Enriched and Impoverished Environments: Effects on Brain and Behaviour is the most recent review of the active area of neuronal plasticity. The question of how experience is recorded is fundamental to psychology; speculations and investigations concerning the role of the brain in this process have entered a particularly exciting phase as of the late 1980''s. Manipulations of environmental complexity is one of the earliest methods utilized in the study of neural plasticity. This monograph organizes the evidence to date concerning the responsiveness of neural and behavioural systems to external manipulation of the environment. Further consideration is given to the issues of causation of the general effects of environment on brain and behaviour.