Immersive scene representation in human visual cortex with ultra-wide-angle neuroimaging.

While human vision spans 220°, traditional functional MRI setups display images only up to central 10-15°. Thus, it remains unknown how the brain represents a scene perceived across the full visual field. Here, we introduce a method for ultra-wide angle display and probe signatures of immersive scene representation.

Effects of Age on Cross-Cultural Differences in the Neural Correlates of Memory Retrieval.

Culture can shape memory, but little research investigates age effects. The present study examines the neural correlates of memory retrieval for old, new, and similar lures in younger and older Americans and Taiwanese. Results show that age and culture impact discrimination of old from new items.

Cross-cultural comparison of the neural correlates of true and false memory retrieval.

Prior work has shown Americans have higher levels of memory specificity than East Asians. Neuroimaging studies have not investigated mechanisms that account for cultural differences at retrieval. In this study, we use fMRI to assess whether mnemonic discrimination, distinguishing novel from previously encountered stimuli, accounts for cultural differences in memory.

Precision Brain Morphometry Using Cluster Scanning.

Measurement error limits the statistical power to detect group differences and longitudinal change in structural MRI morphometric measures (e.g., hippocampal volume, prefrontal thickness).

Immersive scene representation in human visual cortex with ultra-wide angle neuroimaging.

While humans experience the visual environment in a panoramic 220° view, traditional functional MRI setups are limited to display images like postcards in the central 10-15° of the visual field. Thus, it remains unknown how a scene is represented in the brain when perceived across the full visual field. Here, we developed a novel method for ultra-wide angle visual presentation and probed for signatures of immersive scene representation.

Brain morphometry in older adults with and without dementia using extremely rapid structural scans.

T1-weighted structural MRI is widely used to measure brain morphometry (e.g., cortical thickness and subcortical volumes).

Functional connectivity with medial temporal regions differs across cultures during post-encoding rest.

Connectivity of the brain at rest can reflect individual differences and impact behavioral outcomes, including memory. The present study investigated how culture influences functional connectivity with regions of the medial temporal lobe. In this study, 46 Americans and 59 East Asians completed a resting state scan after encoding pictures of objects.

Culture-related differences in the neural processing of probability during mixed lottery value-based decision-making.

This study evaluated how differences in economic risk-taking in Westerners and East Asians reflect cultural differences in the analytic or holistic processing of probabilistic outcomes during value-based decisions. Twenty-seven Americans (US) and 51 Taiwanese (TW) young adults completed a functional magnetic resonance imaging (fMRI) Lottery Choice Task (LCT) experiment. Participants accepted or rejected stakes with varying probabilities of winning or losing different magnitudes of points.

Testing biomechanical models of human lumbar lordosis variability.

Objectives: Lumbar lordosis (LL) is a key adaptation for bipedalism, but factors underlying curvature variations remain unclear. This study tests three biomechanical models to explain LL variability.

Materials And Methods: Thirty adults (15 male, 15 female) were scanned using magnetic resonance imaging (MRI), a standing posture analysis was conducted, and lumbar range of motion (ROM) was assessed.

Brain Genomics Superstruct Project initial data release with structural, functional, and behavioral measures.

The goal of the Brain Genomics Superstruct Project (GSP) is to enable large-scale exploration of the links between brain function, behavior, and ultimately genetic variation. To provide the broader scientific community data to probe these associations, a repository of structural and functional magnetic resonance imaging (MRI) scans linked to genetic information was constructed from a sample of healthy individuals. The initial release, detailed in the present manuscript, encompasses quality screened cross-sectional data from 1,570 participants ages 18 to 35 years who were scanned with MRI and completed demographic and health questionnaires.

Silicon nanoparticles as hyperpolarized magnetic resonance imaging agents.

Magnetic resonance imaging of hyperpolarized nuclei provides high image contrast with little or no background signal. To date, in vivo applications of prehyperpolarized materials have been limited by relatively short nuclear spin relaxation times. Here, we investigate silicon nanoparticles as a new type of hyperpolarized magnetic resonance imaging agent.

Posture-dependent human 3He lung imaging in an open-access MRI system: initial results.

Rationale And Objectives: The human lung and its functions are extremely sensitive to orientation and posture, and debate continues as to the role of gravity and the surrounding anatomy in determining lung function and heterogeneity of perfusion and ventilation. However, study of these effects is difficult. The conventional high-field magnets used for most hyperpolarized (3)He magnetic resonance imaging (MRI) of the human lung, and most other common radiologic imaging modalities including positron emission tomography and computed tomography, restrict subjects to lying horizontally, minimizing most gravitational effects.

Xenon NMR measurements of permeability and tortuosity in reservoir rocks.

In this work we present measurements of permeability, effective porosity and tortuosity on a variety of rock samples using NMR/MRI of thermal and laser-polarized gas. Permeability and effective porosity are measured simultaneously using MRI to monitor the inflow of laser-polarized xenon into the rock core. Tortuosity is determined from measurements of the time-dependent diffusion coefficient using thermal xenon in sealed samples.

Study of gas-fluidization dynamics with laser-polarized 129Xe.

We report initial NMR studies of gas dynamics in a particle bed fluidized by laser-polarized xenon (129Xe) gas. We have made preliminary measurements of two important characteristics: gas exchange between the bubble and emulsion phases and the gas velocity distribution in the bed. We used T2* contrast to differentiate the bubble and emulsion phases by choosing solid particles with large magnetic susceptibility.