Eye movements, gaze- contingency and face perception
Get a pdf file summarizing this research program (updated July 2015)
We have used eye movement recordings essentially in the context of gaze-contingency, a technique developed in reading research and that we introduced in face perception research (Van Belle et al., Journal of Vision August 2009, Vol.9, 541. doi:10.1167/9.8.541) thanks to the work of Goedele Van Belle, in collaboration with Peter de Graef and Karl Verfaillie. Subsequently, we performed these studies in collaboration with Philippe Lefèvre at the University of Louvain.
Related Papers and brief summary
- In this study, we show that eye gaze fixations remain in the top half of the face during the composite face task, whether performance is affected (aligned) or unaffected (misaligned) by the bottom half.
Orban de Xivry, J.-J., Ramon, M., Lefèvre, P., Rossion, B. (2008). Reduced fixation on the upper area of personally familiar faces following acquired prosopagnosia. Journal of Neuropsychology, 2, 245-268. [PDF]
- First eye movement recordings of the patient PS (prosopagnosia), who was involved in a familiar face recognition task (children of the kindergarten where she works). The results show that she focuses most of the time on the mouth (60%). More strikingly, she fixates exactly on each facial feature (mouth, left eye, right eye) while a normal observer who is familiar with the faces fixates in between features, in the centre of the face below the eyes during face identification (“center of mass” of the individual face).
Van Belle, G., de Graef, P., Verfaillie, K., Busigny, T., Rossion, B. (2010). Whole not hole: expert face recognition requires holistic perception. Neuropsychologia, 48, 2609-2620. [PDF]
- To our knowledge, the first study to use gaze-contingency in face perception research, performed here in normal observers and prosopagnosic patient PS. The results show a striking dissociation between a condition in which only one fixated feature is revealed at a time (window: relatively less impairment for the prosopagnosic patient than normal observers and a condition is which the fixated feature is masked (mask: much larger impairment for the prosopagnosic patient). This is probably one of our most interesting piece of work, showing a striking double dissociation between the patient and the controls, in a very simple paradigm.
Van Belle, G.*, Ramon, M.*, Lefèvre, P., Rossion, B. (2010). Fixation patterns during recognition of personally familiar and unfamiliar faces. Frontiers in Cognitive Science. (* equal contribution). Frontiers in Psychology, doi: 10.3389/fpsyg.2010.00020 [PDF]
- Here we looked at fixation patterns on personally familiar faces and found that their individual features are processed more (i.e., they receive more fixations overall) than those of unfamiliar faces. Interestingly, differences (albeit can arise relatively early, i.e. from the first meaningful fixation on.
Van Belle, G., de Graef, P., Verfaillie, K., Rossion, B., Lefèvre, P. (2010). Face inversion impairs holistic perception: Evidence from gaze-contingent stimulation. Journal of Vision. May 1;10. pii: 10.5.10. doi: 10.1167/10.5.10. [PDF]
- When restricting perception to one fixated feature at a time by a gaze-contingent window, performance in an individual face matching task was almost unaffected by inversion. However, when a mask covered the fixated feature, the decrement of performance with inversion was even larger than in a normal—full view—condition. This effect was independent of the distance (size) of the stimulus. This study provides evidence that the face inversion effect is caused by an inability to perceive the individual face as a whole rather than as a collection of specific features and thus support the view that observers' expertise at upright face recognition is due to the ability to perceive an individual face holistically.
Van Belle, G., Busigny, T., Lefèvre, P., Joubert, S., Felician, O., Gentile, F., Rossion, B. (2011). Impairment of holistic face perception following right occipito-temporal damage in prosopagnosia: converging evidence from gaze-contingency. Neuropsychologia, 49, 3145-3150. [PDF]
- In this paper, we show that the pure case of prosopagnosia GG, who has unilateral right hemispheric damage (lingual, parahippocampal and medial part of the fusiform gyrus) also presents with a relatively larger impairment in recognizing faces when preventing him from seeing the central feature of the face (contingent mask) than when restricting his perception to one feature at a time (contingent-window). This is the same pattern of performance as patient PS (Van Belle et al., 2010, paper above), despite almost no overlap between their brain damage.
Busigny, T., Van Belle, G., Jemel, B., Hosein, A., Joubert, S., Rossion, B. (2014). Face-specific impairment in holistic perception following focal lesion of the right anterior temporal lobe. Neuropsychologia, 56, 312-333. [PDF]
- There is only one gaze-contingent experiment in this extensive case report of prosopagnosia (LR, a patient with right anterior temporal lobe damage). The experiment shows also a profile of response similar in the patient LR as for GG and PS: a relatively larger impairment for matching faces with a gaze-contingent mask than a window, contrary to normal observers.
Van Belle, G., Lefevre, P., & Rossion, B. (2015). Face inversion and acquired prosopagnosia reduce the size of the perceptual field of view. Cognition, 136, 403-408. [PDF]
- A study in which participants had to choose which of two faces matched a target face placed on top; this target face corresponding to the face on one side for the participant’s fixated part, and to the other face for the rest of the target face. There was no good or bad answer, simply a preference of similarity based on one part or the whole face. With the same parameters, participants preferred relatively more the face based on a single fixated part when all stimuli were inverted. A very elegant demonstration that our perception of upright and inverted faces differ qualitatively. We also tested the prosopagnosic patient PS in that experiment with upright faces … and she always selected the face corresponding to the fixated (central) part, ignoring the whole face.