Table 3.

Correlations between acute change scores in the two treatment groups

	Placebo			Blueberry			z	p-value
	r	n	p-Value	r	n	p-Value
ΔPA & ΔACC (switch)	0.312	28	0.106	0.424	31	0.017*	−0.47	0.638
ΔPA & ΔACC (non-switch)	0.306	28	0.113	0.148	31	0.427	0.61	0.542
ΔPA & ΔRT (switch)	−0.05	27	0.804	−0.107	31	0.565	0.21	0.834
ΔPA & ΔRT (non-switch)	0.087	27	0.667	0.073	31	0.698	0.05	0.960
ΔACC & ΔRT (switch)	0.214	28	0.275	−0.027	31	0.885	0.89	0.374
ΔACC & ΔRT (non-switch)	−0.207	28	0.290	0.162	31	0.384	−1.36	0.174

p-Values in the last column refer to the significance of the difference between two correlation coefficients using Fisher’s r-to-Z-transformations. One participant from the placebo group was excluded from the each of the analyses for PA and reaction time due to being an outlier

ACC accuracy; PA positive affect; RT reaction time

^*denotes p < 0.05