Infant cries

From How Emotions Are Made
Jump to: navigation, search

Chapter 1 endnote 13, from How Emotions are Made: The Secret Life of the Brain by Lisa Feldman Barrett.
Some context is:

But newborns don’t show differentiated, adult-like expressions like the photographs from the basic emotion method.

Do babies broadcast different needs with their cries, such as hunger, discomfort, or pain? The idea that they do, called the "cry types" hypothesis,[1] states that cries have categorical patterns of sounds that are unique to the conditions that elicit the cries, and that the patterns are specifically recognizable to caregivers by their emotional content — i.e., that each cry has an acoustic fingerprint.

The idea that they don't, called the "graded signal" hypothesis of crying,[2] says that infant cries are potent signals with salient acoustic properties that help caregivers judge an infant’s level of distress and urgency of need. Graded cries change with the need of the infant, although they don't carry a unique, symbolic meaning. For example, adult perceivers can hear intensity gradations in infant crying; e.g., cries during circumcision sound more urgent than those recorded either before or after the surgery.[3] The graded signals hypothesis is similar to the affect induction hypothesis.

Evidence

There is limited evidence to support the "cry types" hypothesis, and much evidence that perceivers make sense of a cry's meaning by using cues from the surrounding context.[1][4][5] In one study, mothers of young infants, and young women who were not mothers, listened to segments of crying taken when infants were in pain (newborn males being circumcised) or hungry (one-month-old infants waiting to be fed).[6] After each segment of crying, test subjects answered the question "Why is this baby crying?" by choosing one of the following explanations: the baby (a) is hungry, (b) is sleepy, (c) needs a diaper change, (d) is in pain, (e) is angry, or (f) is frightened/startled. Responses to the early portion of each cry (15 seconds from within the first minute after the stimulus/in the episode) were more correct than those later in the episode (3 minutes in). Mothers were more accurate than non-mothers, but were not "accurate" in absolute terms:

  • Pain cries had a sudden onset, were high intensity, and generally signaled intense distress. They were labeled as pain, anger, or fright.
  • Hunger cries began at low intensity and grew in intensity, and were labeled sleepy (most often), hunger, or in need of a diaper change.  

Summary: early in the cry, perceivers detected the intensity of distress. Later in each cry episode, test subjects did not distinguish the two classes of cries, because the acoustic organization varied as the cries continued.  Crying changes over time.  The context influences perception throughout an episode of crying, less so early on, and more so later on.[7][8]

The only studies that find support for the "cry type hypothesis" use the (flawed) basic emotion method.[9] They carefully select cry "prototypes" for hunger, pain, pleasure, birth, and so on, and then give subjects a list of responses to choose from.

Infants do more than cry and laugh. They also growl, squeal, and utter vowel-like sounds (called  protophones). They use these sounds flexibly in a variety of pleasant, unpleasant and neutral states.[10] In studies, growls and squeals did not necessarily signal an unpleasant state in infants, even thought adults routinely label them as fearful.[11] There were strong context effects; a protophone might be used to index negativity in one situation but positivity in another. And there were also strong individual differences in the frequency with which babies uttered the various protophones.

Bottom line:

From Gusafson et al.[1]:

  • Infant cries are graded signals; the infant vocal tract is similar to non-human primates who also communicate using graded signals.[12]
  • Infant cries result from changes in the lower rather than upper vocal tract, which is heavily influenced by the autonomic nervous system;[13] the autonomic nervous system influences the acoustical qualities of a cry[14]
  • Gradations in the intensity of infant distress manifest as gradations in cry acoustics.[15]

From Russell et al 2003:[16]

"Different cries were once thought to be associated with different states, such as frustration, fear, hunger, cold, pain, fatigue, or a soiled diaper.[17] The evidence instead is that the cry more simply indexes the degree of the infant’s distress.[18] The cry’s typical acoustic features (abrupt onset, high F0, high amplitude, and characteristic pulsing) attract the attention of and cause negative affect in the receiver. The marked variability in these acoustic features does not mark different states (frustration, etc.) but lessens the chances of the receiver habituating. The receiver then infers the infant’s specific state largely from context."[19]

Older studies

One paper by psychologist Mandel Sherman, in 1927,[20] played neonate cries for test subjects and asked them to identify the cry and the eliciting stimulus. The cries were recorded after a 15 minute delay in feeding, after being dropped suddenly from a height of 2-3 feet, during restraint of head/face, and after four pricks on the face with a needle —presumably, hunger, fear, anger, and pain. The adult test subjects were graduate students in psychology, medical students, neonatal nurses, or regular students, so they had a range of expertise. Subjects either watched the whole thing live (so had the cry, the context, the stimulus, the body movements, etc.) or they watched a silent film of the crying faces only. In the movie condition, where the stimulus not shown, performance was at chance levels. Results became more systematic when test subjects saw each event live, because it included the eliciting stimuli and the other physical cues.

