Effects of environmental diversity on brain morphology

This article provides a review of the literature on the effects of early environmental enrichment or impoverishment on the morphological structure of the brain. A critical re-appraisal of this literature shows that many of these effects have not been consistently observed in all experiments. In many experiments where effects have been observed the morphological methods adopted have not always been appropriate for the features being studied and thus the conclusions are brought into question. The review has also examined recent research concerned with the question of studying whether environmental enrichment in later life can ameliorate some of the morphological deficits known to be produced by undernutrition during early life. A consistent finding in this research has been that there is no statistically significant interaction between nutrition and environment, even for those few features which showed a main effect of environment. This indicates that undernutrition during early life does not preclude animals from interacting with their environment in a manner which can produce similar changes in brain morphology to those observed in normally nourished animals.