PT  - JOURNAL ARTICLE
AU  - Susan J. Bartko
AU  - Boyer D. Winters
AU  - Rosemary A. Cowell
AU  - Lisa M. Saksida
AU  - Timothy J. Bussey
TI  - Perceptual Functions of Perirhinal Cortex in Rats: Zero-Delay Object Recognition and Simultaneous Oddity Discriminations
AID  - 10.1523/JNEUROSCI.5171-06.2007
DP  - 2007 Mar 07
TA  - The Journal of Neuroscience
PG  - 2548--2559
VI  - 27
IP  - 10
4099  - http://www.jneurosci.org/content/27/10/2548.short
4100  - http://www.jneurosci.org/content/27/10/2548.full
SO  - J. Neurosci.2007 Mar 07; 27
AB  - The perirhinal cortex (PRh) is widely accepted as having an important role in object recognition memory in humans and animals. Contrary to claims that PRh mediates declarative memory exclusively, previous evidence suggests that PRh has a role in the perceptual processing of complex objects. In the present study, we conducted an examination of the possible role of PRh in perceptual function in rats. We examined whether bilateral excitotoxic lesions of PRh or PPRh (perirhinal plus postrhinal cortices) in the rat would cause deficits in a zero-delay object-recognition task and a simultaneous oddity discrimination task. Both of these tasks measured spontaneous (untrained, unrewarded) behavior, and the stimuli in these experiments were manipulated to produce varying levels of perceptual difficulty. As predicted by simulations using a computational model, rats with PPRh lesions were impaired in object recognition when the stimuli to be discriminated were manipulated to share many features in common. Furthermore, rats with PPRh and PRh lesions were impaired in a simultaneous oddity discrimination task when the stimuli to be discriminated were manipulated explicitly to be more perceptually similar. These findings provide support for the idea that PRh in the rat is important for the perceptual processing of complex objects, in addition to its well established role in memory.