Comparison of the effects of damage to the perirhinal and parahippocampal cortex on transverse patterning and location memory in rhesus macaques.

Monkeys with damage to the parahippocampal (TH/TF) or perirhinal (PRh) cortex were tested on two sets of the transverse patterning (TP) problem (A+/B-, B+/C-, C+/A- and D+/E-, E+/F-, F+/D-) and delayed nonmatching-to-location paradigm (DNML), with delays ranging from 10 to 600 s. Damage to either area impaired acquisition and performance of TP but not of linear discriminations (e.g., A>B>C>X). Damage to areas TH/TF impaired performance of the DNML at all delays but only affected memory for objects at the longest delay, as measured by a delayed nonmatching-to-sample task (DNMS) (Nemanic et al., 2004). Damage to the PRh impaired performance of the DNMS but not of the DNML. The results present a dissociation in object and place memory for these two cortical regions and suggest a role for each in the cortical circuitry supporting configural/relational memory.