ORCID Profile
0000-0002-6357-615X
Current Organisations
University of California Los Angeles
,
Queensland University of Technology
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Linguistic Processes (incl. Speech Production and Comprehension) | Cognitive Science | Psychology | Learning, Memory, Cognition And Language | Biological Psychology (Neuropsychology, Psychopharmacology, Physiological Psychology) | Biological Psychology (Neuropsychology, Psychopharmacology, | Rehabilitation And Therapy: Hearing And Speech | Neurocognitive Patterns and Neural Networks | Clinical Sciences | Neurosciences Not Elsewhere Classified | Neurology and Neuromuscular Diseases | Linguistic Processes (Incl. Speech Production And Comprehension) | Rehabilitation and Therapy (excl. Physiotherapy)
ANZSRC Socio-Economic Objective (SEO)
Hearing, Vision, Speech and Their Disorders | Hearing, vision, speech and their disorders | Nervous System and Disorders | Expanding Knowledge in Psychology and Cognitive Sciences | "Occupational, speech and physiotherapy" | Behavioural and cognitive sciences | Neurodegenerative Disorders Related to Ageing | Allied Health Therapies (excl. Mental Health Services) | Biological sciences |
Related Links
Publications
Intersubject variability in spoken verb production: Effects of hierarchy and transitivity
Publisher: Center for Open Science
Date: 04-03-2021
Abstract: In two experiments employing the picture-word interference (PWI) paradigm, we explored how a verb’s hierarchy and transitivity influences its retrieval during spoken production. Experiment 1 involved transitive (i.e. object-oriented, e.g. eat) action pictures accompanied by a to-be-ignored distractor word that was either a related coordinate (‘drink’) or troponym (‘devour’), while Experiment 2 employed intransitive (e.g. walk) stimuli. Assuming these relationships operate similarly for verbs and object nouns, we expected to observe faster naming times for troponyms, and slower naming times for coordinates. Conventional group-level analyses of the null average hypothesis revealed no significant effects in either experiment. However, analyses of the global null hypothesis revealed significant interin idual variability for troponym distractors in Experiment 1, with a similar trend in Experiment 2. These results indicate verbs may have a different conceptual-lexical organisation to object nouns in the mental lexicon, less constrained by hierarchical categories, with their processing more influenced by subject-specific variables.
Alterations to dual stream connectivity predicts response to aphasia therapy following stroke
Publisher: Elsevier BV
Date: 04-2020
DOI: 10.1016/J.CORTEX.2019.12.017
Abstract: Predicting aphasia recovery is difficult due to a high variability in treatment response. Detailed measures of treatment response are compounded by a dearth of information that examine brain connections that contribute to clinical improvement. In this study we measure alterations to cortical connectivity pathways during a therapy paradigm to detect whether key brain connections that contribute to language recovery can be detected prior to therapy. We conducted a case-control trial with twenty-three adults including eight adults with chronic, post-stroke aphasia. Aphasia patients underwent 12 naming therapy sessions over 4 weeks, consisting of semantic and phonological treatment approaches. High-density electroencephalography (128 channel EEG) was measured prior to therapy and immediately following treatment in patients with aphasia. Analysis via a dynamic causal modelling (DCM) was used to assess which cortical connections significantly correlated with therapy response. Altered cortical responses in aphasia patients measured bilaterally in a dual stream DCM connectivity model were predictive of treatment-induced improvement in naming. Pre-treatment DCM coupling (i.e., strength of cortical connections) significant correlated with naming improvement for items treated with semantic therapy, as indicated by increased connection strengths between left inferior parietal lobule (LIPL) and inferior frontal gyrus (LIFG, r = .63, p Our findings identify a potential means to stratify larger cohorts of patients in neurorehabilitation settings into distinct treatments that are tailored to their in idual language deficit.
Dissociable Cellular and Genetic Mechanisms of Cortical Thinning at Different Life Stages
Publisher: Research Square Platform LLC
Date: 27-05-2022
DOI: 10.21203/RS.3.RS-1686228/V1
Abstract: Mechanisms underpinning neurotypical age-related variations in cortical thickness in the human brain remain insufficiently specified. Here we used cell-specific marker genes, followed by gene ontology and enrichment analyses, to quantify the association between gene-expression levels and inter-regional age-related variations in neurotypical cortical thinning using multicohort neuroimaging data from 14,248 in iduals ages 4-89 years. We found that early-life ( years), mid-life (20-60 years), and late-life ( years) were associated with distinct patterns of association between inter-regional profiles of cortical thickness and expression profiles of markers genes for CA1 and S1 pyramidal cells, astrocytes, and microglia. Gene ontology and enrichment analyses indicated each of the three life-stages was associated with different biological processes and cellular components these related to synaptic modeling in early life, neurotransmission in mid-life, and neurodegeneration in late-life. These findings provide mechanistic insights on age-related cortical thinning during typical development and ageing.
