Stimulus effects on mood as rated on the 7-point VAS were measured in a similar linear mixed-effects model. Positive mood (“happy, energetic, full of pep, cheerful, vigorous”) was rated as 4.1 (SD=1.1) across all subjects, stimuli and conditions, with no significant main effects of Condition or interactions. There was a significant Genotype main effect (F= 3.553,34, p< 0.05) such that AA subjects rated their mood as slightly more positive (4.6, SD= 0.9) than AG subjects (3.9, SD= 1.1). A significant Stimulus effect (p< 0.05) reflected very small mean increments (0.1 to 0.2; p's < 0.05) in positive mood following AO/related image exposure as compared to the remaining conditions, but which did not differ by genotype. Negative mood (“angry, grouchy, annoyed, bad-tempered”) was rated quite low overall (1.3, SD= 0.6), with the only significant model effect being a Stimulus main effect (F= 3.023,29, p< 0.05), which showed a similarly small mean decrement (−0.1 to −0.2; p< 0.05) in negative mood after AO and related image exposure as compared to baseline and ApCO/related images.
