We examined the effect of age on SSVEP topography. Twenty-four elderly (mean age 70) and twenty young (mean age 22) subjects performed the AX version of the CPT task and a reference task requiring them to respond to the regular appearance of the target letter E. Letters were presented for 300 ms with an interval of 1500 ms. Brain electrical activity was recorded from 64 scalp sites while a diffuse 13 HZ flicker, superimposed over the visual fields, elicited the SSVEP. Compared to the mean of the reference task, SSVEP amplitude reductions were observed on the appearance of the letter A as well as on the appearance of the target X at prefrontal sites for both groups. By contrast, an SSVEP amplitude increase was shown when the letter A disappeared. Appearance of the target letter X was associated with SSVEP latency reductions at prefrontal sites for both groups. SSVEP latency reductions were observed at left temporal site in the young group. By contrast, smaller SSVEP latency reductions were observed at left and right temporal sites in the elderly group. Our data suggests significant age-related differences in cortical activations for this task.