Why rats need toys and mental stimulation

THE ENRICHED INVIRONMENT:

“…Donald Hebb (1949) kept some rats at home as pets… Back in the laboratory, these privileged rats were far superior to their disadvantaged lab-housed relatives in the transfer-learning of a series of maze problems. Krech and his colleagues (1972) followed this up by housing young rats in rather large groups of ten, with or without ‘toys’, a selection from twenty-five varied objects changed every day. Comparing these rats’ brains with those without toys, they found a greater ratio of cortical to sub-cortical cholinesterase activity, larger synaptic junctions, more glial cells, and more cholinesterase in them.”

( Animal behaviour in the Laboratory, Paul Silverman, 1978 )