Dynamics, Fluctuations and Patterns: Ongoing work towards separating physiologic from neuronal information in fMRI

Peter Bandettini, Section on Functional Imaging Methods and the Functional MRI Core Facility, National Institutes of Health, Bethesda, MD In the past 18 years, functional MRI (fMRI) has experienced, by all measures, an explosive growth. The growth of the field is characterized by a continued advancement in the sophistication of the technology, methodology, and depth of interpretation of the signal. This talk will specifically outline some work from my research group which focuses on advances in how much more information we can extract from the time series fMRI signal and how cleanly we can separate neuronal information from the hemodynamics which transduce it. Specifically, my talk has three parts: Dynamics, fluctuations, and patterns. In the first part, I describe attempts using hemodynamic and neuronal modeling combined with Magnetoencephalography (MEG) to better understand the origin of the dynamic nonlinearities that are commonly observed in even-related fMRI. In the second part, I talk about the burgeoning subfield of fMRI fluctuations, and show that respiration and image acquisition itself may be a source of some of the time series correlations, but also show some promising new methods for “resting” state network extraction. Third, I talk about our groups’ work on “fMRI decoding.” I the utility of multi-voxel pattern extraction, and then demonstrate several advancements in this methodology for probing deeper into a more fine –grained spatial scale of brain organization within cortical regions. Overall, I would like to convey that fMRI methodology really does drive fMRI applications and the field of fMRI as a whole and that methodology advancement is showing every indication of increasing in rate of advancement. ]]> Brain Imaging Seminar Series:  Peter Bandettini. 3pm Georgia State University, Urban Life Bldg, Room 1199

]]> http://www.cabiatl.com/CABI/2009/11/november-18-2009/feed/ 0 http://www.cabiatl.com/CABI/2009/10/nov-4-2009/ http://www.cabiatl.com/CABI/2009/10/nov-4-2009/#comments Wed, 28 Oct 2009 14:09:29 +0000 admin http://www.cabiatl.com/CABI/?p=496 Otto Karnath. 3pm Georgia Tech, 250 Coon

The architecture of visual recognition in the human brain – contributions from fMRI and stroke patients

Hans-Otto Karnath, Section for Neuropsychology, Center of Neurology, University of Tuebingen Tuebingen, Germany Based on a body of behavioral and anatomical studies, Ungerleider & Mishkin (1982) and Milner & Goodale (1995) suggested the existence of a ventral occipitotemporal "what" pathway and of a dorsal occipitoparietal "where" pathway of visual information processing. Disorder of visual recognition following stroke lesions as well as functional imaging in healthy subjects are used to uncover how the human brain recognizes visual objects, visual scences as well as our own body. The talk will give an overview of these different aspects and will reflect how they fit with the predictions of the dual stream model.]]> Brain Imaging Seminar Series: Otto Karnath. 3pm Georgia Tech, 250 Coon

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