100 Peers: An open set of controlled emotional facial expressions for use in psychology and neuroscience experiments

Human faces are a ubiquitous stimulus category in experimental psychology and neuroscience, routinely applied in many research domains including perception, emotion, social cognition, and memory. Here, we present a set of portrait photographs of 100 identities with each identity making 9 emotional expressions (anger, calm, contempt, disgust, fear, happiness, sadness, surprise, and neutral), amounting to 900 total photographs. Unlike many existing face databases, these photographs are highly controlled for perceptual features, in that (1) they were taken in a laboratory setting with identical professional lighting, (2) all participants are wearing the exact same neutral clothing (a black t-shirt), (3) all faces have been manually adjusted such that the eyes are approximately at the center of a square without cropping any part of the face from the photograph, and (4) the background has been colored to be exactly the same gray hue in all photographs with no shadows. Given their highly controlled nature, these faces are optimal for experiments aiming to homogenize non-face properties, such as lighting or clothing. We are making the face set open for the benefit of the broader research community, and request that in turn, data collected in response to the faces be made open and linked to the original face database (please cite this technical report). This report presents a high-level summary of the faces using behavioral data (free-response descriptions and emotion categorizations), but these data do not necessarily capture the scope of potential research designs that the stimuli could support. If authors collect relevant pilot data on these stimuli for specific research questions, our hope is that such data can becollaboratively linked to the face set for the community to utilize.