26 documents found, page 1 of 3
Automatic classification of idiopathic Parkinson's disease and atypical parkins...
Martins, Ricardo Filipe Alves; Oliveira, Francisco Paulo Marques de; Moreira, Fradique Vieira de Almeida; Moreira, Ana PaulaObjective. To explore the viability of developing a computer-aided diagnostic system for Parkinsonian syndromes using dynamic [11C]raclopride positron emission tomography (PET) and T1-weighted magnetic resonance imaging (MRI) data. Approach. The biological heterogeneity of Parkinsonian syndromes renders their statistical classification a challenge. The unique combination of structural and molecular imaging data...
A Fundamental Distinction in Early Neural Processing of Implicit Social Interpr...
Madeira, Nuno; Martins, Ricardo Filipe Alves; Valente Duarte, João; Costa, Gabriel Nascimento Ferreira da; Macedo, António Ferreira deBackground: Social cognition impairment is a key phenomenon in serious mental disorders such as schizophrenia (SCZ) and bipolar disorder (BPD). Although genetic and neurobiological studies have suggested common neural correlates, here we hypothesized that a fundamental dissociation of social processing occurs at an early level in these conditions. Methods: Based on the hypothesis that key structures in the soci...
Effects of anodal multichannel transcranial direct current stimulation (tDCS) o...
Pereira, H Catarina; Sousa, Daniela; Simões, Marco; Martins, Ricardo Filipe Alves; Amaral, Carlos; Lopes, Vânia; Crisóstomo, JoanaRecent studies suggest that temporoparietal junction (TPJ) modulation can influence attention and social cognition performance. Nevertheless, no studies have used multichannel transcranial direct current stimulation (tDCS) over bilateral TPJ to estimate the effects on these neuropsychological functions. The project STIPED is using optimized multichannel stimulation as an innovative treatment approach for chroni...
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...
Investigating the Spatial Associations Between Amyloid-β Deposition, Grey Matte...
Jorge, Lília; Martins, Ricardo Filipe Alves; Canário, Nádia; Xavier, Carolina; Abrunhosa, Antero José Pena Afonso de; Santana, IsabelBackground: It has been proposed that amyloid-β (Aβ) plays a causal role in Alzheimer’s disease (AD) by triggering a series of pathologic events—possibly including neuroinflammation—which culminate in progressive brain atrophy. However, the interplay between the two pathological molecular events and how both are associated with neurodegeneration is still unclear. Objective: We aimed to estimate the spatial inte...
Desenvolvimento de uma metodologia e de um sistema de teste para aquisição de d...
Martins, Ricardo Filipe AlvesA produção de água quente sanitária (AQS) é a segunda maior utilização doméstica de energia nas casas portuguesas, representando uma percentagem de, aproximadamente, 24% da energia total consumida nas mesmas, o que torna bastante importante a redução do uso de energia elétrica “não limpa” e gás natural, e começar a apostar nas energias renováveis para a produção de calor. Os sistemas de aquecimento elétrico de ...
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...
Morphometry and gyrification in bipolar disorder and schizophrenia: A comparati...
Madeira, Nuno; Duarte, João Valente; Martins, Ricardo Filipe Alves; Costa, Gabriel Nascimento Ferreira da; Macedo, António; Castelo-Branco, MiguelSchizophrenia is believed to be a neurodevelopmental disease with high heritability. Differential diagnosis is often challenging, especially in early phases, namely with other psychotic disorders or even mood disorders. such as bipolar disorder with psychotic symptoms. Key pathophysiological changes separating these two classical psychoses remain poorly understood, and current evidence favors a more dimensional...
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 ...