Occupational therapists are concerned with the ability of individuals to participate in meaningful activities that support both physical and mental health. As a health profession with a holistic lens, occupational therapy provides a unique understanding of the interaction between an individual’s physiological framework and the external environment. This interaction may result in increased or decreased participation in meaningful activities, depending on the individual person and the resources or barriers available in the environment. One framework that provides insight into this interaction is sensory integration. Dunn (2001) proposed a model of sensory processing that conceptualizes the confluence of two continua: individual neurological thresholds for receiving sensory information and behavioral response strategies following sensory input. Neurological thresholds range between low (e.g. requiring very little sensory input to produce a response) and high (e.g. requiring much sensory input to produce a response); behavioral response strategies range between passive and active. “An active response works to oppose the sensory response and “right” the system. In contrast, a person with a passive response will respond in agreement with his or her sensory threshold” (Pfeiffer, Brusilovskiy, Bauer, & Salzer, 2014, p. 290).
Each individual may present with either passive or active behavioral response strategies and either low or high neurological thresholds, resulting in patterns that Dunn (2001) described using the following quadrants:
low registration (high threshold + passive behavioral response),
sensory sensitivity (low threshold + passive behavioral response),
sensation avoiding (low threshold + active behavioral response) and
sensory seeking (high threshold + active behavioral response).
Studies have shown that engagement in activities, community participation, and social support vary among persons who present with different quadrants of Dunn’s (2001) Sensory Processing Model. In a study that explored whether extreme responses on any of the four quadrants were independently related to differences in community participation, recovery, or quality of life, results showed that “individuals with self-reported higher levels of low registration and sensory sensitivity identified significantly less participation and perceived potential for recovery than did their peers with processing patterns in typical ranges. Individuals with higher levels of self-reported sensory sensitivity also reported reduced quality of life” (Pfeiffer et al., 2014, p.292). One explanation for this hypothesizes that for self-reported low registration, a high threshold response, “activities and environments do not provide the necessary intensity or variability to enable them to sustain attention…in contrast, over attention to stimuli in the environment in individuals with self-reported sensory sensitivity, a low threshold response, interferes with their ability to participate in activities of interest” (Pfeiffer et al., 2014, p.293).
Individuals who identify with passive behavioral response strategies, therefore, seem to have greater difficulty participating in external environments, especially in the community and may be at higher risk for mental health problems. Similarly, some individuals who present with low neurological thresholds may also have difficulty modulating their neurological responses to the environmental sensory stimulation to which they are exposed. One type of sensory modulation difficulty is known as sensory defensiveness or sensory over-responsivity.
“A person is sensory defensive when he or she experiences the fight/ flight reaction to a sensation that other people do not experience as harmful. Sensory defensiveness can occur in one or more or all of the sensory systems, with varying degrees of severity. Like other disorders, the symptoms of sensory defensiveness are changeable, depending on stress and other environmental factors” (Abernathy, 2010, p.211). The experience of sensory defensiveness or over-responsivity in daily life has been described as “irritating, overwhelming, disorganizing, and distracting” (Kinnealey, Koenig, & Smith, 2011, p.320), and is associated with increased experience of mental health issues such as anxiety and depression (Kinnealey et al., 2011). Research into the experiences of adults with sensory defensiveness illustrates the pervasive effect this sensory processing and modulation style has on participation in daily life, in regard to the choices the person makes for engagement in hygiene, leisure, employment, clothing, and interpersonal interactions. For example, “if a person has tactile defensiveness, he or she may not be able to tolerate anything touching his or her face, such as a flannel or water from a shower, which would influence the person’s ability to maintain hygiene” (Abernathy, 2011, p.214).
Results from a study that explored relationships between sensory processing style, symptoms of anxiety and depression, health-related quality of life, and social participation revealed that higher rates of sensory over-responsivity were associated with increased symptoms of anxiety and depression, and decreased rates of perceived social supports (Kinnealey et al., 2011).
Conversely, “individuals with active response patterns engage in behaviors to counteract their sensory thresholds that, likely, allow them to adapt for similar participation, potential for recovery, and quality of life when compared with their peers without these extreme sensory processing responses” (Pfeiffer et al., 2014, p.294). Studies exploring relationships between sensory processing styles and participation or health-related quality of life found that self-reported sensory seeking was associated with increased participation, recovery, empowerment, and vitality (Pfeiffer et al., 2014; Kinnealey et al., 2011).
While individuals with sensory defensiveness or over-responsivity may be at higher risk for mental health symptoms, this is not inevitable. Interventions that promote sensory self-regulation and environmental modification, as well as increasing social support, can provide a foundation for increased quality of life. Interventions for children that focus on sensory regulation using the sensory integration approach have shown positive outcomes when establishing daily and weekly routines that incorporate customized patterns of social, motor, and sensory activities, and these same approaches may be helpful for adults (Kinnealey et al., 2011). Interventions to address sensory regulation should enable and empower individuals through developing insight into a person’s sensory processing style, while also providing guidance in developing and maintaining social support networks. With a profound understanding of sensory processing, a foundation of knowledge in both physiological and neurological functioning, as well as expertise in daily habits and routines, occupational therapists provide an integral contribution to facilitating participation in meaningful activities that support both physical and mental health.
Sharon Vincuilla, OTR/L
Occupational Therapy Doctoral Resident
Abernethy, H. (2010). The assessment and treatment of sensory defensiveness in adult mental health: A literature review. The British Journal of Occupational Therapy, 73(5), 210-218. http://dx.doi.org.libproxy2.usc.edu/10.4276/030802210X12734991664183
Kinnealey, M., Koenig, K. P., & Smith, S. (2011). Relationships between sensory modulation and social supports and health-related quality of life. American Journal of Occupational Therapy, 65, 320–327. doi: 10.5014/ajot.2011.001370
Pfeiffer, B., Brusilovskiy, E., Bauer, J., & Salzer, M. S. (2014). Sensory processing, participation, and recovery in adults with serious mental illnesses. Psychiatric Rehabilitation Journal, 37, 289–296. https://doi.org/10.1037/ prj0000099