The modern marvel of functional magnetic resonance imaging (fMRI) has revolutionized our understanding of the human brain by allowing scientists to monitor brain activity during behavioral tasks in alert homo sapiens sapiens. Early efforts of fMRI merel...

The blood oxygen-level dependent functional magnetic resonance imaging (BOLD fMRI) response is biphasic, consisting of an initial negative component (initial dip), followed by a large positive component (positive peak). The initial dip is thought to be ...

The neural basis of semantic cognition has been investigated using univariate analysis of functional magnetic resonance imaging (fMRI) data for at least the past 20 years. These analyses have proven to be very effective in revealing neural regions invol...

Region-specific cerebral blood flow (CBF) and apparent diffusion coefficient (ADC) of water in the rat brain were quantified by high-field MRI (9.4 T) for 6-7 hours and up to 5 days after middle cerebral artery occlusion (MCAO), either in the permanent occlusion mode or during reperfusion after 85 min of MCAO. Upon occlusion, average CBF fell from ~1.5-2 ml/g/min to <0.5 ml/g/min in cortical areas and to <0.2 ml/g/min in the caudoputamen (CP). CBF in the homologous contralateral areas also decreased by 25-30%. Corresponding ADC decreases were most profound in the CP and parietal cortex (from ~8 × 10−4 to 5 × 10−4 mm2/s), lesser in the frontal cortex, and negligible in the piriform cortex, suggesting that the perfusion threshold for ADC decrease may be different for different brain regions in the same animal. On average, CBF recovered only to ~30% of the baseline in the first 24 h of reperfusion. After 3-4 days of reperfusion, however, CBF and ADC changes were reversed: a strong hyperperfusion in the ipsila...

We used blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI) to investigate the neural circuitry underlying tactile spatial acuity at the human fingerpad. Stimuli for the spatial acuity task were linear, 3-dot arrays in wh...

Developing new strategies for detection of disease activity in multiple sclerosis is important to ameliorate the diagnosis and follow-up of this pathology. For that, we used microparticles of iron oxide (MPIO) coupled to an antibody specific to the p-se...

Responses to monetary reward in humans have been assessed in a number of recent functional imaging studies, and it is clear that the neuronal substrates of financial reinforcement overlap extensively with regions responding to primary reinforcers, such as food. Money has the practical advantage of being an objectively quantifiable reinforcer. In this study, we exploit this advantage using a parametric functional magnetic resonance imaging design to look at the patterns of responding to systematically varying reward values. Twelve healthy volunteers were scanned during performance of a rewarded target detection task, in which the reward value varied between task blocks. We observed three distinct patterns of responding in different regions. Amygdala, striatum, and dopaminergic midbrain responded to the presence of rewards, regardless of value. In contrast, premotor cortex showed a linear increase in response with increasing reward value. Finally, medial and lateral foci of orbitofrontal cortex responded non...

Functional magnetic resonance imaging (fMRI) is an invaluable and non-invasive tool for visualising the emotional and cognitive processes in the brain at the systems level. While mostly used in humans, recent studies have made advancement in using fMRI ...

Resting state functional magnetic resonance imaging (fMRI) is typically acquired over the course of a 5-minute session and subsequently used to estimate functional connectivity in the brain. However, emerging data suggest that it may be necessary to inc...

Brain Single Photon Emission Computed Tomography (SPECT) is useful in the preoperative planning for medically refractory epilepsy and to identify the lateralization and localization of an epileptogenic focus before surgery. Nuclear medicine functional n...