The Interaction of Spatial Frequency with Emotional Content in Search Among Faces

Previous research has suggested that emotional faces have a high priority for perception and attention, and that low spatial frequency components of emotional facial expressions may facilitate their processing over neutral faces. Here we asked whether emotional content can also boost perception of non-emotional facial characteristics. Participants indicated whether an oddball-gendered face (one male face among female faces or vice-versa) was present or absent in an array of eight faces. The facial expressions were all uniformly fearful or neutral, and emotion was irrelevant to the task. The faces were either unmodified or high spatial frequency content was removed. We find that removing high spatial frequencies impedes search, and it does so to a significantly greater extent for neutral than for emotional faces. In a second experiment in which eye movement data was also collected the reaction time results were replicated. The interaction of emotion and spatial frequency was not observed in any of the eye movement parameters measured, however. Preservation of information about emotional faces in low spatial frequencies may help with processing biologically-relevant information under conditions of limited visibility and further into peripheral vision