Jevin W. Zhang1, 2, Condon Lau1, 2, Joe S. Cheng1, 2, Kyle K. Xing1, 2, Iris Y. Zhou1, 2, Matthew M. Cheung1, 2, Ed X. Wu1
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China; 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China
Intensity is an important physical property of the sound wave and is usually reported as sound pressure level (SPL). This study examines the fMRI hemodynamic responses in the rat inferior colliculus (IC), lateral lemniscus (LL), medial geniculate body (MGB) and auditory cortex (AC) over a broad 72dB SPL range using sparse temporal sampling. The BOLD signal change increases significantly with SPL in IC and LL, but not in MGB and AC, which agrees with electrophysiology findings. This is the first fMRI observation of differences in SPL dependences between auditory structures and furthers our understanding of SPL processing.