When in Sorrow, Breathe Mindfully: Neural Modulation of Respiratory Sensation and Heart-Rate Variability

Depression is the most prevalent mental health hazard and also the most common symptom seen in the bereavement grieving population. Depression has been found closely associated with altered neural processing of cardiorespiratory system and a potential risk factor for cardiorespiratory diseases. In the recent years, investigations have focused on its relationship with interoceptive awareness. This is due to the fact that humans’ perception or awareness further dictates people’s subsequent behavioral responses for being adaptive or maladaptive. Promoting a “physiologically efficient” perception would be useful in disease prevention. In the past decade, mindfulness-based training programs have gained significant amount of attention in public and also in research for its well-known purpose of preventing relapse from depression. Mindfulness modulation of individuals’ subject experience on their emotions and well-being has been discussed enormously. Of note is that no matter which type of training program it is, e.g. the mindfulness-based benevolence cultivation (MBBC), or mindfulness-based cognitive therapy (MBCT), they all include a core component of developing interoceptive attention to internal bodily sensations via yogic breathing or meditation exercises. This highlights the importance of identifying the mechanisms related to mindfulness regulation of interoception in the cardiorespiratory system. Effects of emotional regulation in the interoception of the cardiorespiratory systems can be measured by autonomic responses such as respiratory rates and heart-rate variability (HRV), and also by means of measuring brain neuronal activations such as information processing or central inhibitions. However, the evidence to inform the effects of mindfulness intervention in this regard has been scarce. This sub-project intends to test the effect of depression and mindfulness intervention in healthy controls and compare with the bereavement grieving population of the integrated project. Therefore, the purpose of this project is to systematically investigate neural modulation of respiratory awareness caused by depression, and test the effects of mindfulness intervention on respiratory interoception and HRV via both the fMRI and MEG techniques. First, we hypothesize that the levels of depression would affect the individuals’ interoceptive awareness and accuracy in response to different types of respiratory stimulations. We further expect that the behavioral testing results would correlate with neurological evidence of respiratory sensory information processing ability. Secondly, we will examine the effect of MBBC intervention on brain activations and HRV in response to respiratory occlusions under negative and neutral emotional contexts. We hypothesize that after the mindfulness intervention results in more power in High-Frequency HRV, and different brain activation patterns in the limbic system, and the parietal cortex in response to respiratory occlusions. Finally, we will test the effect of mindfulness on respiratory perceptual gating ability. We hypothesize depressed individuals with alexithymia would show a reduced function of inhibiting repetitive respiratory stimuli. After the MBCT training, these individuals would demonstrate better respiratory gating ability, and these individuals would show brain activation patterns similar to non-depressed individuals. Our preliminary results and suggest the feasibility of this proposed project. We expect the results of this project will serve as a base for future outcome studies in mindfulness effects on interoception for depressed population.

Project ID:PF10501-2479
External Project ID:MOST105-2420-H182-002-MY3