Neural basis of the cognitive map: path integration does not require hippocampus or entorhinal cortex.
The hippocampus and entorhinal cortex have been linked to both memory functions and to spatial cognition, but it has been unclear how these ideas relate to each other. An important part of spatial cognition is the ability to keep track of a reference location using self-motion cues (sometimes referred to as path integration), and it has been suggested that the hippocampus or entorhinal cortex is essential for this ability. Patients with hippocampal lesions or larger lesions that also included entorhinal cortex were led on paths while blindfolded (up to 15 m in length) and were asked to actively maintain the path in mind. Patients pointed to and estimated their distance from the start location as accurately as controls. A rotation condition confirmed that performance was based on self-motion cues. When demands on long-term memory were increased, patients were impaired. Thus, in humans, the hippocampus and entorhinal cortex are not essential for path integration.
Shrager
Yael
Y
Department of Neurosciences, University of California at San Diego, La Jolla, CA 92093, USA.
Kirwan
C Brock
CB
Squire
Larry R
LR
D000368:Aged; D001931:Brain Mapping; D003071:Cognition / Q000502:physiology*; D018728:Entorhinal Cortex / Q000502:physiology*; D005260:Female; D006624:Hippocampus / Q000502:physiology*; D006801:Humans; D008297:Male; D009474:Neurons / Q000502:physiology*