The order of presentation of
the two series of photographs was counterbalanced across
subjects. Half of the subjects began to look at the first series
while the other half began to look at the second series of
photographs. For each food and emotional expression, the man’s
and the woman’s face was randomly chosen from among the three
eaters. Within each series, photographs were presented in random
order. For each photograph, the participants assessed the intensity
of their eating desire on a vertical and non-structured scale (from
the bottom, ‘‘I have no desire to eat’’, to the top, ‘‘I have a great
desire to eat’’). When the foods were presented alone, the eating
desire score corresponded to the food liking score, leading us to
assume that the more we desire to eat the food, the more we like it.
Scores varied between 0 and 10. Both the photographs and the
eating desire scale were presented on the same screen. After
participants scored their evaluation, they pressed a button to bring
up the next photograph.