Interoception, the ability to sense and interpret internal bodily signals, is a cornerstone of human functioning. It allows us to identify when we are thirsty, hungry, or need to swallow. For medical Speech Pathologists, this plays a critical role in both swallowing and communication. This blog post explores the importance of interoception in dysphagia and communication, how to assess it, ways to improve it, and considerations for specific populations where interoceptive challenges are prominent.
Interoception in Dysphagia
Swallowing is a complex process that relies heavily on interoceptive feedback to recognize the need to swallow, initiate the act, and coordinate safe and efficient bolus transit. Impairments in interoception can result in:
- Delayed or absent swallow initiation: Individuals may not feel the need to swallow saliva or food, leading to drooling or laryngeal penetration and/or aspiration.
- Pharyngeal residue and aspiration risk: Poor awareness of retained food or liquids in the throat can increase the likelihood of choking and/or aspiration.
- Globus sensation: Some individuals report a persistent feeling of something stuck in the throat, common in Functional Neurological Disorder (FND) as well as stress-related swallowing issues.
In conditions like Ehlers-Danlos Syndrome (EDS), Parkinson’s Disease (PD), and FND, interoceptive deficits often exacerbate swallowing difficulties. For example:
- EDS: Hypersensitivity or hyposensitivity to internal signals may result in unrecognized saliva pooling.
- PD: Altered interoception may reduce awareness of swallowing dysfunction, such as silent aspiration or prolonged pharyngeal residue.
- FND: A mismatch between sensory input and motor output disrupts normal swallowing patterns, sometimes causing exaggerated or absent swallowing behaviours.
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Interoception in Communication
Interoception extends beyond swallowing and is intricately linked to communication. Awareness of internal bodily states underpins emotional regulation, tone of voice, fluency, and pragmatic skills. Specific examples include:
- Voice Disorders: Individuals with vocal hyperfunction often have reduced interoceptive awareness of laryngeal tension, contributing to dysphonia.
- Stuttering: Heightened physiological arousal or poor awareness of internal tension can exacerbate fluency disruptions.
- Cognitive-Communication Impairments: People with traumatic brain injury (TBI) or right hemisphere damage may struggle to identify internal stress signals, affecting their ability to modulate tone of voice or interpret emotional cues.
- FND and Functional Voice Disorders: Disrupted interoception may contribute to inconsistent voice output or whispering dysphonia, as seen in FND. Techniques to reconnect sensory-motor pathways are often required.
Interoception also supports pragmatic communication by helping individuals recognize and express emotions. For example, individuals with autism spectrum disorder (ASD) may have difficulty linking internal states (e.g., tension or excitement) with appropriate social communication behaviours.
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Assessment of Interoception
Accurately assessing interoception is essential for tailoring interventions. Clinically-validated tools and approaches include:
- Interoceptive Awareness Questionnaire (IAQ): Measures a person’s awareness of internal body signals, such as hunger, thirst, or tension.
- Heartbeat Perception Test: Evaluates interoceptive accuracy by comparing perceived and actual heartbeats.
- Mindful Eating Questionnaire: Assesses interoceptive awareness during mealtime, including recognition of hunger and fullness.
- Speech and Voice Observations: Observe for signs of reduced interoception, such as difficulty identifying vocal tension in dysphonia or inconsistent fluency triggers in stuttering.
- Self-Report Tools: Tools like the Toronto Alexithymia Scale assess the ability to recognize and describe emotions, often tied to interoceptive awareness.
Clinical observation is also critical. For example, does the person notice saliva pooling? Can they describe what it feels like before a swallow? These observations provide invaluable insight into their interoceptive functioning.
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Ways to Build Interoception
Interoception is a skill that can be improved with targeted interventions. Evidence-based strategies include:
For Swallowing:
- Mindful Swallowing Exercises: Encourage individuals to focus on sensations in their mouth and throat during eating or saliva management.
