Abstract
Despite our extensive experience with faces, we are surprisingly inefficient at face identification. Previous research in our lab and others has suggested that we use only a small proportion of the available information in face identification tasks, and that this information is centered about the eyes and eyebrows. Interestingly, the eye and brow regions are the most informative for face identification in our stimuli. Here we consider the possibility that observers are simply unable to process information across the entire face, and focus on localized regions as the best way to cope with this limitation. Observers discriminated between two faces in each of two different conditions. In one condition, all of the pixels were presented in localized regions around the eyes and brows (“high information value”). In the other, the pixels were distributed broadly about the face but did not include the same eye/brow regions (“low information value”). A staircase varied the total amount of information available in each condition by varying the number of pixels presented. For example, 10% of the stimulus information is packed into a relatively small number of pixels around the eyes/brows in the “high information value” condition, whereas 10% of the stimulus information in the “low information value” condition is spread about a much larger number of pixels. Observers required a significantly higher percent of information in the “low” condition than in the “high”, suggesting that the total amount of stimulus information is not as important as the spatial distribution of that information. Observers are much more efficient at discriminating faces based on the most informative regions, even when that information is contained in relatively few pixels. We are currently examining the effects of learning and stimulus context to determine the extent of flexibility in observers' face processing strategies.