Clarifying pain behaviour and pain expression

IEEE Transactions on Affective Computing, 2016

Pain-related emotions are a major barrier to effective self rehabilitation in chronic pain. Automated coaching systems capable of detecting these emotions are a potential solution. This paper lays the foundation for the development of such systems by making three contributions. First, through literature reviews, an overview of how chronic pain is expressed and the motivation for detecting it in physical rehabilitation is provided. Second, a fully labelled multimodal dataset containing high resolution multiple-view face videos, head mounted and room audio signals, full body 3-D motion capture and electromyographic signals from back muscles is supplied. Natural unconstrained pain related facial expressions and body movement behaviours were elicited from people with chronic pain carrying out physical exercises. Both instructed and noninstructed exercises where considered to reflect different rehabilitation scenarios. Two sets of labels were assigned: level of pain from facial expressions annotated by eight raters and the occurrence of six pain-related body behaviours segmented by four experts. Third, through exploratory experiments grounded in the data, the factors and challenges in the automated recognition of such expressions and behaviour are described, the paper concludes by discussing potential avenues in the context of these findings also highlighting differences for the two exercise scenarios addressed.

IEEE Transactions on Affective Computing, 2015

Pain-related emotions are a major barrier to effective self rehabilitation in chronic pain. Automated coaching systems capable of detecting these emotions are a potential solution. This paper lays the foundation for the development of such systems by making three contributions. First, through literature reviews, an overview of how chronic pain is expressed and the motivation for detecting it in physical rehabilitation is provided. Second, a fully labelled multimodal dataset containing high resolution multiple-view face videos, head mounted and room audio signals, full body 3-D motion capture and electromyographic signals from back muscles is supplied. Natural unconstrained pain related facial expressions and body movement behaviours were elicited from people with chronic pain carrying out physical exercises. Both instructed and noninstructed exercises where considered to reflect different rehabilitation scenarios. Two sets of labels were assigned: level of pain from facial expressions annotated by eight raters and the occurrence of six pain-related body behaviours segmented by four experts. Third, through exploratory experiments grounded in the data, the factors and challenges in the automated recognition of such expressions and behaviour are described, the paper concludes by discussing potential avenues in the context of these findings also highlighting differences for the two exercise scenarios addressed.

2013

People with chronic musculoskeletal pain can experience pain-related fear of physical activity and low confidence in their own motor capabilities. These pain-related emotions and thoughts are often communicated through communicative and protective non-verbal behaviours. Studies in clinical psychology have shown that protective behaviours affect well-being not only physically and psychologically, but also socially. These behaviours appear to be used by others to appraise not just a person's physical state but also to make inferences about their personality traits, with protective pain-related behaviour more negatively evaluated than the communicative behaviour. Unfortunately, people with chronic pain may have difficulty in controlling the triggers of protective behaviour and often are not even aware they exhibit such behaviour. New sensing technology capable of detecting such behaviour or its triggers could be used to support rehabilitation in this regard. In this paper we briefly discuss the above issues and present our approach in developing a rehabilitation system.

Behavioral and Brain Sciences, 2002

The insights provided by the application of evolutionary psychology to established fields of evidence has clinical relevance in areas such as fears, anxiety, and depression (Dimberg & Ohman 1996; Gilbert 1992; Marks & Nesse 1994). Certain evolved behaviours, such as the attachment behaviour of human and other primate infants, are accepted as orthodoxy. But broader notions of an evolved "human nature," that is, of specialised propensities 1 that generate functional behaviours effective in the social and material world, are still viewed with skepticism or indifference by many in the psychological and medical communities (Andersson 1993; Schaffner 1998). Among the more important reasons for this may be concern about genetic determinism or, at least, a distaste for invoking genetic factors (Crawford 1989; Daly & Wilson 1988; Plomin 1989; Tooby & Cosmides 1992), and suspicion of "Just-So Stories," that is, post hoc explanations from available evidence (Gould & Lewontin 1979). Far from endorsing the over-simple gene explanations that are sporadically revisited in psychiatry (Plomin 1989), evolutionary psychology aims to broaden our understanding of behaviour, in all its flexibility and contingency in relation to the immediate environment and the individual's learning history, by addressing the cognitive adaptations that are part of our heritage (Cronin 1991). 1. The function of pain Pain is the "final mediator" of a wide range of selection pressures (Walters 1994): sublethal injuries that may still threaten survival or reproduction are incurred during predation, intraspecific combat, and competition with conspecifics. By virtue of its aversiveness, pain serves to promote the organism's health and integrity, to the extent that congenital absence of pain on injury significantly shortens human life (Damasio 1999; Wall 1999): "Suffering offers us the best protection for survival" (Damasio 1994, p. 264). The adaptive value of experiencing pain at first seems selfevident: distinguishing harmful from harmless situations, prompting avoidance of harm and its associated cues, giving a high priority to escape from danger, and promoting healing by inhibiting other activities that might cause further tissue damage (Bateson 1991). Research in animals has focussed mainly on immediate escape from pain (e.g.,

