The Neural Instantiation of Number

Fundamental to calculation and arithmetic competency is the ability to abstractly represent numerical quantity. While much is known about the psychophysics of human quantity representation, little is known about the neural instantiation of this key ability. This research study replicates S. Dehaene's findings and also considers the nature of the neural representation of the magnitudes themselves. In this chapter, the authors investigate the neural representation of larger quantities, and the mapping of multidigit numerals to neural quantity representations. Using single and double-digit Arabic numerals ranging from 0 to 99, the authors discovered functionally distinct neural representations for the individual numerals that compose a multidigit number and for overall numerical magnitude. Regression analysis over 20 ms intervals at each electrode site revealed systematic linear variation in neural voltages relative to the numeral presented.