Measurement of auditory hemodynamic response function due to different temporal patterns of imaging acoustic noise using functional magnetic resonance imaging

Imaging acoustic noise (IAN) is a confounding factor that undermines the usefulness of functional magnetic resonance imaging (fMRI), especially in auditory related experiments. This paper presents the methods and results of measuring auditory hemodynamic responses (HDR) due to different temporal patterns of IAN using fMRI. Six different temporal patterns of IAN corresponding to acoustic noise generated while using different numbers of imaging slices and effective repetition times (TR) were used as stimuli in the current study. Hemodynamic responses were measured using a stroboscopic event related paradigm with extra long TRs to minimize the effects due to previous IAN segments. The shape of the HDR and the extent of activation due to each of the above stimuli are reported here and are in agreement with those reported in previous studies. In addition to the responses due to IAN patterns reported in previous studies, responses to several new temporal patterns are also reported here. The results of this study will be used in developing a model-based correction algorithm to account for IAN in auditory fMRI.