Interoception Notes

Interoception

Introduction

• Interoception refers to the perception, processing, and awareness of sensations originating within the internal body organs.

• Seminars help deepen understanding and contribute to assessments.

• Papers for seminars should be read in advance.

• You can not write about the paper you present you need to write about another paper.

Core Reading

• Core reading materials are available on Moodle.

• Additional suggested papers are also available.

• References are provided throughout the PowerPoint for further study.

Lecture Overview

• Definitions of interoception.

• Dimensions of interoception.

• Methods to study interoception.

• Neural correlates of interoception.

• Is skin an interoceptive organ?

• Examples of how interoception might be important for different dimensions of cognition or behavior examples include:

  • Emotional experience

  • Decision-making

  • Social cognition

  • Self-awareness

Senses

• Traditional five senses: sight, hearing, smell, touch, and taste.

• Other senses:

  • Sense of temperature.

  • Proprioception (perception of limb position).

  • Vestibular sense.

Interoception Defined

• Sensations originating within the body (heart rate, respiration, hunger, thirst).

• Core temperature (internal temperature) is classified as interoception.

Importance of Interoception

• Research on vision dominates compared to other sensory modalities.

• Interoception is critical and possibly the most important sense.

• It would be difficult to live without interoception.

• Infants rely on interoception to communicate needs (hunger, temperature, tiredness).

• Emotion regulation and social regulation are grounded in interoception.

• Interoception is formed in relationship with caregivers.

• Deficits in interoception can affect emotional and social processing.

• Research on interoception has surged in the last 15 years.

Homeostasis

• Homeostasis: tendency towards a stable equilibrium maintained by physiological processes.

Allostasis

• Allostasis: regulation to prepare the body before needs arise.

Conscious Detection

• Most interoceptive sensations are below the threshold of conscious detection.

• Brain regulates internal states without conscious awareness.

• Consciousness of interoceptive sensations occurs during:

  • Imbalance.

  • Emotional states.

  • Physical exercise.

  • Extreme tiredness.

• Interoceptive sensations can be overshadowed.

• Breathing involves both interoceptive and exteroceptive cues (e.g., lung expansion).

• Internal organs lack receptors, leading to referred sensations (e.g., heart attack felt in the shoulder and left arm).

Definition of Interoception

• Sherrington introduced the term interoception in the early 20th century.

• Classical definition: processing and awareness of internal body signals.

• Emphasis on sensations within the body related to the state of the body.

• Sensations generated by mechanoreceptors or chemosensors.

• Signals transferred by afferent pathways (body to brain).

• Excludes exteroceptive senses, proprioception, and vestibular sense.

Challenges with Classical Definition

• Difficulty distinguishing between exteroception and interoception.

• Importance of other sensations for homeostasis and allostasis.

Extended Definition of Interoception

• Interoception: all body sensations that carry homeostatic relevance or motivational/affective value.

• Includes sensations carried by the skin (thermoception, cutaneous pain, affective touch).

• Focus on functional and anatomical aspects.

• Sensations processed in the posterior insula.

• Information conveyed by spinal lamina one of the spinal thalamic tract.

Dimensions of Interoception

• Bottom-up to top-down organization:

  • Afferent signaling.

  • Preconscious impact of afferent signals.

  • Intraceptive accuracy.

  • Interceptive sensibility.

  • Interceptive awareness.

  • Execution and attribution.

Afferent signaling

• Processing of physiological signals from the body.

Preconscious Impact of Afferent Signals

• Impact of internal body states on cognition, behavior, and emotion processing, even without awareness.

Intraceptive Accuracy

• Ability to correctly identify intraceptive sensations.

• Measured with objective tasks.

• Sits at the border between preconscious and conscious processes.

Interceptive Sensibility

• Subjective beliefs about interceptive accuracy or interceptive attention.

• Broad term for subjective beliefs about interoceptive states and how we deal with them.

Interceptive Awareness

• Metacognitive awareness of interceptual accuracy.

• Assesses how good we are at judging how good we are in interception.

• Match or mismatch between subjective and objective ability.

Execution and Attribution

• Interpreting causes for intraceptive sensations.

• Attribution of intraceptive sensations and strategies to implement.

Focus Dimensions

• Accuracy

• Sensibility

• Awareness

• These were suggested in the core reading.

Importance of Taxonomy

• The paper brought structure to the study of interception.

• Researchers previously referred to different processes in different ways.

• When reading papers, it is important to understand what the author is referring to.

Measuring Intraceptive Accuracy

• Focus on cardiac and respiratory sensations.

• Easy to study due to concrete events (heartbeat, respiratory cycle).

Heartbeat Counting Task

• Participants count heartbeats without taking their pulse.

• Number of heartbeats counted compared to recorded heartbeats.

Heartbeat Discrimination Task

• Presenting sequences of auditory tones that reflects the heartbeat.

• Participants have to say if that sequence was on beat or off beat.

Altering Arousal

• Give an infusions of adrenaline that will increase arousal, participants need to track changes in arousal.

