Auditory hemispheric asymmetry as a specialization for actions and objects

Abstract

What is the function of auditory hemispheric asymmetry? We propose that the identification of sound sources relies on two complementary and perceptually relevant acoustic invariants — actions and objects — that are processed asymmetrically and sufficient to model and categorize any sound. We observed that environmental sounds are an independent combination of purely temporal and spectral acoustic modulations. Behaviorally, discrimination of actions relied on temporal modulations, while discrimination of objects relied on spectral modulations. Functional magnetic resonance imaging data showed that actions and objects are respectively decoded in the left and right hemispheres, in bilateral superior temporal and left inferior frontal regions. This asymmetry reflects a generic differential processing — through differential neural sensitivity to temporal and spectral modulations present in all environmental sounds — that supports the efficient categorization of actions and objects. These results provide an ecologically valid framework of the functional role of auditory brain asymmetry.

Speech and music recruit frequency-specific distributed and overlapping cortical networks

“…On one hand, one can find claims for a clear distinction between brain regions exclusively dedicated to language versus other cognitive processes (Chen et al, 2023; Fedorenko et al, 2011; Fedorenko & Blank, 2020; Friederici, 2020) and for the existence of specific and separate neural populations for speech, music, and song (Boebinger et al, 2021; Norman-Haignere et al, 2022). On the other hand, other neuroimaging studies suggest that the brain regions that support language and speech also support nonlinguistic functions (Albouy et al, 2020; Fadiga et al, 2009; Koelsch, 2011; Menon et al, 2002; Robert et al, 2023; Schön et al, 2010). This point is often put forward when interpreting the positive impact music training can have on different levels of speech and language processing (Flaugnacco et al, 2015; François et al, 2013; Kraus & Chandrasekaran, 2010; Schön et al, 2004).…”

Region-specific endogenous brain rhythms and their role for speech and language

“…It has been argued that, after an initial bilaterally symmetric neural representation of speech in primary auditory cortex, an auditory hemispheric asymmetry allows for an optimization of auditory processing in general, and speech processing specifically, with complementary and parallel processing in the two hemispheres (Zatorre & Belin, 2001;Zatorre et al, 2002;Poeppel, 2003;Washington & Tillinghast, 2015;Zatorre, 2022;Robert et al, 2023). In the right hemisphere, slower delta-theta brain rhythms (~4-8 Hz) are observed, while the left hemisphere shows a regime of faster gamma brain rhythms (~40 Hz) (Poeppel, 2003).…”

“…In the right hemisphere, slower delta-theta brain rhythms (~4-8 Hz) are observed, while the left hemisphere shows a regime of faster gamma brain rhythms (~40 Hz) (Poeppel, 2003). For auditory processing in general it has been argued that the right hemisphere is involved in the processing of spectral modulations relevant for object discrimination and the left hemisphere in temporal modulations relevant for action processing (R. Zatorre et al, 2002;Albouy et al, 2020;Robert et al, 2023). Along those lines, melody processing is thought to depend more on spectral cues and speech perception more on temporal cues (Albouy et al, 2020).…”

Speech and music recruit frequency-specific distributed and overlapping cortical networks

“…On one hand, one can find claims for a clear distinction between brain regions exclusively dedicated to language versus other cognitive processes ( Chen et al, 2023 ; Fedorenko et al, 2011 ; Fedorenko and Blank, 2020 ; Friederici, 2020 ) and for the existence of specific and separate neural populations for speech, music, and song ( Boebinger et al, 2021 ; Norman-Haignere et al, 2022 ). On the other hand, other neuroimaging studies suggest that the brain regions that support language and speech also support nonlinguistic functions ( Albouy et al, 2020 ; Fadiga et al, 2009 ; Koelsch, 2011 ; Menon et al, 2002 ; Robert et al, 2023 ; Schön et al, 2010 ). This point is often put forward when interpreting the positive impact music training can have on different levels of speech and language processing ( Flaugnacco et al, 2015 ; François et al, 2013 ; Kraus and Chandrasekaran, 2010 ; Schön et al, 2004 ).…”