http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:10903 Facial expressions of emotion display a wealth of important social information that we use to guide our social judgements. The aim of the current study was to investigate whether patients with orbitofrontal cortex (OFC) lesions exhibit an impaired ability to judge the approachability of emotional faces. Furthermore, we also intended to establish whether impaired approachability judgements provided to emotional faces emerged in the presence of preserved explicit facial expression recognition. Using non-parametric statistics, we found that patients with OFC lesions had a particular difficulty using negative facial expressions to guide approachability judgements, compared to healthy controls and patients with frontal lesions sparing the OFC. Importantly, this deficit arose in the absence of an explicit facial expression recognition deficit. In our sample of healthy controls, we also demonstrated that the capacity to recognise facial expressions was not significantly correlated with approachability judgements given to emotional faces. These results demonstrate that the integrity of the OFC is critical for the appropriate assessment of approachability from negatively valenced faces and this ability is functionally dissociable from the capacity to explicitly recognise facial expressions. 2012-06-14T02:56:47.520Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:10902 The aim of this study was to determine if, and when, the neural processes involved in switching associations formed with angry and happy faces start to diverge. We measured event-related potentials (ERPs) and behavioural responses while participants performed a reversal learning task with angry and happy faces. In the task, participants were simultaneously presented with two neutral faces and learned to associate one of the faces with an emotional expression (either angry or happy), which was displayed by the face when correctly selected. After three to seven trials, the face that had consistently been displaying an emotional expression when selected would instead remain neutral, signalling the participant to switch their response and select the other face on the subsequent trial. The neural processes involved in switching associations formed with angry and happy faces diverged 375 ms after stimulus onset. Specifically, P3a amplitude was reduced and P3b latency was delayed when participants were cued to switch associations formed with angry expressions compared to happy expressions. This difference was also evident in later behavioural responses, which showed that it was more difficult to switch associations made with angry expressions than happy expressions. These findings may reflect an adaptive mechanism that facilitates the maintenance of our memory of threatening individuals by associating them with their potential threat. 2012-06-13T04:15:57.454Z ]]>