10
FRANCK RAMUS
tional difference remained between the two languages in the
present saltanaj stimuli, intonation is not likely to be the cue
whose processing is responsible for the language discrimina-
tion patterns observed. For the same reason, intonation can-
not be necessary for rhythm processing. The most plausible
interpretation is therefore that newborns can process speech
rhythm, but something in the sasasa stimuli prevented them
from correctly processing it. For instance, their extremely
low phonetic diversity might lead babies to process them as
non-speech. Alternatively, the constant frication of sasasa
sentences may have been too distressing for babies to cor-
rectly perform the task; indeed, adult subjects also rated these
stimuli lower than the saltanaj in Exp. 3, and complained
about the harsh sound of the /s/s. Whatever the correct ex-
planation may be, the alternatives could be tested by run-
ning further discrimination experiments while manipulating
the nature and the variety of the phonemes used in the resyn-
thesis.
Post-hoc analysis: Preference for
Dutch
After finding a significant effect of language during the
habituation phase of Exp. 3 (with babies sucking more to
Dutch than to Japanese), we have looked for a similar trend
in the other experiments. As shown in Table 2 and Figure 8,
the same trend was present in all four experiments, suggest-
ing a consistent phenomenon.
Table 2
Average number of HA sucks produced during the 5 pre-shift
minutes, as a function of Experiment and language.
Exp. 1 Exp. 2 Exp. 3 Exp. 4
Dutch 33±11 32.2 ± 11.2 35.6±8.3 294±9.6
Japanese 30.9±11.1 27±10.4 25.8±9.1 25.3±8.3
While it is clear now that intonation does not play a cru-
cial role in newborns’ ability to discriminate between lan-
guages, the last two experiments are still open to an alterna-
tive interpretation: that newborns discriminate the saltanaj
stimuli on the basis of basic phonotactic differences between
Dutch and Japanese (e.g., the presence/absence of conso-
nant clusters); since these differences are not preserved in
the sasasa version, this would explain both failure in Exp.
3 and success in Exp. 4. There are, however, good in-
dependent reasons to doubt that newborns are sensitive to
these phonotactic differences. Indeed, this has been di-
rectly tested in experiments where newborns had to dis-
criminate between lists of words of different syllabic struc-
ture. For instance, newborns were unable to discriminate bi-
syllabic words with complex syllabic structure (e.g., CVC-
CCV, CCVCCV, CVCCVC...) from bi-syllabic words with
simple syllabic structure (e.g., CVCV, VCCV, VCVC...),
although they were able to discriminate simple bi-syllabic
(CVCV) from tri-syllabic words (CVCVCV) (Bijeljac-Babic
et al., 1993). Similarly, they were unable to discriminate be-
tween tri-moraic (CVCCV) and bi-moraic words (CVCV),
although they were able to discriminate again bi-syllabic
from tri-syllabic words (Bertoncini et al., 1995). If newborns
were able to extract phonotactic regularities from 3-second
long Dutch and Japanese utterances, they would be expected
to do so also from bi-syllabic words. The fact that they do
not suggests that sensitivity to phonotactic differences is not
available at birth; this is consistent with evidence that famil-
iarity with the native language’s phonotactic pattern emerges
between 6 and 9 months of age (Jusczyk, Friederici, Wessels,
Svenkerud, & Jusczyk, 1993; Friederici & Wessels, 1993;
Jusczyk, Luce, & Charles-Luce, 1994). In summary, the
most plausible interpretation of newborn’s ability to discrim-
inate Dutch from Japanese in their saltanaj version with ar-
tificial intonation, is that they have reacted to the rhythmic
differences between the two languages.
Minutes
—D— Dutch - - -∙- - ■ Japanese
Figure 8. Average number of HA sucks produced during the 5
pre-shift minutes, as a function of language. Error bars represent
±1 standard error of the mean.
Overall, during the 5 minutes preceding the shift, babies
produced on average 32.5 ± 10 HA sucks per minute to lis-
ten to Dutch, and 27.1 ± 9.7 to listen to Japanese. The dif-
ference is significant: F(1,142) = 11.1, p = 0.001. The fact
that this effect is consistent across 4 experiments suggest that
this is not a random sampling effect. It is remarkable that a
similar effect was also noted by Nazzi et al. (1998): they
found that French newborns sucked more to listen to En-
glish than to listen to Japanese. In earlier studies, such pat-
terns had been interpreted as showing babies’ "preference"
for their native-language: Mehler et al. (1988) found that
French newborns sucked more during the habituation phase
to listen to French than to Russian, and Moon et al. (1993),
using a technique directly assessing preference, found that
newborns sucked more to listen to their native language (En-
glish or Spanish). Similar results have been found in older
babies as well (Dehaene-Lambertz & Houston, 1998; Bosch
& Sebastian-Galles, 1997).
Here (and also in Nazzi et al.’s study), where neither lan-
guage was the babies’ native language, one may want to