Cognitive and Affective Neuroscience Unit, University of Zurich, Zurich, Switzerland.
Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland.
PLoS Biol. 2021 Apr 13;19(4):e3000751. doi: 10.1371/journal.pbio.3000751. eCollection 2021 Apr.
Across many species, scream calls signal the affective significance of events to other agents. Scream calls were often thought to be of generic alarming and fearful nature, to signal potential threats, with instantaneous, involuntary, and accurate recognition by perceivers. However, scream calls are more diverse in their affective signaling nature than being limited to fearfully alarming a threat, and thus the broader sociobiological relevance of various scream types is unclear. Here we used 4 different psychoacoustic, perceptual decision-making, and neuroimaging experiments in humans to demonstrate the existence of at least 6 psychoacoustically distinctive types of scream calls of both alarming and non-alarming nature, rather than there being only screams caused by fear or aggression. Second, based on perceptual and processing sensitivity measures for decision-making during scream recognition, we found that alarm screams (with some exceptions) were overall discriminated the worst, were responded to the slowest, and were associated with a lower perceptual sensitivity for their recognition compared with non-alarm screams. Third, the neural processing of alarm compared with non-alarm screams during an implicit processing task elicited only minimal neural signal and connectivity in perceivers, contrary to the frequent assumption of a threat processing bias of the primate neural system. These findings show that scream calls are more diverse in their signaling and communicative nature in humans than previously assumed, and, in contrast to a commonly observed threat processing bias in perceptual discriminations and neural processes, we found that especially non-alarm screams, and positive screams in particular, seem to have higher efficiency in speeded discriminations and the implicit neural processing of various scream types in humans.
在许多物种中，尖叫信号向其他个体传达了事件的情感意义。尖叫信号通常被认为是具有通用的警告和恐惧性质的，用于表示潜在的威胁，感知者能够立即、无意识且准确地识别出这些信号。然而，尖叫信号在情感信号传递方面比仅仅用于警告威胁更为多样化，因此各种尖叫类型的更广泛的社会生物学相关性尚不清楚。在这里，我们使用了 4 种不同的心理声学、感知决策和神经影像学实验，在人类中证明了至少存在 6 种具有不同心理声学特征的尖叫信号，包括具有警告和非警告性质的尖叫信号，而不仅仅是由恐惧或攻击引起的尖叫。其次，基于对尖叫识别过程中的决策进行感知和处理敏感性的测量，我们发现，警报声（有一些例外）总体上被区分得最差，反应最慢，与非警报声相比，对其识别的感知敏感性较低。第三，与非警报声相比，在一个隐含处理任务中，警报声的神经处理仅在感知者中引起了最小的神经信号和连接，这与灵长类动物神经系统对威胁处理的偏见的常见假设相反。这些发现表明，在人类中，尖叫信号在信号传递和通信性质方面比之前假设的更为多样化，与感知辨别和神经过程中常见的威胁处理偏见相反，我们发现，特别是非警报声，尤其是积极的尖叫，在各种尖叫类型的快速辨别和隐含神经处理方面似乎具有更高的效率。
