Picture database of morphed faces (MoFa) : technical report

In the present study, a morphing and picture processing procedure was used to create a database of 100 face-pairs, which were morphed into one another in steps of 5%. Furthermore, 240 face stimuli were also included that were not morphed but may be used for control purposes. The face stimuli chosen for this database were with minimal or neutral emotional facial expression. In two experiments, selected items of the face stimuli were rated by participants in order to reveal (a) the minimal degree to which a face can be morphed such that a physical change but no identity change is apparent and (b) the degree to which a face needs to be morphed such that the morphed face is perceived as representing a different person than the initial face. The results show that 35% morphed faces mainly seem to fulfill condition (a) while 70% morphed faces mainly fulfill condition (b), especially when outlying morph-pairs are excluded. In conclusion, the present database provides morphed stimulus material that was rated by a moderately large number of participants and may be used for broad experimental purposes.