Sensory integration therapy and Jean Ayres

Anna Jean Ayres, PhD, OTR, (January 18, 1920 – December 16, 1988) was a clinician, educator, mentor, author, researcher, and advocate for individuals with special needs. Known as A. Jean Ayres, she was an occupational therapist and educational psychologist who was known within and outside the field of occupational therapy for her pioneering work in sensory integration (SI).

Biography

Born on a walnut farm in Visalia, California in 1920, Ayres’ parents, Fletcher and Louise (Stamm) Ayres, were both school teachers. Growing up, Ayres claimed to have symptoms similar to the dysfunctions she would later study.

Career

Ayres received her B.A. in occupational therapy in 1945, her M.A. in occupational therapy in 1954, and her PhD in educational psychology in 1961, all from theUniversity of Southern California in Los Angeles. She began her post-doctoral work in the UCLA Brain Research Institute from 1964 to 1966 under Dr. Arthur Parmelee. She was also a faculty member in the occupational therapy and special education departments at the University of Southern California from 1955 to 1984. In addition to her academic accomplishments, Ayres wrote two books and more than thirty journal articles. She also standardized tests that were published originally as the Southern California Sensory Integration Tests in 1975 and later revised as the Sensory Integration and Praxis Tests in 1989. In 1976, Ayres founded a private pediatric practice called the Ayres Clinic in Torrance, California. She conducted occupational therapy assessment and intervention on children and adults with a variety of disorders, including learning disabilities and autism. She created and taught the OT61 for four months for the University of Southern California’s clinical training program in the theory and intervention of sensory integration, which still continues to this day.

Awards and Recognition

Ayres received numerous honors from the American Occupational Therapy Association (AOTA)–including the Eleanor Clark Slagle Lectureship, the Award of Merit, and a charter membership in the AOTA Academy of Research—and was named in the Roster of Fellows. She has been described by her students and colleagues as “a pioneer in affective neuroscience” (Schneider, 2005), a “developmental theorist” (Knox, 2005), “one of the original perceptual motor theorists” (Smith Roley, 2005), “a pioneer in our understanding of developmental dyspraxia” (Cermak, 2005), and “an astute observer of human behavior and neurological development” (Bauman, 2005).

She was dedicated to the promotion of science-driven intervention strategies leading a better quality of life for people with disabilities and their families. “Her work made major inroads into the understanding of clinical neuroscience, the importance of experience in brain development, the role of tactile defensiveness and sensory modulation disorders as contributors to behavioral disorders, and the impact of sensory registration in autism, among others.”

If I have been productive, it is partly because I have had the advantage of contact with those with the courage as well as the ability to think independently and along unorthodox lines. It has not been easy for the helping professions to conceive of human behavior as an express of the brain, and they are still struggling to do so… The employing of neural mechanisms to enhance motor development is now well established; the current area of major growth and controversy lies in the use of neurological constructs to aid in understanding and ameliorating cognitive functions such as learning disabilities; the next step may well be a more fruitful attack on emotional and behavior disorders.

 — Jean Ayres (1974, p. xi)

Building on the work of Charles S. Sherrington and others, Dr. Ayres examined the relationship between the brain and behavior and developed a theory and model for therapeutic practice. In the 1950s, Dr. Ayres began developing the theory of Sensory Integration as well as evaluation procedures and intervention strategies associated with this framework. By the 1960s, Dr. Ayres recognized and described “hidden disabilities” or “dysfunction in sensory integrative processes” (Ayres, 1963, 1968), which she later referred to as sensory integrative dysfunction. She originated the theory to “explain the relationship between deficits in interpreting sensation from the body and the environment and difficulties with academic or motor learning.” Dr. Ayres published her definition of sensory integration in 1972 as “the neurological process that organizes sensation from one’s own body and from the environment and makes it possible to use the body effectively within the environment” (p. 11). In 1979, Dr. Ayres published Sensory Integration and the Child, a book to “help parents to recognize sensory integrative problems in their child, understand what is going on, and do something to help their child”

Between 1968 and 1989, Ayres used tests of sensory integrative and practical functions with children with and without learning and sensorimotor difficulties. These were originally published as “Southern California Sensory Integration Tests” (SCSIT; 1975) and later revised as “Sensory Integration and Practice Tests (SIPT; 1989). She published numerous factor analyses of assessment findings that allowed her to identify patterns of sensory integrative dysfunction, which were later confirmed by other researchers and expanded upon (e.g. in the context of attention deficit and hyperactivity disorder).

Ayres’ primary focus in the development of Sensory Integration theory was to understand the contributions of sensation to neurodevelopment and to determine successful intervention techniques, (Ayres, 1972a, 1975a, 1979). She also developed the intervention approach through empirical research, the goal of which was to determine the best responders and most effective types of intervention strategies Dr. Ayres’ “insights and subsequent theory of development were made through keen observation of behavior; review of the neurophysiological underpinnings of behavior; synthesis of literature from neurology, psychology, neurophysiology, and education; ongoing research on assessment and statistical analysis of patterns of dysfunction (Ayres, 1972, 1974).”

