There are many bodily functions that we take for granted because they operate outside of our momentary awareness unless something is awry. Although neuroscientists have studied the internal body sensations systems (i.e., interoception) many decades ago (Kandel et al., 2013; Ceuhen et al., 2016), applied scientists have only more recently paid attention to the relationship between one’s awareness of internal body sensations and various conditions like autism, anxiety, hypochondria, suicide attempts, and anorexia, to name a few (Engel-Yeger et al., 2013; Forrest et al., 2015; Longarzo et al., 2015; Critchley and Garfinkel, 2017; Fiene et al., 2018; Khoury et al., 2018; Abdulhamid et al., 2021).

An understanding of interoception and related conditions provides insight into how both interoceptive awareness and unawareness manifests as symptoms. Many studies have established that alexithymia (the inability to identify and describe one’s emotions) is associated with lower levels of interoception, and there is also evidence that atypical interoceptive perception might result in compromised ability to regulate body functions such as breathing (Abdulhamid et al., 2021). Similarly, adults with autism have high rates of interoceptive confusion (74%), and this lack of awareness of bodily states is associated with alexithymia (Fiene et al., 2018). Anxiety is naturally associated with interoception as many of the symptoms include bodily reactions such as shortness of breath and racing heartbeat. One model suggests that people with anxiety have poor predictive ability at interpreting interoceptive input to determine if it signals a true threat (Paulus and Stein, 2010). This poor predictive ability brings about a constant state of uncertainty for the future. A review of interoception and anxiety highlights the role that body awareness plays in learning and the exertion of a behavioral response (Van Diest, 2019). In panic disorder, interoceptive awareness in the form of feelings of breathlessness results in a conditioned response of cardiorespiratory fear and arousal. In yet another example, eating disorders are associated with a mistrust of bodily sensations (Martini et al., 2021).

Existing interoceptive measures use both physiological and self-report approaches. Garfinkel et al. (2015) suggest there are three dimensions of interoception that must be distinguished. First “interoceptive accuracy” refers to one’s ability to report about internal body sensations when compared to physiological measures. Secondly, “interoceptive sensibility” includes one’s self-perceived ability to notice internally body sensations. Finally, “interoceptive awareness” describes one’s metacognitive ability to recognize the synchrony of one’s reporting with physiological readings of internal sensations. For example, physiological measures, such as heartbeat tasks, quantify how accurately a person can detect their own heartbeat at rest (Schandry, 1981). Other measures use self-report as a means of capturing an individual’s self-perception of acuity or attention to interoception. Some self-report interoception measures focus on physiological observations (e.g., “I have an extra strong heartbeat” I feel when my bowels contract; e.g., Longarzo et al., 2015; Cabrera et al., 2018; Vlemincx et al., 2021). Others link attention to interoception as part of interoceptive sensibility (e.g., “When I’m short of breath, I focus on this”; Bogaerts et al., 2021; “I can return awareness to my body if I am distracted,” Mehling et al., 2018). Desmedt et al. (2022) examined current interoception questionnaires to examine whether they were testing a common interoceptive construct. They found that the most frequently used assessments each tested a different aspect of interoceptive sensibility. They call for additional work on both conceptualization of interoception and on clearly articulating these conceptualizations within assessments.

Yet, interoception has an impact on the person that goes beyond physiological responses, awareness of internal sensations, emotions, cognition, and symptoms. The experience of bodily sensations influences participation in daily life. The International Classification of Functioning, Disability and Health (ICF) (World Health Organization [WHO], 2001) includes physiological responses and internal body awareness as “body functions and structures.” The ICF also includes “participation” as a key factor in health; the ICF defines participation as “involvement in life situations.” For example, if someone is feeling breathless at work, they may choose to step outside for some fresh air. If someone lacks an awareness of the need to empty their bladder, they may experience accidents that could affect the ways they socialize with others. A person who notices the effect of caffeine on their body, may choose to avoid coffee later in the day so that they can get to sleep at a reasonable time. For a comprehensive conceptualization to evolve, researchers must also consider the influence of interoception on everyday life (i.e., “interoceptive impact”). Perhaps this current study extends Garfinkel et al.’s (2015) model to include this fourth dimension.

