What is the primary effect observed in Rosenzweig's environmental enrichment study?

What is the primary effect observed in Rosenzweig's environmental enrichment study?

• A. Increased cortical thickness and weight
• B. Decreased brain size
• C. No change
• D. Slower neural development

Answer: (A)

The key idea is that experience and environment can reshape the brain through neural plasticity. In Rosenzweig’s environmental enrichment study, rats kept in a stimulating, socially enriched setting developed a thicker, heavier cerebral cortex compared with those in a more deprived environment. This increase in cortical thickness and weight reflects more extensive dendritic branching and higher synaptic density, showing that the brain grows more connected when it experiences richer sensory and social input. So, the primary observed effect is the growth of cortical tissue due to increased neural connectivity. The other options don’t fit because enrichment does not reduce brain size, produce no change, or slow neural development; it enhances cortical growth and maturation instead.

The key idea is that experience and environment can reshape the brain through neural plasticity. In Rosenzweig’s environmental enrichment study, rats kept in a stimulating, socially enriched setting developed a thicker, heavier cerebral cortex compared with those in a more deprived environment. This increase in cortical thickness and weight reflects more extensive dendritic branching and higher synaptic density, showing that the brain grows more connected when it experiences richer sensory and social input. So, the primary observed effect is the growth of cortical tissue due to increased neural connectivity. The other options don’t fit because enrichment does not reduce brain size, produce no change, or slow neural development; it enhances cortical growth and maturation instead.