Training with own-race faces can improve processing of other-race faces: evidence from developmental prosopagnosia

Abstract

Faces of one's own race are discriminated and recognized more accurately than faces of an other race (other-race effect - ORE). Studies have employed several methods to enhance individuation and recognition of other-race faces and reduce the ORE, including intensive perceptual training with other-race faces and explicitly instructing participants to individuate other-race faces. Unfortunately, intensive perceptual training has shown to be specific to the race trained and the use of explicit individuation strategies, though applicable to all races, can be demanding of attention and difficult to consistently employ. It has not yet been demonstrated that a training procedure can foster the automatic individuation of all other-race faces, not just faces from the race trained. Anecdotal evidence from a training procedure used with developmental prosopagnosics (DPs) in our lab, individuals with lifelong face recognition impairments, suggests that this may be possible. To further test this idea, we had five Caucasian DPs perform ten days of configural face training (i.e. attending to small spacing differences between facial features) with own-race (Caucasian) faces to see if training would generalize to improvements with other-race (Korean) faces. To assess training effects and localize potential effects to parts-based or holistic processing, we used the part-whole task using Caucasian and Korean faces (Tanaka, J. W., Kiefer, M., & Bukach, C. M. (2004). A holistic account of the own-race effect in face recognition: evidence from a cross-cultural study. Cognition, 93(1), B1-9). Results demonstrated that after training, DPs showed a disproportionate improvement in holistic processing of other-race faces compared to own-race faces, reducing their ORE. This suggests that configural training with own-race faces boosted DPs' general configural/holistic attentional resources, which they were able to apply to other-race faces. This provides a novel method to reduce the ORE and supports more of an attentional/social-cognitive model of the ORE rather than a strictly expertise model.

Figure 1.

Part-Whole Task. A target face appeared in the middle of the screen for 1000 ms followed by a scrambled face mask for 500 ms. Next, either the whole target face was presented next to a distractor face, or an isolated feature from the target face was presented next to a distractor feature. For whole trials, participants indicated which whole face in the test phase matched the target face (correct face shown in green), while in part trials, participants indicated which isolated feature matched that of the original target face (correct part shown in green).

Figure 2.

(A) Examples of faces used in the training procedure based on one template face. Faces varied in their eyebrow height and mouth height to produce a matrix of 10 faces. Faces surrounded by black frames required a left button press (L) and face surrounded by grey frames required a right button press (R). (B) Template faces used for the different training days.

Figure 3.

Pre- vs Post-Training Accuracy Results for Whole (A) and Part (B) Trials for DPs compared to Healthy Controls without training (Caucasian male and Korean female blocks). Error bars indicate the standard error of the mean and the dashed line indicates chance performance.

Figure 4.

Whole vs. Part Advantage for DPs and Healthy Controls during Caucasian male and Korean female blocks. Postive values indicate greater accuracy on whole than part trials whereas negative values indicate greater accuracy on part than whole trials. Error bars indicate the standard error of the mean.