A greater appreciation for the role of interoception and symptoms has led to the development of interventions targeting interoception. There is evidence suggesting that mindfulness-based interventions can lead to increased noticing of interoception input, resulting in decreased stress and increased wellbeing (Fazia et al., 2021). In another study, women in treatment for substance use disorder experienced improvements in interoceptive awareness, emotion regulation and days abstinent after participating in a mindfulness intervention centered on body-awareness (Price et al., 2019). A systematic review of cognitive-behavior therapy for panic disorder found that the most effective interventions were those that were administered face-to-face and included interoceptive exposure (Pompoli et al., 2018). However, many practitioners are also interested in interventions with outcomes related to activities of daily living, instrumental activities of daily living, work, leisure, and socialization. Targeting participation as an outcome is best when the assessment addresses the link between interoception and participation. For example, a participation-based interoceptive measure may alert the practitioner to potential leisure restrictions because the individual is concerned with getting hurt.

When using an interoception measure for intervention planning with outcomes focused on participation, it is important that the measure link internal awareness to activities people do in their daily lives. For example, if a person fails to notice hunger or thirst (low registration of interoceptive cues) which interferes with concentration, we can collaborate to design reminders throughout the day.

The Adolescent/Adult Sensory Profile (A/ASP; Brown and Dunn, 2002) is widely accepted as an important measure for assessing sensory processing in daily life. The assessment is used for both research and clinical practice (e.g., Pfeiffer et al., 2005; Rieke and Anderson, 2009; Chung and Song, 2016; Howe and Stagg, 2016; Bijlenga et al., 2017). The A/ASP is built on an evidence-based conceptual framework (Dunn, 2014) to characterize four sensory processing preferences: sensitivity, avoiding, registration, and seeking. When the A/ASP was developed, seven senses were included: seeing, hearing, tasting, smelling, touching, moving (vestibular), and posturing (proprioception). The availability of an interoceptive measure based on Dunn (2014) provides a conceptual structure for intervention planning. Providers can obtain more details about interoceptive awareness from the four sensory processing preferences (seeking, avoiding, sensitivity, registration) to improve participation. Those who seek interoceptive input require interventions which facilitate more interoceptive activity (e.g., increasing the strenuousness of an activity), while those who are sensitive to interoceptive input require individualized plans that limit interoceptive input (e.g., planning controlled episodes of strenuousness).

In pilot studies focused on item development, researchers clarified wording, evaluated consistency with a conceptual framework (Dunn’s Sensory Processing Framework) using item to scale correlations, internal consistency tests (Chronbach’s alpha) and scale to scale correlations [A/ASP to Sensory Profile Interoception (SPI)], and edited the items based on feedback (Brown and Dunn, 2020). The current version of the SPI will benefit from further psychometric analysis that considers the relationship of the SPI with measures that capture related information already associated with interoception (anxiety, alexithymia, body awareness). If relationships are identified, this would support the construct validity of the SPI. Similarly, construct validity can be examined by determining the relationship between the SPI and Dunn (2014); the A/ASP contains subscales for the sensory patterns in DSPF, i.e., seeking, avoiding, sensitivity, and registration.

The purpose of this study was to evaluate the concurrent (A/ASP) and construct validity (other measures) of the Sensory Profile Interoception (SPI) scale, a participation-focused measure of internal body sensations. We expected that there would be positive correlations between low threshold sensory patterns (Sensitivity and Avoiding) and measures of body awareness and anxiety based on prior literature about interoception (Forrest et al., 2015; Longarzo et al., 2015; Critchley and Garfinkel, 2017; Fiene et al., 2018; Khoury et al., 2018; Abdulhamid et al., 2021). Similar to other researchers, we expected that alexithymia would be related to registration since both of these constructs reflect a failure to detect stimuli (Dunn, 2014; Fiene et al., 2018), and we hypothesized that the SPI sensory patterns would correlate most strongly with the corresponding sensory patterns of the A/ASP (Brown and Dunn, 2002) since we built items for the SPI using the same conceptual framework (DSPF; Dunn, 2014). Additionally, the SPI has the potential to expand the interoceptive framework of Desmedt et al. (2022) to include “interoceptive impact” based on the ICF model (World Health Organization [WHO], 2001) of function, disability and health.

We conducted a correlational analysis to evaluate the construct validity of the SPI.

