THE BRAIN IN PAIN: Our thoughts and emotions
Updated: Sep 21, 2020
“Thoughts and beliefs are nerve impulses too” Explain Pain Butler & Moseley.
This post explores features of brain activity during pain and how it contributes to our lived experience of pain.
Thoughts become things Bob Proctor
Image from Pixabay
This post explores features of brain activity during pain and how it contributes to our lived experience of pain.
As we mentioned in “How Pain Works”, when there is some threat to your body, nerves transmit signals from the tissues to the spinal cord and brain warning of danger i.e. nociception. As nociceptive signals get relayed to the brain there are two distinct pathways that we know of: one pathway relays signals to the sensation section of your brain (sensory cortex I and II), which allows us to identify the location of the threat and /or injury.1 Another pathway relays signals to areas of your brain that regulate emotion. This group of areas is called the limbic system, and include the amygdala (important for emotion regulation), the insula (important for assessing significance and meaning), and hippocampus (important in memory formation). Let's call it the emotional brain. This relay of information from tissues to the limbic system is actually really important; it causes us to react (mostly unconsciously) to protect ourselves.2 We automatically sense danger and behave in ways to protect ourselves…. we brace, hold our breath, limp, hold the affected body part, curl up and lie down. We also create important memories, which should serve to protect us in the future. The fact that the limbic system is activated by incoming nociceptive signals is one reason why when we have pain, we don’t just feel a sensation in a bodily part but we experience unpleasantness, react in physically protective ways and feel worried or anxious. These are normal responses.
EMOTIONS ARE KEY TO PAIN AND THEY INFLUENCE NEUROPLASTICITY….
Activity in the emotional brain can influence if, and how much, pain we actually experience. Research in this field has been revolutionized by the use of functional MRI scans, which scan brain activity while people are awake. Results from these studies have highlighted that the neurons in our brains are very plastic and can become more active and efficient at signaling (neuroplasticity) in certain conditions e.g. if we are afraid or stressed or if we have pain for prolonged periods of time.3 People with chronic pain demonstrate increased signaling in the limbic system4,5 as well as greater protective responses. The result is that for the same amount of nociception from our tissues, we can experience enhanced pain because of greater activity in the emotional brain. In other words, anxious thoughts, being stressed and worried can enhance our pain. It’s a bit of a vicious circle though as persistent pain can drive worried thoughts, which in turn can cause our nervous system to become more sensitized meaning it becomes easier to trigger our nerves into signalling. In terms of pain care, adjusting our thoughts and protective responses can be a window for reducing the sensitivity of our nervous system and hence the pain that we experience.
TAPPING INTO THOUGHTS TO OVER-RIDE EMOTIONAL RESPONSES…
One way to reduce the sensitivity of our nervous system is to tap into our cognitive or thinking brain- the logical part of our brain (anterior cingulate cortex and prefrontal cortex). Involved in executive function, these brain areas deal with decision-making and making sense of life in general. Soon after any danger has been detected, the cognitive parts of the brain become active to analyse what’s going on, if you are in danger, if you can do more damage, what the consequences of this are etc. This part of the brain can have an inhibitory or calming effect on the emotional brain and in turn enhance our natural pain system.7-9 But it can go the other way too – worried or negative thoughts can lead to greater emotional stress and reduce our brain and bodies natural pain relief.
A real- life example...
Consider if you have a fear of heights and while out hiking you come across a suspension bridge over a deep ravine. Your amygdala reacts; you feel fear and are hesitant about crossing; your sympathetic nervous system responds- your heart races, your breath quickens, you start to perspire. Scenario 1- you start to reassure yourself; you start to think logically…. “the bridge looks really sturdy…it must be safe otherwise it wouldn’t be in a national park…lots of other people have crossed and they’re safe etc..” This positive and reassuring self-talk – your pre-frontal cortex talking- can calm your amygdala enough to get you across the bridge.
