TY - THES AU - Lilley, Christine Megan PY - 1995 TI - The facial expression of pain in infants: developmental changes and individual differences KW - Thesis/Dissertation LA - eng M3 - Text AB - The purpose of the study was to examine the role of the negative emotionality dimension of temperament as a factor underlying individual differences in the facial expression of pain in infants. It was also of interest to identify developmental changes in the facial expression of pain during the first two years of life, both in the overall degree of pain expressed and individual facial actions. Subjects were infants undergoing routine immunization injections, which are administered at 2, 4, 6, 12, and 18 months of age. Consequently, the five age groups were compared. Temperament was assessed via a parent report questionnaire. A hand-held video camera was used to record the reactions of infants undergoing inoculation. The infants’ facial reactions, as captured on videotape, were scored by trained coders using two systems: (1) the Neonatal Facial Coding System (NFCS), a brief measure limited to actions relation to pain, and (2) Baby FACS, a comprehensive system with categories for all possible facial actions. The coders scored three 10-second segments for each infant in order t o capture a baseline, the infant’s immediate reaction, and a recovery period. The results of the study did not confirm a relationship between temperament and a pain summary score derived by principal components analysis. This finding was unexpected. The need for further investigation of the stability of individual differences in the pain response and the impact of situational factors was discussed. The investigation of developmental changes revealed some differences in the degree of pain expressed by infants in different age groups. During the baseline and immediate reaction to injection, 2-month old infants displayed more distress than 4- month old infants and 6-month old infants, but not more than 12- or 18-month old infants. During the recovery period, 6-month old infants and 18-month old infants displayed more distress than 4- month old infants. No other differences were significant. While these results require replication, they are suggestive of a drop in the degree of pain expressed around the age of 4 months. Possible reasons for such a pattern were discussed, with attention paid to the development of inhibitory mechanisms and the impact of other negative emotions such as anger and anxiety. Age-related changes in the occurrence of individual actions were also identified. The results of the present study suggest that clinicians assessing pain in infants be aware of developmental changes such that they compare their charges to infants of the same age. N2 - The purpose of the study was to examine the role of the negative emotionality dimension of temperament as a factor underlying individual differences in the facial expression of pain in infants. It was also of interest to identify developmental changes in the facial expression of pain during the first two years of life, both in the overall degree of pain expressed and individual facial actions. Subjects were infants undergoing routine immunization injections, which are administered at 2, 4, 6, 12, and 18 months of age. Consequently, the five age groups were compared. Temperament was assessed via a parent report questionnaire. A hand-held video camera was used to record the reactions of infants undergoing inoculation. The infants’ facial reactions, as captured on videotape, were scored by trained coders using two systems: (1) the Neonatal Facial Coding System (NFCS), a brief measure limited to actions relation to pain, and (2) Baby FACS, a comprehensive system with categories for all possible facial actions. The coders scored three 10-second segments for each infant in order t o capture a baseline, the infant’s immediate reaction, and a recovery period. The results of the study did not confirm a relationship between temperament and a pain summary score derived by principal components analysis. This finding was unexpected. The need for further investigation of the stability of individual differences in the pain response and the impact of situational factors was discussed. The investigation of developmental changes revealed some differences in the degree of pain expressed by infants in different age groups. During the baseline and immediate reaction to injection, 2-month old infants displayed more distress than 4- month old infants and 6-month old infants, but not more than 12- or 18-month old infants. During the recovery period, 6-month old infants and 18-month old infants displayed more distress than 4- month old infants. No other differences were significant. While these results require replication, they are suggestive of a drop in the degree of pain expressed around the age of 4 months. Possible reasons for such a pattern were discussed, with attention paid to the development of inhibitory mechanisms and the impact of other negative emotions such as anger and anxiety. Age-related changes in the occurrence of individual actions were also identified. The results of the present study suggest that clinicians assessing pain in infants be aware of developmental changes such that they compare their charges to infants of the same age. UR - https://open.library.ubc.ca/collections/831/items/1.0099013 ER - End of Reference