Epigenome-wide meta-analysis of blood DNA methylation and its association with subcortical volumes: findings from the ENIGMA Epigenetics Working Group
Publisher: Springer Science and Business Media LLC
Date: 06-12-2019
DOI: 10.1038/S41380-019-0605-Z
Abstract: DNA methylation, which is modulated by both genetic factors and environmental exposures, may offer a unique opportunity to discover novel biomarkers of disease-related brain phenotypes, even when measured in other tissues than brain, such as blood. A few studies of small s le sizes have revealed associations between blood DNA methylation and neuropsychopathology, however, large-scale epigenome-wide association studies (EWAS) are needed to investigate the utility of DNA methylation profiling as a peripheral marker for the brain. Here, in an analysis of eleven international cohorts, totalling 3337 in iduals, we report epigenome-wide meta-analyses of blood DNA methylation with volumes of the hippoc us, thalamus and nucleus accumbens (NAcc)—three subcortical regions selected for their associations with disease and heritability and volumetric variability. Analyses of in idual CpGs revealed genome-wide significant associations with hippoc al volume at two loci. No significant associations were found for analyses of thalamus and nucleus accumbens volumes. Cluster-based analyses revealed additional differentially methylated regions (DMRs) associated with hippoc al volume. DNA methylation at these loci affected expression of proximal genes involved in learning and memory, stem cell maintenance and differentiation, fatty acid metabolism and type-2 diabetes. These DNA methylation marks, their interaction with genetic variants and their impact on gene expression offer new insights into the relationship between epigenetic variation and brain structure and may provide the basis for biomarker discovery in neurodegeneration and neuropsychiatric conditions.
Top-down resolution of lexico-semantic competition in speech production and the role of the left inferior frontal gyrus: an fMRI study
Publisher: Informa UK Limited
Date: 19-05-2021
Perceiving and misperceiving degraded speech: Evidence from homophonically transformed sentences
Publisher: Center for Open Science
Date: 30-10-2023
Are Sex Differences in Human Brain Structure Associated With Sex Differences in Behavior?
Publisher: SAGE Publications
Date: 29-07-2021
Abstract: On average, men and women differ in brain structure and behavior, raising the possibility of a link between sex differences in brain and behavior. But women and men are also subject to different societal and cultural norms. We navigated this challenge by investigating variability of sex-differentiated brain structure within each sex. Using data from the Queensland Twin IMaging study ( n = 1,040) and Human Connectome Project ( n = 1,113), we obtained data-driven measures of in idual differences along a male–female dimension for brain and behavior based on average sex differences in brain structure and behavior, respectively. We found a weak association between these brain and behavioral differences, driven by brain size. These brain and behavioral differences were moderately heritable. Our findings suggest that behavioral sex differences are, to some extent, related to sex differences in brain structure but that this is mainly driven by differences in brain size, and causality should be interpreted cautiously.
A meta-analysis of the relationship between subjective sleep and depressive symptoms in adolescence
Publisher: Elsevier BV
Date: 03-2021
The effects of physical exercise on structural, functional, and biochemical brain characteristics in individuals with chronic whiplash‐associated disorder: A pilot randomized clinical trial
Publisher: Wiley
Date: 09-05-2023
DOI: 10.1111/PAPR.13240
Abstract: Exercise for people with whiplash associated disorder (WAD) induces hypoalgesic effects in some, but hyperalgesic effects in others. We investigated the exercise‐induced neurobiological effects of aerobic and strengthening exercise in in iduals with chronic WAD. Sixteen participants (8 WAD, 8 pain‐free [CON]) were randomised to either aerobic or strengthening exercise. MRI for brain morphometry, functional MRI for brain connectivity, and magnetic resonance spectroscopy for brain biochemistry, were used at baseline and after the 8‐week intervention. There were no differences in brain changes between exercise groups in either the WAD or CON group, therefore aerobic and strengthening data were combined to optimise s le size. After the exercise intervention, the CON group demonstrated increased cortical thickness (left parahippoc us: mean difference = 0.04, 95% CI = 0.07–0.00, p = 0.032 and left lateral orbital frontal cortex: mean difference = 0.03, 95% CI = 0.00–0.06, p = 0.048). The WAD group demonstrated an increase in prefrontal cortex (right medial orbital frontal) volume (mean difference = 95.57, 95% CI = 2.30–192.84, p = 0.046). Functional changes from baseline to follow‐up between the default mode network and the insula, cingulate cortex, temporal lobe, and somatosensory and motor cortices, were found in the CON group, but not in the WAD group. There were no changes post‐exercise in brain biochemistry. Aerobic and strengthening exercises did not exert differential effects on brain characteristics, however differences in structural and functional changes were found between WAD and CON groups. This suggests that an altered central pain modulatory response may be responsible for differential effects of exercise in in iduals with chronic WAD.
