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Research shows that significant discrepancies exist between self-report, non-verbal expressions of pain, and evidence of tissue damage, reflecting the impact of some of these criteria, in children (Doherty et al., 1993) and in adults (Craig et al., 1992). Prkachin et al. (1994) found that self-report, nonverbal expression and observers’ judgments were in agreement when the pain was severe, but that observers had difficulty judging accurately a sufferer’s inner state when the pain was submaximal, even though evidence was manifest in the face. There is no guarantee that pain expression will be detected by the observer or that the observer will be able to draw accurate conclusions about the state of the sufferer.
It has been suggested that this inconsistency reflects the multidimensional nature of pain and human ability to detect only selected features at any given time (Hadjistavropoulos & Craig, 2002). For example, it is common for clinicians to encounter patients who appear to complain unreasonably, but express minimal nonverbal pain, and the opposite. Prkachin and Craig (1995) propose that as the sufferer’s experience is expressed, there is a loss of information transfer, causing discrepancies between the different pain indices.
I propose to understand the relationships among the various components of pain by recalling Wittgenstein’s reminder that the word ‘pain’ refers to ‘patterns in the weave of our life’ (Wittgenstein, 1958), and the complexity of this weave explains why the different pain indices are not always in agreement. It also explains why third-person psychological judgments (e.g. clinical reports) are sometimes uncertain. This reflects an indeterminacy which is constitutive of our concept of pain. That indeterminacy in turn is due to communal patterns of behavior: the concept of pain must be flexible and elastic because human behavior, and our reaction to it, is diverse and unpredictable (Wittgenstein, 1980b; 1982; 1992). Given the complexities of the pain experience, it cannot be expected that simple criteria could capture the full range of the experience (Hadjistavropoulos & Craig, 2002; Wittgenstein, 1980b). Hence, the indeterminacy of the pain experience and the challenges associated with characterizing emotional states logically exclude either self-report or nonverbal behavior alone as capable of giving expression to the subtleties involved.
As Wittgenstein (1958) observes, connections between the sensation of pain and reporting pain are highly context-dependent and depend on the criteria used to judge it (e.g. self-report or observational criteria), who is expressing the self-report, the reasons for expressing the self-report, and the person’s understanding of the consequences of reporting pain. Moreover, there is considerable potential for response bias when self-report is used to communicate features of painful experience to others (Anand & Craig, 1996). Since self-report is a fallible source of data (Schwartz, 1999), nonverbal information is often needed and employed for pain assessment (Craig, 1993). Finally, even those who are closely acquainted with a person can make even the most subtle judgments with certainty, without being able to specify conclusive criteria, since their evidence is ‘imponderable’, that is, consists of a complex syndrome of behavior, context and prior events (Wittgenstein, 1958). The constitutional indeterminacy of our concept of pain means that the different pain indices are not typically connected in a rigid way.
A researcher has discovered a way to use facial expressions to speed and slow video playback.
By using a combination of facial expression recognition software and automated tutoring technology Jacob Whitehill, a computer science Ph.D. student from UC San Diego’s Jacobs School of Engineering, is leading the project that ultimately is part of a larger venture to use automated facial expression recognition to make robots more effective teachers.
Rebecca Smith, Telegraph, June 24, 2008
Newborn babies show pain and discomfort through body movements, changes in blood pressure and facial expressions although they may or may not cry.
But new research has shown that the traditional signs medical professionals look for may only detect the most severe pain.
A team at University College London warned that infants may appear to be pain free but actually are still experiencing discomfort.
Babies display pain by grasping, flexing their arms and legs, arching their back and splaying their fingers as well as a range of facial expressions.
Researchers at UCL studied brain activity in 12 babies, some of whom were born prematurely, when they were having a painful medical procedure.
They found changes in facial expression, including a grimace, squeezing eyes shut and furrowing the brow, were best indicators the baby was in pain.
But also some of the babies showed brain changes associated with pain but no physical sign raising concerns doctors could be underestimating discomfort in these children.
The team believes the work can help doctors and eventually parents to use physical clues to establish if and how much pain babies are experiencing.
Dr Rebeccah Slater, lead author from UCL Neuroscience, Physiology and Pharmacology, said: “Although our study was small, it does raise concerns about the tools normally used by doctors to establish whether a baby is feeling pain.
“Infants may appear to be pain free, but may, according to brain activity measurements, still be experiencing pain. It would be exciting to explore whether measures of brain activity could complement current methods for measuring pain in infants.”
Dr Slater said relying on a baby’s cry may not be the best way to establish pain, especially in premature or very young babies in hospital.
She added: “Babies do cry when they are in pain, but they also cry when they are cold, hungry, tired and stressed. So, just because a baby is crying it might not be in pain – it is not a specific response to pain.
“Also, some babies do not cry at all when they are in pain.”
There are also physical reflexes to a pain such as withdrawing a hand or foot which does not necessarily mean the baby is experiencing pain, it is just an automatic reflex action.
The Telegraph, June 17, 2008
Scientists may have discovered the reason why some people always look glum.
Limited or very specific facial expressions could be explained by the fact that some humans have fewer muscles in their face than others, research from the University of Portsmouth suggests.
