CHAPTER 19 Sensory Overresponsivity Timothy W. Soto Vivian M. Ciaramitaro Alice S. Carter Sensory overresponsivity (SOR) is character- Theoretical Orientations of Sensory Processing ized by extreme or atypical negative reactions to sensory stimuli across one or more sensory Sensory processing issues were first described domains (Dunn, 1999; Interdisciplinary Coun- in 1963 by Anna Jean Ayres, who was trained cil on Developmental and Learning Disorders as an occupational therapist and educational [ICDL], 2005; Lane, 2002; Parham & Mailloux, psychologist, to explain, assess, and treat the 2004; Reynolds & Lane, 2008). Broadly, there behavioral and learning challenges experi- are several hypothesized models that explain enced and expressed by children with various the neurological and behavioral underpinnings disabilities by relating neurological processing of atypical sensory processing. SOR is one par- of and behavioral responses to sensory stimuli ticular manifestation of sensory dysfunction; (Miller, Anzalone, Lane, Cermak, & Osten, it often co-occurs with psychiatric disorders 2007). Ayres (1985) used the term “sensory (i.e., attention-deficit/hyperactivity disorder integration” (SI) to describe these phenomena. [ADHD], generalized anxiety disorder, oppo- Underlying the developmental component of sitional defiant disorder) (Ben-Sasson, Soto, SI theory is the assumption that learning stems Heberle, Carter, & Briggs-Gowan, 2017; Carter, from one’s ability to detect, process, and use Ben-Sasson, & Briggs-Gowan, 2011; Conelea, sensory information from the environment and Carter, & Freeman, 2014) and is characterized from one’s movement to plan and organize be- as a possible symptom of autism spectrum dis- havior (Bundy, Lane, & Murray, 2002). More order (ASD) within the repetitive and restrictive specifically, individuals differ in their way of behavior criteria of DSM-5 (American Psychi- processing information from the visual, audito- atric Association, 2013). SOR also occurs and is ry, tactile, vestibular, proprioceptive, gustatory, associated with clinical impairment without co- and olfactory senses (Huebner & Dunn, 2001). morbid psychiatric or neurocognitive disorders Since Ayres’s initial work in SI, theoretical (Carter et al., 2011). We review in this chapter models and research evidence for this construct the theoretical orientations that have framed have been further developed, and through the SOR as a disorder, and current developmental advancement of such models, the operational- and neurocognitive understandings of sensory ization and clinical characterization of SOR has processing within and across the senses (i.e., become better understood. multimodal processing), and discuss potential The following three described models that Copyright @ 2019. The Guilford Press. All rights reserved. May not be reproduced in any form without permission from the publisher, except fair uses permitted under U.S. or applicable copyright law. future directions for research. have evolved from Ayres’s initial work provide 330 EBSCO : eBook Collection (EBSCOhost) - printed on 7/2/2019 3:12 PM via TUFTS UNIV AN: 1843598 ; Zeanah, Charles H..; Handbook of Infant Mental Health, Fourth Edition Account: s3579704.main.ehost 19. Sensory Overresponsivity 331 the foundation for the primary ways in which sponsivity (SOR), which describes exaggerated, sensory processing, particularly SOR, is cur- rapid onset and/or prolonged reactions to senso- rently conceptualized and measured. First, ry stimulation (e.g., distress from loud noises); Winnie Dunn’s (1997) conceptual model of sen- (2) sensory underresponsivity (SUR), which ex- sory processing combines neurological thresh- plains unawareness or slow response to sensory olds of responding (low or high) with self-reg- input (e.g., not noticing extreme changes in tem- ulation behavioral strategies (passive or active), perature); and (3) sensory seeking (SS), which and includes four hypothesized patterns: sen- describes craving of, and interest in, sensory sation seeking, sensation avoiding, poor reg- experiences that are prolonged or intense (e.g., istration, and sensitivity to stimuli (i.e., SOR). engaging in repeated, rhythmical movements) The model suggests that individuals with low (ICDL, 2005; Miller, Anzalone, et al., 2007). neurological thresholds need less stimulation These patterns are not mutually exclusive and than those with high neurological thresholds to may co-occur in individual children across notice and respond to input. Indeed, high levels sensory modalities (Baranek et al., 2006; Liss, of stimulation may be aversive for individuals Saulnier, Fein, & Kinsbourne, 2006). For our with low neurological thresholds. Individuals purposes in this chapter, while the previously with