Social prioritisation in scene viewing is not automatic: Evidence from the effects of a spatial memory load

When free-viewing scenes, participants tend to preferentially fixate social elements (e.g. people). We investigated whether this bias is automatic by testing whether it would be disrupted by increasing the demands of a secondary dual-task: holding a set of (1 or 6) spatial locations in memory, presented either simultaneously or sequentially. Following a retention interval, participants judged whether a test location was present in the to-be-remembered stimuli. During the retention interval participants free-viewed scenes containing a social element (e.g. a person) and a non-social element (object) that served as regions of interest. In order to assess the impact of physical salience, the non-social element was presented in both an unaltered baseline version, and in a version where its salience was artificially increased. The results showed that the preference to look at social elements decreased when the demands of the spatial memory task were increased from 1 to 6 locations, regardless of presentation mode (simultaneous or sequential). This reduction in the social prioritisation effect was accompanied by an increased tendency to fixate on the centre of the screen. The results place important boundary conditions on the social prioritisation effect and suggest clear limits to its automaticity.