Emotional sounds in space: asymmetrical representation within early-stage auditory areas

Abstract

Evidence from behavioral studies suggests that the spatial origin of sounds may influence the perception of emotional valence. Using 7T fMRI we have investigated the impact of the categories of sound (vocalizations; non-vocalizations), emotional valence (positive, neutral, negative) and spatial origin (left, center, right) on the encoding in early-stage auditory areas and in the voice area. The combination of these different characteristics resulted in a total of 18 conditions (2 categories x 3 valences x 3 lateralizations), which were presented in a pseudo-randomized order in blocks of 11 different sounds (of the same condition) in 12 distinct runs of 6 min. In addition, two localizers, i.e., tonotopy mapping; human vocalizations, were used to define regions of interest. A three-way repeated measure ANOVA on the BOLD responses revealed bilateral significant effects and interactions in the primary auditory cortex, the lateral early-stage auditory areas, and the voice area. Positive vocalizations presented on the left side yielded greater activity in the ipsilateral and contralateral primary auditory cortex than did neutral or negative vocalizations or any other stimuli at any of the three positions. Right, but not left area L3 responded more strongly to (i) positive vocalizations presented ipsi- or contralaterally than to neutral or negative vocalizations presented at the same positions; and (ii) to neutral than positive or negative non-vocalizations presented contralaterally. Furthermore, comparison with a previous study indicates that spatial cues may render emotional valence more salient within the early-stage auditory areas.

Dual Representation of the Auditory Space

“…These results offer an explanation for the previously reported enhanced intensity and arousal associated with emotional sounds presented in space [82][83][84][85]. [55,56,57,81]. Schematic representation of early-stage auditory areas, including primary auditory cortex (A1, R), medial belt areas (M1, M2, M3, M4), lateral belt areas (L1, L2, L3, L4) and the parabelt region.…”

“…Investigating the location-linked representation of sound objects requires the use of environmental sounds and comparison between conditions in which a given sound object changes its location vs. remains stationary. Several studies compared the effect of changing location to a stationary condition (paradigm I in Figure 1 ) [ 48 , 49 , 50 , 51 ], whereas other studies investigated the effect of location vs. identity changes in a 2-factorial design (II in Figure 1 ) [ 52 , 53 , 54 , 55 , 56 , 57 ]. We review here the evidence from these studies in the context of location-linked representation of sound objects.…”

“…Comparing the two conditions with location change (i.e., with same or different species) to those without location change (again for both the same or different species), they identified significant clusters bilaterally on the planum temporale. The comparison with the published coordinates of individual auditory areas [53,55,79] indicates that both clusters involve the postero-lateral area L1 (Figure 4B). (A) Repetition suppression effect used in our 7T fMRI study [53].…”

“…Brain Sci. 2024, 14, x FOR PEER REVIEW 14 of 20 neutral, negative) and three locations (left, center, right) [55]. Significant interaction between the factors valence and location was present bilaterally in the voice area.…”

“…Second, the combined representation of emotional valence and location may confer distinct emotional values to specific parts of space. Thus, Grisendi and colleagues have [55][56][57]81]. Schematic representation of early-stage auditory areas, including primary auditory cortex (A1, R), medial belt areas (M1, M2, M3, M4), lateral belt areas (L1, L2, L3, L4) and the parabelt region.…”