A Neural Basis for General Intelligence

TLDR

Universal positive correlations between cognitive tests motivate the concept of general intelligence (Spearman's g), and prior studies have shown that the same frontal regions are recruited across diverse cognitive demands. Here the neural basis for g is investigated by means of positron emission tomography. Spatial, verbal, and perceptuo‑motor tasks with high‑g involvement are compared with matched low‑g control tasks. High‑g tasks do not recruit diffuse brain regions but selectively engage lateral frontal cortex, a pattern consistent across spatial, verbal, and perceptuo‑motor tasks, indicating that general intelligence stems from a specific frontal system that supports diverse behavior.

Abstract

Universal positive correlations between different cognitive tests motivate the concept of “general intelligence” or Spearman's g . Here the neural basis for g is investigated by means of positron emission tomography. Spatial, verbal, and perceptuo-motor tasks with high- g involvement are compared with matched low- g control tasks. In contrast to the common view that g reflects a broad sample of major cognitive functions, high- g tasks do not show diffuse recruitment of multiple brain regions. Instead they are associated with selective recruitment of lateral frontal cortex in one or both hemispheres. Despite very different task content in the three high- g –low- g contrasts, lateral frontal recruitment is markedly similar in each case. Many previous experiments have shown these same frontal regions to be recruited by a broad range of different cognitive demands. The results suggest that “general intelligence” derives from a specific frontal system important in the control of diverse forms of behavior.