This research could be a useful counter argument to the classic Rosenzweig, Bennett and Diamond study (1972) into enriched environment and neuroplasticity.   It suggests disco lights are out, but toys are in!

This study was based on earlier findings by Christakis et al. (2004) that young children’s excessive television watching led to later attention problems. Christakis, Ramirez and Ramirez (2012) subjected ten mice to overstimulation by flashing lights and noise for six hours a day for 42 days.  They then compared them with a control group on four different cognitive tests, and found that the experimental group subjected to the stimulation performed the tasks significantly worse than the control group in terms of memory and attention, exhibiting ‘increased activity and risk taking, diminished short term memory, and decreased cognitive function.’

The results suggest that overstimulation during periods of critical development can have unexpected negative effects on cognition.  However, this is a very small experimental study, and no measurements of brain changes were taken, so its reliability remains open to question.