NO_YO —- but hey, SCREAMS ARE EFFICIENTS ! Scholarly study on screaming.
Screaming is arguably one of the most relevant communication signals for survival in humans. Despite their practical relevance and their theoretical significance as innate [ 1 ] and virtually universal [ 2, 3 ] vocalizations, what makes screams a unique signal and how they are processed is not known. Here, we use acoustic analyses, psychophysical experiments, and neuroimaging to isolate those features that confer to screams their alarming nature, and we track their processing in the human brain. Using the modulation power spectrum (MPS [ 4, 5 ]), a recently developed, neurally informed characterization of sounds, we demonstrate that human screams cluster within restricted portion of the acoustic space (between ~30 and 150 Hz modulation rates) that corresponds to a well-known perceptual attribute, roughness. In contrast to the received view that roughness is irrelevant for communication [ 6 ], our data reveal that the acoustic space occupied by the rough vocal regime is segregated from other signals, including speech, a pre-requisite to avoid false alarms in normal vocal communication. We show that roughness is present in natural alarm signals as well as in artificial alarms and that the presence of roughness in sounds boosts their detection in various tasks. Using fMRI, we show that acoustic roughness engages subcortical structures critical to rapidly appraise danger. Altogether, these data demonstrate that screams occupy a privileged acoustic niche that, being separated from other communication signals, ensures their biological and ultimately social efficiency.
Human Screams Occupy a Privileged Niche in the Communication Soundscape Highlights
We provide the first evidence of a special acoustic regime (roughness) for screams
Roughness is used in both natural and artificial alarm signals
Roughness confers a behavioral advantage to react rapidly and efficiently
Acoustic roughness selectively activates amygdala, involved in danger processing
Luc H. Arnal, Adeen Flinker, Andreas Kleinschmidt, Anne-Lise Giraud, David Poeppel
Arnal et al. show that, unlike speech, screams exploit a privileged acoustic attribute: roughness. Sounds in this modulation regime specifically
target subcortical brain areas involved in danger processing and improve behavior in various ways, suggesting that this acoustic niche may be preserved to
insure efficient warning