I had been working quite happily on the basic biology of the brain when a good friend of mine called for advice about his daughter, who had just been diagnosed with autism.

I could hear the anguish and fear in his voice when he asked me whether there was anything that could be done to make her better.  I told him about the standard-care therapies, including Intensive Behavioral Intervention, Early Intensive Behavioral Intervention, Applied Behavior Analysis, and the Early Start Denver Model (ESDM). These therapies also are expensive, time-consuming and have variable outcomes, with the best outcomes seen for ESDM. There are, however, few ESDM therapists, and the cost of such intensive therapy can be quite high. Moreover, my friend’s daughter was already past the age of the oldest children in the study that demonstrated the efficacy of ESDM.

My feeling was that there was a good chance that there was an effective therapy for her using a simple, inexpensive at-home approach involving daily exposure to a wide variety of sensory stimulation.  This is a partial list of the disorders whose symptoms can be greatly reduced, or even completely reversed, with what is known as “environmental enrichment”:

  1. Autism
  2. Stroke
  3. Seizures
  4. Brain damage
  5. Neuronal death during aging
  6. ADHD
  7. Prenatal alcohol syndrome
  8. Lead exposure
  9. Multiple sclerosis
  10. Addiction
  11. Schizophrenia
  12. Memory loss
  13. Huntington’s disease
  14. Parkinson’s disease
  15. Alzheimer’s disease
  16. Down syndrome
  17. Depression


But why haven’t you heard about this?  The reason is that all of these disorders that have been successfully treated only in animal models of these neurological problems. However, the effects seen in lab animals can be dramatic. For example, experimental animals living in an enriched environment and exposed to a serious brain toxin such as lead, actually have better memory than those living in a standard environment without any lead exposure.

But you’re probably thinking that this approach certainly couldn’t work for people. We live in a world in which we seem to be over-stimulated. My guess is that we get plenty of visual stimulation, but our environment may lack the enrichment that it needs from other sensory pathways.

I knew that a remarkable one-third of children who had been deprived of normal sensory stimulation while they were living in orphanages developed what has been called post-institutional autistic syndrome, with symptoms quite similar to autism. If decreasing sensory stimulation could increase the probability of expressing autism symptoms, then perhaps increasing sensory stimulation might decrease that probability.

Furthermore, I knew of some parents who had tried environmental enrichment successfully with their children. So, even though it had not been evaluated by biomedical researchers, I thought there was a chance it could help my friend’s daughter — and was unlikely to cause any harm.

My friend’s daughter was then were led through environmental enrichment program for their child, based on our work with experimental animals. She showed a significant improvement in her behaviors and was eventually able to join regular classes in her school. Impressed with this, we initiated a randomized clinical trial in which we recruited children with autism and then compared those given an enriched environment by their own parents at home, to those receiving only the standard treatments.

For the environmental enrichment, we asked parents to provide a changing set of sensory exercises each morning and evening. The children were exposed to several different fragrances each day, paired each time with a light rub on their back; they listened to classical music before bedtime; and in the morning and evening, the parents engaged their child in several of 34 exercises in which at least two senses (sound, touch, temperature, vision, and motor) were paired in somewhat arbitrary combinations.  The parents changed the set of exercises every two weeks and the exercises became increasingly challenging. For example, the children were asked to place their hands in water of different temperatures, or they were asked to squeeze objects of different shapes and textures, or they were asked to pick out a specific toy from a bag that contained several objects.

After six months, all of the children were evaluated by assessors with no knowledge of their group assignment. We found that 42% of the enriched children showed a clinically significant improvement in their autism symptoms, according to the Childhood Autism Rating Scale, while only 7% of those receiving standard care did. In addition, the cognitive score of the enriched children (measured with the Leiter International Performance ScaleRevised) was more than 10 points higher than those receiving standard care.  We have now repeated and extended the original study with many more children.

Among many additional questions that need to be answered regarding this therapy, it’s important to know both whether these improvements are long-lived and whether these children can keep on improving. While we don’t have these answers, we did follow the progress of one girl who was diagnosed with autism at 2.5 years old. She was inattentive, uncommunicative, and did not interact much with anyone. She had received standard-care therapies until she was eight years old, and showed some improvement. At that time, she started environmental enrichment therapy with no concurrent treatments, and continued it for 18 months. Her behavior significantly improved.

About a year ago, I received an email from her father saying that they had been to a TEDx conference and he included a link to a talk that he thought I would find particularly interesting. On that video, the previously uncommunicative, non-interactive child, who was now in high school, was delivering a brilliant, engaging talk to a large audience; it was difficult to imagine her as a child with profound autism symptoms. Later that day, her father and I shared a wonderfully emotional time recalling where she started and where she is now. She has now been accepted to a top college and her father subsequently built a Web site that leads other parents through the therapy.

It looks like environmental enrichment is a way to improve the treatment of children with autism and perhaps other mental disorders. Moreover, the therapy can be done at almost no cost and with no need for any kind of expertise. But the really big idea is that there may be no reason to wait until you or your child has a neurological disorder to enrich your mind. We are currently working to evaluate the notion that it may be possible to use this approach to maximize our mind’s capabilities throughout our lifetime.