Vienna, April 22, 2022 -- Do animals care about nothing? Human thought readily relies on such concepts, for instance, when we stare at the night sky and think about the deep void. What’s more, we even have a number that denotes nothing or no items, which is zero.
Humans can use language to encode and express such elevated thoughts, but where do these concepts come from? Is it possible that we share the roots of such abilities with other species? Could animals, for which language is not available, form similar abstract representations? Non-linguistic creatures are usually assumed to be limited to the here and now, but are they able to capture information about nothing? Can they think about the absence of an entity? The presence of food, or that of predators are crucial for their survival, and there is no doubt that animals track such information. However, it is unclear whether they can explicitly represent the absence of an entity.
New experimental findings of an international research group with Eszter Szabo from the CEU Cognitive Development Center as the lead author suggest that they can. In a recent paper published in eLife entitled “Young domestic chicks spontaneously represent the absence of objects”, they report evidence for absence representation in 8-day-old domestic chicks. This discovery might also suggest that the ability to represent the absence of an entity belongs to the initial cognitive repertoire of vertebrate species.
This is the first experimental study with animals showing evidence for spontaneous absence representation at a very early age without any kind of training. This suggests that the abilities supporting such representations might be shared with other vertebrates, which might be the roots of more abstract thoughts in humans, such as void or zero.
The research method:
CEU researchers Eszter Szabo, Erno Teglas, Gergely Csibra, and Agnes Melinda Kovacs teamed up with Cinzia Chiandetti (University of Trieste), Elisabetta Versace (Queen Mary University of London), and Giorgio Vallortigara (University of Trento) to investigate whether young domestic chicks show signs of absence representation without any previous training across four experiments performed at the University of Trento.
They presented 8-day-old chicks with situations in which either the presence or the absence of an imprinting object should be expected, and compared their reactions - for example, how long they looked at the scenes and which eye they preferred to use when inspecting expected and unexpected outcomes. While chicks reacted differently to surprising outcomes in both cases, there was also a difference in their response pattern depending on whether the object should have been present or absent in the first place. Importantly, when they could encode the absence of the imprinting object (because it left the scene) and were faced with an unexpected outcome (it magically appeared), chicks, and in particular females, responded like they were seeing something new. They have preferentially used their left eyes to inspect the scene, which is typical behavior displayed for novel objects. However, the imprinting object could be considered as novel only if they have previously explicitly represented its absence at that location. Thus, this response suggests that chicks must have formed an expectation about the absence of the imprinting object, and perceived the appearing object as a novel one, even though it looked identical to the imprinting object.