We describe our results based on our hypotheses. Seventy-four students participated in the study. Eighty-five percent (n = 63) were White, 1.5% (n = 1) was black or African American, 4% (n = 3) were Hispanic or Latinx, 4% (n = 3) were Pacific Islanders, and 5.4% (n = 4) reported “other”; 90% were female (n = 67). They ranged in age from 21 to 45 years, with a mean of 26 years old and a standard deviation of 4.6 years. Eleven participants were 30 years of age or older. Table 2 provides the means and standard deviations for the other measures in the study. There were no differences between age groups (21–23 years, n = 22, 24–29 years, n = 41, 30 years and older, n = 11) on the measures in the study based on an Analysis of Variance by age (Hotelling’s Trace = 0.752, F = 1.128, significance = 0.338). We did not collect any additional information about the participant demographics.

Table 3 provides the correlations between the subscales of the A/ASP and the SPI. Supplementary Appendix 1 contains scatterplots of significant correlations. The constructs of Dunn’s Sensory Processing Framework (DSPF) were correlated across the A/ASP and the SPI. All of the SPI subscales correlated most strongly with their corresponding A/ASP subscale except for the avoiding subscale, with its highest correlation with the A/ASP sensitivity subscale (r = 0.366), but only a slightly lower correlation with the A/ASP avoiding subscale (r = 0.338). These findings support the SPI’s concurrent validity in terms of the measure’s consistency with its theoretical basis (the DSPF) (see Table 1 for examples), and a participation-based sensory processing measure. As outlined in Table 3, seeking is only correlated with the corresponding subscale between the 2 scales (seeking = 0.523). Registration and sensitivity have their highest correlations with their corresponding subscales (registration = 0.552; sensitivity = 0.582), although these scales also have significant correlations with other subscales.

Consistent with our hypotheses, we found that alexithymia had a small but significant correlation with the registration score on the SPI. Body awareness had moderate correlations with avoiding and seeking and a small but significant correlation with the sensitivity scores on the SPI. The State/Trait Anxiety measure had moderate correlations with sensitivity and registration on the SPI. Table 4 provides the correlations. Supplementary Appendix 1 provides scatterplots of significant correlations.

In this study, we examined the validity of the newly developed SPI in two ways. First, we examined the relationship between the SPI and the A/ASP to determine whether the SPI has a strong conceptual foundation, specifically Dunn’s Sensory Processing Framework (DSPF), with an established participation-based measure of sensory processing (i.e., the A/ASP) (concurrent validity). Secondly, we examined the relationship between the SPI and related mental health measures to determine whether the SPI reflects known relationships between interoception and psychological factors (construct validity). We provide examples of the SPI items in Table 1.

Knowing more precisely how interoceptive awareness will affect every day routines provides knowledge for effective intervention planning at the participation level. The State Anxiety scale includes “I feel tense” and “I feel upset”; the Trait Anxiety scale includes “I feel nervous and restless.” The SPI provides more detail about how “tense,” “nervous,” and “upset” might affect one’s daily routine, such as “I worry about stomach/digestive processes” and “I select hobbies that are orderly and predictable so I can stay calm” which indicate possible focus for intervention planning (e.g., in these examples, eating, or hobbies). Additionally, by also reflecting the four sensory patterns from DSPF, more precision is possible. For example, “I stay away from activities where I think I could get hurt” (avoiding), “I get bruises or other injuries, and I do not remember how the injury happened” (registration), “I enjoy activities that make my heart beat faster (e.g., vigorous physical activity, amusement park rides, scary movies)” (seeking), and “I try to control my heartbeat when it becomes too fast (e.g., by slowing down, meditating)” (sensitivity) suggest different approaches to supporting participation.

The concurrent validity of the four-quadrant model of the SPI was supported by the correlation of the SPI with the Adolescent/Adult Sensory Profile. The low to moderate correlations with the psychological factors (construct validity) already related to interoception suggest that the SPI reflects related concepts while being a distinct assessment of interoception. As the first participation-based interoception assessment, the SPI may be particularly useful for clinical use when intervention goals focus on participation-oriented outcomes.

The datasets presented in this article are not readily available because the measure described by the authors is under development and we would want to approve of any use of the data before offering it to others. Requests to access the datasets should be directed to cbrown2@midwestern.edu.

The studies involving human participants were reviewed and approved by Midwestern University Institutional Review Board. Written informed consent for participation was not required for this study in accordance with the national legislation and the institutional requirements.

WD and CB contributed to the conceptualization and design of the study, data analysis, and writing and editing of the manuscript. AB contributed by assisting with the selection of relevant assessment and editing of the manuscript. AS contributed by assisting with data collection and editing of the manuscript. All authors contributed to the article and approved the submitted version.

WD and CB were authors of the Adolescent/Adult Sensory Profile, a measure that was used in this study. We receive royalties for the assessment. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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