Conflicting Emotions DOI: 10.1038/Nrn2288 Indicating That This Region Might Represent a General Conflict- Detection Mechanism

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n e u r oi m ag i n g Conflicting emotions DOI: 10.1038/nrn2288 indicating that this region might represent a general conflict- detection mechanism. Interestingly, behavioural adaptation correlated with activation of the right LPFC in non-emotional tasks, but with activation of the rostral ACC (rACC) in emotional tasks, suggesting that separate neural mechanisms mediate adaptation to interference from non- emotional and emotional distracters. A subsequent connectivity analy- sis revealed that during emotional conflict adaptation, activity in the To focus on a task we must ignore higher activity during low-conflict rACC predicted reduced activity in irrelevant stimuli. The more trials, whereas others fired more dur- the amygdala, whereas during non- distracting an interfering stimulus ing high-conflict trials. Interestingly, emotional conflict adaptation, activity is, the more conflict it creates, and individual neurons retained this in the the LPFC predicted activity in the longer we take to react to the activity until the start of the following the fusiform face area (FFA), a region relevant stimulus. But we can adapt trial, indicating that DLPFC cells that is involved in face processing. to conflict: studies have shown that retain a ‘memory’ of the previous These studies indicate that in the effect of a high-conflict distracter conflict. This might be important for monkeys and humans the LPFC on reaction time decreases when it the behavioural adjustment that was resolves conflict from non-emotional is preceded by another high-conflict observed. distracters, but that in humans distracter. Mansouri et al. now show In the study by Egner et al., partici- interference by emotional distracters that the dorsolateral prefrontal pants in an fMRI scanner were shown activates a different network involv- cortex (DLPFC) is involved in this photographs of male and female faces ing the rACC, which then exerts behavioural adjustment in monkeys expressing either fear or happiness. In top-down inhibition of processing of and, in a different study, Egner et al. non-emotional trials the label ‘male’ or irrelevant emotional stimuli by the show that, in humans, this region is ‘female’ was projected over the photo amygdala. As the dACC was found involved in non-emotional conflict as a distracter, and the participants to be involved in monitoring conflict adaptation whereas a different indicated the person’s gender while from both emotional and non- network mediates the resolution of trying to ignore the labels. In emo- emotional stimuli, it is possible that emotional conflict. tional trials, participants identified the activated dACC subsequently Mansouri et al. used non- the expressed emotion while ignoring recruits either the rACC or the LPFC, emotional distracters to demonstrate affect labels (‘happy’ or ‘fear’) that depending on the type of distracter. that, like humans, monkeys show were displayed over the faces. Leonie Welberg conflict adaptation. Furthermore, As in previous studies, in both

monkeys with lesions in the DLPFC emotional and non-emotional tasks, Original Research PaperS Egner, T. et al. did not adapt, whereas lesions in the participants showed conflict adapta- Dissociable neural systems resolve conflict from anterior cingulate gyrus (ACC) had tion in the second of two consecutive emotional versus nonemotional distracters. Cereb. Cortex 16 Oct 2007 (doi:10.1093/cercor/ no effect. incongruent (high-conflict) trials. bhm179) | Mansouri, F. A. et al. Mnemonic The authors then measured activ- The authors then showed that, function of the dorsolateral prefrontal cortex in ity in DLPFC neurons in two intact in both tasks, incongruent trials conflict-induced behavioral adjustment. Science 25 Oct 2007 (doi:10.1126/science.1146384) monkeys. Some neurons showed activated the dorsal ACC (dACC),