estimate of 5–13% of elementary school aged children. critics have noted that such a high incidence for just one of the subtypes of spd raises questions about the degree to which spd is a specific and clearly identifiable disorder. proponents have also claimed that adults may also show signs of sensory processing difficulties and would benefit for sensory processing therapies, although this work has yet to distinguish between those with spd symptoms alone vs adults whose processing abnormalities are associated with other disorders, such as autism spectrum disorder. society the american occupational therapy association (aota) and british royal college of occupational therapy (rcot) support the use of a variety of methods of sensory integration for those with sensory integration and processing difficulties. both organization recognise the need for further research about ayres' sensory integration and related approaches. in the usa this important to increase insurance coverage for related therapies. aota and rcot have made efforts to educate the public about sensory integration and related approaches. aota's practice guidelines and rcot's informed view "sensory integration and sensory-based interventions" currently support the use of sensory integration therapy and interprofessional education and collaboration in order to optimize treatment for those with sensory integration and processing difficulties. the aota provides several resources pertaining to sensory integration therapy, some of which includes a fact sheet, new research, and continuing education opportunities. controversy there are concerns regarding the validity of the diagnosis. spd is not included in the dsm-5 or icd-10, the most widely used diagnostic sources in healthcare. the american academy of pediatrics (aap) in 2012 stated that there is no universally accepted framework for diagnosis and recommends caution against using any "sensory" type therapies unless as a part of a comprehensive treatment plan. the aap has plans to review its policy, though those efforts are still in the early stages. a 2015 review of research on sensory integration therapy (sit) concluded that sit is "ineffective and that its theoretical underpinnings and assessment practices are unvalidated", that sit techniques exist "outside the bounds of established evidence-based practice", and that sit is "quite possibly a misuse of limited resources". some sources point that sensory issues are an important concern, but not a diagnosis in themselves. critics have noted that what proponents claim are symptoms of spd are both broad and, in some cases, represent very common, and not necessarily abnormal or atypical, childhood characteristics. where these traits become grounds for a diagnosis is generally in combination with other more specific symptoms or when the child gets old enough to explain that the reasons behind their behavior are specifically sensory. manuals spd is in stanley greenspan's diagnostic manual for infancy and early childhood and as regulation disorders of sensory processing part of the zero to three's diagnostic classification. is not recognized as a stand-alone diagnosis in the manuals icd-10 or in the recently updated dsm-5, but unusual reactivity to sensory input or unusual interest in sensory aspects is included as a possible but not necessary criterion for the diagnosis of autism. history sensory processing disorder as a specific form of atypical functioning was first described by occupational therapist anna jean ayres (1920–1989). original model ayres's theoretical framework for what she called sensory integration dysfunction was developed after six factor analytic studies of populations of children with learning disabilities, perceptual motor disabilities and normal developing children. ayres created the following nosology based on the patterns that appeared on her factor analysis: dyspraxia: poor motor planning (more related to the vestibular system and proprioception) poor bilateral integration: inadequate use of both sides of the body simultaneously tactile defensiveness: negative reaction to tactile stimuli visual perceptual deficits: poor form and space perception and visual motor functions somatodyspraxia: poor motor planning (related to poor information coming from the tactile and proprioceptive systems) auditory-language problems both visual perceptual and auditory language deficits were thought to possess a strong cognitive component and a weak relationship to underlying sensory processing deficits, so they are not considered central deficits in many models of sensory processing. in 1998, mulligan found a similar pattern of deficits in a confirmatory factor analytic study. quadrant model dunn's nosology uses two criteria: response type (passive vs. active) and sensory threshold to the stimuli (low or high) creating four subtypes or quadrants: high neurological thresholds low registration: high threshold with passive response. individuals who do not pick up on sensations and therefore partake in passive behavior. sensation seeking: high threshold and active response. those who actively seek out a rich sensory filled environment. low neurological threshold sensitivity to stimuli: low threshold with passive response. individuals who become distracted and uncomfortable when exposed to sensation but do not actively limit or avoid exposure to the sensation. sensation avoiding: low threshold and active response. individuals actively limit their exposure to sensations and are therefore high self regulators. sensory processing model in miller's nosology "sensory integration dysfunction" was renamed into "sensory processing disorder" to facilitate coordinated research work with other fields such as neurology since "the use of the term sensory integration often applies to a neurophysiologic cellular process rather than a behavioral response to sensory input as connoted by ayres." the sensory processing model's nosology divides spd in three subtypes: modulation, motor based and discrimination problems.