Role of the parahippocampal cortex in memory for the configuration but not the identity of objects: converging evidence from patients with selective thermal lesions and fMRI

Frontiers in Human Neuroscience

Katerina eStepankova¹  Miroslav eKalina²  Michael ePetrides³  Alan eEvans³  Veronique D Bohbot³  Alain eDagher³  Lynn eNadel⁴  John J.B. Allen⁴  Serge O Dumoulin⁵ 

[1] Charles University;Hospital Na Homolce;McGill University;University of Arizona;Utrecht University;

关键词: Hippocampus;    Parahippocampal Gyrus;    human;    spatial;    location;   

DOI  :  10.3389/fnhum.2015.00431

来源: DOAJ

【 摘 要 】

The parahippocampal cortex and hippocampus are brain structures known to be involved in memory. However, the unique contribution of the parahippocampal cortex remains unclear.The current study investigates memory for object identity and memory of the configuration of objects in patients with small thermo-coagulation lesions to the hippocampus or the parahippocampal cortex. Results showed that in contrast to control participants and patients with damage to the hippocampus leaving the parahippocampal cortex intact, patients with lesions that included the right parahippocampal cortex were severely impaired on a task that required learning the spatial configuration of objects on a computer screen; these patients, however, were not impaired at learning the identity of objects. Conversely, we found that patients with lesions to the right hippocampus or left hippocampus, sparing the parahippocampal cortex, performed just as well as the control participants. Furthermore, they were not impaired on the object identity task. In the fMRI experiment, healthy young adults performed the same tasks. Consistent with the findings of the lesion study, the fMRI results showed significant activity in the right parahippocampal cortex in the memory for the spatial configuration condition, but not memory for object identity. Furthermore, the pattern of fMRI activity measured in the baseline control conditions decreased specifically in the parahippocampal cortex as a result of the experimental task, providing evidence for task specific repetition suppression. In summary, while our previous studies demonstrated that the hippocampus is critical to the construction of a cognitive map, both the lesion and fMRI studies have shown an involvement of the right parahippocampal cortex for learning spatial configurations of objects but not object identity, and that this takes place independent of the hippocampus.

【 授权许可】

Unknown