Fluid intelligence relates to neural measures of cognitive map formation
Psychometric research on intelligence consistently identifies latent factors underlying performance correlations across cognitive tasks, with one general factor (g) explaining most variance and predicting general life outcomes. Their biological basis is yet unresolved, in particular with regard to the neural information processing mechanisms that may underlie intelligence. Here we test the hypothesis that interindividual differences in relational processing, supported by cognitive maps in the hippocampus, are related to fluid intelligence (gf), a statistical approximation of the general factor. Using standardized cognitive tests and fMRI of mnemonic tasks, we demonstrate a positive correlation specifically between gf and map-like relational encoding of task information. This relationship was neither present for non-relational mnemonic responses in the hippocampus nor for less g-related factors. These findings offer first empirical support for a link between neural mechanisms related to relational reasoning and general cognitive performance and probe the presumed relevance of hippocampal coding properties for cognition more broadly.