IEEE Transactions on Affective Computing

Clinicians tailor intervention in chronic pain rehabilitation to movement related self-efficacy (MRSE). This motivates us to investigate automatic MRSE estimation in this context towards the development of technology that is able to provide appropriate support in the absence of a clinician. We first explored clinical observer estimation, which showed that body movement behaviours, rather than facial expressions or engagement behaviours, were more pertinent to MRSE estimation during physical activity instances. Based on our findings, we built a system that estimates MRSE from bodily expressions and bodily muscle activity captured using wearable sensors. Our results (F1 scores of 0.95 and 0.78 in two physical exercise types) provide evidence of the feasibility of automatic MRSE estimation to support chronic pain physical rehabilitation. We further explored automatic estimation of MRSE with a reduced set of low-cost sensors to investigate the possibility of embedding such capabilities in ubiquitous wearable devices to support functional activity. Our evaluation for both exercise and functional activity resulted in F1 score of 0.79. This result suggests the possibility of (and calls for more studies on) MRSE estimation during everyday functioning in ubiquitous settings. We provide a discussion of the implication of our findings for relevant areas.

2016

The automatic detection of chronic pain-related expression: requirements, challenges and the multimodal EmoPain dataset

Frontiers in Pain Research, 2023

This article contributes a perspective on pain motivated by the philosopher Ludwig Wittgenstein. According to Wittgenstein, the child learns from others that the occasions on which it manifests certain reactions - the reactions that human beings manifest when injured - make it appropriate to self-ascribe 'pain'. When the child can signal correctly that she is in the requisite bodily state, then she has a conception of pain. Using the concept pain to symbolise an experience also makes it possible to tell other people what is going on and to solicit their help in managing the pain. In pain discourse, we can say "Sam can tell that Jason is with pain", or "She could tell you that Jason is with pain if she wanted to". These uses are linked to social milieu where rules are learnt for the application of concepts, such as the concept stoicism. In many rural communities, adults tell other adults about pain when it interrupts work or social activities. Otherwise, it is normative to "carry on". The rural stoic who tells another about pain only if he wants to can complicate clinical pain management, which can undermine the patient's special authority. In contrast, convergence in pain definitions and judgements between the patient and health professional can protect the authority of the patient and improve the clinical interaction. Pain is not simply a quale that is privately perceived; it must be capable of being expressed. Thus, pain has a social role, which is learnt. The study of linguistic rules in pain discourse could help explain the learning and application of the concept pain.

The journal of pain : official journal of the American Pain Society, 2010

Recent developments in clinical, cognitive, and behavioral sciences as well as in social neuroscience can provide new perspectives on our understanding of different forms of pain expression and the social reactions of observers to various types of pain expression. Studies indicate that pain expression is governed by both automatic (unintentional, reflexive) and controlled (intentional, purposive) neuroregulatory systems. Reciprocal mechanisms in observers responsible for automatic (unintentional, reflexive) and controlled (intentional, reflective) reactions also are important. Observers appear more likely to display immediate "visceral" emotional reactions to unintentional, reflexive expression, whereas controlled expression characterized by purposive behavior appears more likely to elicit reflection on the nature and origins of the person's pain. This review summarizes research within the context of a theoretical model for understanding how pain is perceived in other...

2000

s and Commentaries on Pain in Infants, Children and Adolescents

2019

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