Adults With Autism ◽  
Treatment As Usual ◽  
Positive Effects ◽  
Adults With Asd ◽  
Gait Posture

Background and Objectives: Despite the scientific evidence of the positive effects of animal-assisted therapy (AAT) in adults with autism spectrum disorder (ASD), it is not still considered an evidence-based practice for this population. The proposed study will aim to evaluate the effects of a dog-assisted therapy program on gait, posture, and communication skills. Materials and Methods: A total of 24 adults with ASD will participate in this non-randomized controlled trial. The experimental group will involve 12 participants who will receive AAT for 10 weeks, at two sessions per week. The focus of these sessions will be conducting different activities and physical exercises, facilitated by dogs. The control group will receive treatment as usual. The outcome measures will be the ability to walk and climbing stairs, balance, risk of falls and communication skills. Conclusions: The role of dogs as facilitators of the movement may lead to relevant benefits in the gait, posture and communication skills of adults with ASD, improving their ability to perform activities of daily living.

scholarly journals The appropriacy of fluency tests in assessing epileptic seizure lateralization in children with partial epilepsy

Psihologija ◽  
2008 ◽  
Vol 41 (2) ◽  
pp. 195-211
Author(s):  
Jasmina Vuksanovic ◽  
Milena Djuric
Keyword(s):  
Left Hemisphere ◽  
Right Hemisphere ◽  
Partial Epilepsy ◽  
Quantitative Comparison ◽  
Control Group ◽  
Healthy Children ◽  
Healthy Controls ◽  
Seizure Focus ◽  
Qualitative And Quantitative ◽  
The Right

Fluency tests are frequently used in clinical practice to asses executive functions. The literature data are not unequivocal although in a great number of papers is pointed out the importance of the left hemisphere, specially of the left frontal lobes in the mediation of phonological fluency and the right hemisphere in the mediation of nonverbal fluency. This paper considers the suitability of fluency tests for the detection of left versus right seizure laterality. The sample consisted of thirty-two epilepsy patients divided into two groups: LHF-participants with the seizure focus in the left hemisphere (n=16), and DHF-participants with the seizure focus in the right hemisphere (n=16), and K-the control group of t age-matched healthy children (n=50) aged 7-11 years. The qualitative and quantitative comparison of the phonological and nonverbal fluency performance was carried out in consideration of the seizure laterality as well as compared to the healthy controls. The results of phonological fluency performance revealed that the performance of the LHF group was significantly reduced as compared to both DHF and K group. The analysis of nonverbal fluency performance revealed that the performance of the DHF group was significantly reduced as compared to both LHF and K group The qualitative analysis obtained valuable data, which could additionally contribute to the neuropsychological evaluation of the left versus right seizure laterality.

scholarly journals Computerized physical and cognitive training improves the functional architecture of the brain in adults with Down syndrome: A network science EEG study

2020 ◽  
pp. 1-21
Author(s):  
Alexandra Anagnostopoulou ◽  
Charis Styliadis ◽  
Panagiotis Kartsidis ◽  
Evangelia Romanopoulou ◽  
Vasiliki Zilidou ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Functional Connectivity ◽  
Cognitive Training ◽  
Resting State ◽  
Network Architecture ◽  
Right Hemisphere ◽  
Random Network ◽  
Brain Activity ◽  
Hierarchical Organization ◽  
The Brain

Understanding the neuroplastic capacity of people with Down syndrome (PwDS) can potentially reveal the causal relationship between aberrant brain organization and phenotypic characteristics. We used resting-state EEG recordings to identify how a neuroplasticity-triggering training protocol relates to changes in the functional connectivity of the brain’s intrinsic cortical networks. Brain activity of 12 PwDS before and after a 10-week protocol of combined physical and cognitive training was statistically compared to quantify changes in directed functional connectivity in conjunction with psychosomatometric assessments. PwDS showed increased connectivity within the left hemisphere and from left-to-right hemisphere, as well as increased physical and cognitive performance. Our findings reveal a strong adaptive neuroplastic reorganization as a result of the training that leads to a less-random network with a more pronounced hierarchical organization. Our results go beyond previous findings by indicating a transition to a healthier, more efficient, and flexible network architecture, with improved integration and segregation abilities in the brain of PwDS. Resting-state electrophysiological brain activity is used here for the first time to display meaningful relationships to underlying Down syndrome processes and outcomes of importance in a translational inquiry. This trial is registered with ClinicalTrials.gov Identifier NCT04390321.

scholarly journals Graph Ricci Curvatures Reveal Disease-related Changes in Autism Spectrum Disorder

2021 ◽  
Author(s):  
Pavithra Elumalai ◽  
Yasharth Yadav ◽  
Nitin Williams ◽  
Emil Saucan ◽  
Jürgen Jost ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Resting State ◽  
Neurodevelopmental Disorders ◽  
Data Exchange ◽  
Meta Analysis ◽  
Resting State Fmri ◽  
Brain Regions ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
The Brain

