Number-space associations in the brain

ended

Research in cognitive science has revealed that the temporal, spatial, and numerical features of a stimulus can interact with one another. An example is the tendency to map increasing numerical magnitudes with a left-to-right orientation. Numerical-spatial associations (NSA) are pervasive in human behaviour and have relevance to health (e.g., dyscalculia is thought to be related to improper understanding of the so-called «mental number line»). NSA have been shown to occur in human newborns and in non-human animals for non-symbolic numerousness. SPANUMBRA aims to investigate NSA in different animal models (domestic chicks, mice and zebrafish) and in human neonates and infants to provide a comprehensive and comparative perspective on the developmental, neural and genetic origins of this phenomenon. The project will be guided by a new hypothesis that links the direction of NSA to a differential role of the two sides of the brain to the perceived value (valence) of changes in magnitudes. The role of the experience (WP1) in the development of NSA will be investigated making use of early exposure to light in chicks’ embryos to modulate brain asymmetry, and controlled-rearing experiments in which newly-hatched chicks will be exposed to correlated and anti-correlated discrete and continuous magnitudes. Development of NSA will be also studied in human neonates and infants (WP2) before, during, and after the exposure to culture-specific NSA associations (numbers organized in spatially oriented layouts) to investigate the role of culture in shaping/reinforcing NSA. The study of the neural basis of the NSA (WP3) will combine neurobiological techniques (immediate early gene expression in chicks and zebrafish), and non-invasive methods (EEG and fNIRS in human neonates). The genetic bases of NSA (WP4) will be investigated using transgenic lines of zebrafish and mice, in order to understand the role of some genes implicated in the development of lateralization and in dyscalculia.