Interoception, mindfulness and touch: A meta-review of functional MRI studies

Objectives: Deficits in interoception have been identified in wide range of patients with complex, long-term health conditions including chronic pain, anxiety, depression and somatoform disorders. This review analysed findings from functional MRI studies illustrating the neural correlates of interoception, mindfulness and touch and aimed to identify possible areas of convergence between different neural processing pathways. Design: A meta-review was conducted to appraise existing systematic reviews (SR) and to explore the potential action mechanisms, which underpin manual therapy approaches that combine touch and mindfulness interventions. Methods: Five electronic databases were systematically searched from September 2017 to March 2018. SRs were evaluated for methodological quality and risk of bias using the AMSTAR 2 instrument. Results: Two high quality SRs studied neural correlates of mindfulness, two moderate quality SRs studied interoceptive tasks, and one low quality SR studied touch. Mindfulness and touch showed functional convergence in the interoceptive cortices. However, neural activation in different parts of the cortex was influenced by type of task and individual functional biases in processing tactile stimuli. Conclusions: These findings provide a rationale for further studies into the effects of combined touch and mindfulness-based interventions for treating conditions associated with central sensitization and interoceptive deficits.