. 2020 Jul 1;47(1):87–96. doi: 10.1093/schbul/sbaa080

Table 2.

Results of Late Positive Potentials (LPP) at the Pz Electrode Site and Negative Emotion Ratings in the 3 Conditions

	FEP	CHR	HC	Statistical Analysis^a			Post hoc Analysis^b
	(N = 54)	(N = 34)	(N = 30)		F	P
Mean LPP amplitudes (μV) for each condition							NEG vs CR	NEG vs NEU	CR vs NEU
NEG condition	3.4 ± 3.1	4.3 ± 2.5	4.1 ± 2.8	Group	0.886	.415
CR condition	3.3 ± 3.2	4.5 ± 2.6	3.4 ± 2.7	Condition	4.201	.016*	.205	<.001**	<.001**
NEU condition	2.1 ± 2.4	2.7 ± 2.2	2.5 ± 2.1	Group × Condition	3.054	.018*	.010*	.379	.061
Paired samples t-test	NEG = CR	NEG = CR	NEG > CR*
	NEG > NEU**	NEG > NEU**	NEG > NEU**
	CR > NEU**	CR > NEU**	CR > NEU**
Negative emotion rating scores (0–4)							FEP vs CHR	FEP vs HC	CHR vs HC
NEG condition	2.9 ± 0.8	2.8 ± 0.7	2.6 ± 0.7	Group	3.641	.029*	.708	.112	.262
CR condition	2.2 ± 0.7	2.2 ± 0.6	1.9 ± 0.5	Condition	348.897	<.001**	.632	.012*	.059
NEU condition	1.4 ± 0.4	1.4 ± 0.5	1.1 ± 0.1	Group × Condition	0.594	.668	.320	.014*	.002**
Emotion regulation scores (μV)							FEP vs CHR	FEP vs HC	CHR vs HC
Mean LPP amplitude (NEG-CR)	0.0 ± 1.3	−0.3 ± 1.4	0.7 ± 1.4		3.443	.019*	.316	.024*	.004**

Note: FEP, first-episode psychosis; CHR, clinical high risk; HC, healthy control; NEG, negative; CR, cognitive reappraisal; NEU, neutral. The NEG condition indicates a negative audio description followed by an unpleasant image. The CR condition indicates a neutral audio description followed by an unpleasant image, which promotes the use of a cognitive reappraisal strategy for emotion regulation. The NEU condition indicates a neutral audio description followed by a neutral image. Data are given as the mean ± standard deviation.

^aAnalysis of variance with sex as a covariate.

^bPost hoc Fisher’s least significant difference analysis.

*The mean difference is significant at the .05 level.

**The mean difference is significant at the .005 level.