Interestingly, only the cuneal areas were significantly more recruited by the allocentric encoding in comparison to other spatial conditions. Moreover, the enhancement of hippocampal activation was found during Egocentric-updating encoding whereas the retrosplenial activation was observed during the Egocentric with rotation only condition. doi: 10.1162/089892904323057254 Pubmed Abstract | Pubmed Full Text | Cross Ref Full Text Sharp, P. In order to interact with space, humans need to integrate spatial information according to new objects encountered and/or new motion information (e.g., object- or self-motion, Wolbers and Hegarty, 2010). Path integration deficits during linear locomotion after human medial temporal lobectomy. Encoding and storing spatial information is supposed to rely on the activity of one of these two types of spatial representation (Burgess, 2006): (a) egocentric, centered on the subject, coding for self-to-object relations; (b) allocentric, centered on the environment, coding for object-to-object relations. Hippocampal involvement in spatial coding could reflect the integration of new information generated by “online” self-related changes. Fixed versus dynamic orientations in environmental learning from ground-level and aerial perspectives. In this f MRI study, the participants started by encoding several object locations in a virtual reality environment and then performed a pointing task. Allocentric encoding was maximized by using a survey perspective and an object-to-object pointing task. Neural correlates of individual differences in spatial learning strategies. doi: 10.1037/0894-4126.96.36.1992 Pubmed Abstract | Pubmed Full Text | Cross Ref Full Text Shelton, A.
These results indicate that the raw differentiation between allocentric versus egocentric representation seems to no longer be sufficient in understanding the complexity of the mechanisms involved during spatial encoding.
Various evidence sources, ranging from single neuron recordings in animals (O' Keefe and Dostrovsky, 1971; Andersen et al., 1985) to f MRI and neuropsychological observations (Bisiach and Luzzatti, 1978; Aguirre and D' Esposito, 1999; Holdstock et al., 2000; Mellet et al., 2000; Spiers et al., 2001; Chokron, 2003; Burgess et al., 2006; Fields and Shelton, 2006; Maguire et al., 2006; Shrager et al., 2008), suggest that the two types of spatial representations rely on the occipito-temporo-parietal cortices.