The Queensland Twin Adolescent Brain Project, a longitudinal study of adolescent brain development
Publisher: Cold Spring Harbor Laboratory
Date: 20-05-2022
DOI: 10.1101/2022.05.19.492753
Abstract: We describe the Queensland Twin Adolescent Brain (QTAB) dataset and provide a detailed methodology and technical validation to facilitate data usage. The QTAB dataset comprises multimodal neuroimaging, as well as cognitive and mental health data collected in adolescent twins over two sessions (session 1: N = 422, age 9-14 years session 2: N = 304, 10-16 years). The MRI protocol consisted of T1-weighted (MP2RAGE), T2-weighted, FLAIR, high-resolution TSE, SWI, resting-state fMRI, DWI, and ASL scans. Two fMRI tasks were added in session 2: an emotional conflict task and a passive movie-watching task. Outside of the scanner, we assessed cognitive function using standardised tests. We also obtained self-reports of symptoms for anxiety and depression, perceived stress, sleepiness, pubertal development measures, and risk and protective factors. We additionally collected several biological s les for genomic and metagenomic analysis. The QTAB project was established to promote health-related research in adolescence.
Neural correlates of attentional deficits in Parkinson's disease patients with mild cognitive impairment
Publisher: Elsevier BV
Date: 04-2021
DOI: 10.1016/J.PARKRELDIS.2021.02.009
Abstract: Deficits in attentional processing observed in Parkinson's disease (PD) patients with mild cognitive impairment (MCI) increase risk of PD dementia. However, the neural basis of these attentional deficits are presently unknown. The present study aimed to explore the neural correlates of attention dysfunction in PD-MCI using the Attention Network Test (ANT) and functional Magnetic Resonance Imaging (fMRI). Fifteen (15) PD-MCI patients, 26 PD patients without MCI (PD-NC) and 22 healthy controls (HC) were scanned (3T Siemens PRISMA) whilst performing the ANT. Reaction time, accuracy and fMRI BOLD activation were compared between groups for the three attentional task components of 1) alerting, 2) orienting, and 3) executive control. PD-MCI patients showed an overall slower reaction time compared to PD-NC and HC, and showed less interference of reaction time in the orienting effect than HC. fMRI data demonstrated greater activation in the bilateral cerebellum crus 1 during the alerting attention condition in both PD-MCI and PD-NC compared to HC. However, activation was supressed in the left postcentral gyrus in PD-MCI compared to PD-NC and HC. Alterations in the alerting attention functional network despite intact task performance in PD-MCI suggests that functional brain changes may precede cognitive changes in the attention domain. Furthermore, increased activation in the cerebellum may reflect an attentional compensatory mechanism unique to the PD pathology. Taken together, the findings suggest that PD has a complex effect on attentional ability that can, at least in part, be elucidated using functional neuroimaging.
Stimulation of Dorsolateral Prefrontal Cortex Enhances Adaptive Cognitive Control: A High-Definition Transcranial Direct Current Stimulation Study
Publisher: Society for Neuroscience
Date: 14-12-2016
DOI: 10.1523/JNEUROSCI.2450-16.2016
Abstract: Conflict adaptation is a hallmark effect of adaptive cognitive control and refers to the adjustment of control to the level of previously experienced conflict. Conflict monitoring theory assumes that the dorsolateral prefrontal cortex (DLPFC) is causally involved in this adjustment. However, to date, evidence in humans is predominantly correlational, and heterogeneous with respect to the lateralization of control in the DLPFC. We used high-definition transcranial direct current stimulation (HD-tDCS), which allows for more focal current delivery than conventional tDCS, to clarify the causal involvement of the DLPFC in conflict adaptation. Specifically, we investigated the regional specificity and lateralization of potential beneficial stimulation effects on conflict adaptation during a visual flanker task. One hundred twenty healthy participants were assigned to four HD-tDCS conditions: left or right DLPFC or left or right primary motor cortex (M1). Each group underwent both active and sham HD-tDCS in crossover, double-blind designs. We obtained a sizeable conflict adaptation effect (measured as the modulation of the flanker effect as a function of previous response conflict) in all groups and conditions. However, this effect was larger under active HD-tDCS than under sham stimulation in both DLPFC groups. In contrast, active stimulation had no effect on conflict adaptation in the M1 groups. In sum, the present results indicate that the DLPFC plays a causal role in adaptive cognitive control, but that the involvement of DLPFC in control is not restricted to the left or right hemisphere. Moreover, our study confirms the potential of HD-tDCS to modulate cognition in a regionally specific manner. SIGNIFICANCE STATEMENT Conflict adaptation is a hallmark effect of adaptive cognitive control. While animal studies have suggested causal involvement of the DLPFC in this phenomenon, such evidence is currently lacking in humans. The present study used high-definition transcranial direct current stimulation (HD-tDCS) to demonstrate that the DLPFC is causally involved in conflict adaptation in humans. Our study confirms a central claim of conflict monitoring theory, which up to now has predominantly relied on correlational studies. Our results further indicate an equal involvement of the left and right DLPFC in adaptive control, whereas stimulation of a control region—the primary motor cortex—had no effect on adaptive control. The study thus confirms the potential of HD-tDCS to modulate cognition in a regionally specific manner.
