Variation in environmental complexity and brain measures.

Abstract

This report is one in a series of studies investigating the effects of exposure to environmental complexity and training (ECT) upon brain biochemistry and anatomy. The data reported here replicate and extend two generalizations from previous studies: First, there is a monotonic relation between complexity of environment and terminal cerebral measures. Second, the cerebral effects of an early period in an impoverished environment can be reversed, in part at least, by a succeeding period in an enriched environment.

Enhancing endogenous capacity to repair a stroke-damaged brain: An evolving field for stroke research

“…Hymovitch’s findings confirmed the Hebb’s observation that rats reared in a complex environment showed an enhancement in problemsolving ability. In the early 1960s, Rosenzweig and coworkers (Rosenzweig et al, 1961; Rosenzweig et al, 1962a) further elaborated the Hymovitch’s complex environment (free environment) and named it as “environmental complexity and training” (Krech et al, 1960), “enriched condition” (Rosenzweig and Bennett, 1996) and “enriched environment” (Rosenzweig et al, 1962b). Since then, the enriched environment, as a testable scientific concept, was widely accepted and used in neuroscience research.…”

Brain and cognitive evolution: Forms of modularity and functions of mind.

“…Experience-based change in brain functioning and topographic organization has also been demonstrated in normally developing brains, beginning with the seminal studies of Rosenzweig and colleagues (e.g., Rosenzweig & Bennett, 1972;Rosenzweig, Krech, Bennett, & Diamond, 1962;Rosenzweig, Krech, Bennett, & Zolman, 1962) and Greenough and colleagues (see Greenough et al, 1987). In the former studies, newly weaned rats were exposed to varying degrees of social and environmental enrichment or impoverishment.…”

Structural brain plasticity in adult learning and development

“…It should be noted however that the enriched condition is only enriched relative to standard cages housing these strains of animals in isolation, and not relative to what the population of animals that live in the wild experiences. Rosenzweig and colleagues reported changes in brain weight (Rosenzweig et al, 1962 and cortical thickness Rosenzweig et al, 1972) following environmental enrichment in rats (see Anderson, 2011;Markham and Greenough, 2004, for reviews). Increases between 1% and 6% in total cortical weight were observed after enrichment in weanling aged rats (Rosenzweig et al, 1972).…”

“…In the early 1960s, Rosenzweig et al (1962Rosenzweig et al ( , 1964 were the first to apply the complex enrichment paradigm (e.g., Hebb, 1949) to study effects of experience on the brain. This paradigm is also referred to as environmental enrichment and involves housing animals (typically rats or mice) in a cage containing toys that are frequently changed.…”

“…Recent research using techniques for imaging the human brain in vivo, particularly magnetic resonance (MR) imaging, suggests that the brain's macrostructure manifests experience-dependent plasticity in adulthood (Draganski et al, 2004(Draganski et al, , 2006. Although experience-dependent morphological brain changes have been investigated in animal models for a long time (Altman and Das, 1964;Greenough et al, 1973;Rosenzweig et al, 1962Rosenzweig et al, , 1964Volkmar and Greenough, 1972), the discovery that such changes are detectable with MR imaging has opened up new avenues for research. In particular, structural correlates of learning can now be identified and studied in humans.…”