Following rapid methodological advances, ultra-high field (UHF) functional and anatomical magnetic resonance imaging (MRI) has been repeatedly and successfully used for the investigation of the human auditory system in recent years. Here, we review this work and argue that UHF MRI is uniquely suited to shed light on how sounds are represented throughout the network of auditory brain regions. That is, the provided gain in spatial resolution at UHF can be used to study the functional role of the small subcortical auditory processing stages and details of cortical processing. Further, by combining high spatial resolution with the versatility of MRI contrasts, UHF MRI has the potential to localize the primary auditory cortex in individual hemispheres. This is a prerequisite to study how sound representation in higher-level auditory cortex evolves from that in early (primary) auditory cortex. Finally, the access to independent signals across auditory cortical depths, as afforded by UHF, may reveal the computations that underlie the emergence of an abstract, categorical sound representation based on low-level acoustic feature processing. Efforts on these research topics are underway. Here we discuss promises as well as challenges that come with studying these research questions using UHF MRI, and provide a future outlook.
Bibliographical noteFunding Information:
This work was supported by the Netherlands Organization for Scientific Research (NWO) [grant numbers 451-15-012 and 864-13-012 ]; the National Institutes of Health (NIH) [grant numbers P41 EB027061 , P30 NS076408 , and RF1 MH116978 ]; and the Dutch Province of Limburg .
- Auditory system
- Laminar fMRI
- Sound representation
- Subcortical processing
- Ultra-high field MRI