Instructions are not enough: Go/No-Go training requires motor responses to change food evaluations

Across both studies, instructions alone did not change stimulus evaluations. In contrast, subsequent GNG training produced evaluative shifts, with a consistent go valuation effect across studies. The no-go devaluation effect varied by stimulus familiarity, with significant devaluation for familiar foods overall, whereas for novel foods it emerged only among participants with higher trait impulsivity.

Higher trait impulsivity was also associated with stronger devaluation of familiar food items. These findings may reflect the role of stimulus value in devaluation effects. Devaluation is typically stronger for stimuli with higher initial value, which may explain why familiar foods showed more robust devaluation effects than novel foods.

Similarly, individuals higher in impulsivity may assign greater value to appetitive stimuli, potentially facilitating devaluation following GNG training. Overall, these findings indicate that propositional knowledge of stimulus-response contingencies is insufficient to change food evaluations in GNG paradigms. Instead, evaluative change appears to depend on direct experience of these response contingencies during task performance.