Bálint Anna, Szabó Ádám, Andics Attila, Gácsi Márta
ELKH-ELTE Comparative Ethology Research Group, H-1117 Budapest, Pázmány Péter sétány 1/C, Hungary.
Department of Neuroradiology at the Medical Imaging Centre of the Semmelweis University, H-1082 Budapest, Üllői út 78a, Hungary.
Neuroimage. 2023 Jan;265:119791. doi: 10.1016/j.neuroimage.2022.119791. Epub 2022 Dec 5.
Voice-sensitivity in the auditory cortex of a range of mammals has been proposed to be determined primarily by tuning to conspecific auditory stimuli, but recent human findings indicate a role for a more general tuning to voicelikeness. Vocal emotional valence, a central characteristic of vocalisations, has been linked to the same basic acoustic parameters across species. Comparative neuroimaging revealed that during voice perception, such acoustic parameters modulate emotional valence-sensitivity in auditory cortical regions in both family dogs and humans. To explore the role of voicelikeness in auditory emotional valence-sensitivity across species, here we constructed artificial emotional sounds in two sound categories: voice-like vs. sine-wave sounds, parametrically modulating two main acoustic parameters, f0 and call length. We hypothesised that if mammalian auditory systems are characterised by a general tuning to voicelikeness, voice-like sounds will be processed preferentially, and acoustic parameters for voice-like sounds will be processed differently than for sine-wave sounds - both in dogs and humans. We found cortical areas in both species that responded stronger to voice-like than to sine-wave stimuli, while there were no regions responding stronger to sine-wave sounds in either species. Additionally, we found that in bilateral primary and emotional valence-sensitive auditory regions of both species, the processing of voice-like and sine-wave sounds are modulated by f0 in opposite ways. These results reveal functional similarities between evolutionarily distant mammals for processing voicelikeness and its effect on processing basic acoustic cues of vocal emotions.
一系列哺乳动物听觉皮层中的语音敏感性被认为主要由对同种听觉刺激的调谐决定，但最近的人类研究结果表明，对语音相似性的更普遍调谐也发挥了作用。语音情感效价是发声的一个核心特征，在不同物种中与相同的基本声学参数相关联。比较神经影像学研究表明，在语音感知过程中，这些声学参数会调节家犬和人类听觉皮层区域对情感效价的敏感性。为了探究语音相似性在跨物种听觉情感效价敏感性中的作用，我们在此构建了两类人工情感声音：类语音声音与正弦波声音，通过参数调节两个主要声学参数，即基频（f0）和叫声时长。我们假设，如果哺乳动物的听觉系统具有对语音相似性的普遍调谐特征，那么类语音声音将被优先处理，并且类语音声音的声学参数与正弦波声音的处理方式会有所不同——在狗和人类中都是如此。我们发现，两个物种的皮层区域对类语音声音的反应都比对正弦波刺激的反应更强，而在两个物种中都没有区域对正弦波声音的反应更强。此外，我们发现，在两个物种的双侧初级和对情感效价敏感的听觉区域中，类语音声音和正弦波声音的处理受到基频的相反方式调制。这些结果揭示了在进化上距离遥远的哺乳动物之间，在处理语音相似性及其对处理发声情感的基本声学线索的影响方面的功能相似性。
