Monday, 1 October 2007

Testing foetal cognition

Annette Karmiloff-Smith: "Two lines of research have motivated my choice of a psychology experiment that has hitherto never been done. The first involves scientifically-controlled studies of the typically developing foetus during the last three months of intra-uterine life, pioneered in Belfast by Peter Hepper and his collaborators. Measurement of intra-uterine changes in rate of heart beat or of limb movement can be used to ascertain whether the foetus is sensitive to changes in auditory stimuli such as music, words, male/female voices. The second line of research comes from a PhD experiment in my lab (Paterson, et al., 1999) which indicated that infants and toddlers with Williams syndrome were as sensitive to changes in small numbers (1, 2, 3) as chronological-age-matched controls, whereas those with Down's syndrome (DS) performed more poorly than both chronologically age-matched and mental-age-matched controls. How could these seemingly disparate lines of research meet?

The experiment I propose has three steps:

Step 1) Hitherto, work on the foetus has not involved number. Can the typically developing foetus notice changes in small number in the auditory domain (we know, for instance, that young infants can do cross-modal matching of small numbers from auditory to visual stimuli)? If we repeatedly tap two sounds until the foetus habituates, will the foetus renew heart-rate or limb movements when we change to three sounds (or from repeated three to two sounds)?

Step 2) I would test the DS foetus in the final 3 months of intra-uterine life for sensitivity to changes in auditory stimuli, as has already been carried out with the typically developing foetus (music, language, etc.). Then I would test the DS foetus for sensitivity to changes in small number discriminability, as in step 1.

Step 3) If some of the DS foetuses are sensitive to auditory changes in numerosity, and subsequently perform well in the visual number domain, whereas those who fail to react to changes during intra-uterine life also fail to notice change in the visual domain after birth, a training study for the DS foetus would be set up to ascertain whether this induces changes in the trajectory of number development after birth.

This experiment is important in my view because it really takes development seriously, i.e., that the roots of all cognitive development are in low-level mechanisms operative at the very outset of development (Karmiloff-Smith, 1992, 1998, 2007). There are, however, ethical issues involved. How would expectant parents of DS children react to a request to participate in research? In my view, parents who have decided to carry a Down syndrome foetus to term are likely to be happy to be involved in any research that might encourage their foetus to process auditory stimuli as a possible preparation for life outside the womb. Moreover, even if the training were not successful during intra-uterine life, the experiment might lay the foundations for postnatal research placing the focus on early training in the auditory and visual domains for both typically and atypically developing infants."

Dr Annette Karmiloff-Smith is Professorial Research Fellow in the Developmental Neurocognition Lab, Centre for Brain & Cognitive Development, Birkbeck College, University of London.

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