Autism Spectrum Disorder (ASD) is a set of neurodevelopmental disorders that pose a significant global health burden. Measures from graph theory have been used to characterise ASD-related changes in resting-state fMRI functional connectivity networks (FCNs), but recently developed geometry-inspired measures have not been applied so far. In this study, we applied geometry-inspired graph Ricci curvatures to investigate ASD-related changes in resting-state fMRI FCNs. To do this, we applied Forman-Ricci and Ollivier-Ricci curvatures to compare networks of ASD and healthy controls (N = 1112) from the Autism Brain Imaging Data Exchange I (ABIDE-I) dataset. We performed these comparisons at the brain-wide level as well as at the level of individual brain regions, and further, determined the behavioral relevance of region-specific differences with Neurosynth meta-analysis decoding. We found brain-wide ASD-related differences for both Forman-Ricci and Ollivier-Ricci curvatures. For Forman-Ricci curvature, these differences were distributed across 83 of the 200 brain regions studied, and concentrated within the Default Mode, Somatomotor and Ventral Attention Network. Meta-analysis decoding identified the brain regions showing curvature differences as involved in social cognition, memory, language and movement. Notably, comparison with results from previous non-invasive stimulation (TMS/tDCS) experiments revealed that the set of brain regions showing curvature differences overlapped with the set of brain regions whose stimulation resulted in positive cognitive or behavioural outcomes in ASD patients. These results underscore the utility of geometry-inspired graph Ricci curvatures in characterising disease-related changes in ASD, and possibly, other neurodevelopmental disorders.

Coherence on Electroencephalography and Aberrant Functional Organisation of the Brain in Schizophrenic Patients During Activation Tasks

1991 ◽  
Vol 159 (5) ◽  
pp. 636-644 ◽  
Author(s):  
Sandra L. Morrison-Stewart ◽  
Peter C. Williamson ◽  
William C. Corning ◽  
Stanley P. Kutcher ◽  
Harold Merskey
Keyword(s):  
Left Hemisphere ◽  
Normal Control ◽  
Right Hemisphere ◽  
Normal Subjects ◽  
Cognitive Activation ◽  
Functional Organisation ◽  
Schizophrenic Patients ◽  
Discriminant Analyses ◽  
Eeg Alpha ◽  
The Brain

Thirty schizophrenic patients (20 medicated, 10 off medication) were compared with 30 normal control subjects matched for age, sex, handedness, and intelligence. During the performance of left-hemisphere cognitive activation tasks, normal subjects had significantly increased EEG alpha coherence in areas related to left focal frontal sites, with decreases in temporal and posterior areas. Schizophrenic patients did not show the same degree of focal activation of left frontal areas. During the performance of right-hemisphere cognitive activation tasks, normal subjects and schizophrenic patients had similar patterns of right posterior increases in alpha coherence. Discriminant analyses were able to classify 81.4% of all subjects correctly. It is suggested that the findings indicate an aberrant functional organisation of the brain in schizophrenia, particularly affecting the left hemisphere.

scholarly journals Beta-adrenergic antagonism alters functional connectivity during associative processing in a preliminary study of individuals with and without autism

Autism ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 795-801
Author(s):  
John P Hegarty ◽  
Rachel M Zamzow ◽  
Bradley J Ferguson ◽  
Shawn E Christ ◽  
Eric C Porges ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Functional Connectivity ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Semantic Fluency ◽  
Beta Adrenergic ◽  
Associative Processing ◽  
The Brain

Beta-adrenergic antagonism (e.g. propranolol) has been associated with cognitive/behavioral benefits following stress-induced impairments and for some cognitive/behavioral domains in individuals with autism spectrum disorder. In this preliminary investigation, we examined whether the benefits of propranolol are associated with functional properties in the brain. Adolescents/adults (mean age = 22.54 years) with (n = 13) and without autism spectrum disorder (n = 13) attended three sessions in which propranolol, nadolol ( beta-adrenergic antagonist that does not cross the blood–brain barrier), or placebo was administered before a semantic fluency task during functional magnetic resonance imaging. Autonomic nervous system measures and functional connectivity between language/associative processing regions and within the fronto-parietal control, dorsal attention, and default mode networks were examined. Propranolol was associated with improved semantic fluency performance, which was correlated with the baseline resting heart rate. Propranolol also altered network efficiency of regions associated with semantic processing and in an exploratory analysis reduced functional differences in the fronto-parietal control network in individuals with autism spectrum disorder. Thus, the cognitive benefits from beta-adrenergic antagonism may be generally associated with improved information processing in the brain in domain-specific networks, but individuals with autism spectrum disorder may also benefit from additional improvements in domain-general networks. The benefits from propranolol may also be able to be predicted from baseline autonomic nervous system measures, which warrants further investigation.

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