Abstract
Despite developmental prosopagnosia (DP) being a deficit in face recognition memory, researchers have yet to characterize impairments in specific memory mechanisms. DPs have demonstrated deficits in explicitly recognizing faces, but at times have shown preserved implicit recognition such as increased electrodermal activity or the presence of an N250 ERP component when presented with famous faces. We sought to build on these findings and test the integrity of two facets of face recognition memory: recollection (retrieving specific details associated with the face) and familiarity (general feeling you’ve seen the face before). In particular, we had 13 DPs/13 matched controls perform an old-new face recognition memory paradigm where they studied 60 novel faces presented for two-seconds each over two rounds. After the study phase, subjects were immediately presented with 120 faces (60 old/60 new) and asked to indicate on a scale of 1–6 their level of confidence in classifying each face as “old” or “new” (confident old, somewhat sure old, guessing old, guessing new, somewhat sure new, confident new). By employing the dual-process signal detection model from Koen et al. 2014’s receiver operating characteristics toolbox, we were able to determine the contribution of familiarity and recollection to recognition memory performance. In this model, recognition memory is theorized to initially rely on recollection in which qualitative information is retrieved about the studied items, but if recollection fails, recognition memory relies on a “feeling” of familiarity. We found that the recollection parameter was significantly smaller in DPs (0.14+/−0.11) than controls (0.45+/−0.21, p< 0.001) whereas DPs’ familiarity parameter (0.62+/−0.34) was similar to controls (0.54+/−0.61, p=0.678). These results show that at least some aspects of face recognition familiarity are intact in DPs and we are currently performing a follow-up experiment to determine if the source of this familiarity signal is similar to controls.
Acknowledgement: National Eye Institute