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Biomedical subjects

Kenneth D Craig

Publications and source records attributed to Kenneth D Craig.

32 records · Page 2Linked to original sources
PubMed1991

Genuine, suppressed and faked facial behavior during exacerbation of chronic low back pain.

Facial activity was examined as 60 female and 60 male chronic low back pain patients responded to a painful range of motion exercise during a scheduled physical examination. Subsequently, they were asked to fake the facial response to the movement inducing the most pain or to attempt to suppress evidence that they were experiencing pain when this same movement was again repeated. Facial behavior was measured using the Facial Action Coding System. Self-reports of pain also were provided. The genuine expression was consistent with that observed in previous research, but minor differences indicated that the facial display of pain reflects differences between sources of pain, social context in which pain is induced and individual differences among patients. Considerable voluntary control over the facial expression of pain was observed, although the faked expression was more an intensified caricature of the genuine expression, and an attempt to suppress the facial grimace of pain was not entirely successful as residual facial activity persisted. Self-reports were only moderately correlated with facial behavior.

Acute Disease↗
PubMed1990

Neonatal facial and cry responses to invasive and non-invasive procedures.

Evaluation of pain in neonates is difficult due to their limited means of communication. The aim was to determine whether behavioural reactions of cry and facial activity provoked by an invasive procedure could be discriminated from responses to non-invasive tactile events. Thirty-six healthy full-term infants (mean age 2.2 h) received 3 procedures in counterbalanced order: intramuscular injection, application of triple dye to the umbilical stub, and rubbing thigh with alcohol. Significant effects of procedure were found for total face activity and latency to face movement. A cluster of facial actions comprised of brow bulging, eyes squeezed shut, deepening of the naso-labial furrow and open mouth was associated most frequently with the invasive procedure. Comparisons between the 2 non-invasive procedures showed more facial activity to thigh swabbing and least to application of triple dye to the umbilical cord. Acoustic analysis of cry showed statistically significant differences across procedures only for latency to cry and cry duration for the group as a whole. However, babies who cried to two procedures showed higher pitch and greater intensity to the injection. There were no significant differences in melody, dysphonation, or jitter. Methodological difficulties for investigators in this area were examined, including criteria for the selection of cries for analysis, and the logical and statistical challenges of contrasting cries induced by different conditions when some babies do not always cry. It was concluded that facial expression, in combination with short latency to onset of cry and long duration of first cry cycle typifies reaction to acute invasive procedures.

Analysis of Variance↗
PubMed1988

Medically incongruent chronic back pain: physical limitations, suffering, and ineffective coping.

Chronic low back pain (CLBP) patients with pain and symptomatology incongruent with physical pathology have been found to have a poorer outcome to medical treatment and rehabilitation, and to use health care resources excessively. To examine possible psychological and behavioral bases for this pattern, this investigation contrasted 40 CLBP patients who displayed non-organic physical signs, inappropriate symptoms, and/or anatomically incongruent pain drawings with 40 'control' CLBP patients without incongruent pain criteria. Multivariate analyses revealed that the incongruent CLBP group reported greater pain intensity and depression, received higher observer ratings of pain, displayed more ambulatory/postural pain behavior, and reported more dysfunctional cognitions during pain. Incongruent CLBP patients also were found to have greater physical impairment and disability. When group differences on physical impairment/disability were controlled statistically, all the afore-mentioned differences disappeared, with one exception. Incongruent CLBP patients still displayed more maladaptive and dysfunctional cognitions. These findings indicate that incongruent CLBP patients may be conceptualized as ineffective and overwhelmed in their attempts to cope and as more physically disabled as a result of their pain. The role of cognitive factors, reasons for failure of physically based interventions, and implications for patient management are discussed.

Adaptation, Psychological↗
PubMed1987

Pain expression in neonates: facial action and cry.

Pain expression in neonates instigated by heel-lance for blood sampling purposes was systematically described using measures of facial expression and cry and compared across sleep/waking states and sex. From gate-control theory it was hypothesized that pain behavior would vary with the ongoing functional state of the infant, rather than solely reflecting tissue insult. Awake-alert but inactive infants responded with the most facial activity, consistent with current views that infants in this state are most receptive to environmental stimulation. Infants in quiet sleep showed the least facial reaction and the longest latency to cry. Fundamental frequency of cry was not related to sleep/waking state. This suggested that findings from the cry literature on qualities of pain cry as a reflection of nervous system 'stress', in unwell newborns, do not generalize directly to healthy infants as a function of state. Sex differences were apparent in speed of response, with boys showing shorter time to cry and to display facial action following heel-lance. The findings of facial action variation across sleep/waking state were interpreted as indicating that the biological and behavioral context of pain events affects behavioral expression, even at the earliest time developmentally, before the opportunity for learned response patterns occurs. Issues raised by the study include the importance of using measurement techniques which are independent of preconceived categories of affective response.

Crying↗
PubMed1985

Influencing non-verbal expressions of pain: signal detection analyses.