1q21.1 distal copy number variants are associated with cerebral and cognitive alterations in humans
Publisher: Center for Open Science
Date: 15-01-2021
Abstract: Low-frequency 1q21.1 distal deletion and duplication copy number variant (CNV) carriers are predisposed to multiple neurodevelopmental disorders including schizophrenia, autism and intellectual disability. Human carriers display a high prevalence of micro- and macrocephaly in deletion and duplication carriers, respectively. The underlying brain structural ersity remains largely unknown.We systematically called CNVs in 38 cohorts from the large-scale ENIGMA-CNV collaboration and the UK biobank and identified 28 1q21.1 distal deletion and 22 duplication carriers and 37,088 non-carriers (48 % male) derived from 15 distinct MRI scanner sites. With standardized methods, we compared subcortical and cortical brain measures (all) and cognitive performance (UK biobank only) between carrier groups also testing for mediation of brain structure on cognition. We identified positive dosage effects of copy number on intracranial volume (ICV) and total cortical surface area, with largest effects in frontal and cingulate cortices, and negative dosage effects on caudate and hippoc al volumes. The carriers displayed distinct cognitive deficit profiles in cognitive tasks from the UK biobank with intermediate decreases in duplication carriers and somewhat larger in deletion carriers – the latter potentially mediated by ICV or cortical surface area. These results shed light on pathobiological mechanisms of neurodevelopmental disorders, by demonstrating gene dose effect on specific brain structures and effect on cognitive function.
Substrates of speech treatment-induced neuroplasticity in adults and children with motor speech disorders: A systematic scoping review of neuroimaging evidence
Publisher: Informa UK Limited
Date: 24-05-2021
Early Subacute White Matter Hyperintensities and Recovery of Language After Stroke
Publisher: SAGE Publications
Date: 04-2023
DOI: 10.1177/15459683231168384
Abstract: White matter hyperintensities (WMH) are considered to contribute to diminished brain reserve, negatively impacting on stroke recovery. While WMH identified in the chronic phase after stroke have been associated with post-stroke aphasia, the contribution of premorbid WMH to the early recovery of language across production and comprehension has not been investigated. To investigate the relationship between premorbid WMH severity and longitudinal comprehension and production outcomes in aphasia, after controlling for stroke lesion variables. Longitudinal behavioral data from in iduals with a left-hemisphere stroke were included at the early subacute (n = 37) and chronic (n = 28) stage. Spoken language comprehension and production abilities were assessed at both timepoints using word and sentence-level tasks. Magnetic resonance imaging (MRI) was performed at the early subacute stage to derive stroke lesion variables (volume and proportion damage to critical regions) and WMH severity rating. The presence of severe WMH explained an additional 18% and 25% variance in early subacute ( t = −3.00, p = .004) and chronic ( t = −3.60, P = .001) language comprehension abilities respectively, after controlling for stroke lesion variables. WMH did not predict additional variance of language production scores. Subacute clinical MRI can be used to improve prognoses of recovery of aphasia after stroke. We demonstrate that severe early subacute WMH add to the prediction of impaired longitudinal language recovery in comprehension, but not production. This emphasizes the need to consider different domains of language when investigating novel neurobiological predictors of aphasia recovery.
Exercise Parameters for Postconcussion Symptom Rehabilitation: A Systematic Review
Publisher: Human Kinetics
Date: 07-2023
Abstract: Context : Exercise rehabilitation for postconcussion symptoms (PCS) has shown some benefits in adolescent athletes but a synthesis of evidence on exercise per se has been lacking. Objective : This systematic review aimed to determine if unimodal exercise interventions are useful to treat PCS and if so, to identify a set of clearly defined and effective exercise parameters for further research. Evidence Acquisition : Relevant health databases and clinical trial registries were searched from inception to June 2022. The searches used a combination of subject headings and keywords related to mild traumatic brain injury (mTBI), PCSs, and exercise. Two independent reviewers screened and appraised the literature. The Cochrane Collaboration’s Risk of Bias-2 tool for randomized controlled trials was used to assess methodological quality of studies. Evidence Synthesis : Seven studies were included in the review. Four studies were assessed to have a low overall risk of bias, 2 with low risk and 1 with some concerns. Participants in the studies comprised mostly adolescents with sports-related concussion. The review found exercise to be more beneficial than control conditions in 2 studies investigating acute PCS and 2 studies investigating persistent PCS. Within-group differences showing symptom improvement over time were observed in all 7 studies. In general, the review found support for programmatic exercise that commences after an initial period of rest for 24 to 48 hours. Recommendations for exercise parameters that can be explored in subsequent research include progressive aerobic exercise starting from 10 to 15 minutes at least 4 times a week, at a starting intensity of 50% HR of the subsymptom threshold, with length of program depending on recovery. Conclusion : The evidence in support of exercise rehabilitation for PCSs is moderate based on the small pool of eligible studies. Further research can be guided by the exercise parameters identified in this review.
