The combination of optogenetics and functional magnetic resonance imaging (fMRI) is referred to as opto-fMRI. Optogenetics utilises genetic engineering to introduce light sensitive actuator proteins into cells. Functional MRI (fMRI) is a specialist form of magnetic resonance imaging concerned with imaging changes in blood flow and oxygenation, linked to regional variation in metabolic activity,...

introduction: a fixed hemodynamic response function (hrf) is commonly used for functional magnetic resonance imaging (fmri) analysis. however, hrf may vary from region to region and subject to subject. we investigated the effect of locally estimated hrf (in functionally homogenous parcels) on activation detection sensitivity in a heroin cue reactivity study. methods: we proposed a novel explora...

Adaptation has been widely used in functional magnetic imaging (fMRI) studies to infer neuronal response properties in human cortex. fMRI adaptation has been criticized because of the complex relationship between fMRI adaptation effects and the multiple neuronal effects that could underlie them. Many of the longstanding concerns about fMRI adaptation have received empirical support from neuroph...

Because of poor signal-to-noise ratio (SNR) of the fMRI time series and confounding effects, the results of fMRI analysis are often unsatisfactory. Existence of significant noise and artifacts in fMRI time-series as well as their unknown structure, complicates the problem of activation detection in the time domain. This makes the fMRI noise suppression a challenging problem. Based on some assum...

Patients with schizophrenia commonly revealed difficulties in understanding humor. Previous research suggested links between impaired humor comprehension, psychopathology symptoms and cognitive deficits. In this study, we investigated the associations neural substrates of processing cognition schizophrenia. We assessed 25 outpatients an functional magnetic resonance imaging (fMRI) procedure 40 ...

Valid comparisons of functional activation volumes from fMRI and PET require accurate registration, matched spatial resolution, and if possible matched noise. We coregistered 4.0T-fMRI and PET volumes, using a series of linear and nonlinear transformations applied to the PET volumes. Because of the limited number of fMRI slices that were available, PET volumes were transformed to the fMRI space...

This case report describes absent blood oxygen level–dependent (BOLD) functional magnetic resonance imaging (fMRI) activation of the orbitofrontal cortex in a 25-year-old woman with persistent cacosmia and cacogeusia after coronavirus disease 2019 (COVID-19) infection.

INTRODUCTION Single-shot Echo-Planar Imaging (EPI) is the sequence most commonly used for fMRI experiments. At high field, e.g. 7T, magnetic field inhomogeneities cause spins to become out of phase quickly, and distortion and signal dropout become severe [1]. Consequently, single-shot EPI fMRI suffers technical limitations at high field. Here we consider two alternatives to EPI for high field f...

BACKGROUND A prevailing assumption in neuroimaging studies is that relatively low fMRI signals are due to weak neuronal activation, and, therefore, they are commonly ignored. However, lower fMRI signals may also result from intense activation by highly selective, albeit small, subsets of neurons in the imaged voxel. We report on an approach that could form a basis for resolving this ambiguity i...