Handy numbers: finger counting and numerical cognition

Book excerpt: We are born with a “number sense” - the ability to respond to numerosity, which we share with other vertebrates. This inherited numerosity representation is approximate and follows the Weber-Fechner law that governs sensory perception. As educated adults we can also use culturally developed abstract symbol systems to represent exact numerosities – in particular number words and Arabic numbers. This developmental stage is preceded by an apparently transient phase of finger counting and finger calculation. In fact, the use of fingers to represent number is ubiquitous across ages and cultures. Children use finger counting even if they are discouraged to do so, sometimes even before they are able to utter the number word sequence. Furthermore, finger counting strategies may also be used by adults diagnosed with dyscalculia to make up for a deficient or absent mental number representation. The advantages of finger counting are evident: Fingers are readily available and perceptually salient, finger-numerical representations support short term memory and they provide a transparent one-to-one relationship between to-be-counted objects and their representation. Obviously, however, these advantages only hold for small numbers. Fully transparent finger counting systems are limited to the number range between zero and ten. Larger numbers can only be represented in perceptually less salient or symbolic ways. In recent years, a growing body of evidence has suggested that finger-based representations of number do not form an arbitrary and transient stage of cognitive development. Rather, they seem to provide a good example of embodied cognition. According to this influential viewpoint, all of our knowledge is represented together with the sensory and motor activity that was present during its acquisition. As a consequence, even a supposedly abstract cognitive ability such as numerical cognition reuses the neural substrate and inherits functional properties of more basic perceptual and/or motor processes. Consistent with this assumption, finger counting habits and numerical processing do interact even in educated adults, casting doubts on purely abstract accounts of mental number representations. The objective of this Research Topic is to document embodiment signatures in number processing and calculation – a domain of cognition that was long considered to epitomize the abstract symbol manipulation approach to human cognition. To this end, we invite empirical contributions using different methodologies including behavioural, developmental, neuroscientific, educational, cross-cultural, and neuropsychological studies. Moreover, we also seek theoretical contributions, review articles, or opinion papers. Questions to be tackled may include, but are not restricted to the following: Is finger counting only a useful or even a necessary step towards the acquisition of symbolic number representations? What are the neural correlates of the finger-number relationship? Which features of finger counting influence adult number processing – both approximate and exact? How can finger counting systems be classified typologically and how do different finger counting systems influence numerical cognition across cultures and populations? Should finger counting and finger calculation be promoted or discouraged in maths education? How are disturbances of finger gnosis and numerical abilities linked? We hope that this Research Topic will bring together researchers from different backgrounds to fruitfully discuss a topic which has both scientific and every-day relevance.