Emotion-modulated misidentification to person

Abstract

   We report a case of herpes encephalitis with right dominant temporal damage and bilateral ventromedial prefrontal damage, who after the acute phase developed a unique misidentification to person. Persons with strong emotional valence were misidentified as significant others, as in the case of his wife taken as his mother. On the other hand, persons with little emotional valence, as in hospital staff, were reduplicated, for example stating that he was seeing another doctor quite identical but perhaps a bit older than the one attending him presently. In recent face recognition models, it has been shown that two separate routes— the classical route for overt recognition, and a secondary route for covert recognition— are needed to explain manifestations such as prosopagnosia with intact SCR face discrimination, and Capgras delusion with impaired SCR face discrimination. To apply this model to the misidentification symptoms of this case, we have tailored a misidentification triggering test using photographs of his wife and hospital staff. The results showed that for photographs of his wife, multiple misidentifications as significant others were seen under conditions where the covert route is the dominant input, but only minimal reduplication when the overt route was the dominant input. For photographs of hospital staff, both reduplication and misidentification as significant others were minimally seen under both conditions. We propose this symptom as impaired integration of the two routes ; when encountered by a familiar person, the autonomic route for covert recognition becomes the dominant input route, whereby he can recognize the emotional valence of the person but cannot integrate it with the configurational processes of the overt route, resulting in misidentification as significant others, while upon encountering a person without strong emotional valence, the overt recognition becomes dominant, assuring intact configurational identification, but failing to integrate it with emotional recognition results in reduplication.