Table 2.

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

Formulation	Difference between before and after drug administration	95% confidenceb intervals
Placebo	−0.8 ± 2.2	[−3.0, 1.4]
4 mg i.n.	−2.8 ± 3.1	[−5.9, 0.3]
7 mg i.n.	−5.0 ± 2.4**a	[−6.7, −3.2]
5 mg i.v.	−5.6 ± 2.8**	[−8.4, −2.7]

^aP < 0.05

^*P < 0.01

^**P < 0.001

^***vs placebo.

^bNo significant differences were found between formulations or subjects.