Facial expressions yielding Context-Dependent Effect: The additive contribution of eye movements.

This study tested Context-Dependent Effect (CDE) on face recognition by viewing facial expressions as context and face identity as the target. Three groups were defined - Neutral, Happy and Angry, reflecting the facial expressions of the faces presented at the study phase. At the study phase, participants were presented with 42 color photos of faces for 5 s each. At the test phase, participants were presented with 84 pictures of faces, half of which had been viewed beforehand (old). One-third of the old and new faces displayed the same facial expression shown at study, and the remaining two-thirds had one of the other two expressions. Behavioral results show that consistency of facial expressions between study and test facilitated face recognition (i.e., CDE). Eye-tracking results showed that lengthier focus on a face at the study phase gives the participant an advantage only when the same face is presented again at the test phase. Angry expressions intensify binding more than happy or neutral expressions, resulting in higher costs when changing facial expression between study and test. The theoretical implications of these results in terms of the relationship between facial identity and facial expression are discussed. The practical implications, particularly for eyewitness memory literature, are also discussed.