Interactions between the lipidome and genetic and environmental factors in autism
Publisher: Springer Science and Business Media LLC
Date: 04-2023
DOI: 10.1038/S41591-023-02271-1
Abstract: Autism omics research has historically been reductionist and diagnosis centric, with little attention paid to common co-occurring conditions (for ex le, sleep and feeding disorders) and the complex interplay between molecular profiles and neurodevelopment, genetics, environmental factors and health. Here we explored the plasma lipidome (783 lipid species) in 765 children (485 diagnosed with autism spectrum disorder (ASD)) within the Australian Autism Biobank. We identified lipids associated with ASD diagnosis ( n = 8), sleep disturbances ( n = 20) and cognitive function ( n = 8) and found that long-chain polyunsaturated fatty acids may causally contribute to sleep disturbances mediated by the FADS gene cluster. We explored the interplay of environmental factors with neurodevelopment and the lipidome, finding that sleep disturbances and unhealthy diet have a convergent lipidome profile (with potential mediation by the microbiome) that is also independently associated with poorer adaptive function. In contrast, ASD lipidome differences were accounted for by dietary differences and sleep disturbances. We identified a large chr19p13.2 copy number variant genetic deletion spanning the LDLR gene and two high-confidence ASD genes ( ELAVL3 and SMARCA4 ) in one child with an ASD diagnosis and widespread low-density lipoprotein-related lipidome derangements. Lipidomics captures the complexity of neurodevelopment, as well as the biological effects of conditions that commonly affect quality of life among autistic people.
Understanding the Sociocognitive Determinants Underlying Intentions to Exercise for Postconcussion Symptom Relief: An Application of the Theory of Planned Behavior
Publisher: Human Kinetics
Date: 2023
Abstract: Context : This study investigated in idual sociocognitive factors from the theory of planned behavior and their relationship to exercise for postconcussion recovery. Design and Methods : Four hundred and fifty-nine Australian adults, two-thirds of whom had no concussion history (66%), completed an online survey of their beliefs and attitudes toward exercise for postconcussion recovery. Secondary questions evaluated program design features that could affect engagement (eg, session frequency). Results : Structured equation modeling found that subjective norms were the strongest significant predictor of intention to participate in exercise for postconcussion recovery. Perceived behavioral control was also a significant predictor of intention to participate but to a lesser extent. Attitude did not predict participation intention. The design features identified as key were personalization and being supervised during the program. Conclusions : This study found that people’s intention to participate in a program of exercise postconcussion recovery is shaped by in idual psychological factors and identified program design features that could be adjusted for increased engagement. Program success could be maximized through strategies such as supporting in iduals to have a stronger sense of control over their participation through the choice of session timing or frequency and harnessing the influence of significant others via supportive messaging from key professionals.
Brain Lesions Associated with Communication-Related Quality of Life Following Surgical Removal of Primary Left-Hemisphere Tumours
Publisher: Informa UK Limited
Date: 28-11-2022
The reliability and heritability of cortical folds and their genetic correlations across hemispheres
Publisher: Springer Science and Business Media LLC
Date: 15-09-2020
DOI: 10.1038/S42003-020-01163-1
Abstract: Cortical folds help drive the parcellation of the human cortex into functionally specific regions. Variations in the length, depth, width, and surface area of these sulcal landmarks have been associated with disease, and may be genetically mediated. Before estimating the heritability of sulcal variation, the extent to which these metrics can be reliably extracted from in-vivo MRI must be established. Using four independent test-retest datasets, we found high reliability across the brain (intraclass correlation interquartile range: 0.65–0.85). Heritability estimates were derived for three family-based cohorts using variance components analysis and pooled (total N 3000) the overall sulcal heritability pattern was correlated to that derived for a large population cohort (N 9000) calculated using genomic complex trait analysis. Overall, sulcal width was the most heritable metric, and earlier forming sulci showed higher heritability. The inter-hemispheric genetic correlations were high, yet select sulci showed incomplete pleiotropy, suggesting hemisphere-specific genetic influences.
