Figure 5.

Group differences in activation for relative reward anticipation contrast. (A) We grouped our participant population into two categories based on RMI. An index value less than one (more than one) implied a relatively greater motivation for candy (money), so we divided our participant pool using this threshold. Using a whole-brain correction, we found significantly greater activation in the BM > BC contrast for our money group (N = 46) than in our candy group (N = 14). (B) The average parameter estimates for the money and candy groups in the NAcc region found in the whole-brain analysis for the relative BM > BC contrast. (C) We extracted both BC > Zero and BM > Zero contrasts for the NAcc from the group test, for both groups. We found no significant differences in BM between the two groups, but did find significant differences between the two groups in the BC contrast.