Abstract
Background: Judgments involving face perception have been reported to show some inherent biases, notably the self-face advantage and a preference for the halve of the face seen in the left hemifield. How these interact and whether these biases show the inversion effects that are the signature of face processing expertise is not known. Goal: We used whole and chimeric split-gender faces to study field bias, own-gender bias, and self-face bias to determine the relative magnitude of these effects in stimuli where these may interact. Methods: Twenty participants underwent a gender decision task with female/male chimeric faces, some of which used unknown faces of the same gender and some of which used the self-face, in both upright and inverted presentation. We measured participants' response bias in accuracy in the different conditions. Results: our control non-chimeric stimuli confirmed both a self-face advantage and an inversion effect for gender decisions. Gender decisions about non-self faces did not differ in accuracy. With our experimental chimeric stimuli, we found a robust left field bias for upright faces, which did not vary with whether self or non-self faces were used as the own gender face-half. Inverted faces did not show a significant field bias. The self-face advantage was equally strong in right and left face halves. There was an equally robust self-face bias for upright but not inverted faces. However the own-gender bias did not reach significance. Conclusion: Gender decisions by human observers show equally strong left-field and self-face biases, but not own-gender biases, and these appear to be independent effects. Like many other perceptual decisions about faces, these effects are specific to upright faces.
Meeting abstract presented at VSS 2018