Dissociable Cellular and Genetic Mechanisms of Cortical Thinning at Different Life Stages
Publisher: Cold Spring Harbor Laboratory
Date: 22-03-2022
DOI: 10.1101/2022.03.21.484899
Abstract: Mechanisms underpinning age-related variations in cortical thickness in the human brain remain poorly understood. We investigated whether inter-regional age-related variations in cortical thinning (in a multicohort neuroimaging dataset from the ENIGMA Lifespan Working Group totalling 14,248 in iduals, aged 4-89 years) depended on cell-specific marker gene expression levels. We found differences amidst early-life ( years), mid-life (20-60 years), and late-life ( years) in the patterns of association between inter-regional profiles of cortical thickness and expression profiles of marker genes for CA1 and S1 pyramidal cells, astrocytes, and microglia. Gene ontology and enrichment analyses indicated that each of the three life-stages was associated with different biological processes and cellular components: synaptic modeling in early life, neurotransmission in mid-life, and neurodegeneration in late-life. These findings provide mechanistic insights into age-related cortical thinning during typical development and aging.
Absolute and relative estimates of genetic and environmental variance in brain structure volumes
Publisher: Springer Science and Business Media LLC
Date: 19-08-2019
DOI: 10.1007/S00429-019-01931-8
Abstract: Comparing estimates of the amount of genetic and environmental variance for different brain structures may elucidate differences in the genetic architecture or developmental constraints of in idual brain structures. However, most studies compare estimates of relative genetic (heritability) and environmental variance in brain structure, which do not reflect differences in absolute variance between brain regions. Here we used a population s le of young adult twins and singleton siblings of twins (n = 791 M = 23 years, Queensland Twin IMaging study) to estimate the absolute genetic and environmental variance, standardised by the phenotypic mean, in the size of cortical, subcortical, and ventricular brain structures. Mean-standardised genetic variance differed widely across structures [23.5-fold range 0.52% (hippoc us) to 12.28% (lateral ventricles)], but the range of estimates within cortical, subcortical, or ventricular structures was more moderate (two to fivefold range). There was no association between mean-standardised and relative measures of genetic variance (i.e., heritability) in brain structure volumes. We found similar results in an independent s le (n = 1075, M = 29 years, Human Connectome Project). These findings open important new lines of enquiry: namely, understanding the bases of these variance patterns, and their implications regarding the genetic architecture, evolution, and development of the human brain.
The Queensland Twin Adolescent Brain Project, a longitudinal study of adolescent brain development
Publisher: Springer Science and Business Media LLC
Date: 08-04-2023
DOI: 10.1038/S41597-023-02038-W
Abstract: We describe the Queensland Twin Adolescent Brain (QTAB) dataset and provide a detailed methodology and technical validation to facilitate data usage. The QTAB dataset comprises multimodal neuroimaging, as well as cognitive and mental health data collected in adolescent twins over two sessions (session 1: N = 422, age 9–14 years session 2: N = 304, 10–16 years). The MRI protocol consisted of T1-weighted (MP2RAGE), T2-weighted, FLAIR, high-resolution TSE, SWI, resting-state fMRI, DWI, and ASL scans. Two fMRI tasks were added in session 2: an emotional conflict task and a passive movie-watching task. Outside of the scanner, we assessed cognitive function using standardised tests. We also obtained self-reports of symptoms for anxiety and depression, perceived stress, sleepiness, pubertal development measures, and risk and protective factors. We additionally collected several biological s les for genomic and metagenomic analysis. The QTAB project was established to promote health-related research in adolescence.
Associations between brain structure and perceived intensity of sweet and bitter tastes
Publisher: Elsevier BV
Date: 05-2019
Lingual Gyrus Surface Area Is Associated with Anxiety-Depression Severity in Young Adults: A Genetic Clustering Approach
Publisher: Society for Neuroscience
Date: 2018
DOI: 10.1523/ENEURO.0153-17.2017
Abstract: Here we aimed to identify cortical endophenotypes for anxiety-depression. Our data-driven approach used vertex-wise genetic correlations (estimated from a twin s le: 157 monozygotic and 194 dizygotic twin pairs) to parcellate cortical thickness (CT) and surface area (SA) into genetically homogeneous regions (Chen et al., 2013). In an overlapping twin and sibling s le ( n = 834 aged 15–29, 66% female), in those with anxiety-depression Somatic and Psychological Health Report (SPHERE) scores (Hickie et al., 2001) above median, we found a reduction of SA in an occipito-temporal cluster, which comprised part of the right lingual, fusiform and parahippoc al gyrii. A similar reduction was observed in the Human Connectome Project (HCP) s le ( n = 890, age 22–37, 56.5% female) in those with Adult Self Report (ASR) DSM-oriented scores (Achenbach et al., 2005) in the 25–95% quantiles. A post hoc vertex-wise analysis identified the right lingual and, to a lesser extent the fusiform gyrus. Overall, the surface reduction explained by the anxiety-depression scores was modest ( r = −0.10, 3rd order spline, and r = −0.040, 1st order spline in the HCP). The discordant results in the top 5% of the anxiety-depression scores may be explained by differences in recruitment between the studies. However, we could not conclude whether this cortical region was an endophenotype for anxiety-depression as the genetic correlations did not reach significance, which we attribute to the modest effect size ( post hoc statistical power %).
