 In adult humans the volume of the hippocampus on each side of the brain is about 3.0 to 3.5 cm3 as compared to 320 to 420 cm3 for the volume of the neocortex.There is also a general relationship between the size of the hippocampus and spatial memory.When comparisons are made between similar species, those that have a greater capacity for spatial memory tend to have larger hippocampal volumes.