Scenario 2- you panic, all you can think about is the bridge snapping and you falling into the ravine…it’s like a re-run of an Indiana Jones movie. You can’t even think…that’s it, you’re done, you’re not going any further. As a person with a fear of heights, I’ve lived out both scenarios. I’ve definitely had that experience where my fear got the better of my logical brain, which ultimately ended up with me walking the long (and sometimes wet) way round to avoid a suspension bridge! Thankfully, I’ve become better at tapping into cortical over-ride! How does this relate to pain? Well, the cognitive brain can reassure the emotional brain, and release neurotransmitters that have a calming effect both on the amygdala and on pain. This situation is not so threatening, so you don’t need to feel so much pain or be so protective.
Learning about how pain works can be very reassuring for pain sufferers and reduce fear that they are doing damage, allowing them to function better, feel less stressed and potentially experience less pain.
YOGA AND THE BRAIN IN PAIN- MEDITATION TO SOOTHE SENSITIVITY…
If part of the problem with the brain in pain is over-activity and sensitisation of emotional centres, then tapping into mind-body practices that deliberately aim to adjust emotional responses makes sense. This encompasses breath control, mindfulness and focused attention, either as solo practices (meditation and pranayama) or through asana (physical postures) practices. A key focus and area for skill development is focusing attention on bodily parts, thoughts, responses to movement and accepting resultant feelings and sensations without becoming anxious; accepting the present moment as it arises without reacting. Practices that encourage breath control may also help emotional regulation.
RESEARCH DEMONSTRATES THAT MEDITATION REDUCES EMOTIONAL REACTIVITY….
Reviews of research in this area provide some support that yoga/meditation results in reduced distress (self-reported by participants) and reductions in cortisol levels (a measure of stress response) in both healthy and clinical populations. What is impressive is the growing data supporting the value of meditation to regulate brain activity specifically, with a number of functional MRI studies demonstrating that meditation practice and/or being an expert meditator leads to reduced activity in the emotional brain and greater integration between our thoughts and emotions. Interestingly, these effects can occur in response to relatively short periods of practice.
WHILE WITHIN THE WORLD OF PAIN, there is moderate quality evidence that yoga can lead to modest improvements in pain and disability in people with chronic pain conditions and some evidence that mindfulness-based stress reduction may also be effective for pain. One particularly interesting study investigated responses to painful stimuli in meditators versus controls and found that while both groups reported the same pain intensity, meditators reported less unpleasantness associated with the pain.24
A final cautionary note… we should be careful in assuming that because research results indicate that yoga practices may be broadly beneficial, that they will be beneficial for everyone. In a thought-provoking piece Farias & Wikholm caution us that mindfulness is not for everyone- there will be people who do not respond, or who have adverse reactions whom we need to watch out for and refer for appropriate care as needed.
1. Kingsley RE. Concise Text of Neuroscience. 2nd ed. Baltimore: Lippincott, Williams & Wilkins; 2000.
2. Lumley MA, Cohen JL, Borszcz GS, et al. Pain and emotion: a biopsychosocial review of recent research. Journal of clinical psychology. 2011;67(9):942-968.
3. De Felice M, Ossipov MH. Cortical and subcortical modulation of pain. Pain management. 2016;6(2):111-120.
4. Kupers R, Witting N, Jensen TS. Brain-Imaging Studies of Experimental and clinical Forms of Allodynia and Hyperalgesia In: Brune K, Handwerker H, eds. Hyperalgesia: Molecular Mechanisms and Clinical Implications. Seattle: IASP Press; 2004.
5. Jiang Y, Oathes D, Hush J, et al. Perturbed connectivity of the amygdala and its subregions with the central executive and default mode networks in chronic pain. Pain. 2016;157(9):1970-1978.
6. Bartley EJ, Rhudy JL, Williams AE. Experimental assessment of affective processing in fibromyalgia. J Pain. 2009;10(11):1151-1160.