active self-regulation strategies attempt to stated terms are used when referencing specific control sensory input through active behaviors, studies, the term “sensory dysfunction” is used whereas those with passive self-regulation strat- to describe abnormal sensory processing in a egies respond to the input as it occurs. Varia- general sense. tions of these four patterns are common in the broader population and do not always represent dysfunction. Mechanisms Underlying Sensory Dysfunction Second, Baranek, Reinhartsen and Wan- namaker (2001) developed a model of sensory Although sensory dysfunction may involve processing, which postulates that hyper- and hypersensitivity, hyposensitivity, or an atypi- hyporesponsive sensory modulation behavioral cal interaction and/or integration of informa- patterns may result from shifts in two sensory tion between sensory systems, the majority of processing thresholds: sensory aversion and studies considering the neural basis of sensory sensory orienting. According to their model, dysfunction in developmental disorders have optimal engagement in play and other activi- focused on a single sensory modality and on ties is determined by the width between the two neural mechanisms underlying hypersensitiv- thresholds. Moreover, Baranek and colleagues ity, or SOR. In SOR, behavioral responses to theorize that the width between the orientation sensory stimuli across one or more sensory do- and aversion thresholds is determined by both mains are exaggerated or negative (Dunn, 1999; child characteristics (e.g., attention, affect) and ICDL, 2005; Lane, 2002; Parham & Mailloux, external factors (e.g., environmental and con- 2004; Reynolds & Lane, 2008; Zero to Three, textual features, caregiver interactions). They 2016). This may arise from the nervous system further suggest that this optimal band of en- overenhancing or failing to weaken neural re- gagement may be narrower in individuals who sponsiveness to sensory input. have sensory dysfunction (e.g., children with SOR or autism), leading to variations and fluc- Atypical Sensory Adaptation tuations in responses. Third, and more recently, Miller, Anzalone, Evidence suggests that neural mechanisms for and colleagues (2007) proposed a diagnostic weakening neural responses to sensory input, classification of sensory dysfunction called sen- sensory adaptation, may be dysfunctional in sory processing disorder (SPD), which includes several disorders when SOR is comorbid, such three patterns: (1) sensory discrimination disor- as in children with ASD, and individuals with der (SDD)—difficulty processing and/or inter- social anxiety or schizophrenia. Adaptation is preting sensory information; (2) sensory-based a powerful mechanism, allowing our nervous motor disorder (SMBD)—a motor challenge systems to remain most sensitive and respon- with an underlying sensory basis, such as pos- sive to novel, nonredundant, information via a tural disorder and dyspraxia; and (3) sensory weakening or dampening of responsiveness to modulation disorder (SMD). SMD disorder is repeated, redundant stimuli. For example, adap- Copyright @ 2019. The Guilford Press. All rights reserved. May not be reproduced in any form without permission from the publisher, except fair uses permitted under U.S. or applicable copyright law. classified into three types: (1) sensory over-re- tive mechanisms contribute to our ability to dis- EBSCO : eBook Collection (EBSCOhost) - printed on 7/2/2019 3:12 PM via TUFTS UNIV AN: 1843598 ; Zeanah, Charles H..; Handbook of Infant Mental Health, Fourth Edition Account: s3579704.main.ehost 332 IV. Psychopathology tinguish between many exemplars of similar study, 11-year-old children were asked to dis- faces (Clifford & Rhodes, 2005). Adapting to criminate two facial identities when they had or noninformation stimuli also helps to highlight had not been previously adapted to an opposite the information in our environment of the high- identity face. Exposure to a given face identity est behavioral relevance, in which the allocation biased perception, resulting in an aftereffect of limited attentional and processing resources biased toward the opposite identity face. This should be optimized. Thus, a failure of adap- design allowed investigators to determine the tation maintains heightened responsiveness to degree of adaptation to faces independent of stimuli, failing to adjust the gain or sensitivity the ability of children to discriminate between to sensory inputs. A failure of adaptation also faces. While face identification was unimpaired limits the reprioritization of sensory process- in children with ASD—they could discriminate ing resources and the redirecting of attention to facial identities as well as controls—they exhib- allow recent