Connecting places causes mental maps to merge

Realising how places connect geographically causes local maps in the brain to join, forming one big map which helps with planning future journeys, finds a new UCL study. Changes like this can occur when people vary their route to work during a tube strike, for example. Commuters may be familiar with the location of two underground stations but only realise how one is linked to the other by walking between them. Knowing how the stations are connected can then be used to decide which route to take next time. The study in rats provides the first evidence that grid cells can form maps for large-scale navigation between distinct areas, adding to previous Nobel-prize winning research showing that grid cells appear to map the local environment, acting as a coordinate system to measure distances between places. Published today in Current Biology and funded by the Wellcome Trust, Medical Research Council and the Royal Society, the study monitored grid cell firing in the brains of eight rats as they moved between two identical compartments connected with a corridor. Initially, the grid cells fired in the same pattern in each compartment, creating two identical but separate maps.