Event-related fMRI and the hemodynamic response

Event-related fMRI and the hemodynamic response.

Event-related functional magnetic resonance imaging (ER-fMRI) methods are allowing a new spectrum of task designs to be explored with brain imaging techniques. Individual trial events can be presented rapidly, in randomly intermixed order, and the hemodynamic responses associated with individual trial events appreciated. The basis of ER-fMRI is that the hemodynamic response tracks neuronal acti...

Stimulus repetition and hemodynamic response refractoriness in event-related fMRI.

We investigated the extent of hemodynamic recovery following the paired presentation of either identical or different faces at two different inter-stimulus intervals (ISI). Signal recovery was consistently better at an ISI of 6 sec compared to 3 sec. Significantly less signal recovery was associated with identical faces compared to different faces in bilateral mid-fusiform and right prefrontal ...

Regional differences in the refractory period of the hemodynamic response: an event-related fMRI study.

We investigated the characteristics of the hemodynamic response (HDR) to paired presentations of visual face stimuli using functional magnetic resonance imaging (fMRI). Photographs of faces were presented singly or in pairs with either a 1-s or 6-s intrapair interval (IPI). Each trial (single face or face pairs) was followed by an intertrial interval of 16-20 s. Faces were presented at fixation...

Robust estimation of the hemodynamic response function in asynchronous multitasks multisessions event-related fMRI paradigms

Memory Impairment in MS correlates to Hemodynamic Response in Event-related fMRI of Episodic Memory

Introduction An estimated 40-50% of MS patients have some cognitive deficit, with memory deficits included as a common manifestation of cognitive dysfunction [1]. In previous studies of healthy controls engaged in word recognition tasks, functional differentiation has been found between novel words and previously presented works [2]. Furthermore, one study investigated the correlation between t...