Developmental changes in ERPs to visual language stimuli

ERPs to visual language stimuli were recorded in normal children (7-18 years) and adults from Fpz, Fz, Cz, Pz, Oz, F3, F4, C3, C4, P3, P4, T3, T4, T5 and T6. An oddball paradigm was employed with letter discrimination and lexical decision tasks. N2 and P3 latencies decreased significantly with age, N2 until adolescence, P3 until adulthood. The P3 amplitude increased until 11-12 years and then decreased until adulthood. In younger children there was a large frontal negativity and posterior positivity to targets. With increasing age there was a gradual increase in anterior positivity, concomitant with a decrease in posterior positivity. On the Pz and Cz coronal chains P3 was always largest at Pz while P3 was rarely largest at Cz. Asymmetric ERPs over the temporal lobes were recorded in the younger children. These data extend earlier studies by demonstrating variations in ERP scalp topography that occur with age.