Many professionals hold that Dr. Ayres created one of the first structures for evidence-based practice in occupational therapy through her theory development (Ayres, 1972), model development (Ayres, 1979-2005), assessment development (Ayres, 1989) and intervention strategies (Ayres, 1972). However, sensory integration theory and intervention were controversial at the time and remain controversial still today. As the renowned occupational model researcher Gary Kielhofner put it, measured by the passion of debate, sensory integration seems to be a worthy theory.

Sensory Integration Dysfunction

There are different approaches to categorize patterns of sensory integration dysfunction. Based on Ayres’ original empirical findings (Ayres 1965, 1966a, 1966b, 1969, 1972b, 1977, 1989) and new studies, the current categories of sensory integrative dysfunction are (1) vestibular-proprioceptive bilateral integration and sequencing disorder, (2) tactile and visual discrimination disorder, (3) tactile defensiveness & attention deficit, and (4) visuo- and somatodyspraxia.

Other researchers, including Dr. Winnie Dunn, developed their own tools for evaluation of sensory functions (Sensory Profile), categorizing sensory dysfunctions in different ways based on their data. It must be noted, however, that the Sensory Profile is a parent questionnaire and as such an indirect and “noisy” measure of function compared to a direct psychometric measure such as the SIPT. Another researcher who researched sensory sensitivities (sensory modulation disorder), Dr. Lucy Miller, proposed to replace the term “sensory integration dysfunction” with “sensory processing disorder Miller et al. also proposed a novel categorization (nosology) of sensory integrative dysfunction, differentiating three categories: sensory modulation disorder, sensory discrimination disorder, and sensory-based motor disorder. None of these proposals have been generally accepted. The term sensory integration has been validated by recent research – particularly in the context of autism – that highlighted the importance of the integration of sensory input. The importance of the integration of sensory input is further validated by a branch of research in the neurosciences, Multisensory Integration (MSI), that examines sensory integration on a cellular level (e.g. Stein, Meredith, Wallace). Currently, both terms – sensory integrative dysfunction and sensory processing disorder – are used interchangeably by authors and scholars. The proposed nosology has not been generally accepted because it was not derived from empirical research.

Sensory Integration

The term sensory integration stands for a theory, a neurological process, and an intervention approach. “Sensory integration theory is used to explain why individuals behave in particular ways, plan intervention to ameliorate particular difficulties, and predict how behavior will change as a result of intervention” (p. 5). Sensory integration theory originated from the work of A. Jean Ayres, PhD, OTR, an occupational therapist and psychologist, whose clinical insights and original research revolutionized occupational therapy practice with children. Dr Ayres defined sensory integration as “the organization of sensations for use. Our senses give us information about the physical conditions of our body and the environment around us…The brain must organize all of our sensations if a person is to move and learn and behave in a productive manner” (p. 5).

As a neurological process, it is a “particular way of viewing the neural organization of sensory information for functional behavior” (p. 325).

As a theory, Sensory Integration is “a dynamic and ecological theory that specifies the critical influence of sensory processing on human development and function” (p. 793). “It contributes to the understanding of how sensation affects learning, social-emotional development, and neurophysiological processes, such as motor performance, attention, and arousal” (p. 792).

As an intervention approach, Sensory Integration therapy Sensory integration therapy is used as “a clinical frame of reference for the assessment and treatment of people who have functional disorders in sensory processing” (p. 325). Ayres considered sensory integration intervention “a speciality of occupational therapy” (Ayres 1979, p. 155). Thus, the assessment and intervention from a sensory integration perspective are most commonly used by occupational therapy practitioners in their treatment of children with difficulties in occupational performance and participation related to sensory integrative or sensory processing dysfunction.

Ayres’ pioneering research and practice in Sensory Integration proliferated among therapeutic and educational professionals over the past several decades and is now known and practiced in over 100 countries worldwide. Sensory integration theory and practice has been met with resistance within the occupational therapy profession as well as other disciplines. Despite controversy, the research base of sensory integration theory and practice is growing and expanding. Ayres Sensory Integration was trademarked to delineate the core tenets of her theory and intervention techniques that continue to be used and taught today. Currently the intervention methods and tools Dr. Ayres pioneered continue to be questioned and investigated. Dr. Ayres anticipated and understood the necessity for the refinement and evolution of her work with the advancements in neurological science and our increased understanding of the brain and our central nervous system. A growing number of practitioners around the world are educated in sensory integration theory, assessment, and intervention techniques as well as taking up the call for further research to strengthen and enhance Dr Ayres’ original body of work.