Evidence for normal novel object recognition abilities in developmental prosopagnosia

The question of the face specificity of recognition deficits in prosopagnosia is fundamental to the organization of high-level visual processing and memory and has been vigorously debated numerous times over the last 20 years. This debate was recently revived in developmental prosopagnosics (DPs) by a meta-analysis reporting that a large percentage of DPs (ranging from 22-80%) have mild to major object recognition deficits (Geskin & Behrmann, 2017). Subsequent studies have also shown significantly lower DP group-level object recognition performance. However, previous investigations measuring object recognition have largely used familiar objects (e.g., cars) where performance may depend on object-specific experience, leaving the question open as to whether DPs would perform similarly when the stimuli are completely unfamiliar objects. To investigate this, in the current study we tested 30 DPs and 30 matched controls on a novel object memory test (NOMT Ziggerins) and the Cambridge Face Memory Test (CFMT). DPs were impaired on the CFMT but performed similarly to controls on the NOMT. We also compared DP NOMT performance to a larger matched sample of 274 web-based controls and found no difference in accuracy or reaction time. Individual analyses demonstrated that only one DP reached major impairment in object recognition on the NOMT, an impairment rate no different from that in either control group. Together, these results demonstrate essentially normal object recognition in DPs for a class of novel objects that serves as a powerful index for broader novel object recognition capacity. These results raise the possibility that DPs do not have object recognition deficits per se, but rather may have a decreased capacity to benefit from their experience with highly familiar object categories.