Figure 1
Schematic of study procedure, go/no-go training and affective priming paradigm A. After screening, eligible participants adjusted the volume at which they would hear the tones (cues) during training. In the pre-training phase, they provided liking ratings for food and non-food stimuli and stimuli were selected for training and the affective priming paradigm (go, no-go, and untrained foods). Participants performed eight blocks of the go/no-go training task in total and in each block of 32 trials, go and no-go foods appeared with equal probability (50:50). In the post-training phase, the affective priming paradigm (APP) and food ratings were presented in counterbalanced order across participants. The APP consisted of both food and non-food prime blocks, presented in a fixed order and food prime blocks included go, no-go and untrained foods. For the explicit evaluation of foods, participants provided liking ratings and at the end of the study several questionnaires were completed. B. In the go/no-go training task, participants were asked to press “B” to respond on trials where a specific cue (tone) was presented (i.e., no-signal, or go trial). When another cue was heard, participants had to refrain from responding (i.e., signal, or no-go trial). The cues, which were randomly assigned to trial types across participants, were presented 100 ms after stimulus onset and lasted 300 ms. The trial duration was fixed to 1000 ms. C. In the APP, participants responded to positive and negative targets by pressing the “G” and “H” keys (counterbalanced) which were preceded by food and non- food primes. The maximum reaction time was 1500 ms and the stimulus-onset asynchrony (SOA) between primes and targets was 250 ms, including the mask duration (17 ms).
Table 1
Preregistered t-test results for hypotheses in Experiment 1.
| 95% CI FOR DAV | ||||||
|---|---|---|---|---|---|---|
| Preregistered t-test | BF10 | T(112) | p | DAV | LOWER | UPPER |
| H1a. ΔLikingNOGO < ΔLikingGO | 109.42 | –3.68 | <.001 | –0.38 | –0.59 | –0.17 |
| H1b. ΔLikingNOGO < ΔLikingUNTRAINED | 678.73 | –4.22 | <.001 | –0.39 | –0.58 | –0.20 |
| H2a. ΔRTNOGO < ΔRTGO | 44.30 | –3.39 | <.001 | –0.37 | –0.58 | –0.15 |
| H2b. ΔRTNOGO < ΔRTUNTRAINED | 30.06 | –3.26 | 0.001 | –0.32 | –0.51 | –0.12 |
| H3. RTCON < RTINC (non-food primes) | 158.99 | –3.80 | <.001 | –0.16 | –0.25 | –0.07 |
[i] ΔLiking: Difference in mean liking ratings from pre-to post-training (post – pre); ΔRT: Difference in median RTs from congruent and incongruent trials (i.e., reaction time priming effect; incongruent – congruent).
Figure 2
Plots of liking ratings and priming effects in Experiment 1. A. The distributions of mean liking ratings indicate that on average all foods were rated less positively after training relative to baseline, but this negative change in explicit evaluations (ΔLiking) was reliably larger for no-go foods compared to both go (H1a) and untrained foods (H1b). B. The distributions of individual median reaction times (RTs) from congruent and incongruent trials of the affective priming paradigm (APP) show that positive priming effects were observed for both go and untrained foods. As expected, the priming effect (ΔRT) was lower for no-go foods compared to both go (H2a) and untrained food primes (H2b). Upon closer inspection, the average no-go priming effect was close to zero, even though these foods were rated high on liking before training. Note. The ‘split-half violin’ elements in the raincloud plot show smoothed distributions and boxplot vertical lines represent the range, excluding outliers based on the Interquartile Range. Square boxes depict the sample means and the dashed lines show the differences across training conditions.
Table 2
Preregistered t-test results for hypotheses in Experiment 2.
| 95% CI FOR DAV | ||||||
|---|---|---|---|---|---|---|
| Preregistered t-test | BF10 | T(189) | P | DAV | LOWER | UPPER |
| H1a. ΔLikingNOGO < ΔLikingGO | 18809.23 | –4.70 | <.001 | –0.30 | –0.43 | –0.17 |
| H1b. ΔLikingNOGO < ΔLikingUNTRAINED | 3.35 | –2.37 | 0.010 | –0.13 | –0.24 | –0.02 |
| H2a. ΔRTNOGO < ΔRTGO | 70522.41 | –5.00 | <.001 | –0.39 | –0.55 | –0.23 |
| H2b. ΔRTNOGO < ΔRTUNTRAINED | 0.59 | –1.73 | 0.043 | –0.14 | –0.3 | 0.02 |
| H3. RTCON < RTINC (non-food primes) | 96875.68 | –5.08 | <.001 | –0.16 | –0.23 | –0.1 |
| H4a. RTCON-GO < RTINC-GO | 60993.53 | –4.97 | <.001 | –0.18 | –0.25 | –0.11 |
| H4b. RTCON-UNTRAINED < RTINC-UNTRAINED | 0.53 | –1.69 | 0.047 | –0.06 | –0.13 | 0.01 |
| H4c. RTCON-NOGO < RTINC-NOGO | 0.02 | 0.29 | 0.615 | 0.01 | –0.06 | 0.08 |
[i] ΔLiking: Difference in mean liking ratings from pre-to post-training (post – pre); ΔRT: Difference in median RTs from congruent and incongruent trials (i.e., reaction time priming effect; incongruent – congruent).
Figure 3
Plots of liking ratings and priming effects in Experiment 2. A. The plots show that compared to go foods, the change in liking for no-go (ΔLiking) foods was greater (H1a), but not relative to untrained foods (H1b; see Figure 1A for comparison with Experiment 1). B. As expected, participants’ median reaction times (RTs) from congruent and incongruent trials in the affective priming paradigm indicate that a positive priming effect was observed for go foods (H4a), but not for no-go foods (H4c) which have an overall RT priming effect (ΔRT) close to zero, as shown in the boxplot. However, for untrained foods the priming effects in the sample are not as positive as those observed in Experiment 1 (H4b; see Figure 1B). Note. The ‘split-half violin’ elements in the raincloud plot show smoothed distributions and boxplot vertical lines represent the range, excluding outliers based on the Interquartile Range. Square boxes depict the sample means and the dashed lines show the differences across training conditions.