11 documents found, page 1 of 2
The hemodynamic response function as a type 2 diabetes biomarker: a data-driven...
Guimarães, Pedro; Serranho, Pedro; Duarte, João V.; Crisóstomo, Joana; Moreno, Carolina; Gomes, Leonor; Bernardes, Rui; Castelo-Branco, MiguelIntroduction: There is a need to better understand the neurophysiological changes associated with early brain dysfunction in Type 2 diabetes mellitus (T2DM) before vascular or structural lesions. Our aim was to use a novel unbiased data-driven approach to detect and characterize hemodynamic response function (HRF) alterations in T2DM patients, focusing on their potential as biomarkers. Methods: We meshed task-b...
The role of early functional neuroimaging in predicting neurodevelopmental outc...
Pinto, Carla R.; Duarte, João V.; Marques, Carla; Vicente, Inês N.; Paiva, Catarina; Éloi, João; Pereira, Daniela J.; Correia, Bárbara R.Reliably assessing the early neurodevelopmental outcomes in infants with neonatal encephalopathy (NE) is of utmost importance to advise parents and implement early and personalized interventions. We aimed to evaluate the accuracy of neuroimaging modalities, including functional magnetic resonance imaging (fMRI) in predicting neurodevelopmental outcomes in NE. Eighteen newborns with NE due to presumed perinatal ...
Functional neuroimaging of responses to multiple sensory stimulations in newbor...
Pinto, Carla R.; Duarte, João V.; Dinis, Alexandra; Duarte, Isabel C.; Castelhano, João; Pinto, Joana; Oliveira, Guiomar; Castelo-Branco, MiguelBackground: Functional neuroimaging can provide pathophysiological information in perinatal asphyxia (PA). However, fundamental unresolved questions remain related to the influence of neurovascular coupling (NVC) maturation on functional responses in early development. We aimed to probe the feasibility and compare the responses to multiple sensory stimulations in newborns with PA using functional magnetic reson...
Changes in hemodynamic response function components reveal specific changes in ...
Duarte, João V.; Guerra, Catarina; Moreno, Carolina; Gomes, Leonor; Castelo-Branco, MiguelType 2 Diabetes Mellitus (T2DM) is a metabolic disease that leads to multiple vascular complications with concomitant changes in human neurophysiology, which may lead to long-term cognitive impairment, and dementia. Early impairments of neurovascular coupling can be studied using event-related functional magnetic resonance imaging (fMRI) designs. Here, we aimed to characterize the changes in the hemodynamic res...
The dual nature of the BOLD signal: Responses in visual area hMT+ reflect both ...
Sousa, Teresa; Duarte, João V.; Costa, Gabriel Nascimento Ferreira da; Kemper, Valentin G.; Martins, Ricardo Filipe Alves; Goebel, RainerNeuroimaging studies have suggested that hMT+ encodes global motion interpretation, but this contradicts the notion that BOLD activity mainly reflects neuronal input. While measuring fMRI responses at 7 Tesla, we used an ambiguous moving stimulus, yielding the perception of two incoherently moving surfaces-component motion-or only one coherently moving surface-pattern motion, to induce perceptual fluctuations a...
Identification of competing neural mechanisms underlying positive and negative ...
Sayal, Alexandre; Sousa, Teresa; Duarte, João V.; Costa, Gabriel Nascimento Ferreira da; Martins, Ricardo Filipe Alves; Castelo-Branco, MiguelHysteresis is a well-known phenomenon in physics that relates changes in a system with its prior history. It is also part of human visual experience (perceptual hysteresis), and two different neural mechanisms might explain it: persistence (a cause of positive hysteresis), which forces to keep a current percept for longer, and adaptation (a cause of negative hysteresis), which in turn favors the switch to a com...
Tracking perceptual decision mechanisms through changes in interhemispheric fun...
Sousa, Teresa; Duarte, João V.; Costa, Gabriel Nascimento Ferreira da; Kemper, Valentin G.; Martins, Ricardo Filipe Alves; Goebel, RainerThe role of long-range integration mechanisms underlying visual perceptual binding and their link to interhemispheric functional connectivity, as measured by fMRI, remains elusive. Only inferences on anatomical organization from resting state data paradigms not requiring coherent binding have been achieved. Here, we used a paradigm that allowed us to study such relation between perceptual interpretation and fun...
Evidence for distinct levels of neural adaptation to both coherent and incohere...
Sousa, Teresa; Sayal, Alexandre; Duarte, João V.; Costa, Gabriel Nascimento Ferreira da; Martins, Ricardo Filipe Alves; Castelo-Branco, MiguelVisual adaptation describes the processes by which the visual system alters its operating properties in response to changes in the environment. It is one of the mechanisms controlling visual perceptual bistability - when two perceptual solutions are available - by controlling the duration of each percept. Moving plaids are an example of such ambiguity. They can be perceived as two surfaces sliding incoherently ...
Extending Inferential Group Analysis in Type 2 Diabetic Patients with Multivari...
Ferreira, Fábio S.; Pereira, João; Duarte, João V.; Castelo-Branco, MiguelBackground: Although voxel based morphometry studies are still the standard for analyzing brain structure, their dependence on massive univariate inferential methods is a limiting factor. A better understanding of brain pathologies can be achieved by applying inferential multivariate methods, which allow the study of multiple dependent variables, e.g. different imaging modalities of the same subject. Objective:...
Permutations of functional magnetic resonance imaging classification may not be...
Al-Rawi, Mohammed S.; Freitas, Adelaide; Duarte, João V.; Cunha, Joao P.; Castelo-Branco, MiguelA fundamental question that often occurs in statistical tests is the normality of distributions. Countless distributions exist in science and life, but one distribution that is obtained via permutations, usually referred to as permutation distribution, is interesting. Although a permutation distribution should behave in accord with the central limit theorem, if both the independence condition and the identical ...