In many places we have used text passages out of order to support the narrative flow. For references, please refer to the original paper: Norman A.S. Farb et al. Mindfulness meditation training alters cortical representations of interoceptive attention, Soc Cogn Affect Neurosci (2013) 8 (1): 15-26. Extracted with permission from Oxford University Press.
This post, like the last one, resonates in an interesting way with Thomas Metzinger’s article on out of body experiences, in which one senses one’s own body more from an external perspective.
MBSR = Mindfulness-Based Stress Reduction
[I]nteroception involves sensation of the body itself, integrating visceral afferents associated with internal systems such as digestion, circulation, proprioception and respiration. ... [T]he posterior insula may constitute a primary interoceptive region, the anterior insula appears to integrate internal and external signals, regulating the direction of external attention both in constructive biases such as empathy and maladaptive biases such as addiction. ...While there are strong anatomical connections between the insula’s posterior interoceptive regions and its anterior zones, it is likely that the anterior regions are also heavily influenced by attention to external stimuli. Critically, the dominance of IA [Internal Attention] or EA [External Attention] in promoting anterior insula activity may be influenced by the attentional habits of the individuals being investigated...
The propagation of interoceptive signals from the posterior to anterior insula makes it an intriguing candidate mechanism for investigating training-related plasticity in interoceptive representation. Behaviorally, training appears to improve interoceptive accuracy for tasks such as heartbeat detection, suggesting possible neuroplasticity in an interoceptive representation network.
This interoceptive seed region was also strongly responsive to IA [breath] over EA [suppress or maintain] in both [meditation trained (MT) and untrained groups]... (Figure 4a), serving as a common region wherein attention modulates the representation of the interoceptive signal.
|Figure 4c [Note: Red represents internal attention; Blue represents external attention]|
Thus while untrained participants were able to voluntarily invoke IA to promote connectivity of interoceptive signal from the primary interoceptive cortex towards more anterior sensory intergration regions, MT participants appeared to possess this increased connectivity regardless of task. Such a finding is consistent with a...goal of MBSR practices, to provide individuals with a consistent ‘on-line’ representation of body awareness even in the face of exogenously cued stressors, weakening conceptual knowledge with competing knowledge of constantly changing interoceptive sensations.
VAC, ventral accessory gyrus; VS, ventral short gyrus; PL, posterior long gyrus;
AL, anterior long gyrus; PS, posterior short gyrus; MS, middle short gyrus;
AS, anterior short gyrus; AC, accessory gyrus.
Additionally ...MT enhanced interoceptive representation in adjacent anterior insular cortex, a region more responsive to towards exteroception than than interoception prior to training. [Data not shown]
Thus, participation in the in the MBSR program appeared to facilitate interoceptive integration across the MT group, regardless of practice compliance, consistent with an intention to integrate interoceptive information into present moment awareness. However only through daily practice was the tone of the primary insular representation enhanced...