In a second study,[21] listeners (medical, nursing, and psychology graduate students) sat in small groups, and infants were placed behind a screen, one at a time, and subjected to one of the four eliciting events. In the absence of any context, all listeners were unsuccessful in naming either the eliciting stimulus or the cry type from the cry information alone. Even in 1927, Sherman was aware of the importance of context in producing evidence for a classical view of emotion.

See also:


Notes on the Notes

  1. 1.0 1.1 1.2 Gustafson, Gwen E., Rebecca M. Wood, and James A. Green. 2000. "Can we hear the causes of infants' crying?" In Crying as a Sign, a Symptom, and a Signal: Clinics in Developmental Medicine No. 152, edited by Ronald G. Barr, Brian Hopkins, and James A. Green. Suffolk: Lavernum Press Ltd.
  2. Green, 1975 [full reference to be provided]
  3. Porter et al., 1986 [full reference to be provided]
  4. LaGasse, Linda L., A. Rebecca Neal, and Barry M. Lester. 2005. "Assessment of infant cry: acoustic cry analysis and parental perception." Mental Retardation and Developmental Disabilities Research Reviews 11 (1): 83-93.
  5. Muller et al., 1974 [full reference to be provided]
  6. Gustafson, Gwen E., and Karen L. Harris. 1990. "Women's responses to young infants' cries." Developmental Psychology 26 (1): 144-152.
  7. Wilson 1975 [full reference to be provided]
  8. Murray, 1979 [full reference to be provided]
  9. Wasz-Höckert, O., T. J. Partanen, V. Vuorenkoski, K. Michelsson, and E. Valanne. 1964. "The identification of some specific meanings in infant vocalization." Experientia 20 (3): 154.
  10. Oller, D. Kimbrough, Eugene H. Buder, Heather L. Ramsdell, Anne S. Warlaumont, Lesya Chorna, and Roger Bakeman. 2013. "Functional flexibility of infant vocalization and the emergence of language." Proceedings of the National Academy of Sciences 110 (16): 6318-6323.
  11. Sauter, Disa A., Frank Eisner, Paul Ekman, and Sophie K. Scott. 2010. “Cross-Cultural Recognition of Basic Emotions Through Nonverbal Emotional Vocalizations.” Proceedings of the National Academy of Sciences 107 (6): 2408–2412.
  12. Lieberman, 1973 [full reference to be provided]
  13. Bastian, 1965 [full reference to be provided]
  14. For example, Porges, Stephen W., Jane A. Doussard‐Roosevelt, and Ajit K. Maiti. 1994. "Vagal tone and the physiological regulation of emotion." Monographs of the Society for Research in Child Development 59 (2‐3): 167-186. Specifically, through the vagal nerve — as parasympathetic tone decreases, arousal increases and so does the urgency and arousing qualities of the cry.
  15. Porter et al., 1988 [full reference to be provided]
  16. Russell, James A., Jo-Anne Bachorowski, and José-Miguel Fernández-Dols. 2003. "Facial and vocal expressions of emotion." Annual Review of Psychology 54 (1): 329-349.
  17. Berry, Kenneth K. 1975. "Developmental study of recognition of antecedents of infant vocalizations." Perceptual and Motor Skills 41 (2): 400-402.
  18. Barr, Ronald G., Brian Hopkins, and James A. Green. 2000. Crying as a Sign, a Symptom, and a Signal: Clinical, Emotional and Developmental Aspects of Infant and Toddler Crying.  New York: Cambridge University Press.
  19. Bachorowski, Jo-Anne, and Michael J. Owren.. 2002. "Vocal acoustics in emotional intelligence." In The Wisdom in Feeling: Psychological Processes in Emotional Intelligence, edited by Lisa Feldman and Peter Salovey, 11–36. New York: Guilford.
  20. Sherman, Mandel. 1927. "The differentiation of emotional responses in infants. I. Judgments of emotional responses from motion picture views and from actual observation." Journal of Comparative Psychology 7 (3): 265-284
  21. Sherman, Mandel. 1927. "The differentiation of emotional responses in infants. II. The ability of observers to judge the emotional characteristics of the crying of infants, and of the voice of an adult." Journal of Comparative Psychology 7 (5): 335-351.