Strengths and Limitations

• Heartbeat counting task: traditionally most widely used.

• Heartbeat discrimination task: if you're good at one you tend to be good at the other one.

• Interceptive manipulation measures consists of arousal, and has important limitations that it's invasive.

Respiratory Domain

• Participants breathe through a device with varying resistance.

• Detect changes in airflow resistance.

Measuring Intraceptive Sensibility

• After heartbeat counting, ask participants how confident they are in their number.

• After each answer, on beat or off beat in interceptive discrimination you can ask them how confident are you in this decision.

Self Report Questionnaires

• One of these questionnaires is the MAIA multidimensional assessment of interseptive awareness.
  *Measuring various aspects of interceptive awareness.

• Other questionnaires: body perception questionnaire.

Alexithymia

• Difficulties in perceiving, differentiating, and expressing own emotions.

• Not strictly interception but related.

• High correlation between alexithymia and interception.

Meta Cognitive Awareness Measurement

• Measured through objective ability (intraceptive accuracy) and subjective beliefs (confidence).

• Match or mismatch indicates interoceptive insights.

• Someone, good at judging their self would have a good interoceptive insight.

How Dimensions Relate

• Research is mixed.

• Some studies find correlation within those who are good.

• Other research finds no relation.

Neural Underpinnings

• Network of brain regions involved in processing interoceptive sensations:

  • Brainstem.

  • Insula.

  • Anterior cingulate cortex.

  • Somatosensory cortices.

• Insula: helps bring sensations to awareness and integrate with other information.

• Somatosensory cortex: process tactile information and sensory modalities.

Neural Correlates Study

• Used fMRI to measure brain activity during heartbeat discrimination task.

• Individuals that in that were good this interceptive task, they showed more activity in the insula, especially in the anterior and right insula.

• Volume of gray matter associated with how good they are at the tasks.

Touch

• Classical definition would not classify touch as interoception.

• Standards anatomical functional definition of interoception can be related to some types of touch.

• Touch is important for emotions and well-being.

• Neural pathways convey touch through the spinal cord to somatosensory cortices.

CT Afferents

• Unmyelinated low threshold accents that we call CT afferents that have been studied widely in animals but neglected in humans for the first for a long time.

• Type of neurons: carry effective valence.

• Conveyed to specialized spina thalamic lamina one tract, projected in the insula.

• Touch is slow and pleasant (caressing).

• Activated by CT afferents, specialized group of skin afferents.

• Found mainly in hairy skin of the body.

• Slow conducting and don't respond to pressure.

• Fire mostly in velocities between one to 10 centimeters a second.

Effective Touch

• Important for social connection, emotion regulation for both adults and kids.

• We have this touch that has an effective quality to it and is conveyed to the brain through the specific, you pathway.

• Depriving a baby of this touch can be crucial.

Interoception and Cognition

• Relationship between interoceptive accuracy and:

  • Emotional experience.

  • Decision making.

  • Social cognition.

  • Self awareness.

• Mental health.

Emotional Experience

• Individuals with high intercept accuracy showed more physiological changes to the perception of emotional images.

• Individual ability to access intraceptive sensations at rest might also be helpful in accessing intraceptive sensations in conditions of mild arousal as as in this case.

Decision Making

• Task: different decks, some win and some lose money.

• Individuals who have better interest accuracy were better at this intuitive decision making.

Classical Conditioning

• Present images spiders or snakes subliminally.

• If image were followed by an electric shock, participants will form an explicit association, of the image and of shock.

• Was also measured, interceptor accuracy task separately.

• What researchers found, the research the individuals that were better at interceptor accuracy task were bet were better at judging whether they would receive the shock or not.

Social Cognition

• Distinction between cognitive theory of mind emotional states and that other person is feeling.

• In this study interoceptive accuracy correlates with effective theory of mind.

• Important for processing interception, social emotion, and affective emotion.

• Information social is integrated in the insula.

Affective Touch and Social Cognition

• Role of affective touch on feelings of social exclusion.

• Individuals that received this affective touch felt less excluded, felt less negative affect compared to those that were excluded but received affect touch afterwards.

• Slow effective touch suites the sense of social exclusion and increases social connection, even if the person that excluded the participants was not the ones that were giving effective touch.
  *When doing CT optimal touch the results where found to be what was expected.

Self Awareness

• Rubber hand illusion: individual sees a rubber hand in front of them and is simulated and their own hand is occluded. The feeling and seeing someone that is congruent tells the brain maybe their hands belongs to me. And because the interoceptive accuracy that is recorded later they will fill an average amount of ownership.

• In this study those that were better at intraceptive accuracy were better at this cardio visual synchrony modulating body awareness.

Five Month Infants

• They do is to present this stimuli flashing the screen, either synchronized with the babies but and whats being measure how long the baby is the figure the baby looks away, and measure their eye gaze. And their behaviour and study has been modulated by their behaviours integrating extracellular signals, so not synchronous.

Affective Touch and Self

*The research done was more, better, or the simulation was in CT afferent and simulation that showed it better.