Assessment of Social Cognition and Theory of Mind: Initial Validation of the Geneva Social Cognition Scale.

BACKGROUND: Social cognition is widely studied in neurology. At present, such evaluations are designed for research or for specific diseases and simple general clinical tools are lacking. We propose a clinical evaluation tool for social cognition, the Geneva Social Cognition Scale (GeSoCS). METHODS: The GeSoCS is a 100-point scale composed of 6 subtests (theory of mind stories, recognition of social emotions, false beliefs, inferences, absurdity judgement and planning abilities) chosen from different validated tests of social and cognitive evaluation. Eighty-four patients with neurological disorders and 52 controls participated in the study. Evaluation duration lasted 20-60 min. RESULTS: Mean scores were 92.6 ± 4.5 for controls and 76.5 ± 15.3 for patients and differentiate patients and controls in all subtests. With a cut-off score of 84, the scale had a sensitivity of 62% and a specificity of 94%. In our stroke subgroup, right CVAs failed in cartoons, inferences, 'mind in the eyes', and in the temporal rule task while left CVAs were impaired in verbal/discourse tasks (social cognition, inferences, absurd stories, and cartoons. CONCLUSIONS: The GeSoCS is a medium duration assessment tool that appears to detect and characterize significant social impairment in neurological patients.

Direction of Biological Motion Affects Early Brain Activation: A Link with Social Cognition.

A number of EEG studies have investigated the time course of brain activation for biological movement over this last decade, however the temporal dynamics of processing are still debated. Moreover, the role of direction of movement has not received much attention even though it is an essential component allowing us to determine the intentions of the moving agent, and thus permitting the anticipation of potential social interactions. In this study, we examined event-related responses (ERPs) in 15 healthy human participants to light point walkers and their scrambled counterparts, whose movements occurred either in the radial or in the lateral plane. Compared to scrambled motion (SM), biological motion (BM) showed an enhanced negativity between 210 and 360ms. A source localization algorithm (sLORETA) revealed that this was due to an increase in superior and middle temporal lobe activity. Regarding direction, we found that radial BM produced an enhanced P1 compared to lateral BM, lateral SM and radial SM. This heightened P1 was due to an increase in activity in extrastriate regions, as well as in superior temporal, medial parietal and medial prefrontal areas. This network is known to be involved in decoding the underlying intentionality of the movement and in the attribution of mental states. The social meaning signaled by the direction of biological motion therefore appears to trigger an early response in brain activity.

Emotional expressions modulate low α and ß oscillations in a cortically blind patient.

Studies of cortical blindness have suggested that some residual visual function may persist without perceptual awareness, a condition known as blindsight. To investigate electrophysiological evidence of unconscious processing of emotional stimuli, we examined the event-related oscillations (EROs) in a 62year-old male patient (TN) with affective blindsight during random stimulation of three facial expressions (fearful, happy and neutral). Spectral power analysis in response to the different emotions revealed significant differences between fearful and happy faces over the right frontal regions at 7-8Hz (low α), and between emotional and neutral faces over the left frontal sites at 12-13Hz (low ß) in a time period between 100-400ms after visual stimulus onset. These results demonstrate that emotional face processing occurs very early in time in the absence of any functional striate cortex, and further reveals the existence of specific oscillatory frequencies that reflect unconscious processing of facial expressions in affective blindsight.