Stepwise Stochastic Dictionary Adaptation Improves Microstructure Reconstruction with Orientation Distribution Function Fingerprinting.

Fitting of the multicompartment biophysical model of white matter is an ill-posed optimization problem. One approach to make it computationally tractable is through Orientation Distribution Function (ODF) Fingerprinting. However, the accuracy of this method relies solely on ODF dictionary generation mechanisms which either sample the microstructure parameters on a multidimensional grid or draw them randomly with a uniform distribution.

Reducing audio stimulus presentation latencies across studies, laboratories, and hardware and operating system configurations.

Using differing computer platforms and audio output devices to deliver audio stimuli often introduces (1) substantial variability across labs and (2) variable time between the intended and actual sound delivery (the sound onset latency). Fast, accurate audio onset latencies are particularly important when audio stimuli need to be delivered precisely as part of studies that depend on accurate timing (e.g.

A virtual reality system for neurobehavioral and functional MRI studies.

We are developing a VR system of integrated software and hardware for scientific research and clinical application. The system is sufficiently flexible and broad-based in appeal that neurobehavioral researchers from a variety of disciplines might be interested in using it for basic research and clinical studies. The system runs on a standard Windows-based personal computer with a high-performance graphics card.