Magnetic Resonance Imaging (MRI)

Neural correlates of dueling affective reactions to win-win choices

Win-win choices cause anxiety, often more so than decisions lacking the opportunity for a highly desired outcome. These anxious feelings can paradoxically co-occur with positive feelings, raising important implications for individual decision styles and general well-being. Across three studies, people chose between products that varied in personal value. Participants reported feeling most positive and most anxious when choosing between similarly high-valued products.

Publication Type: 
Journal Articles
Journal: 
Proc Natl Acad Sci U S A

Temperature-ramped (129)Xe spin-exchange optical pumping

We describe temperature-ramped spin-exchange optical pumping (TR-SEOP) in an automated high-throughput batch-mode (129)Xe hyperpolarizer utilizing three key temperature regimes: (i) "hot"-where the (129)Xe hyperpolarization rate is maximal, (ii) "warm"-where the (129)Xe hyperpolarization approaches unity, and (iii) "cool"-where hyperpolarized (129)Xe gas is transferred into a Tedlar bag with low Rb content (

Publication Type: 
Journal Articles
Journal: 
Anal Chem

Dissociable genetic contributions to error processing: a multimodal neuroimaging study

BACKGROUND: Neuroimaging studies reliably identify two markers of error commission: the error-related negativity (ERN), an event-related potential, and functional MRI activation of the dorsal anterior cingulate cortex (dACC). While theorized to reflect the same neural process, recent evidence suggests that the ERN arises from the posterior cingulate cortex not the dACC. Here, we tested the hypothesis that these two error markers also have different genetic mediation.

Publication Type: 
Journal Articles
Journal: 
PLoS One

fMRI-compatible rehabilitation hand device

BACKGROUND: Functional magnetic resonance imaging (fMRI) has been widely used in studying human brain functions and neurorehabilitation. In order to develop complex and well-controlled fMRI paradigms, interfaces that can precisely control and measure output force and kinematics of the movements in human subjects are needed. Optimized state-of-the-art fMRI methods, combined with magnetic resonance (MR) compatible robotic devices for rehabilitation, can assist therapists to quantify, monitor, and improve physical rehabilitation.

Publication Type: 
Journal Articles
Journal: 
J Neuroeng Rehabil

An empirical investigation of motion effects in eMRI of interictal epileptiform spikes

We recently developed a functional neuroimaging technique called encephalographic magnetic resonance imaging (eMRI). Our method acquires rapid single-shot gradient-echo echo-planar MRI (repetition time=47 ms); it attempts to measure an MR signal more directly linked to neuronal electromagnetic activity than existing methods. To increase the likelihood of detecting such an MR signal, we recorded concurrent MRI and scalp electroencephalography (EEG) during fast (20-200 ms), localized, high-amplitude (>50 μV on EEG) cortical discharges in a cohort of focal epilepsy patients.

Publication Type: 
Journal Articles
Journal: 
Magn Reson Imaging

Variable precision registration via wavelets: optimal spatial scales for inter-subject registration of functional MRI

The detection of significantly activated brain regions in multi-subject functional magnetic resonance imaging (fMRI) studies almost invariably entails the coregistration of individual subjects' data in a standard space. Here, we investigate how sensitivity to detect loci of generic activation in such studies may be conditioned by the precision of anatomical registration. We describe a novel algorithm, implemented in the wavelet domain, for inhomogeneous deformation of individual images to match a template.

Publication Type: 
Journal Articles
Journal: 
Neuroimage

Differential selectivity for dynamic versus static information in face-selective cortical regions

Neuroimaging studies have identified multiple face-selective regions in human cortex but the functional division of labor between these regions is not yet clear. A central hypothesis, with some empirical support, is that face-selective regions in the superior temporal sulcus (STS) are particularly responsive to dynamic information in faces, whereas the fusiform face area (FFA) computes the static or invariant properties of faces. Here we directly tested this hypothesis by measuring the magnitude of response in each region to both dynamic and static stimuli.

Publication Type: 
Journal Articles
Journal: 
Neuroimage

Feedback of visual object information to foveal retinotopic cortex

The mammalian visual system contains an extensive web of feedback connections projecting from higher cortical areas to lower areas, including primary visual cortex. Although multiple theories have been proposed, the role of these connections in perceptual processing is not understood. We found that the pattern of functional magnetic resonance imaging response in human foveal retinotopic cortex contained information about objects presented in the periphery, far away from the fovea, which has not been predicted by prior theories of feedback.

Publication Type: 
Journal Articles
Journal: 
Nat Neurosci

Atypical brain activation patterns during a face-to-face joint attention game in adults with autism spectrum disorder

Joint attention behaviors include initiating one's own and responding to another's bid for joint attention to an object, person, or topic. Joint attention abilities in autism are pervasively atypical, correlate with development of language and social abilities, and discriminate children with autism from other developmental disorders. Despite the importance of these behaviors, the neural correlates of joint attention in individuals with autism remain unclear. This paucity of data is likely due to the inherent challenge of acquiring data during a real-time social interaction.

Publication Type: 
Journal Articles
Journal: 
Hum Brain Mapp

Similar brain activation during false belief tasks in a large sample of adults with and without autism

Reading about another person's beliefs engages 'Theory of Mind' processes and elicits highly reliable brain activation across individuals and experimental paradigms. Using functional magnetic resonance imaging, we examined activation during a story task designed to elicit Theory of Mind processing in a very large sample of neurotypical (N = 462) individuals, and a group of high-functioning individuals with autism spectrum disorders (N = 31), using both region-of-interest and whole-brain analyses.

Publication Type: 
Journal Articles
Journal: 
PLoS One

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