Fuzzy ripple artifact in high resolution fMRI: identification, cause, and mitigation.

Purpose: High resolution fMRI is a rapidly growing research field focused on capturing functional signal changes across cortical layers. However, the data acquisition is limited by low spatial frequency EPI artifacts; termed here as Fuzzy Ripples. These artifacts limit the practical applicability of acquisition protocols with higher spatial resolution, faster acquisition speed, and they challenge imaging in lower brain areas.

Improved sensitivity and microvascular weighting of 3T laminar fMRI with GE-BOLD using NORDIC and phase regression.

Introduction: Functional MRI with spatial resolution in the submillimeter domain enables measurements of activation across cortical layers in humans. This is valuable as different types of cortical computations, e.g.

Contralateral Transfer of the Phenomenon of Repeated Bout Rate Enhancement in Unilateral Index Finger Tapping.

These hypotheses were tested: (1) Freely chosen frequency in unilateral index finger tapping is correlated between the two index fingers, and (2) A 3-min bout of unilateral index finger tapping followed by 10 min rest results in an increase of the freely chosen tapping frequency performed by the contralateral index finger in a second bout. Thirty-two adults participated. Freely chosen tapping frequencies from first bouts were 167.