Interoception

In this episode, we explored the neuroscience and psychology behind interoception, the process that guides our sense of self and is often termed our "sixth sense". How does our perception of our internal bodily states drive our emotions and cognitive state? We discussed the place for interoception in our sense of being. We also discussed what happens when we lack interoceptive abilities, a condition known as alexithymia, and in what ways interoception has been scientifically probed in humans to help us better understand the brain regions and processes underlying it.

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We begun the episode by overviewing theories that have attributed cognitive function and emotional states to internal bodily states and processes. In other words, how we are feeling and therefore what we are thinking and doing could be down to what state our body is in, whether that be stressed or relaxed, nourished or starved, tired or energetic. We may or may not be conscious of these internal processes.

“The somatic marker hypothesis and the possible functions of the prefrontal cortex” Damasio, 1996

What is the role of interoception in shaping our cognitive function?

Individuals who are more attuned to bodily responses experience emotions with heightened intensity and have better prospective memory according to these two papers:

"Heartbeat detection and the experience of emotions" Wiens et al., 2000

“Prospective memory mediated by interoceptive accuracy: a psychophysiological approach” Umeda et al., 2016

What happens when interoception is impaired? We talked about the condition of alexithymia, which is characterised by an inability to recognise one's own emotions, and whether this can be attributed to deficits in interoception:

Here is a good review: “Alexithymia: a general deficit of interoception” Brewer, Cook, Bird, 2016

One study examining interoception in alexithymia highlighted the limitations of the heartbeat counting task to study interoception:

"Is alexithymia characterised by impaired interoception? Further evidence, the importance of control variables, and the problems with the Heartbeat Counting Task" Murphy et al., 2018

We also related interoception to the psychological processes of empathy and theory of mind

We spoke about Theory of Mind- the knowledge we have of other people's thoughts, emotions, and intentions- and the task that has been used to test it called the Sally Anne task, which was created by Baron-Cohen et al. (1985) to test Theory of Mind in autism called "Does the autistic child have a “theory of mind”?" 

And speculated on how empathy and theory of mind may relate the the neuroscientif phenomenon of mirror neurons. Here is a review about mirror neurons: “Mirror neurons: Enigma of the metaphysical modular brain" Acharya & Shukla, 2012

How does the brain process interoceptive information? How are brain and body connected?

Monitoring of the heart rate by regions of the brain associated with representation of self may link self-perception with bodily state:

“Is the cardiac monitoring function related to the self in both the default mode network and right anterior insula?” Babo-Rebelo et al., 2016