Line drawings of faces reduce configural processing.

The highly specialised skill of face recognition found in humans is thought to be dependent on the processing of a combination of edge-based and surface-based information, and of single-feature as well as of configural information. An investigation was carried out into how the saliency of facial information differs between faces presented as line drawings and the same faces presented as photographs. In experiment 1, the participants showed a decreased sensitivity in their detection of changed configural properties if the faces were presented as line drawings. In experiment 2 an investigation was carried out into whether distinctiveness due to configural properties loses its impact on recognition when faces are transformed to line drawings. For each of twenty unfamiliar male faces, a more 'distinctive' version was created by moving the eye region down. The increase of distinctiveness was confirmed in a rating phase. In a later recognition test, with the same stimuli presented either as line drawings or as photographs, the more distinctive stimuli produced higher recognition rates when presented as photographs but the advantage disappeared when the same faces were presented as line drawings. The changes in sensitivity to configural properties thus contribute to the poor recognition of faces presented as line representations.