The left visual hemispace bias for the perception of composite faces: A test of the difficulty-of-discrimination hypothesis

When people are asked to make judgements about mirror-image composite human faces, they usually draw preferentially on cues in their left visual hemis pace (LVH). Not all faces, however, elicit an LVH bias. In two studies of f aces which elicited biases ranging from LVH to RVH, we tested the hypothesi s that the LVH bias is directly related to task difficulty as indexed by th e absolute difference between the left and right sides of the face. The hyp othesis was not supported: that is, degree of facial asymmetry proved to be unrelated to strength or direction of the visual hemispace bias. (C) 1999 Academic Press.