Representation of auditory motion directions and sound source locations in the human planum temporale

Abstract

The ability to precisely compute the location and direction of sounds in external space is a crucial perceptual process to efficiently interact with dynamic environments. Little is known, however, about how the human brain implements spatial hearing. In our study, we used fMRI to characterize the brain activity of humans listening to left, right, up and down moving as well as static sounds. Whole brain univariate results contrasting moving and static sounds varying in their location revealed a robust functional preference for auditory motion in bilateral human Planum Temporale (hPT). Importantly, multivariate pattern classification analysis showed that hPT contains information about both auditory motion directions and, to a lesser extent, sound source locations. More precisely, we observed that our classifier successfully decoded opposite axes of motion (vertical versus horizontal) but was less able to classify opposite within-axis direction (left versus right or up versus down); reminiscent of the axis of motion organization observed in the middle-temporal cortex for vision. Further multivariate analyses demonstrated that even if motion direction and location rely on partially shared pattern geometries in PT, the responses elicited by static and moving sounds were however highly distinct. Altogether our results demonstrate that human PT codes for auditory motion and location but that the underlying neural computation linked to motion processing is more reliable and partially distinct from the one supporting sound source location.All rights reserved. No reuse allowed without permission.

Representation of Auditory Motion Directions and Sound Source Locations in the Human Planum Temporale

“…For anatomically defined hPT ROIs, all further analyses were performed in subject space for enhanced anatomical precision and to avoid spatial normalization across participants. We replicated our pattern of results in anatomically defined parcels (lhPT and rhPT) obtained from the single-subject brain segmentation (for further analysis, see Battal et al, 2018).…”

Electrocorticography Evidence of Tactile Responses in Visual Cortices

“…According to one parcellation (Glasser et al 2016 ), electrode 2 was located on the border of the fundus of the superior temporal area FST and the putative human temporal area PHT. Interestingly, the latter was recently shown to code for auditory motion and source location (Battal et al 2019 ). Moreover, the electrode’s visual pRF properties are in line with the localization of the electrode within TO2.…”

“…Even primary visual cortex has been shown to be involved in Braille reading by the visually impaired (Sadato et al 1996 ; Zangaladze et al 1999 ). Moreover, in the last decades several neuroimaging studies have reported auditory and tactile responses to motion stimuli in the human Middle Temporal complex hMT+, more specifically in the most anterior part of the complex, known as visual extrastriate area MST (Blake et al 2004 ; Van Boven et al 2005 ; Beauchamp et al 2007 ; Ricciardi et al 2007 ; Ptito et al 2009 ; Summers et al 2009 ; Sani et al 2010 ; Van Kemenade et al 2014 ) and also in the human planum temporale (Battal et al 2019 ). Other fMRI studies offer contradictory findings about the contribution of extrastriate cortex to tactile motion processing.…”

Direct Structural Connections between Auditory and Visual Motion-Selective Regions in Humans

“…Even if less research has been dedicated to study the neural substrates of auditory motion, the human planum temporale (hPT), in the superior temporal gyrus, is thought to notably specialize in the processing of moving sounds (Baumgart et al, 1999;Warren et al, 2002). Analogous to hMT 1 /V5, hPT shows an axis-of-motion organization reminiscent of the organization observed in hMT 1 /V5 (Battal et al, 2019).…”