| |
Abstract:
Evidence has indicated that humans, chimpanzees, and
orangutans are the only species capable of own-face recognition.
Functional neuroimaging has indicated a possible right hemisphere
(RH) bias in the perception of self-faces, and RH lesions and
anesthetization of the right hemisphere can lead to asomatognosia,
or lack of awareness of or ownership or identity of one's own left
arm. Yet, case studies in which loss of self-face identification
occurs (i.e., self-misidentification or 'mirror sign') are
extremely rare, though in reported cases, there is a bias towards
RH lesions. In the first experiment, 7 Ss were presented their own
image or that of a familiar person in an identification/reaction
time (RT) task. During presentation , repetitive Transcranial
Magnetic Stimulation (rTMS) was applied in a virtual lesion manner
via trains to either ventral or dorsal RH or LH prefrontal cortex
(PFC). It was found that there was an increase in RT during RH
ventral rTMS. These data were followed up in 2 Ss in which
extensive mapping was employed (RH only). It was found that rTMS
delivered to more ventral structures, including posterior PFC
resulted in a small increase in RT. These data are discussed within
terms of the rarity of 'mirror sign' following brain trauma.
|
