NeuroCon · Understanding the mechanisms of pain modulation through expectations (conscious and unconscious) in placebo analgesia induced in the context of fear conditioning - MEG and EEG study
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2020-09-01 → 2022-08-31
- EU contribution
- €172,932
- Participants
- 1
- Scheme
- MSCA-IF
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Results in brief
Understanding the mechanisms of pain modulation through expectations (conscious and unconscious) in placebo analgesia induced in the context of fear conditioning - MEG and EEG study
Modern pharmacology provides us with several effective analgesia methods (e.g. pills, injections, creams). Despite working well for acute pain, they are ineffective for chronic pain, a major problem affecting approx. 20% of the EU population. Chronic pain can persist for months or even years and is associated with an over-sensitive and over-responsive nervous system. In contrast to acute pain, it is not caused by physical damage to the body and is believed to result from a complex interplay of biological, psychological and social factors, where conditioned pain-related fear is partially responsible for the symptom's chronicity maintenance and perpetuation. For this reason, even strong opioids are usually helpless but often overprescribed. Their abuse is a serious health problem which can even lead to death through overdose. As a result, it is crucial to investigate other analgesia methods not based on active substances. Their effectiveness depends on many factors, e.g. earlier positive/negative experiences or our attitude and expectations related to their effectiveness. Such relationships are acquired via a learning mechanism called classical conditioning (CC). In CC a previously neutral stimulus (the conditioned stimulus, CS) is paired with a biologically potent stimulus (the unconditioned stimulus, US) and starts to elicit a conditioned reaction (CR) that is similar to the one elicited by the US. Our cognition modulates pain perception and placebo analgesia, which works through the expectation of pain decrease induced via CC, is the best example of it. Concluding, laboratory studies where placebo manipulation is introduced during fear conditioning may help to recognise the specific role of expectations that modulate pain perception. Moreover, investigating fear conditioning processes can be important to explain and find markers that may help in the early recognition of potential pain problems. Specifically, examining how the sensory response system adapts to relevant or irrelevant information and recognising the abnormalities in this process provides a promising method of prediction of further disabilities. Such investigation has great potential in clinical practice since it can help develop adequate pain therapy and pain management strategy. Consequently, the main objectives of this project were to understand the mechanisms of information prioritization, how neutral stimuli gain their relevance in the process of learning (fear conditioning) and to investigate if placebo manipulation (consciously or unconsciously formed expectations) influences different aspects of experience (e.g. during anticipation of pain/mid-pain/tactile/no-stimuli delivery, administration of stimulus and post-stimulus pain ratings).
Data: CORDIS, © European Union
Project objective
Chronic pain patients cannot be efficiently treated with pharmacological methods and hence investigating alternatives such as psychological-based treatments is essential. One of the well-recognised method of analgesia is placebo which is based on learning processes – classical conditioning (CC). Through CC, expectations about pain relief are formed and those are recognised to mediate the placebo effect. Moreover, the effects of CC play a prominent role in the development of chronic pain-related fear and disability, so investigating the basis of fear conditioning may help developing better pain management strategies.Expectations about pain relief are shown to reduce the activation of pain-related brain regions and cues associated with pain decrease are processed in higher-order areas of the brain. However, the latest studies are inconclusive in determining to what extent expectations are elicited consciously or unconsciously and it is suggested that it depends the way the effect is generated - simple conditioning or conditioning with verbally induced expectations. In order to bring new light on this subject, the neural basis of the process and how the brain activity changes in order to recognise relevant and irrelevant information during conditioning still needs further investigation.In order to understand the relation between CC and expectancy in placebo analgesia, this project will implement both types of CC in the context of basic fear conditioning procedure. The brain activity will be measured using MEG and EEG technique and investigated using multiple methods of signal analysis which is a novelty in placebo research. The aim of the project is investigating how sensory cortices are modified to better detect relevant information using MEG and studying anticipatory brain activity using EEG. It may provide an answer to what extent conscious and unconscious processes are involved in pain modulation and what regions of are involved in this process.
Original text from CORDIS.
Participants
- UNIVERSIDAD COMPLUTENSE DE MADRID · MadridCoordinatorSpain
Links
Data: CORDIS, © European Union