Table 1.

Demographic, behavioural and psychopathological data

	Placebo	SEM	Ketamine	SEM	Statistics
Age, years	29 ± 0.9				–
Gender	12 male / 2 females				–
PANSS scores
Negative	8.0	0.6	13.5	1.0	t(13) = 5.0, P < 0.0001
Excitement	5.4	0.3	6.8	0.5	t(13) = 2.9, P < 0.0015
Cognitive	5.4	0.3	10.5	0.7	t(13) = 7.4, P < 0.0001
Positive	4.1	0.1	7.2	0.5	t(13) = 6.8, P < 0.0001
Depression	5.6	0.2	10.5	0.4	t(13) = 10.7, P < 0.0001
Disorganization	3.1	0.1	5.8	0.6	t(13) = 4.9, P < 0.0001
Total	35.7	0.9	60.1	2.3	t(13) = 11.6, P < 0.0001
Behaviour
Mean RT, ms	564	16.8	645	18.1	F(1,13) = 18.4, P = 0.001
Accuracy, % hits	92.5	1.1	68.7	3.3	F(1,13) = 71.6, P < 0.0001
MEG trials, n	349	20.6	353	19.2	n.s.
	Controls		FEP
Age, years	23.1	1.0	23.2	1.3	n.s.
Gender	5 males / 5 females		5 males / 5 females		–
PANSS scores					a
Negative	–	–	13.8	0.9	n.s.
Excitement	–	–	7.7	1.1	n.s.
Cognitive	–	–	18.0	2.0	t(23) = 3.9, P = 0.002
Positive	–	–	19.1	2.1	t(23) = 3.9, P = 0.002
Depression	–	–	12.0	1.5	n.s.
Total	–	–	70.6	5.5	t(23) = 2.9, P = 0.011
Behaviour
Mean RT, ms	514	20.6	575	28.6	F(1,9) = 5.5, P = 0.044
Accuracy, % hits	92.9	1.2	87.1	3.6	n.s.
MEG trials, n	225	6.3	221	9.4	n.s.
	Controls		Chronic schizophrenia
Age, years	30.8	8.0	34.1	10.6	n.s.
Gender	10 males / 6 females		10 males / 6 females		–
PANSS scores					–
Negative	–	–	14.3	1.6	–
Excitement	–	–	6.9	0.7	–
Cognitive	–	–	9.6	0.7	–
Positive	–	–	9.9	1.0	–
Depression	–	–	11.3	0.7	–
Total	–	–	51.9	3.4	–
Behaviour
Mean RT, ms	572	52.0	596	50.0	n.s.
Accuracy, % hits	94.7	1.0	82.5	3.1	F(1,15) = 129.3, P < 0.001
MEG trials, n	322	23.6	336	27.9	n.s.

^aIndependent-sample t-tests, 1000 samples bootstrapping applied: PANSS scores, FEP versus schizophrenia.

n.s. = not significantly different; RT = response times.