title: A longitudinal analysis of the development of infant facial expressions in response to acute pain: immediate and regulatory expressions.
abstract: Facial expressions during infancy are important to examine, as infants do not have the language skills to describe their experiences. This is particularly vital in the context of pain, where infants depend solely on their caregivers for relief. The objective of the current study was to investigate the development of negative infant facial expressions in response to immunization pain over the first year of life. Infant facial expressions were examined longitudinally using a subsample of 100 infants that were each videotaped during their 2-, 4-, 6-, and 12-month routine immunization appointments. Infant facial expressions were coded using BabyFACS (facial action coding system) for the first minute after a painful needle prick. Facial expressions were examined with a catalogue of the most commonly occurring facial expressions. Results demonstrated that clear differences were seen over ages. Infants display a variety of facial expressions with some of the components of adult pain expressions immediately after the needle and they abate shortly after. However, infants did not display adult expressions of discrete negative emotions. Instead, infants displayed a variety of generalized pain and distress faces aimed at gaining caregiver aid. The development of nonverbal communication in infants, particularly facial expressions, remains an important area of inquiry. Further study into accurately measuring infant negative emotions, pain, and distress is warranted.
authors.affiliation: York University, The O.U.C.H. Lab, Department of Psychology, Faculty of Health, 119 Behavioural Sciences Building, Toronto, Ontario, Canada M3J 1P3 Hospital for Sick Children, Psychiatry Research, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8 University of Toronto, King's College Circle, Toronto, Ontario, Canada M5S 1A1 New York University School of Continuing and Professional Studies Paul McGhee Division, 7 East 12th Street, Room 625-B2, New York, NY 10003, USA.
authors.forename: Sara Ahola
authors.initials: SA
authors.lastname: Kohut
authors.forename: Rebecca Pillai
authors.initials: RP
authors.lastname: Riddell
authors.forename: David B
authors.initials: DB
authors.lastname: Flora
authors.forename: Harriet
authors.initials: H
authors.lastname: Oster
mesh_terms: D059787:Acute Pain / Q000503:physiopathology*; D000375:Aging / Q000502:physiology*; D005149:Facial Expression; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male