Article Figures & Data
Figures
- Figure 1.
Task and behavioral results. A, Timing of the noninstrumental outcome prediction task. Locations of response options on the response mapping screen were randomized across trials. B, Different cue-outcome pairs were used to control for visual features of cues and outcomes. C, Percentage of correctly predicted outcomes for amisulpride (Ami) and placebo (Pla) group across time (bins of 4 trials each). Because three response options are provided in each trial, chance level is 33%. D, Percentage of correctly predicted no reward (noRew) and reward (Rew) outcomes. Error bars depict 95% CIs.
- Figure 2.
Effects of D2-receptor blockade on reward signals. A, Schematic of the searchlight decoding approach. Activity patterns were extracted for all four cue-outcome pairs from each searchlight. An SVC model was trained to discriminate reward from no reward on set I only or set II only. This yielded predictions that were then tested on the other set (testing on set II after training on set I and vice versa) to obtain decoding accuracy, which was assigned to the center voxel. This procedure was repeated for every searchlight (center voxel) in the entire brain, resulting in a 3D map of decoding accuracy. B, Cluster in the medial OFC with significantly (pFWE-corr< 0.05) higher decoding accuracy in the amisulpride (Ami) than placebo (Pla) group. C, For illustration purposes, bar plots depict averaged decoding accuracy from individual peak searchlights in the OFC cluster for both groups. Error bars depict 95% CI.
- Figure 3.
Amisulpride enhances pattern separation in the OFC. A, Bar plots depict average squared difference between activity patterns related to reward and no reward. Asterisk depicts significant two-sample t test at p < 0.05 (one-tailed). Error bars depict SEM. B, Squared difference between activity patterns related to reward and no reward for a representative subject in the amisulpride group (Ami; left) and in the placebo group (Pla; right). Each pixel represents the squared difference (reward minus no reward) in the activity of one voxel in the medial OFC. The color map represents squared activity difference and is min − max scaled across both displayed patterns. The two subjects were selected such that their average squared pattern difference is close to the mean of their respective group (amisulpride subject = 0.55 [amisulpride group average = 0.57], placebo subject = 0.43 [placebo group average = 0.42]).
- Figure 4.
Effects of D2-receptor blockade on reward signals in anatomical ROIs. A, Anatomically defined ROIs in the orbitofrontal cortex derived from the automated anatomical labeling (AAL) atlas. B, Difference in decoding accuracy for reward between groups [amisulpride (Ami) − placebo (Pla)]. Asterisk depicts significant two-sample t tests at p < 0.05 (one-tailed). Error bars depict 95% CI. Medial OFC, mOFC; central OFC, cOFC; lateral OFC, lOFC.
- Figure 5.
Effects of D2-receptor blockade on motor signals. Coronal (A), sagittal (B), and transversal (C) slices depicting a cluster in motor cortex with significantly higher decoding accuracy for motor response (finger of right hand was used for behavioral response) in the amisulpride (Ami) compared with the placebo (Pla) group. D, For illustration purposes, bar plots depict averaged decoding accuracy from individual peak searchlights in the cluster for both groups. Error bars depict 95% CI.
Tables
- Table 1.
Brain regions with higher decoding accuracy for reward in the amisulpride > placebo group
Region MNI coordinate T k voxel x y z Medial OFC −3 35 −23 6,07 186 Left dorsolateral PFC −27 14 55 4,04 115 Dorsomedial PFC −6 41 49 3,76 60 Left ventrolateral PFC −30 50 1 3,74 27 Right inferior TC 54 −43 −8 3,98 40 Left inferior TC −33 −43 −23 3,95 42 Results thresholded at p < 0.001, uncorrected (k > 15). TC, temporal cortex.