Non-verbal expressive behaviour may provide important information about pain not available through verbal report. Nevertheless, it has received little attention in pain research. In the present study, changes in expressive behaviour resulting from electric shock were related to shock intensity, self-report of discomfort, observers' judgements of subjects' distress and social modelling influences. Subjects were videotaped while they rated low-, medium- and high-intensity shocks. Simultaneously, they were exposed to a tolerant social model or an inactive companion. Observers then viewed videotapes of subjects and judged the level of shock being delivered on the basis of non-verbal behaviour. Observers' judgements were analysed by signal detection methods to quantify expressive behaviour. Change in expressive reactions to the shocks was directly related to stimulus intensity, self-report of pain, and observers' judgements of subjects' distress. Expressive behaviour resulting from high shocks was diminished by exposure to a tolerant model. These findings establish the feasibility of pain measurement based on expressive behaviour, suggest that expressive behaviour provides a sensitive and valid index of pain, and indicate that tolerant modelling reduces evidence of pain across multiple measures.

Discrimination, Psychological↗
PubMed1977

Perceived control over pain: individual differences and situational determinants.

Determinants of perceived control over pain were varied to assess their impact on pain tolerance to electric shock in an experimental setting where variably tolerant models were used to influence pain reports and behaviour. On the basis of locus of control scores, subjects were assigned to internal and external groups. Instructions were presented emphasizing personal or environmental determinants of pain. Fifty subjects were assigned randomly to 5 groups based on these instructions and whether they were paired with a model who was tolerant, intolerant or inactive. Findings indicated internals manifested greater pain tolerance, but that the instructions on situational as contrasted with personal sources of control over pain did not influence pain behaviour. As expected, the models promoted or inhibited exposure to the shocks consistent with the model's role. Subsequent disclosure of the model's roles, followed by further pain tolerance assessment, did not lead to changes in pain behaviour, indicating that the training effect was persistent. The discussion examines relative contributions of individual differences and situational factors to pain behaviour.

Electroshock↗
PubMed1977

Factors of the langugage of pain in patient and volunteer groups.

An empirical determination of the nature and minimum number of dimension necessary to describe responses to the McGill Pain Questionnaire, and a comparison of groups, experiencing clinical or experimentally induced pain, on the dimensions were carried out. Eighty-five patients referred to a low back pain diagnostic clinic and groups of 129 volunteer students exposed to electric shock to pain threshold and pain tolerance levels described their pain using the McGill Pain Questionnaire's descriptive words. An incomplete principle component factor analysis of subjects' ratings suggested that 5 factors should be retained. These factors were judged to reflect: (I) immediated anxiety, (II) perception of harm, (III) somesthetic pressure, (IV) cutaneous sensitivity, and (V) sensory information. Canonical Analysis of Variance and univariate comparisons of back pain, threshold, and tolerance groups on these dimensions were conducted and implications for clinical and laboratory research discussed.

Adult↗
PubMedDate not supplied

The impact of maternal behavior on children's pain experiences: an experimental analysis.

OBJECTIVE: To provide an experimental investigation of the impact of maternal behavior on children's pain experiences. METHOD: Participants were 120 healthy children (60 boys, 60 girls) between the ages of 8 and 12 years and their mothers. Mothers were randomly assigned and trained to interact with their children in one of three ways while the children were exposed to lab-induced cold pressor pain: (1) a pain-promoting interaction, (2) a pain-reducing interaction, and (3) a no training control group. Training was based on behaviors presumed to have the expected impact, as based on correlational studies reported in the literature. Children's pain experiences during the cold pressor were assessed using self-reports of intensity and affect, coding of facial activity, tolerance, and heart rate responsiveness. RESULTS: Girls whose mothers interacted with them in the pain-promoting manner reported more pain than daughters of mothers in the control group, who in turn reported more pain than girls whose mothers interacted with them in the pain-reducing manner. This effect was not significant for boys. Maternal interaction type had no effect on children's pain affect, facial activity, tolerance, or heart rate. CONCLUSIONS: Results indicate that maternal behavior can have a direct impact on their daughters' subjective reports of pain. These data support the importance of social learning factors in influencing children's pain experiences.

Adaptation, Psychological↗
PubMedDate not supplied

Expression of pain in children with autism.

OBJECTIVES: Reduced pain sensitivity is widely reported to be a common feature of children with autism, yet this conclusion frequently has been based on anecdotal observations and questionable measures of pain. The aims of the study were to (1) characterize the behavioral response of children with autism experiencing a venepuncture using objective observational measures of pain and distress, (2) examine parents' assessments of pain behavior in children with and without autism, including comparison of the relationship of parental reports with behavioral measures, and (3) compare the behavioral reactions and parental assessments of children with autism with children without autism undergoing venepuncture. METHODS: Pain reactions to the invasive procedure of venepuncture were videotaped, systematically described and compared in 21 children with autism (3-7 years old) and 22 nonimpaired children, the latter providing a chronological age and gender equivalent comparison group. Parents provided observer reports of pain, and facial activity was used as an objective behavioral measure of pain. RESULTS: The children with autism displayed a significant facial pain reaction in response to the venepuncture procedure. There was a lack of concordance between parental reports of pain and observed pain responses for the children with autism. Behavioral responses of the children with autism were generally similar to the comparison group, except the substantial facial pain reactivity instigated by the venepuncture in the children with autism exceeded that displayed by the nonimpaired comparison children. Parent reports of pain severity did not differ between the autism and comparison groups. The degree of concordance between parental report and observed pain responses was consistently better for the comparison group. DISCUSSION: The findings demonstrate that children with autism display a significant behavioral reaction in response to a painful stimulus, and these findings are in sharp contrast to the prevailing beliefs of pain insensitivity described in the literature to date. The findings also raise questions about the appropriateness of parental global report as an assessment tool for pain in children with autism.

