Behavioral data

Purchase rate
Only trials that registered responses in <4 s after stimulus onset were included for behavioral analyses. The one-way repeated-measure ANOVA revealed a significant main effect of price frame on purchase rate, F(2, 56) = 7.793, p = 0.007, ηp2 = 0.218. As illustrated in Figure 2A, subsequent pairwise comparison indicated that participants made buy decisions more often in ZP (M = 0.550, S.E. = 0.033) compared to NP (M = 0.440, S.E. = 0.036, p = 0.009). But the contrast between ZP and LP (M = 0.529, S.E. = 0.032, p = 0.241), as well as the contrast between NP and LP (p = 0.065), was not significant.
Figure 2  Behavioral results. (A) The purchase rate for each condition and (B) the RT for each condition. The error bars indicate standard error of the mean. **p < 0.01.

Reaction time
The ANOVA showed a significant main effect of price frame on reaction time (RT), F(2, 56) = 7.030, p = 0.004, ηp2 = 0.201. As illustrated in Figure 2B, pairwise comparison indicated shorter RT for ZP (M = 1,387.390 ms, S.E. = 86.931) than NP (M = 1,484.370 ms, S.E. = 95.516, p = 0.004). However, the contrast between ZP and LP (M = 1,406.854 ms, S.E. = 79.764, p = 1.000), as well as that between NP and LP (p = 0.073), was not significant.