EFFECT OF ENRICHED (COMPLEX) ENVIRONMENT ON NERVE-CONDUCTION VELOCITY - NEW DATA AND REVIEW OF IMPLICATIONS FOR THE SPEED OF INFORMATION-PROCESSING

Extensive research with genetically heterogeneous rats and other mammals has shown many effects of environmental enrichment (EE; comparing complex, stimulating environment with simple environment) on brain and behavior. Increased nerve conduction velocity (NCV) in brain nerve pathways is one of these effects. Research with a genetically heterogeneous mouse strain (HS) also strongly suggests that increased stimulation or usage increases peripheral NCV (PNCV) and this study on 54 HS mice confirms this. Human data also indicate that increased activity increases PNCV. Therefore, both brain NCV and PNCV appear to increase after EE. Since extensive human data indicate that the speed of information processing (SIP) is positively correlated with intelligence level, and brain NCV should be a component of SIP, these results suggest a role, at the physiological level, for EE (or deprivation) in affecting measured intelligence.