Biographical knowledge: modality-specific or modality-neutral?

A number of patients have been reported who produce more semantic information in response to faces than to names, and vice versa (e.g., Eslinger et al., 1996). It has sometimes been claimed that these patterns are consistent with the hypothesis that faces and names gain access to separate, modality-specific, biographic knowledge systems. Resolving this debate has proved somewhat difficult, however, given limitations of existing data. Not only are there relatively few patients showing these particular patterns of differentiation, but also testing has often not been sufficiently thorough to rule out alternative accounts. In this paper, we present results of two studies investigating biographical knowledge differences in neurological patients and healthy adult controls. The first study focused on two patients who appeared to access more information about famous people in response to their names than to their faces. On superficial analysis, this pattern could be seen to support the notion of modality-specific biographical knowledge systems. However, closer examination revealed that, for both cases, the findings could be explained by a difficulty in face recognition, rather than by assuming separate semantic representations for faces and names. The second study investigated the role of face and name cues in accessing biographical information in younger and older healthy adults. We found that accuracy in retrieval of biographical information was significantly better with name cues for both groups. Results from these studies not only highlight the processes that must be examined in order to demonstrate modality-specific differences conclusively, but also reveal a fundamental bias in retrieval of biographical knowledge that has not been addressed in research of this nature.