This question has long interested psychologists, especially following Canadian psychologist Donald Hebb’s original discovery that rats who lived in enriched environments were markedly superior intellectual beings than laboratory rats living in more Spartan surroundings. Hebb’s enriched rats could solve more complicated maze problems in shorter times than their less-fortunate labmates. In his initial discovery, Hebb compared rats that had been raised by his children as pets with rats that lived in his laboratory. More controlled studies that compared the behavior of rats living in luxury condo-style environments within the walls of the laboratory showed that these rats enjoyed a favorable edge compared to rats living in standard “shoebox” cages that were the norm in the 1950s and before. Later
work carried out by Berkeley’s Mark Rosenzweig showed that such enriched rats were not only superior performers, but that they also had a thicker neocortex with more richly developed synaptic connections between brain cells. Indeed, this finding was the cornerstone of the modern view in neuroscience that the brain, far from being a fully formed and immutable organ by adulthood, could show dramatic physical responses to environmental changes all through the lifespan (and it’s one of the reasons why so many of us place such great hope in the possibility that crossword puzzles and brain-training games like Lumosity will enrich our brains so as to stave off cognitive decline as
we age).8
But what about people? The brain mechanisms responsible for the
enrichment effects discovered by Hebb, Rosenzweig, and legions of
other researchers are so fundamental that it would be an extraordi nary thing if these principles did not apply to us as well as to laboratory rats. And, indeed, different kinds of experiments looking at the influence of skill development on brain organization have shown that our brains possess a remarkable degree of plasticity. To give one example, musicians who have engaged in demanding practice of manual skills required for performance show measurable increases in brain activity and connections in areas of their brains related to the skills they have developed. It’s fortunate that there are very few parallels in human neuroscience that can be compared to the experiences of Hebb’s rats living in tiny cages faced only with four enclosing steel walls.