Neurocognitive stages of spatial cognitive mapping measured during free exploration of a large-scale virtual environment.
Using a novel, fully mobile virtual reality paradigm, we investigated the EEG correlates of spatial representations formed during unsupervised exploration. On day 1, subjects implicitly learned the location of 39 objects by exploring a room and popping bubbles that hid the objects. On day 2, they again popped bubbles in the same environment. In most cases, the objects hidden underneath the bubbles were in the same place as on day 1. However, a varying third of them were misplaced in each block. Subjects indicated their certainty that the object was in the same location as the day before. Compared with bubble pops revealing correctly placed objects, bubble pops revealing misplaced objects evoked a decreased negativity starting at 145 ms, with scalp topography consistent with generation in medial parietal cortex. There was also an increased negativity starting at 515 ms to misplaced objects, with scalp topography consistent with generation in inferior temporal cortex. Additionally, misplaced objects elicited an increase in frontal midline theta power. These findings suggest that the successive neurocognitive stages of processing allocentric space may include an initial template matching, integration of the object within its spatial cognitive map, and memory recall, analogous to the processing negativity N400 and theta that support verbal cognitive maps in humans.
Institute for Neural Computation, University of California, San Diego, La Jolla, California;
Markus
M
Plank
Institute for Neural Computation, University of California, San Diego, La Jolla, California;
Joseph
J
Snider
Interdepartmental Neuroscience Program, University of California, San Diego, La Jolla, California; and.
Erik
E
Kaestner
Interdepartmental Neuroscience Program, University of California, San Diego, La Jolla, California; and Departments of Radiology, Neurosciences, and Psychiatry, University of California, San Diego, La Jolla, California.
Eric
E
Halgren
Institute for Neural Computation, University of California, San Diego, La Jolla, California; Interdepartmental Neuroscience Program, University of California, San Diego, La Jolla, California; and hpoizner@ucsd.edu.
Howard
H
Poizner
D000328:Adult; D001931:Brain Mapping; D058256:Brain Waves; D003071:Cognition; D005106:Exploratory Behavior; D005260:Female; D006801:Humans; D008297:Male; D010296:Parietal Lobe / Q000502:physiology*; D013037:Spatial Behavior; D013702:Temporal Lobe / Q000502:physiology*; D014584:User-Computer Interface
N400; cognitive map; event-related potential; frontal cortex; parietal cortex; processing negativity; spatial information; temporal cortex; theta