9 documents found, page 1 of 1

Distinct oscillatory patterns differentiate between segregation and integration...

Recently, there has been a resurgence in experimental and conceptual efforts to understand how brain rhythms can serve to organize visual information. Oscillations can provide temporal structure for neuronal processing and form a basis for integrating information across brain areas. Here, we use a bistable paradigm and a data-driven approach to test the hypothesis that oscillatory modulations associate with the...

Editorial: Neuroimaging in early intervention in psychiatry

Cerebellar morphometric and spectroscopic biomarkers for Machado-Joseph Disease

Machado-Joseph disease (MJD) or Spinocerebellar ataxia type 3 (SCA3) is the most common form of dominant SCA worldwide. Magnetic Resonance Imaging (MRI) and Proton Magnetic Resonance Spectroscopy (1H-MRS) provide promising non-invasive diagnostic and follow-up tools, also serving to evaluate therapies efficacy. However, pre-clinical studies showing relationship between MRI-MRS based biomarkers and functional pe...

Quantitative Assessment of the Impact of Geometric Distortions and Their Correc...

Functional magnetic resonance imaging (fMRI) data is typically collected with gradient-echo echo-planar imaging (GE-EPI) sequences, which are particularly prone to the susceptibility artifact as a result of B0 field inhomogeneity. The component derived from in-plane spin dephasing induces pixel intensity variations and, more critically, geometric distortions. Despite the physical mechanisms underlying the susce...

Morphometry and gyrification in bipolar disorder and schizophrenia: A comparati...

Schizophrenia 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...

Pivotal role of hMT+ in long-range disambiguation of interhemispheric bistable ...

It remains an open question whether long-range disambiguation of ambiguous surface motion can be achieved in early visual cortex or instead in higher level regions, which concerns object/surface segmentation/integration mechanisms. We used a bistable moving stimulus that can be perceived as a pattern comprehending both visual hemi-fields moving coherently downward or as two widely segregated nonoverlapping comp...

Interhemispheric Binding of Ambiguous Visual Motion Is Associated with Changes ...

In vision, perceptual features are processed in several regions distributed across the brain. Yet, the brain achieves a coherent perception of visual scenes and objects through integration of these features, which are encoded in spatially segregated brain areas. How the brain seamlessly achieves this accurate integration is currently unknown and is referred to as the "binding problem." Among the proposed mechan...

The role of long-range neural oscillatory synchrony as a mechanism underlying i...

Tese de doutoramento em Ciências da Saúde, no ramo de Ciências Biomédicas, apresentada à Faculdade de Medicina da Universidade de Coimbra; Uma área fascinante em neurociência cognitiva é a investigação dos mecanismos neuronais que estão na base de representações distintas na percepção visual. Em humanos a percepção de objectos e cenas é excepcionalmente eficiente, mas pode ser posta à prova quando são apresenta...

Machine learning approaches in genome-wide association studies: SNP2Net: a tool...

As redes Bayesianas são instrumentos poderosos para aprender modelos genéticos de dados de estudos de associação, uma vez que a correlação entre marcadores genéticos e traços fenotípicos pode ser derivada, bem como as relações entre os próprios. No entanto, o aprendimento das redes Bayesianas é muitas vezes não-trivial, devido ao elevado número de variáveis que devem ser tidas em conta no modelo. Desta forma, d...