Figure 2.

The stress insensitivity to outcome devaluation is reversible and associated with variations of the activation of the corticostriatal networks. (a) Response rate for the high probability option of the devalued reward before (last block of the first scanning session) and after (first block of the second scanning session) devaluation. Controls significantly reduced their preference (control: t₁₁=3.767, P=0.003), whereas stressed subjects were insensitive to the decrease in the value of the outcome (stress: t₁₁=1.464, P=0.171), but regained a goal-directed behavior after a stress-free period (stress recovered: t₁₁=3.336, P=0.007). Group comparisons showed that the stress group significantly differs in the number of devalued choices from both controls (t₂₂=−2.143, P=0.043) and stress-recovered subjects (t₁₁=2.918, P=0.014). (b) Pattern of activation during devaluation phase of the task. Controls display a higher activation in the right caudate nuclei (x=8, y=6, z=12; Z score=3.45; P<0.05 corrected for small volume for FWE) than stressed subjects (b1), whereas stressed subjects display a greater activation of the left putamen (x=−26, y=0, z=16; Z score=3.35; P<0.05 corrected for small volume for FWE) than controls (b2); after a period of recovery from stress, a higher activation of the right caudate (x=20, y=−4, z=22; Z=3.39; P<0.005, uncorrected) is observed when compared with activation immediately after stress (b3). ^*P<0.05; line: within group comparisons; dashed line: between groups comparisons.