Past events: Javier Gonzalez-Castillo. The study of brain-wide activations and functional connectivity dynamics using BOLD fMRI.

What: The study of brain-wide activations and functional connectivity dynamics using BOLD fMRI.

Where: BCBL Auditorium

Who: Javier Gonzalez-Castillo, PhD., Staff Scientist, Section on Functional Imaging Methods, Laboratory of Brain and Cognition, National Institute of Mental Health (NIMH), Bethesda, MD, US.

When: 12 PM, noon.

In this talk I will discuss results from two current lines of research at the Section on Functional Imaging Methods from the National Institute of Mental Health in Bethesda, Maryland. In the first half of the talk I will discuss a series of projects in which we show the presence of task-locked hemodynamic responses across the whole brain for a simple visual stimulation plus character discrimination task. I will discuss the implications of this observation for BOLD fMRI, similar results from other labs, as well as pose some methodological questions derived from this observation. The second part of the talk will focus on the topic of resting state connectivity dynamics. Resting state networks are commonly computed under the assumption of temporal stationarity for the duration of the scan. Recent studies have shown how patterns of resting connectivity change substantially at the scale of seconds. I will present some recent work in which we show that connectivity dynamics have a rich spatial structure (with primary sensory regions having more stable connectivity patterns than higher order cognitive regions) and how changes in whole-brain connectivity patterns can be used to track ongoing mental states as dictated by tasks.