Abstract
Adding an affix to transform a word is common across the world languages, with the edges of words more likely to carry out such a function. However, detecting affixation patterns is also observed in learning tasks outside the domain of language, suggesting that the underlying mechanism from which affixation patterns have arisen may not be language or even human specific. We addressed whether a songbird, the zebra finch, is able to discriminate between, and generalize, affixation-like patterns. Zebra finches were trained and tested in a Go/Nogo paradigm to discriminate artificial song element sequences resembling prefixed and suffixed ‘words.’ The ‘stems’ of the ‘words,’ consisted of different combinations of a triplet of song elements, to which a fourth element was added as either a ‘prefix’ or a ‘suffix.’ After training, the birds were tested with novel stems, consisting of either rearranged familiar element types or novel element types. The birds were able to generalize the affixation patterns to novel stems with both familiar and novel element types. Hence, the discrimination resulting from the training was not based on memorization of individual stimuli, but on a shared property among Go or Nogo stimuli, i.e., affixation patterns. Remarkably, birds trained with suffixation as Go pattern showed clear evidence of using both prefix and suffix, while those trained with the prefix as the Go stimulus used primarily the prefix. This finding illustrates that an asymmetry in attending to different affixations is not restricted to human languages.
Highlights
Language is a uniquely human trait, which makes it a challenge to understand how different components of the language faculty have evolved
The discrimination resulting from the training was not based on memorization of individual stimuli, but on a shared property among Go or Nogo stimuli, i.e., affixation patterns
The results of Experiment 1 showed that the birds perfectly generalized the discrimination obtained during the training to test stimuli that shared the affixes with the training stimuli, but had a novel stem constructed from familiar element types
Summary
Language is a uniquely human trait, which makes it a challenge to understand how different components of the language faculty have evolved. One window to provide insights and hypotheses about their origins is by comparative studies on the cognitive abilities of non-human animals (Fitch 2010; Hauser et al 2002) Such studies can be directed at phylogenetically related taxa, like apes and monkeys. Neural and genetic similarities with humans in vocal perception, production and auditory–vocal learning (e.g., Bolhuis and Everaert 2013; Bolhuis et al 2010; Doupe and Kuhl 1999; Kriengwatana et al 2015; Ohms et al 2010; ten Cate 2014; ten Cate and Okanoya 2012) For this reason, they are excellent model species to explore cognitive abilities that might have been at the basis of language evolution. We use a songbird species, the zebra finch, to examine whether it is able to categorize strings of acoustic elements based on ‘affixation’-like patterns
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have