递归程序允许将声音信号放置在另一种类似类型的声音中,为口语和人类歌曲中的语法和语音提供了神经计算蓝图。有,然而,在非人灵长类动物中没有已知的声乐序列,这些序列以自我嵌入的模式排列,表明声乐递归或其潜在的初期或进化过渡形式,暗示了人类独有的神经认知转变。这里,我们发现野生法兰雄性猩猩长呼叫具有嵌套在同步呼叫序列中的有节奏的同步呼叫序列,与两个等级地层一致。值得注意的是,下层的三个时间和声学上不同的呼叫节奏与高层的总体节奏无关,这表明这些递归结构既不是并行非分层程序的结果,也不是身体约束或共振的解剖伪影。研究结果代表了在没有语法的情况下时间递归的原始人声组合的情况,语义,语音学,或音乐。二阶组合,\'序列中的序列\',在古代原始人中涉及分层组织和周期性结构的声音,可能预示了现代语言能力强的人类递归的演变。
语言是自然界中已知的最强大的交流工具。通过组合一组有限的元素,它允许我们编码无限的信息。这使得几乎任何事情的沟通,提醒他人潜在的危险,推荐一本最喜欢的书。过去70年流行的理论表明,这种能力依赖于人类独特的大脑计算过程,称为递归。递归使人类能够产生并将一种语言元素或元素模式放置在另一种相同类型的元素或模式中。这样,一个子句可以嵌入另一个“载体”子句中以扩展一个想法,argument,或场景,例如,"狗,追赶那只猫,在吠叫。"虽然递归提供了一个简单的,然而有力,解释语言的无限可能性,如何以及为什么递归-以及通过扩展语言-在人类中出现,但没有其他动物仍然是一个谜。Lameira等人。观察到野生猩猩的声音模式似乎由不同的元素组成。因为猩猩和其他类人猿是我们最亲密的亲戚,它们代表了研究人类祖先使用和理解语言能力的最现实模式。因此,Lameira等人。着手确定这是否是嵌入在类似声音模式中的声音模式的情况,这可能表明递归支持这些调用的产生。分析野生雄性猩猩发出的长叫声的录音显示,它们分为两层,其中具有常规节拍(或节奏)的呼叫是在另一个不同节奏的“载波”呼叫中产生的。多达三种不同的呼叫类型,每个人都有自己的标志性节奏,可以在同一运营商呼叫中发生。进一步的分析证实这些呼叫类型与运营商无关。Lameira等人的发现。证明猩猩产生递归的声音序列,可以代表人类递归的可能前兆,为研究递归提供了一个潜在的途径,最终是语言,在人类中进化。在未来,更好地理解语言是如何进化的,可能有助于改进旨在识别的机器学习算法,预测或生成文本。
Recursive procedures that allow placing a vocal signal inside another of a similar kind provide a neuro-computational blueprint for syntax and phonology in spoken language and human song. There are, however, no known vocal sequences among nonhuman primates arranged in self-embedded patterns that evince vocal recursion or potential incipient or evolutionary transitional forms thereof, suggesting a neuro-cognitive transformation exclusive to humans. Here, we uncover that wild flanged male orangutan long calls feature rhythmically isochronous call sequences nested within isochronous call sequences, consistent with two hierarchical strata. Remarkably, three temporally and acoustically distinct call rhythms in the lower stratum were not related to the overarching rhythm at the higher stratum by any low multiples, which suggests that these recursive structures were neither the result of parallel non-hierarchical procedures nor anatomical artifacts of bodily constraints or resonances. Findings represent a case of temporally recursive hominid vocal combinatorics in the absence of syntax, semantics, phonology, or music. Second-order combinatorics, \'sequences within sequences\', involving hierarchically organized and cyclically structured vocal sounds in ancient hominids may have preluded the evolution of recursion in modern language-able humans.
Language is the most powerful communication tool known in nature. By combining a finite set of elements, it allows us to encode infinite messages. This enables communication about virtually anything, from alerting others to potential dangers, to recommending a favourite book. The prevailing theory of the last 70 years suggests that this ability rests on a computational process in the brain that is unique to humans, known as recursion. Recursion enables humans to produce and place a language element or pattern of elements inside another element or pattern of the same kind. In this way, a clause can be embedded inside another ‘carrier’ clause to extend a thought, argument, or scenario, for example, “the dog, which chased the cat, was barking”. While recursion offers a simple, yet potent, explanation for the endless possibilities of language, how and why recursion – and by extension language – emerged in humans but no other animals remains a mystery. Lameira et al. observed vocal patterns in wild
orangutans that appeared to be composed of different elements. As
orangutans and other great apes are our closest living relatives, they represent the most realistic model for studying the ability of human ancestors to use and comprehend language. Therefore, Lameira et al. set out to determine if this was a case of vocal patterning embedded within a similar vocal pattern, which could indicate that recursion underpins production of these calls. Analysing recordings of long calls made by wild male
orangutans showed that they are organized as two layers, where calls with a regular beat (or tempo) are produced within another “carrier” call of a different tempo. Up to three different call types, each with their own signature tempo, can occur within the same carrier call. Further analysis confirmed these call types were unrelated to the carrier. The findings of Lameira et al. demonstrate that
orangutans produce recursive vocal sequences that could represent a possible precursor to recursion in humans, offering a potential avenue for studying how recursion, and ultimately language, evolved in humans. In the future, better understanding of how language evolved may help to refine machine learning algorithms that aim to recognize, predict or generate text.