- Biofeedback Tools: Devices like sEMG provide visual feedback of muscle activity, helping people connect internal sensations with external actions.
- Verbal Cues and Descriptions: Ask patients to describe what swallowing feels like (e.g., “How does your throat feel before you swallow saliva?”).
For Voice and Speech:
- Semi-Occluded Vocal Tract Exercises: These improve proprioceptive and interoceptive awareness of the vocal mechanism, reducing tension and improving voice quality.
- Resonant Voice Therapy: These techniques encourage individuals to reflect on where sounds can be felt resonating in the vocal tract.
- Body Scanning Techniques: Focus on sensations in the throat, chest, or diaphragm before speaking.
For Cognitive-Communication:
- Emotional Labeling Exercises: Help individuals to identify physical sensations linked to emotions (e.g., “What does nervousness feel like in your body?”).
- Pragmatic Training: Encourage pairing internal sensations with social cues, enhancing emotional regulation and appropriate communication.
For Other Disorders:
- Grounding Techniques: Focused breathing, tactile feedback, or humming can help clients reconnect with their bodies.
- Mindfulness Training: Practices like guided meditations can improve interoceptive awareness and reduce physiological arousal in stuttering or functional voice disorders.
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Specific Populations with Interoceptive Challenges
Interoceptive difficulties are not limited to FND, EDS, and PD. They are also prominent in:
- Autism Spectrum Disorder (ASD): Research shows that individuals with ASD often struggle with interoceptive awareness, affecting emotional regulation, hunger cues, and pragmatic communication (Mahler, 2016).
- Traumatic Brain Injury (TBI): TBI often disrupts interoceptive pathways, leading to impaired emotional regulation and communication difficulties (Barrett et al., 2004).
- Anxiety Disorders: Heightened interoceptive sensitivity can amplify stress responses, contributing to communication and swallowing difficulties.
- Eating Disorders: Poor interoceptive awareness of hunger and fullness signals is a core feature of anorexia nervosa and bulimia (Fassino et al., 2004).
- Chronic Pain Syndromes: Conditions like fibromyalgia involve altered interoceptive processing, which can affect both swallowing and speech due to pain-related hypersensitivity.
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Conclusion
Interoception is a foundational yet underappreciated aspect of swallowing and communication therapy. By assessing and improving interoceptive awareness, we can better support our clients in achieving functional, meaningful outcomes. Whether it’s helping someone with FND rebuild trust in their swallowing process or guiding a client with ASD to connect emotions with social cues, interoception should be a key consideration in our clinical reasoning.
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References:
- Barrett, L. F., Quigley, K. S., Bliss-Moreau, E., & Aronson, K. R. (2004). Interoceptive sensitivity and self-reports of emotional experience. Journal of Personality and Social Psychology, 87(5), 684–697. https://doi.org/10.1037/0022-3514.87.5.684
- Craig, A. D. (2002). How do you feel? Interoception: the sense of the physiological condition of the body. Nature Reviews Neuroscience, 3(8), 655–666. https://doi.org/10.1038/nrn894
- Edwards, M. J., Adams, R. A., Brown, H., Pareés, I., & Friston, K. J. (2012). A Bayesian account of ‘hysteria’. Brain, 135(11), 3495–3512. https://doi.org/10.1093/brain/aws129
- Fassino, S., Pierò, A., Gramaglia, C., & Abbate-Daga, G. (2004). Clinical, psychopathological, and personality correlates of interoceptive awareness in anorexia nervosa, bulimia nervosa, and obesity. Psychosomatics, 45(3), 238–245. https://doi.org/10.1176/appi.psy.45.3.238
- Mahler, K. (2016). Interoception: The Eighth Sensory System. Shawnee Mission, KS: AAPC Publishing.
- Titze, I. R. (2008). The human instrument. Scientific American, 298(1), 94–101. https://doi.org/10.1038/scientificamerican0108-94
