Figure 1
From: Apparent Effects of Opioid Use on Neural Responses to Reward in Chronic Pain
Behavioral Ratings. After the MID task fMRI experiment, study participants provided ratings of retrospective arousal and valence (7-point scale) to each of the 6 cues that had been presented during the MID task (e.g., +/− $0, $1, $5). Positive arousal and negative arousal ratings were calculated from ratings of arousal and valence. Two-way ANOVA was used for analysis of all behavioral values (effect of cue, effect of group, and cue by group interaction). (a) Arousal ratings showed a main effect of group [F(2,215) = 4.5; p = 0.017], main effect of cue [F(5,215) = 32.3; p < 0.001], and no group by cue interaction [F(10,215) = 0.3; p = 0.971]. (b) Valence ratings showed no effect of group [F(2,215) = 0.2; p = 0.840], a main effect of cue [F(5,215) = 61.3; p < 0.001], and no group by cue interaction [F(10,215) = 1.7; p = 0.088]. (c) Positive arousal showed a main effect of group [F(2,210) = 4.5; p = 0.017], main effect of cue [F(5,210) = 60; p < 0.001], and no group by cue interaction [F(10,210) = 1.3; p = 0.232]. (d) Negative arousal showed no effect of group [F(2,210) = 0.3; p = 0.739], a main effect of cue [F(5,210) = 20.8; p < 0.001], and no group by cue interaction [F(10,210) = 0.5; p = 0.918]. Asterisks indicate significant group differences for individual cues (*p < 0.05; **p < 0.01). One control and two fibromyalgia participants did not complete arousal and valence ratings after the scan.
