Summary: A new study finds that stimulating the vagus nerve via a small electrical pulse to the outer ear can amplify the benefits of self-compassion meditation. Participants who received stimulation alongside meditation training saw larger immediate boosts in self-kindness and gradual increases in mindfulness over time.
The vagus nerve, a key player in the body’s rest-and-digest system, links the brain to major organs and influences emotional regulation. While neurostimulation alone offered limited effects, pairing it with meditation could offer therapists and patients a new way to strengthen emotional well-being.
Key Facts
- Enhanced Training Impact: Vagus nerve stimulation made self-compassion meditation more effective at increasing self-kindness and mindfulness.
- Targeted Stimulation: Electrical pulses were applied to the tragus, activating vagus nerve fibres beneath the skin.
- Future Potential: May one day help individuals with anxiety, depression, or trauma.
Source: UCL
Stimulating the vagus nerve with a device attached to the outer ear can help make compassion meditation training more effective at boosting people’s capacity for self-kindness and mindfulness, finds a new study led by University College London (UCL) researchers.
The study, published in Psychological Medicine, adds to evidence of the potential benefits of stimulating this key nerve that connects the brain with major organs in the chest and abdomen.
The vagus nerve plays a crucial role in the ‘rest-and-digest’ (parasympathetic) system, counteracting the ‘fight-or-flight’ (sympathetic) stress response, and allows the brain to communicate with all major organs in the body.
By transmitting signals from the body up to the brain, the vagus nerve can also regulate a range of psychological processes, including some involved in social interactions and emotional control.
The researchers stimulated study participants’ vagus nerve by delivering a painless electric pulse to the tragus, the small cartilaginous flap located in front of the ear canal on the outer ear. This electronic pulse was designed to activate nerve fibres that pass close to the skin surface.
The academics tested 120 healthy participants who either received vagus nerve stimulation through the skin on their tragus, or a placebo stimulation to another part of the ear. This was combined either with self-compassion meditation training or another form of training not designed to promote compassion.
The participants who received the vagus nerve stimulation alongside the self-compassion training experienced a larger and more immediate increase in self-compassion than those in the other three groups.
The participants’ level of mindfulness (awareness of the present moment and calm acknowledgement of one’s thoughts and feelings) was also measured, and the benefits to mindfulness accumulated across multiple training sessions, suggesting that while some effects of stimulation and training are immediate, others build over time.
Lead author Professor Sunjeev Kamboj (UCL Psychology & Language Sciences) said: “We found that delivering a small shock to the ear, to stimulate the vagus nerve, can amplify the benefits of certain meditation techniques, particularly those involved in cultivating self-compassion.
“Our findings reveal how neuroscience technology may have a meaningful impact on how we feel about ourselves. Neurostimulation alone had limited benefits, but it may have an important role to play in supporting meditation therapies, which are increasingly used to help people with mental and physical health problems.
“Meditation can be hard work, requiring persistence and dedication, so a way to boost and accelerate its impacts could be a welcome development for therapists and patients alike.”
The researchers say that further research is needed to refine the technique and to see how long the effects last.
Additionally, as this study only investigated healthy participants without a diagnosed psychological disorder, further research is needed to see if this approach could benefit people with conditions such as anxiety, depression or trauma.
In a separate study published last week, a separate team co-led by a UCL researcher also found that vagus nerve stimulation could help to improve fitness and exercise tolerance.
About this neurotech and psychology research news
Author: Chris Lane
Source: UCL
Contact: Chris Lane – UCL
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Electroceutical enhancement of self-compassion training using transcutaneous vagus nerve stimulation: results from a preregistered fully factorial randomized controlled trial” by Sunjeev Kamboj et al. Psychological Medicine
Abstract
Electroceutical enhancement of self-compassion training using transcutaneous vagus nerve stimulation: results from a preregistered fully factorial randomized controlled trial
Background
Physiological signals conveyed by the vagus nerve may generate quiescent psychological states conducive to contemplative practices. This suggests that vagal neurostimulation could interact with contemplative psychotherapies (e.g. mindfulness and compassion-based interventions) to augment their efficacy.
Methods
In a fully factorial experimental trial, healthy adults (n = 120) were randomized to transcutaneous vagus nerve stimulation (tVNS) plus Self-Compassion-Mental-Imagery Training (SC-MIT) or alternative factorial combinations of stimulation (tVNS or sham) plus mental imagery training (MIT: SC-MIT or Control-MIT). Primary outcomes were self-reported state self-compassion, self-criticism, and heart rate variability (HRV).
Exploratory outcomes included state mindfulness and oculomotor attentional bias to compassion-expressing faces. Most outcomes were assessed acutely on session 1 at the pre-stimulation (T1), peri-stimulation (T2), and post-MIT + stimulation (T3) timepoints, and after daily stimulation+MIT sessions (eight sessions).
Results
During session 1, a significant Timepoint × Stimulation × MIT interaction (p = 0.025) was observed, reflecting a larger acute T1→T3 increase in state self-compassion after tVNS+SC-MIT, with similar rapid effects on state mindfulness. Additionally, significant Session × MIT and Session × Stimulation interactions (p ≤ 0.027) on state mindfulness (but not self-compassion) suggested that tVNS+SC-MIT’s effects may accumulate across sessions for some outcomes.
By contrast, changes in state self-criticism and compassion-related attentional bias were only moderated by MIT (not stimulation) condition. HRV was unaffected by stimulation or MIT condition.
Conclusion
tVNS augmented the effects of SC-MIT and might, therefore, be a useful strategy for enhancing meditation-based psychotherapies. Our findings also highlight the value of oculomotor attentional metrics as responsive markers of self-compassion training and the continued need for sensitive indices of successful vagal stimulation.
