Psychopharmacology (2012) 219:981–990 987 Fig. 5 Brain activity during feedback. a Brain activity during feedback averaged across ROIs; b reward feedback in separate ROIs. Error bars denote standard error of the mean (SEM). L=left, R=right; Inf=inferior; Sup=superior; Post =posterior; Cx=cortex; a.u.=arbi- trary units. Single asterisk significant drug effect (p<0.05); double asterisk significant drug by condition interaction effect (p <0.05). p values are not corrected for multiple comparisons parietal and temporal cortex. The inferior parietal cortex is a pivotal part of the attention network (Naghavi and Nyberg 2005; Pessoa et al. 2002). More specifically, the inferior parietal cortex is associated with a salience representation of the outside world (Gottlieb 2007), indicating that attention is directed towards salient- or task-relevant objects. Previous studies have shown that eCB affects inferior parietal cortex function, as decreased activity has been reported after THC administration in association with auditory attention (Roser et al. 2008) and during emotional processing (Fusar-Poli et al. 2009). Hence, our result suggests a general effect of THC on attentional processes during salient feedback. Subjects reacted faster on the task when a reward could be won, during both THC and placebo, an effect that has been reported previously (Knutson et al. 2001b; Bjork and Hommer 2007). This indicates that subjects were motivated to perform the task during both placebo and THC. However, Table 3 Regions of interest during reward anticipation Area Max T Cluster size MNI coordinates Max T maximum T value, R right, L left 1 2 3 4 5 6 7 8 9 10 11 12 13 14 L cerebellum R cerebellum Brain stem R inferior orbitofrontal cortex L insula L caudate R caudate L pre/postcentral gyrus SMA/anterior cingulate Posterior cingulate L superior parietal cortex R precentral gyrus R middle frontal cortex R superior parietal cortex 4.6 4.2 4.5 8.7 6.5 4.2 6.0 4.4 5.8 4.8 5.5 7.1 7.9 4.9 42 31 68 27 49 30 70 209 326 36 65 123 37 71 x −32 44 0 28 −44 −8 12 −48 0 −12 −40 48 40 12 y −52 −48 −20 24 12 4 8 −24 −4 −72 −60 0 44 −72 z −32 −24 −12 −24 8 4 0 56 60 44 60 40 32 44