The findings could perhaps explain why certain people, such as the character Victor Meldrew in the television series One Foot in The Grave, seem to have a permanent scowl.
The study, published in the American Psychological Association Journal, found that all human being have the same set of five “core” facial muscles.
Dr Bridget Waller, who led the research, believes that these muscles control our ability to produce standard expressions showing anger, happiness, surprise, fear, sadness and disgust.
But there are an extra 14 muscles which can be present in the face, and many people do not have a full set.
Dr Waller, from the university’s Centre for the Study of Emotion in the Department of Psychology, said: “Everyone communicates using a set of common signals and so we would expect to find that the muscles do not vary among individuals. “The results are surprising – in some individuals we found only 60 per cent of the available muscles.”
One muscle, used to control our ability to create an expression of extreme fear, is found in only two thirds of the population, the study shows.
Dr Waller, from the university’s Centre for the Study of Emotion in the Department of Psychology, added: “Some less common facial expressions may be unique to certain people.
“The ability to produce subtly different variants of facial expressions may allow us to develop individual ‘signatures’ that are specific to certain individuals.”
She said that the only other part of the body where muscles were not uniform was the forearm, where 15 per cent of the population lack a specific muscle.
Philippe Sommet, Face of Fear
Here, I posted an article on the facial expression of fear. The authors of the study, Adam Anderson and Joshua Susskind (University of Toronto) argue that the facial expression of fear
increases our range of vision, speeds up eye movement and improves air flow through the nose. All of these reactions boost our ability to see or smell threats and prepare ourselves for the “fight or flight” response, where we either battle it out with our attacker or take to our heels.
This result suggests that the facial expression of fear does not exist merely to accurately express fear. The facial expression of fear exists rather to promote the survival of the individual organism. But, the adaptive value of fear points beyond the biological individual (the signaller) to include benefits concerning the onlooker. One benefit to onlookers may be information about possible danger. This is contrasted with the resource costs of signalling and the potential danger of increasing vulnerability to the signaller.
The blend of benefits and risks for the facial expression of fear (fear-behavior) suggests that it may be adaptive for a species to modify the intentsity of its fear expression. Control in the individual in fear over the amplitude of fear expression in the face permits planned use of the expression; the ability of the onlooker to make distinctions between degrees of fear may be beneficial.
Hence, the facial expression of fear is a social phenomenon, a dimension not investigated in Anderson’s study. It is always part of a ‘form of life’, to use Wittgenstein’s term, and in this setting it is connected logically to many significant activities concerned with caregiving and care-solicitation, responsibility and kindness toward others.
If the facial expression of fear is a social phenomenon, is the meaning of fear founded on the use of fear in that context? (cf. Philosophical Investigations 43) As opposed to what? As opposed to its reference to a private ‘fear sensation’. That is to say, the facial expression of fear does not function to picture a private sensation or feeling. This means the sensation of fear does not cause the facial expression of fear.
The Guardian, June 15, 2008
The evolutionary mystery of why our faces contort when we are scared has been solved by a team of Canadian neuroscientists.
When our facial expression shifts to one of eye-bulging, nostril-flaring fear, our ability to sense attackers or other imminent danger improves dramatically, researchers found.
The findings lend support to an idea first laid out by Charles Darwin in one of his less well-known tomes, The Expression of the Emotions in Man and Animals, published in 1872. Darwin noted that facial expressions of emotion were often remarkably similar across human cultures, and even the animal kingdom, implying they may have a common evolutionary benefit.
“Most people think expressions are social signals, that they are intended to communicate what someone’s feeling. We’re saying they probably evolved as a sensory function first, even if they do help convey our feelings to others,” said Adam Anderson, a cognitive neuroscientist who led the study at the University of Toronto.
Writing in the journal Nature Neuroscience, Anderson and his colleague Joshua Susskind reveal how the classic expression of fear increases our range of vision, speeds up eye movement and improves air flow through the nose. All of these reactions boost our ability to see or smell threats and prepare ourselves for the “fight or flight” response, where we either battle it out with our attacker or take to our heels.
In the study, Susskind developed computer models for the facial expressions of fear and disgust. He then trained volunteers to pull each face. A fearful expression required participants to widen their eyes, raise their eyebrows and flare their nostrils, while a disgusted face was the opposite: a lowered brow, closed eyes and scrunched-up nose.
Measurements from video footage revealed those pulling fearful faces were not only better at spotting objects either side of them, but scanned their eyes faster, suggesting they could see danger coming more quickly.
In another round of tests, volunteers pulling disgusted faces were found to have a reduced field of vision and slower air flow through the nose.
“Fear expressions open up the face and expose the sensory surfaces, whereas disgust does the opposite, it’s a protective wincing. Fear is about vigilance and disgust is rejection,” said Anderson.
The team confirmed their findings by asking volunteers to pull different expressions while inside a magnetic resonance imaging scanner. The images reveal that fear expressions open up the nasal tubes, allowing air to be breathed in twice as fast as someone pulling a disgusted expression.
“What we’re doing is psychological archaeology. We’re unearthing the residues of the functions of these expressions. Facial expressions might be more important as social signals, but that doesn’t explain where they came from. This work explains why these expressions are common across cultures,” said Anderson.
Take the test here at the BBC.
More portraits here.