1q21.1 distal copy number variants are associated with cerebral and cognitive alterations in humans
Publisher: Springer Science and Business Media LLC
Date: 22-03-2021
DOI: 10.1038/S41398-021-01213-0
Abstract: Low-frequency 1q21.1 distal deletion and duplication copy number variant (CNV) carriers are predisposed to multiple neurodevelopmental disorders, including schizophrenia, autism and intellectual disability. Human carriers display a high prevalence of micro- and macrocephaly in deletion and duplication carriers, respectively. The underlying brain structural ersity remains largely unknown. We systematically called CNVs in 38 cohorts from the large-scale ENIGMA-CNV collaboration and the UK Biobank and identified 28 1q21.1 distal deletion and 22 duplication carriers and 37,088 non-carriers (48% male) derived from 15 distinct magnetic resonance imaging scanner sites. With standardized methods, we compared subcortical and cortical brain measures (all) and cognitive performance (UK Biobank only) between carrier groups also testing for mediation of brain structure on cognition. We identified positive dosage effects of copy number on intracranial volume (ICV) and total cortical surface area, with the largest effects in frontal and cingulate cortices, and negative dosage effects on caudate and hippoc al volumes. The carriers displayed distinct cognitive deficit profiles in cognitive tasks from the UK Biobank with intermediate decreases in duplication carriers and somewhat larger in deletion carriers—the latter potentially mediated by ICV or cortical surface area. These results shed light on pathobiological mechanisms of neurodevelopmental disorders, by demonstrating gene dose effect on specific brain structures and effect on cognitive function.
Cascading Delays in the Monsoon Rice Growing Season and Postmonsoon Agricultural Fires Likely Exacerbate Air Pollution in North India
Publisher: American Geophysical Union (AGU)
Date: 15-12-2022
DOI: 10.1029/2022JD036790
Abstract: Over the past two decades, smoke aerosols from crop residue burning have increasingly degraded postmonsoon (October‐November) air quality in north India. We use satellite data and atmospheric modeling to investigate whether cascading delays in monsoon rice growth and postmonsoon fires over 2003–2019 have exacerbated the already poor urban air quality downwind of the fires. Beginning in 2008, a government effort to combat groundwater depletion in Punjab mandated rice sowing until closer to the arrival of monsoon rains. We find evidence of district‐level delays in the timing of both monsoon rice growth and postmonsoon fires, which vary from 1 to 4 weeks with largely an east‐west gradient. These delays are correlated spatially ( r = 0.51–0.77), with northern and western districts in Punjab, which rely less on groundwater for irrigation, tending to have the greatest delays. Had the delays in fire activity not occurred, we estimate that cities downwind and near the fire source would have consistently seen less smoke‐related fine particulate matter (PM 2.5 ), on average ranging from 11% to 21% for New Delhi, Bathinda, and Jind during 2008–2019. This net benefit of earlier postmonsoon burning could have been even larger given that (a) a longer rice‐to‐wheat transition could incentivize farmers to find alternatives to burning crop residues and (b) background PM 2.5 is less abundant earlier in the season, decreasing the likelihood of extreme pollution episodes. Strategies aiming to mitigate air pollution while conserving groundwater may be more effective by promoting an earlier monsoon growing season in districts with less groundwater depletion.
Brain aging in major depressive disorder: results from the ENIGMA major depressive disorder working group
Publisher: Springer Science and Business Media LLC
Date: 18-05-2020
DOI: 10.1038/S41380-020-0754-0
Abstract: Major depressive disorder (MDD) is associated with an increased risk of brain atrophy, aging-related diseases, and mortality. We examined potential advanced brain aging in adult MDD patients, and whether this process is associated with clinical characteristics in a large multicenter international dataset. We performed a mega-analysis by pooling brain measures derived from T1-weighted MRI scans from 19 s les worldwide. Healthy brain aging was estimated by predicting chronological age (18–75 years) from 7 subcortical volumes, 34 cortical thickness and 34 surface area, lateral ventricles and total intracranial volume measures separately in 952 male and 1236 female controls from the ENIGMA MDD working group. The learned model coefficients were applied to 927 male controls and 986 depressed males, and 1199 female controls and 1689 depressed females to obtain independent unbiased brain-based age predictions. The difference between predicted “brain age” and chronological age was calculated to indicate brain-predicted age difference (brain-PAD). On average, MDD patients showed a higher brain-PAD of +1.08 (SE 0.22) years (Cohen’s d = 0.14, 95% CI: 0.08–0.20) compared with controls. However, this difference did not seem to be driven by specific clinical characteristics (recurrent status, remission status, antidepressant medication use, age of onset, or symptom severity). This highly powered collaborative effort showed subtle patterns of age-related structural brain abnormalities in MDD. Substantial within-group variance and overlap between groups were observed. Longitudinal studies of MDD and somatic health outcomes are needed to further assess the clinical value of these brain-PAD estimates.
