Small numbers in the right brain: Evidence from patients without and with spatial neglect

Following seminal introspective evidence reported by Francis Galton (1880), several investigations have suggested that people with left-to-right reading habits, mentally organize numbers along the equivalent of a horizontal ruler, the mental number line (MNL), with small magnitudes located to the left of larger ones. Here we show that RBD suffer a specific impairment in the representation of the smallest number in the series of integers it is this representational deficit, rather than left spatial neglect, that provokes a bias toward higher numbers during the mental bisection of long 7- and 9-unit number intervals