Multisensory investigation on acquiring expertise in face recognition

Introduction

Faces are often considered to be different from other object categories both because of the sociobiological necessity for humans to differentiate members of their own group, and because of the differences in cognitive demands for face perception relative to general object recognition. A tremendous amount of research has shown that human observers are experts at visual face recognition due to specialized visual mechanisms for face processing that evolve with perceptual expertise. In this work, we introduce haptic and gaze-restricted, visual face processing as tools for studying the mechanisms underlying face processing expertise.

Goals

The goals of this research are threefold: to test cross-modal transfer of face recognition in vision and haptics; to investigate serial encoding of face information in vision and haptics, and to examine effects of expertise in serial encoding.

Methods

A dataset of faces from the MPI face database was used to produce 3D printout, which could be explored visually or haptically [1,2]. We used a novel gaze-restricted display for promoting serial encoding in vision, in which participants could explore the face through a mouse-controlled small aperture of 2 degrees of visual angle. Face recognition was tested with a standard old-new paradigm. A group of participants was trained for several days using gaze-restricted exploration to investigate changes in processing strategies over time.

Results

We showed that the haptic modality has the capacity to learn and recognize faces, and that face-relevant information can be shared across sensory modalities [1]. Using gaze-restricted visual exploration, we also found that face recognition was disrupted to levels of haptic recognition, with a clear switch from configural to featural processing. Finally, results from training experiments on gaze-restricted exploration demonstrated that practice with serial encoding can lead to some of the recognition effects typically associated with unrestricted visual face recognition, such as face inversion effects [2].

Conclusion

Overall our work highlights how modality-specific differences in information acquisition affect processing strategies in face recognition, and under which conditions those differences can be compensated for by perceptual expertise. The results show that face recognition strategies can be acquired easily in untrained modalities and through novel means of exploration.

References

1.      Dopjans L, Wallraven C and Bülthoff HH (2009) Cross-Modal Transfer in Visual and Haptic Face Recognition, IEEE Transactions on Haptics (4) 236-240.

2.      Dopjans L, Bülthoff HH, Wallraven C (2011) Serial exploration of faces: Comparing vision and touch, Under revision.