|
|
|
Neurobiology of Brain Function
Here are a few of the projects in our laboratory trying to understand how global networks in the brain interact.
Temporal Dynamics of Functional Connectivity
Areas of the brain that have related functions have been shown to have synchronized noise on imaging, but at very low frequencies. We have completed a study that helps answer why these frequencies are so low. Our results show that low frequencies arise from a combination of low-pass filtering through small blood vessels and amplitude modulation of neural activity (like an AM radio.) Look for the results in the October issue of AJNR.
Magnetoencephalography of Resting State Networks
Thanks to a helpful suggestion by Michael Fox at the last Human Brain Mapping meeting in Melbourne, we have studied more carefully resting state networks using MEG and found some exciting conclusions about which frequencies of neural activity give rise to the very low frequency synchronized BOLD fluctuations.
fMRI of Visual Attention
We have been evaluating the network architecture responsible for processing visual attention. We believe much of visual attention works as a gain control mechanism in the brain. A surprising consequence comes from our data. Most people who do fMRI experiments try to have subjects pay attention to the stimuli shown in order to increase the signal in the responses, but this may be exactly the wrong thing to do. Andrea Schwager will present these results at the Society for Neuroscience meeting in Washington D. C. in November.
Neurobiology of Yoga
A new effort in our laboratory is looking for ways to evaluate large-scale brain networks in complex tasks that involve states of consciousness, transcendence, or spirituality. We are beginning an investigation of whether high-level network architecture in the brain behaves differently in response to ashtanga yoga.
BOLD EPI with Booster Gradients
Dennis Parker from UCAIR has recently succeeded in navigating the complex physics involved in using booster gradients within the MRI scanner. We are hoping soon to be able to take his new technique for a test drive by running BOLD sequences 4 times as fast as the old-fashioned way. We think this could revolutionize resting state fMRI analysis, because at those speeds correction for cardiac and respiratory artifacts should be trivial.
|
|
|