Autistic Disorder↗
PubMedDate not supplied

Detecting deception in facial expressions of pain: accuracy and training.

Clinicians tend to assign greater weight to nonverbal expression than to patient self-report when judging the location and severity of pain. However, patients can be successful at dissimulating facial expressions of pain, as posed expressions resemble genuine expressions in the frequency and intensity of pain-related facial actions. The present research examined individual differences in the ability to discriminate genuine and deceptive facial pain displays and whether different models of training in cues to deception would improve detection skills. Judges (60 male, 60 female) were randomly assigned to 1 of 4 experimental groups: 1) control; 2) corrective feedback; 3) deception training; and 4) deception training plus feedback. Judges were shown 4 videotaped facial expressions for each chronic pain patient: neutral expressions, genuine pain instigated by physiotherapy range of motion assessment, masked pain, and faked pain. For each condition, the participants rated pain intensity and unpleasantness, decided which category each of the 4 video clips represented, and described cues they used to arrive at decisions. There were significant individual differences in accuracy, with females more accurate than males, but accuracy was unrelated to past pain experience, empathy, or the number or type of facial cues used. Immediate corrective feedback led to significant improvements in participants' detection accuracy, whereas there was no support for the use of an information-based training program.

Adolescent↗
PubMedDate not supplied

Faces scales for the measurement of postoperative pain intensity in children following minor surgery.

OBJECTIVES: Faces scales are commonly used to obtain self-reports of pain intensity from children. Previous research using hypothetical vignettes and pain following venepuncture has found differences in children's pain ratings as a function of the type of faces scale used. The purpose of the present study was to determine whether scales beginning with a smiling rather than neutral "no pain" face would produce higher ratings in the assessment of postoperative pain intensity in children and to compare ratings using different faces scales to those reported with an additional independent measure of pain intensity. METHODS: Participants were 78 children between the ages of 5 and 13 years undergoing surgery, one of their parents, and their postoperative care nurse. Following surgery, children were asked to provide a rating of their current pain intensity using a set of 5 successively administered faces scales and the Colored Analog Scale (CAS). Parents and nurses provided independent ratings using the same measures. RESULTS: Results showed that parents and nurses rated significantly more pain when using scales with a smiling rather than a neutral "no pain" face. This pattern was not as clear for the children's ratings, although their highest ratings were provided when using a smiling "no pain" faces scale. Children's and nurses' ratings on the CAS were generally more similar to their ratings using scales with neutral "no pain" faces, whereas parents' CAS ratings tended to fall in between ratings provided on the smiling and neutral "no pain" faces scales. Scale preference, age and sex differences in pain ratings, and child-parent-nurse agreement in pain ratings are also examined. DISCUSSION: Children's and parents' ratings of postoperative pain intensity are influenced by the presence of a smiling "no pain" face at the beginning of faces scales, with such scales producing significantly higher ratings than scales with neutral "no pain" faces. Ratings on the independent CAS measure were more comparable to those provided on faces scales with neutral "no pain" faces. Nurses are also susceptible to the influencing effect of a smiling face at the beginning of a faces scale.

Adolescent↗
PubMedDate not supplied

"Ow!": spontaneous verbal pain expression among young children during immunization.

OBJECTIVES: Although self-reports are a commonly used means of assessing pain in clinical settings, little is understood about the nature of children's spontaneous verbal expressions of pain. The purpose of this study was to describe verbalizations of pain among children receiving a preschool immunization and to examine how pain verbalizations correspond to children's facial expressions and self-reports of pain intensity. METHODS: Fifty-eight children between the ages of 4 years 8 months and 6 years 3 months (67% female) were videotaped while receiving their routine preschool immunization. Global ratings of facial expression and detailed transcription and coding of pain verbalizations were undertaken. Children provided self-reports of pain using a 7-point faces pain scale. RESULTS: Fifty-three percent of children used verbalizations spontaneously to express their pain. The modal verbalization was the interjection "Ow!," which expressed negative affect and was specific to the experience of pain. Older children were less likely to use verbalizations to express their pain. Children who used verbalizations to express pain displayed greater facial reactions to pain and rated their pain experience as being more intense than children who did not use words to express their pain. DISCUSSION: Results indicate that many young children do not spontaneously use verbalizations to express pain from immunization. When 5-year-olds use verbalizations to express pain, the verbalizations are most often brief statements that express negative affect and directly pertain to pain. Knowledge of how children verbalize pain may lead to an improved ability to assess and manage pediatric pain.

Child↗