Authors: Ana-Maria Gore¹; Ryszard Auksztulewicz¹; Michelle Moerel¹
¹Maastricht University
Background: Selective auditory attention allows humans to focus on a relevant sound stream while ignoring competing noise. However, the neural mechanisms underlying this capacity remain poorly understood. Animal studies have implicated the corticothalamic circuitry in attention, but whether these findings extend to humans remains unexplored.
Method: To address this, ultra-high field (7T) fMRI was collected while participants performed an auditory selective attention task. Participants attended to tone frequency (low vs. high) or temporal modulation rate (slow vs. fast) and performed a gap detection task. Using this paradigm, we map cortical depth-dependent responses in auditory cortex and in subcortical nuclei, including the medial geniculate body (MGB) and inferior colliculus. With population receptive field modelling (pRF), we characterise tonotopic and temporal tuning profiles (preferred feature and tuning width) and test whether attention shifts tuning preferences or modulates response gain across cortical depths and subcortical structures.
Results: Pilot 7T fMRI data (N = 1) show tonotopic maps and modulation rate preference separately in deep, middle, and superficial cortical depths. Subcortically, frequency-specific responses were observed in both MGB and inferior colliculus with MGB responses allowing segregation into ventral and dorsal divisions. While we observe shifts in frequency preference with attention in this participant, more data is needed to evaluate the robustness of this finding.
Conclusion: These findings demonstrate the feasibility of collecting fMRI data in auditory subcortical structures and across cortical depth within the same acquisition, allowing the exploration of the role of the corticothalamic circuitry in human auditory selective attention. Data collection and analysis are ongoing.
