Our eyes are constantly in motion and the various kinds of eye movements are closely linked to many aspects of human cognitive processing. Measuring all possible eye movements unobtrusively is not achievable with current methods. Video-based eye-trackers only measure rotational but not translational motion of the eye, require a calibration process relying on the participant’s self-report of accurate fixation, and do not work if vision of the eyeball is blocked. Scleral search coils attach physical weight on the eyeball and also do not measure translation. Here, we describe a novel and fully automated method to use real-time magnetic resonance imaging (MRI) for eye tracking. We achieved a temporal resolution sufficient to measure eye rotations and translations as short as those that occur within a blink and behind a closed eyelid. To demonstrate this method, we measured the full extent of the blink-related eye movement for two individuals, suggesting that the eye approaches a holding position during lid clo...

Identifying pathways for, and impacts of, SARS-CoV-2 infection of the brain

Background/motivation: Neurological disorders are common in patients with coronavirus disease 2019 (COVID-19), but their underlying mechanisms are poorly understood. While hospitals worldwide are acquiring clinical MRI data in patients with COVID-19, th...

Abstract: The hemodynamic response function (HRF) measured by functional magnetic resonance imaging (fMRI) is the signature of neurovascular coupling in the brain. It is possible that this measured response can be used as a biomarker of diseases that la...

The preprocessing of structural and functional MRI scans is a computationally-intensive operation, typically taking several hours per subject. This results in prohibitively long waits between MRI data acquisition and analysis, particularly in large data...

Diffusion weighted Magnetic Resonance Imaging (dMRI) combined with fiber tracking algorithms enables the measuring of anatomy and tissue properties of the human white-matter in living brains (Wandell 2016; Jbabdi et al. 2015). By measuring living brains...

True memory for spatial location reactivates contralateral regions of the visual cortex, which is thought to reflect the constructive nature of memory. In a recent functional magnetic resonance imaging (fMRI) study, we demonstrated that false memory for...

Blood Oxygenation Level Dependent (BOLD) used in functional Magnetic Resonance Imaging (fMRI) allows an indirect measure of brain activity, but is blind to the ongoing interplay between excitation and inhibition. A recent study showed inhibition to not ...

Mild cognitive impairment (MCI) is a term for non-demented individuals with memory complaints and deficits greater than age-adjusted normal performance. Functional MRI (fMRI)may be a more sensitive method than other techniques to reveal functional abnormalities in individuals with MCI, only a proportion of whom progress to Alzheimer’s disease (AD). fMRI images were acquired using single shot spiral imaging. Subjects performed incidental encoding and retrieval tasks for coloured and black & white photographs contrasted to baseline fixation. During encoding subjects were required to make a semantic decision (natural vs. man-made) or a perceptual decision (colour vs. black & white). During retrieval, subjects judged whether they had seen the photographs in the previous encoding conditions. Initial analysis of young healthy adults (n=6) revealed activation in a network of regions in the memory tasks when contrasted to baseline fixation. Semantic encoding engaged a network of regions (fusiform gyrus, parietal, ...

Functional magnetic resonance imaging (fMRI) studies show that functional connectivity in resting state networks (RSNs) develop across the lifespan. RSNs are seen as early as in utero (Schöpf et al., 2012) and develop through adolescence (Supekar et al....