Despite considerable evidence in older populations that food intake can improve mental performance, little is known about the acute effects of feeding on cognition in the newborn period, a time when learning and memory are critical for discovering and adapting to everyday experiences. Feeding occurs well over 2500 times in the first year of life, raising the possibility that iterative effects on cognition may have cumulative effects over time. We recently demonstrated feeding enhancement of memory in two-to-three day old infants. Infants tested after a feed (versus before) displayed better memory for unfamiliar spoken words they previously habituated to and that were represented after a 100s delay. In this Doctoral Thesis, Studies 1 and 2 explore further the influence of feeding on short-term retention of spoken words. Memory was assessed using headturning and the Habituation-Recovery response. Study 1 extended the effect to older infants aged two-to-three weeks. Memory was enhanced after a feed over even longer delays, including 100s, 200s, 300s, 400s, and 500s. The overall gain in memory as measured by prefeed and postfeed differences at each delay was over two minutes long. Because newborn infants are more likely to hear recurrent words spoken by familiar voices, auditory experiences that they preferentially recognize, Study 2 looked at the separate effects of familiarity and feeding. Two day-old infants were assessed for either familiar speech-sound ("baby" spoken by the mother) or unfamiliar speech-sound from Study 1 ("beagle" spoken by a female stranger). The baby-mother sound stimulus was remembered better over a retention interval of 85 seconds than unfamiliar beagle-stranger, suggesting a strong influence of familiarity. To define the extent of the feeding effect, Study 3 examined sensorimotor processing of a reflex response. Three day-olds were assessed on habituation and retention of habituation of the glabella blink reflex over delays of 8s and l8s. No effect of feeding was found. Taken together, the implications of these findings are twofold. First, enhancement of memory for speech-sound by iterative feeding or recurrent exposure to familiar speech-sound stimuli may facilitate the acquisition of language. Second, feeding effects on cognition may depend on the nature of the task and previous experience with the stimulus. Further research is necessary for identifying what kinds of information and what processing abilities are more susceptible to the effects of feeding in early infancy.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.115845 |
| Date | January 2008 |
| Creators | Valiante, A. Grace (Antonella Grace) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Division of Neuroscience.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 003131185, proquestno: AAINR66593, Theses scanned by UMI/ProQuest. |
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