Neurovascular coupling is a physiological process involving a local hemodynamic response associated with surrounding neuronal activity. Functional magnetic resonance imaging (fMRI) uses this relation to infer neuronal activity by measuring magnetic sign...

In many cases of callosal dysgenesis in both human patients and mouse models, misguided fibers from the cortex form abnormal bilateral, barrel-shaped structures known as Probst bundles. Because little is known about how axons are arranged within these anomalous fiber bundles, understanding this arrangement may provide structural and molecular insights into how axons behave when they are misguided in vivo . Previous studies described these bundles as longitudinal swirls of axons that fail to cross the midline ([Ozaki et al., 1987][1]). However, recent studies on human acallosal patients using diffusion tensor magnetic resonance imaging (DTMRI) technology suggest that axons project in an anteroposterior direction within the Probst bundle ([Lee et al., 2004][2]; [Tovar-Moll et al., 2007][3]). This led us to ask the question, is DTMRI an accurate method for analyzing axonal tracts in regions of high axon overlap and disorganization, or is our current perception of axon arrangement within these bundles inaccura...

Humans can acquire appropriate behaviors that maximize rewards on a trial-and-error basis. Recent electrophysiological and imaging studies have demonstrated that neural activity in the midbrain and ventral striatum encodes the error of reward prediction. However, it is yet to be examined whether the striatum is the main locus of reward-based behavioral learning. To address this, we conducted functional magnetic resonance imaging (fMRI) of a stochastic decision task involving monetary rewards, in which subjects had to learn behaviors involving different task difficulties that were controlled by probability. We performed a correlation analysis of fMRI data by using the explanatory variables derived from subject behaviors. We found that activity in the caudate nucleus was correlated with short-term reward and, furthermore, paralleled the magnitude of a subject's behavioral change during learning. In addition, we confirmed that this parallelism between learning and activity in the caudate nucleus is robustly m...

Objective. Brain networks recruited during threat anticipation and threat confrontation differ widely and depend on stimulus predictability. Paralleling findings from animal electrophysiology, human functional magnetic resonance imaging (fMRI) suggests ...

Functional magnetic resonance imaging (fMRI)-based neurofeedback is an emerging therapeutic tool for neurological and psychiatric conditions. Resting-state functional connectivity (rsFC) studies in clinical samples suggest fMRI neurofeedback induces neu...

Introduction: Several studies have suggested a direct association between human cognition and functional/structural connectivity patterns in the human brain; the latter, obtained through Resting State Functional Magnetic Resonance Imaging measurements (...

The study of early brain development is challenging due to limitations in both imaging modalities and stimulus protocols. While considered the gold-standard, functional magnetic resonance imaging (fMRI) presents challenges in pediatric populations as th...

An accurate description of changes in the brain in healthy aging is needed to understand the basis of age-related changes in cognitive function. Cross-sectional magnetic resonance imaging (MRI) studies suggest thinning of the cerebral cortex, volumetric reductions of most subcortical structures, and ventricular expansion. However, there is a paucity of detailed longitudinal studies to support the cross-sectional findings. In the present study, 142 healthy elderly participants (60–91 years of age) were followed with repeated MRI, and were compared with 122 patients with mild to moderate Alzheimer's disease (AD). Volume changes were measured across the entire cortex and in 48 regions of interest. Cortical reductions in the healthy elderly were extensive after only 1 year, especially evident in temporal and prefrontal cortices, where annual decline was ∼0.5%. All subcortical and ventricular regions except caudate nucleus and the fourth ventricle changed significantly over 1 year. Some of the atrophy occurred ...

Background: Functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) are non-invasive techniques that allow insights into the re-organization of the cortical motor system and resultant hand function after perinatal stroke...

Functional magnetic resonance imaging (fMRI) is commonly used to study the effects of drugs on the brain. fMRI blood oxygenation level dependent (BOLD) signal increases depend on increased blood flow. Many drugs, including drugs of abuse, cause vasocons...