7. Zhuo M. Descending facilitation. Mol Pain. 2017;13:1744806917699212.
8. Gupta A, Love A, Kilpatrick LA, et al. Morphological brain measures of cortico-limbic inhibition related to resilience. J Neurosci Res. 2016.
9. Neugebauer V. Amygdala pain mechanisms. Handbook of experimental pharmacology. 2015;227:261-284.
10. Yackle K, Schwarz LA, Kam K, et al. Breathing control center neurons that promote arousal in mice. Science. 2017;355(6332):1411-1415.
11. Doll A, Holzel BK, Mulej Bratec S, et al. Mindful attention to breath regulates emotions via increased amygdala-prefrontal cortex connectivity. Neuroimage. 2016;134:305-313.
12. Menezes CB, Dalpiaz NR, Kiesow LG, Sperb W, Hertzberg J, Oliveira AA. Yoga and emotion regulation: A review of primary psychological outcomes and their physiological correlates. Psychology & Neuroscience. 2015;8(1):82-101.
13. Froeliger BE, Garland EL, Modlin LA, McClernon FJ. Neurocognitive correlates of the effects of yoga meditation practice on emotion and cognition: a pilot study. Frontiers in integrative neuroscience. 2012;6:48.
14. Holzel BK, Carmody J, Evans KC, et al. Stress reduction correlates with structural changes in the amygdala. Social cognitive and affective neuroscience. 2010;5(1):11-17.
15. Taren AA, Gianaros PJ, Greco CM, et al. Mindfulness meditation training alters stress-related amygdala resting state functional connectivity: a randomized controlled trial. Social cognitive and affective neuroscience. 2015;10(12):1758-1768.
16. Taren AA, Gianaros PJ, Greco CM, et al. Mindfulness Meditation Training and Executive Control Network Resting State Functional Connectivity: A Randomized Controlled Trial. Psychosom Med. 2017.
17. Gotink RA, Meijboom R, Vernooij MW, Smits M, Hunink MG. 8-week Mindfulness Based Stress Reduction induces brain changes similar to traditional long-term meditation practice - A systematic review. Brain and cognition. 2016;108:32-41.
18. Leung MK, Lau WK, Chan CC, Wong SS, Fung AL, Lee TM. Meditation-induced neuroplastic changes in amygdala activity during negative affective processing. Social neuroscience. 2017:1-12.
19. Bussing A, Ostermann T, Ludtke R, Michalsen A. Effects of yoga interventions on pain and pain-associated disability: a meta-analysis. J Pain. 2012;13(1):1-9.
20. Cramer H, Lauche R, Haller H, Dobos G. A systematic review and meta-analysis of yoga for low back pain. Clin J Pain. 2013;29(5):450-460.
21. Cramer H, Lauche R, Klose P, Lange S, Langhorst J, Dobos GJ. Yoga for improving health-related quality of life, mental health and cancer-related symptoms in women diagnosed with breast cancer. Cochrane Database Syst Rev. 2017;1:Cd010802.
22. Bawa FL, Mercer SW, Atherton RJ, et al. Does mindfulness improve outcomes in patients with chronic pain? Systematic review and meta-analysis. The British journal of general practice : the journal of the Royal College of General Practitioners. 2015;65(635):e387-400.
23. Gotink R, Chu P, Busschbach J, Benson H, Fricchione G, Hunink M. Standardised Mindfulness-Based Interventions in Healthcare: An Overview of Systematic Reviews and Meta-Analyses of RCTs. PLoS ONE. 2015;10(4:e0124344).
24. Lutz A, McFarlin DR, Perlman DM, Salomons TV, Davidson RJ. Altered anterior insula activation during anticipation and experience of painful stimuli in expert meditators. Neuroimage. 2013;64:538-546.
25. Farias M, Wikholm C. Has the science of mindfulness lost its mind? BJPsych Bulletin. 2016;40(6):329-332.