Figure 1.

Experimental design and face stimuli. A. Participants were first trained in identifying the voices and faces of three male speakers (Training) and participated in a psychophysical pilot experiment (Pilot) (see Methods). Then, participants performed a cross‐modal priming experiment and a face‐area localizer during fMRI. In the cross‐modal priming experiment, voices of three speakers (indicated by amplitude waveforms) were followed by images of their faces after a 75 ms delay. The voices and faces could match (light gray font) or mismatch (dark gray font). Because the faces were morphed continua between two face identities (see panel B), voice and face could match or mismatch with regard to identity or physical properties. Participants performed a face‐identity recognition task on every trial (face task); on some trials they additionally performed a voice‐identity recognition task (“voice task”; excluded from fMRI analysis; see Methods). This was indicated by a colored fixation cross that followed the voice presentation. The faces were morphed between the three speakers (see Methods, panel B). B. Morphed face stimuli of the three speakers: Each combination of two possible face‐identity pairs was morphed, resulting in three morphed continua (Bernd–Anton, Anton–Carsten, and Carsten–Bernd). In the cross‐modal priming experiment, the morph levels 0, 33, 67, and 100% were used. These levels parametrically differed in physical properties (light blue), but perception of identity differed in a categorical manner (dark blue, morph levels 0 and 30% were perceived as matching in identity to the voice and morph levels 67 and 100% were perceived as the other person, mismatching in identity) (see Methods).