Parametric analysis.
The parametric design analysis, with all the magnitudes of possible
gains and losses included as parameters for each trial, revealed three
main results: First, when examining the influence of wins, the dorsal
ACC was significantly more activated during mixed-risk trials than in
high- or low-risk trials (Table 3, Figure 6). Second, losses
significantly activated the insular cortex (BA 13) and parts of the
lateral OFC only during mixed-risk trials but not during high- or
low-risk trials (Table 3, Figure 7). Third, for ambiguous trials,
significant activation was found in the amygdala during mixed-risk
trials with high ambiguity but not in response to mixed-risk trials with
low ambiguity for the parameter magnitude of gains (Table 3, Figure 8).
For ambiguous trials we found no significant activation with respect to
the loss parameter.