Table 2.

Neuropsychological test outcomes (mean ± SD) at 0 (baseline), 2 and 8 hours after LPS administration

	LPS group (n = 15)				Reference group (n = 10)				P value (between group)
Age (Dutch) STAI total	22.8 ± 2.2				25.5 ± 2.5				0.87*
	32.7 ± 1.5				29.1 ± 3.7				0.13*
Neuropsychological test	t = 0	t = 2	t = 8	P value (within group)	t = 0	t = 2	t = 8	P value (within group)
Stroop A (in seconds) 1	39 ± 2	35 ± 2	35 ± 2	0.0001	37 ± 5	34 ± 4	34 ± 4	0.001	0.49
Stroop B (in seconds) 1	51 ± 3	45 ± 3	43 ± 2	0.0001	48 ± 7	44 ± 7	43 ± 7	0.001	0.45
Stroop C (in seconds) 1	75 ± 6	65 ± 4	64 ± 4	0.003	67 ± 10	62 ± 12	61 ± 11	0.004	0.23
Pasat 2	49 ± 2	50 ± 2	56 ± 2	0.001	50 ± 7	54 ± 4	54 ± 5	0.031	0.07
Digits forward 2	11 ± 1	12 ± 1	11 ± 1	0.115	10 ± 2	11 ± 1	11 ± 2	0.235	0.81
Digits backward 2	8 ± 1	9 ± 1	9 ± 1	0.30	9 ± 2	9 ± 1	9 ± 2	0.454	0.65
Digits total 2	19 ± 1	20 ± 1	20 ± 1	0.066	19 ± 4	20 ± 3	21 ± 4	0.203	0.63
Pegboard 1	64 ± 2	59 ± 2	61 ± 2	0.037	58 ± 5	56 ± 6	56 ± 7	0.362	0.35
Symbol substitution task2	87 ± 3	99 ± 4	101 ± 3	0.0001	98 ± 14	108 ± 17	112 ± 19	0.0001	0.53

All values are means ± SD unless other reported.

* Unpaired T-test.

¹ Decrease indicates an improvement of the test.

² Increase indicates an improvement of the test.

Reading speed was measured by Stroop A-B-C word naming test.

Attention under time pressure was measured by the paced auditory serial addition test (PASAT).

Working memory was tested in numbers with the Digits forward and backward test.

The fine motor control was tested with the Grooved Pegboard test.

Psychomotor speed capacity was measured by the symbol substitution task.

LPS, lipopolysaccharide; SD, standard deviation; STAI, Dutch State-Trait Anxiety Inventory scale.