Dual-task interference patterns reveal differential processing of upright and inverted faces

The concurrent-task method was used to investigate the hemispheric locus of face encoding. In each of three experiments, 48 right-handed adults performed unimanual finger tapping while encoding whole or partial faces for subsequent recognition. Faces were upright in Experiments 1 and 2 but inverted in Experiment 3. Irrespective of stimulus orientation, face encoding disrupted left- and right-hand tapping equally. Upright faces were less accurately recognized if learned during left-hand tapping than during right-hand tapping; inverted faces showed no lateralized interference. The results support tachistoscopic findings that indicate predominantly right-hemispheric processing of upright faces and bilateral processing of inverted faces.