Table 3.

Mean (± s.d., n = 7) changes in P300-N100 potential differences (µV) at the vertex electrode between before and after drug administration.

Formulation	Difference between before and after drug administration	95% confidenceb intervals
Placebo	−0.9 ± 7.5	[−6.5, 4.7]
4 mg i.n.	−6.4 ± 5.0*	[−10.1, −2.7]
7 mg i.n.	−8.6 ± 3.8**	[−11.4, −5.8]
5 mg i.v.	−9.6 ± 3.4***	[−12.1, −7.1]

^aP < 0.05

^*P < 0.01

^**P < 0.001

^***vs placebo.

^bSignificant differences were found between formulations, but not between subjects.