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This study proposes a method to objectively differentiate surgical motor skill by analyzing brain activation in the prefrontal cortex, supplementary motor area (SMA), and primary motor cortex (M1) using functional near infrared spectroscopy (fNIRS) while performing a bimanual surgical task. Results show that experts have a significant decrease (p<0.05) in functional activation in the prefrontal...
With the arrival of the state of the art medical imaging equipment, a plethora of images are acquired not only in higher dimensions (3D+) but also with various presenting forms of either still or motion, complicating data management systems even further. This paper offers, from an application point of view, representations of content features from both still 3D MR brain images and 3D ultrasound cardiac...
We apply support vector machines (SVMs) in the context of fMRI analysis, in order to identify brain regions that are predictive of the experimental conditions. For the spatial SVM, we use the data within local 3D windows, called a searchlight, to train an SVM classifier to distinguish different experimental protocol conditions. Brain regions with high classification accuracy are identified as being...
Neuroimaging via fMRI reveals that the neural networks behind the visual system are one of the most complex systems for processing information regarding the external world. Ocular movements can be classified as conjugate saccadic or disconjugate vergence eye movements. Motor learning is another highly complex function residing in the cortical and subcortical regions of the brain that utilizes both...
This paper proposes a parametric, multivariate method for the joint detection and segmentation of brain activation based on fMRI data. The proposed technique uses region based level sets to separate between the task-related and non-task-related regions and performs, at each iteration of level set evolution, a separate multivariate linear model (MLM) analysis in each of the two regions. Simulations...
Chunking is a unifying information-processing mechanism in human cognition and plays an important role in problem solving. In the present experiment, we use a Chinese character chunking task to explore the neural basis of the goal-oriented chunking, which were classified into loose chunking and tight chunking. The behavioral result confirmed our prediction that the tight chunking was more difficult...
Using functional magnetic resonance imaging (fMRI) we have researched the variation in response magnitude, in each visual areas (V1-V3), as a function of visual retintotopic areas (V1-V3) and temporal frequency (TF). Each visual area was identified in each subject using a combination of retinotopic mapping fMRI and cortical flattening techniques. A checkerboard was used as the stimulus in the study...
Using functional magnetic resonance imaging, we examined whether distinct activity patterns are elicited by natural and unnatural visual stimuli. Stimuli were black and white pictures portraying various scenes (e.g., cities, country fields); natural pictures were unaltered, while unnatural pictures were produced by reversing their contrast curves (negative images). Low-contrast pictures were used...
Stereo panoramas, a pair of 360?? cylindrical panoramic images where one image for the left eye and the other for the right eye, have been widely used for image-based virtual reality systems. In comparison to traditional 3D modeling approach, this image-based approach assures a high quality photorealism and is fast in rendering speed. This paper addresses issue on camera parameter specification, which...
The purpose of this study was to explore the time course of cerebral lactate concentration in ischemic rat brain after sacrifice, in which area the morphology signal was still normal in the early phase. Ischemic rat model was used in this study. Eighty rats were fasted overnight before sacrifice and divided into 16 groups randomly. Lactate concentration was measured by using LD kit. Results showed...
This study examines whether the brain activity data from the NIRS imaging system can be used to determine levels of studentspsila understanding in the classroom. We measured the hemoglobin concentration of four points in the frontal cortex of fifth grade children using the NIRS imaging system while they were solving a calculation puzzle. Studentspsila differing degrees of difficulty in understanding...
In this paper, a first prototype of a multifunctional tactile sensor using ionic polymer metal composites (IPMCs) is proposed, designed, and tested. Two IPMC strips are used, one as an actuator and one as a sensor, both positioned in a cantilever configuration; working together they enable the system to detect the presence of a material in contact with it and to measure its stiffness. These sensing...
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