Autism-related dietary preferences mediate autism-gut microbiome associations.
Publisher: Elsevier BV
Date: 11-2021
DOI: 10.1016/J.CELL.2021.10.015
Abstract: There is increasing interest in the potential contribution of the gut microbiome to autism spectrum disorder (ASD). However, previous studies have been underpowered and have not been designed to address potential confounding factors in a comprehensive way. We performed a large autism stool metagenomics study (n = 247) based on participants from the Australian Autism Biobank and the Queensland Twin Adolescent Brain project. We found negligible direct associations between ASD diagnosis and the gut microbiome. Instead, our data support a model whereby ASD-related restricted interests are associated with less- erse diet, and in turn reduced microbial taxonomic ersity and looser stool consistency. In contrast to ASD diagnosis, our dataset was well powered to detect microbiome associations with traits such as age, dietary intake, and stool consistency. Overall, microbiome differences in ASD may reflect dietary preferences that relate to diagnostic features, and we caution against claims that the microbiome has a driving role in ASD.
Brain Correlates of Suicide Attempt in 18,925 Participants Across 18 International Cohorts
Publisher: Elsevier BV
Date: 08-2021
Are sex differences in human brain structure associated with sex differences in behaviour?
Publisher: Center for Open Science
Date: 28-04-2021
Abstract: On average, men and women differ in brain structure and behaviour, raising the possibility of a link between sex differences in brain and behaviour. But women and men are also subject to different societal and cultural norms. We navigated this challenge by investigating variability of sex-differentiated brain structure within each sex. Using data from the Queensland Twin IMaging study (N=1,040) and Human Connectome Project (N=1,113), we obtained data-driven measures of in idual differences along a male-female dimension for brain and behaviour based on average sex differences in brain structure and behaviour, respectively. We found a weak association between these brain and behavioural differences, driven by brain size. These brain and behavioural differences were moderately heritable. Our findings suggest that behavioural sex differences are to some extent related to sex differences in brain structure, but that this is mainly driven by differences in brain size, and causality should be interpreted cautiously.
The reliability and heritability of cortical folds and their genetic correlations across hemispheres
Publisher: Cold Spring Harbor Laboratory
Date: 07-10-2019
DOI: 10.1101/795591
Abstract: The structure of the brain’s cortical folds varies considerably in human populations. Specific patterns of cortical variation arise with development and aging, and cortical traits are partially influenced by genetic factors. The degree to which genetic factors affect cortical folding patterning remains unknown, yet may be estimated with large-scale in-vivo brain MRI. Using multiple MRI datasets from around the world, we estimated the reliability and heritability of sulcal morphometric characteristics including length, depth, width, and surface area, for 61 sulci per hemisphere of the human brain. Reliability was assessed across four distinct test-retest datasets. We meta-analyzed the heritability across three independent family-based cohorts (N 3,000), and one cohort of largely unrelated in iduals (N~9,000) to examine the robustness of our findings. Reliability was high (interquartile range for ICC: 0.65−0.85) for sulcal metrics. Most sulcal measures were moderately to highly heritable (heritability estimates = 0.3−0.7). These genetic influences vary regionally, with the earlier forming sulci having higher heritability estimates. The central sulcus, the subcallosal and the collateral fissure were the most highly heritable regions. For some frontal and temporal sulci, left and right genetic influences did not completely overlap, suggesting some lateralization of genetic effects on the cortex.
Non-arbitrary mappings between size and sound of English words: Form typicality effects during lexical access and memory
Publisher: SAGE Publications
Date: 06-07-2023
DOI: 10.1177/17470218231184940
Abstract: A century of research has provided evidence of limited size sound symbolism in English, that is, certain vowels are non-arbitrarily associated with words denoting small versus large referents (e.g., /i/ as in teensy and /ɑ/ as in tall). In the present study, we investigated more extensive statistical regularities between surface form properties of English words and ratings of their semantic size, that is, form typicality, and its impact on language and memory processing. Our findings provide the first evidence of significant word form typicality for semantic size. In five empirical studies using behavioural megastudy data sets of performance on written and auditory lexical decision, reading aloud, semantic decision, and recognition memory tasks, we show that form typicality for size is a stronger and more consistent predictor of lexical access during word comprehension and production than semantic size, in addition to playing a significant role in verbal memory. The empirical results demonstrate that statistical information about non-arbitrary form-size mappings is accessed automatically during language and verbal memory processing, unlike semantic size that is largely dependent on task contexts that explicitly require participants to access size knowledge. We discuss how a priori knowledge about non-arbitrary form-meaning associations in the lexicon might be incorporated in models of language processing that implement Bayesian statistical inference.
Brain activity during spoken word recognition in subacute aphasia
Publisher: Elsevier BV
Date: 08-2019
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