To study the number cognition process, we recorded event-related potentials
(ERPs) in 14 subjects when they were indicating whether a number pair was
the same or not. The two numbers given in sequence were either the same (co
ndition 1) or different (condition 2). After 270 ms following the onset of
the second stimulus in condition 2, a negative component N270 was recorded
on the scalp with the most negative amplitude at the central and occipital
areas. Hemispheric asymmetry was not observed in the potential. This negati
ve component is considered to reflect the mismatching process for numbers i
n the brain. NeuroReport 11:1195-1197 (C) 2000 Lippincott Williams & Wilkin
s.