Little evidence for fast mapping in adults with developmental amnesia.

Cooper, Greve, and Henson (this issue) conclude that hippocampal-independent learning, as operationalised by 'fast mapping' (FM), is unlikely to facilitate learning in adults. We provide evidence from patients with Developmental Amnesia (DA), who acquire language and semantic knowledge despite early hippocampal pathology. We administered an FM paradigm to three patients with DA and controls. Patients showed no benefit of FM compared to explicit encoding. These data support the conclusion that FM is unlikely to facilitate learning in amnesia, regardless of age at onset. Hippocampal-independent learning may be possible in adults with DA, but such learning requires a prolonged consolidation period.