Imaging Neurosci (Camb)
July 2025
The brain expresses activity in complex spatiotemporal patterns, reflecting the influence of spatially distributed cytoarchitectural, biochemical, and genetic properties. The correspondence between these different "brain maps" is a topic of substantial interest. However, these maps possess intrinsic smoothness (spatial autocorrelation, SA) which can inflate spurious cross-correlations, leading to false positive associations.
View Article and Find Full Text PDFImaging Neurosci (Camb)
February 2025
The study of functional MRI (fMRI) data is increasingly performed after mapping from volumetric voxels to surface vertices. Processing pipelines commonly used to achieve this mapping produce meshes with uneven vertex spacing, with closer neighbours in sulci compared to gyri. Consequently, correlations between the fMRI time series of neighbouring sulcal vertices are stronger than expected.
View Article and Find Full Text PDFImaging Neurosci (Camb)
August 2024
Aligning brain maps using functional features rather than anatomical landmarks potentially improves individual identifiability and increases power in group neuroimaging studies. However, alignment based purely on functional magnetic resonance imaging (fMRI) risks omitting useful anatomical constraints. An optimized combination of anatomical and functional feature alignment could balance the advantages of each approach.
View Article and Find Full Text PDFMelancholia has been proposed as a qualitatively distinct depressive subtype associated with a characteristic symptom profile (psychomotor retardation, profound anhedonia) and a better response to biological therapies. Existing work has suggested that individuals with melancholia are blunted in their display of positive emotions and differ in their neural response to emotionally evocative stimuli. Here, we unify these brain and behavioural findings amongst a carefully phenotyped group of seventy depressed participants, drawn from an established Australian database (the Australian Genetics of Depression Study) and further enriched for melancholia (high ratings of psychomotor retardation and anhedonia).
View Article and Find Full Text PDFThe study of functional MRI data is increasingly performed after mapping from volumetric voxels to surface vertices. Processing pipelines commonly used to achieve this mapping produce meshes with uneven vertex spacing, with closer neighbours in sulci compared to gyri. Consequently, correlations between the fMRI time series of neighbouring sulcal vertices are stronger than expected.
View Article and Find Full Text PDFBackground And Hypothesis: There is mounting evidence that cardiac interoception, the perception of one's heartbeat, is central to affective experiences. It has been proposed that symptoms of psychosis could arise from interoceptive dysfunction. Here we hypothesized that people with psychotic disorders would have a specific impairment in cardiac interoception, over and above broader perceptual deficits.
View Article and Find Full Text PDFBackground And Hypothesis: Impairments in the expression, experience, and recognition of emotion are common in early psychosis (EP). Computational accounts of psychosis suggest disrupted top-down modulation by the cognitive control system (CCS) on perceptual circuits underlies psychotic experiences, but their role in emotional deficits in EP is unknown.
Study Design: The affective go/no-go task was used to probe inhibitory control during the presentation of calm or fearful faces in young persons with EP and matched controls.
The functional organization of the hippocampus mirrors that of the cortex, changing smoothly along connectivity gradients and abruptly at inter-areal boundaries. Hippocampal-dependent cognitive processes require flexible integration of these hippocampal gradients into functionally related cortical networks. To understand the cognitive relevance of this functional embedding, we acquired fMRI data while participants viewed brief news clips, either containing or lacking recently familiarized cues.
View Article and Find Full Text PDFFacial affect is expressed dynamically - a giggle, grimace, or an agitated frown. However, the characterisation of human affect has relied almost exclusively on static images. This approach cannot capture the nuances of human communication or support the naturalistic assessment of affective disorders.
View Article and Find Full Text PDFLancet Psychiatry
August 2021
Predictive coding has played a transformative role in the study of psychosis, casting delusions and hallucinations as statistical inference in a system with abnormal precision. However, the negative symptoms of schizophrenia, such as affective blunting, avolition, and asociality, remain poorly understood. We propose a computational framework for emotional expression based on active inference-namely that affective behaviours such as smiling are driven by predictions about the social consequences of smiling.
View Article and Find Full Text PDFRecent investigations have used diffusion-weighted imaging to reveal disturbances in the neurocircuitry that underlie cognitive-emotional control in bipolar disorder (BD) and in unaffected siblings or children at high genetic risk (HR). It has been difficult to quantify the mechanism by which structural changes disrupt the superimposed brain dynamics, leading to the emotional lability that is characteristic of BD. Average controllability is a concept from network control theory that extends structural connectivity data to estimate the manner in which local neuronal fluctuations spread from a node or subnetwork to alter the state of the rest of the brain.
View Article and Find Full Text PDFBackground: While inflammatory bowel diseases (IBD) require long-term medication usage to maintain remission, nonadherence is common and adversely associated with poorer clinical outcomes. Personalized IBD Pharmacist Adherence Counselling, based on the Health Beliefs Model of medication perception, may increase medication adherence.
Methods: This prospective multi-center longitudinal parallel study recruited consecutive IBD subjects that were classified as baseline medication non-adherers and adherers.
Background: Medication nonadherence is common in inflammatory bowel disease and is associated with poor outcomes. There has been no study on pediatric-to-adult transition as a risk factor for nonadherence in inflammatory bowel disease, which has been demonstrated in other diseases. We aimed to assess whether transitioned (TR) patients have higher nonadherence rates than young adults (YAs) diagnosed in adulthood.
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