Organizing conceptual knowledge in humans with a gridlike code.
It has been hypothesized that the brain organizes concepts into a mental map, allowing conceptual relationships to be navigated in a manner similar to that of space. Grid cells use a hexagonally symmetric code to organize spatial representations and are the likely source of a precise hexagonal symmetry in the functional magnetic resonance imaging signal. Humans navigating conceptual two-dimensional knowledge showed the same hexagonal signal in a set of brain regions markedly similar to those activated during spatial navigation. This gridlike signal is consistent across sessions acquired within an hour and more than a week apart. Our findings suggest that global relational codes may be used to organize nonspatial conceptual representations and that these codes may have a hexagonal gridlike pattern when conceptual knowledge is laid out in two continuous dimensions.
Oxford Centre for Functional MRI of the Brain, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DU, UK.
Alexandra O
AO
Constantinescu
Oxford Centre for Functional MRI of the Brain, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DU, UK.|Department of Experimental Psychology, University of Oxford, 9 South Parks Road, Oxford OX1 3UD, UK.|Donders Institute, Radboud University, Nijmegen, The Netherlands.
Jill X
JX
O'Reilly
Oxford Centre for Functional MRI of the Brain, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DU, UK.|Donders Institute, Radboud University, Nijmegen, The Netherlands.
Timothy E J
TEJ
Behrens
D000328:Adult; D001921:Brain / Q000166:cytology / Q000502:physiology*; D005260:Female; D059907:Functional Neuroimaging; D006184:Habits; D006801:Humans; D019359:Knowledge; D008279:Magnetic Resonance Imaging; D008297:Male; D009474:Neurons / Q000502:physiology*; D065854:Spatial Navigation / Q000502:physiology*; D055815:Young Adult