"Equipped with his five senses, man explores the universe around him and calls the adventure science." Edwin Powell Hubble

As a child I recall seeking out the best opportunities my neighborhood, nearby fields and playgrounds had to offer for thrilling activities and risk taking opportunities. I was always in "search mode" for the next largest or steepest hill to speed down on a BMX bike, the next largest ramp to launch off of, the next highest fence to scale, and the next tallest tree to climb. There was an intangible thrill and sense of accomplishment that came with the successes and with the bruises, bloody noses and broken bones as well. At that young age I had no idea, and truthfully wouldn't have even cared to know, that this desire to participate in thrilling activities was actually an innate response and compensation for a lack of sensory stimulation. I was quite literally elevating the level of sensory stimuli in my environment through risky play behaviors. This is not an uncommon scenario but is merely one of several types of reactions that children in our society have to sensory stimulation in their play environments.

Play is one method that children use to experience, avoid or create the stimulation they personally need to develop. The graphic to the right (an adapted version of Dunn's research) illustrates a current theory about how different children react to sensory stimuli during activities such as play. Most children will fall into four basic groups: Children with a high tolerance for sensory stimuli who respond passively (Group 1), children with a high tolerance for sensory stimuli who respond actively (Group 2), children with a low tolerance for stimuli who respond passively (Group 3), and children with a low tolerance for stimuli who respond actively (Group 4).²

It is important to note that children are all different; preferences for sensory experiences will vary and these experiences may be beneficial or detrimental to the children's development. Preferences will often be manifested in the behavior of the children and are outward expressions of their need for those stimuli.²

Children in Group 1 have high tolerances for sensory stimuli but do not recognize it resulting in non-engaged and complacent behaviors. These children tend not to respond quickly and require physical contact to get their attention.¹ Children in Group 2 have high tolerances for sensory stimuli and will search for opportunities to increase stimuli in their environment. These children tend to enjoy active play, noisy toys, splashing water, exploring textures, and rhythmic activities.¹ Children in Group 3 have low tolerances for sensory stimuli and react passively. They have difficulty with concentration as they cannot completely process all the stimulation occurring around them at one time. They tend to become agitated when they get dirty or walk across different surfaces and have trouble sleeping.¹ Children in Group 4 have low tolerances for sensory stimuli and react with avoidance or repetitive behaviors to combat over stimulation. They tend to avoid noisy toys and instruments, avoid rough play, resist close physical contact and avoid sensory rich surfaces.¹

With such a broad range of reactions to the same stimuli, it is imperative that play environments be carefully planned in advance to provide children in all four groups with opportunities for positive and beneficial levels of stimulation. One of the most effective methods of sensory planning is to observe the children who play in, pretend in and actively recreate in the play space. Whether it is an indoor classroom, a schoolyard or a public playground, play spaces can be designed with sensory integrated activities that promote inclusive development and social interaction. One of the most effective approaches to help meet this objective is to provide a wide diversity of play opportunities within which sensory seeking children can find the extra stimulation they need (musical instruments, varied textures etc.), create areas where stimuli are highly focused and repetitive for children who do not recognize the stimuli readily, provide areas with only a few very simple stimuli for children who are sensitive to stimuli (enclosed sand boxes limit outside stimuli, don't require excessive movement and provide a single texture), and create spaces for retreat where stimuli are less invasive and can be avoided for children with low tolerances (i.e. cozy spaces, the picture above shows how one child is using the play environment as a space for retreat where stimuli is limited by an enclosed space). With variety in the play environment, children are able to effectively customize their sensory experience to meet their needs.

There is currently very little research dealing with sensory integration in play environments and additional studies need to be performed to further understand the role of the senses in the play environment, particularly with children with disabilities. This research will help planners create more effective spaces that integrate the senses with children's play and development.