The missing whole in perceptual models of perirhinal cortex

The possibility that perirhinal cortex (PRh) plays a role in perceptual processing of objects, in addition to its well-established memory functions, has produced a growing body of research that was recently summarized by Buckley and Gaffan and integrated in their ‘levels of representation’ (LR) thesis [1]. The most important new experiments reviewed probed the ability of PRh-lesioned primates (human and non-human) to make perceptual discriminations in the presence of minimal memory demands. They were conducted to counter the criticism that the impairments previously observed in concurrent discrimination learning (CDL) might reflect mnemonic rather than perceptual difficulties (e.g.