Absence of size congruency effects in amnesic patients' recognition: a failure of perceptually based recollection.

This study examined the status of recollection in amnesia when recollection is supported by perceptual rather than conceptual processes. Two experiments investigated the size congruency effect-the advantage in recognition of patterns presented in the same size, rather than in different sizes-at study and test. In Experiment 1, the authors used a remember-know paradigm in nonamnesic individuals and demonstrated that the size congruency effect was due to enhanced recollection. In Experiment 2, the authors examined whether amnesic patients would show a size congruency effect when their overall level of performance was matched to that of controls. Amnesic patients failed to show a size congruency effect. These findings provide evidence for a disproportionate disruption in recollection compared with familiarity in amnesia, even when recollection is supported by perceptual processes.