The role of the mother's voice in developing mother's ... - FIU Infant Lab

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F. Z. Sai
the mother’s face at birth. The infants were, therefore, not exposed to their
mother’s voice from birth through testing.
Some clarification of our understanding of infants’ learning about faces, and
the role of the mother’s face in developing facial processing is likely to emerge
when newborn infants are tested using the same procedures as in our previous
studies (Sai, 1990; Bushnel et al., 1989), with a visual preference task and paired
rather than sequential presentations of the comparison faces. This paper
describes four studies which used non-Caucasian participants.
EXPERIMENT 1
The purpose of the present experiments was to determine the role of experience
with the mother’s voice in facilitating face recognition in the neonatal period.
However, since our previous studies (Sai and Bushnell, 1987; Bushnell et al., 1989;
Sai, 1990) demonstrating recognition of the mother’s face in the neonatal period
tested only Caucasian neonates from the area of Glasgow, Scotland (UK), and the
participants in this research were Malaysians, it was seen advisable to first
replicate these earlier findings on Malaysian neonates.
Before presenting details about the methodology and procedures followed in
these experiments, it is worth pointing out that the newborn infants were
retained on the ward at all times, in bassinets located adjacent to their mother’s
bed. The mothers had continuous responsibility for the care of their infants.
Although the total interactive contact hours involved within each mother–infant
dyad was not assessed, some provisional observations (Sai, 1990) showed that
there was a fairly substantial period of contact within the first 24 h. However,
there was a considerable variability across dyads.
Since our earlier findings had indicated no significant relationship between age
and extent of preference, age was not considered as a potential factor, and was
therefore not included. Similarly, sex factor was not incorporated for the same
reason (see Sai, 1990).
Method
Participants
Fourteen newborn infants, seven males and seven females (M ¼ 3:00 h,
range ¼ 224h;M birth weight ¼ 2:75 kg, range ¼ 2:7022:90) participated in this
study. They all had normal Apgar scores after 5 min (M ¼ 9, range ¼ 8210), and
throughout testing they remained in the behavioural state of alert inactivity
(Ashton, 1973). All the infants in this and subsequent studies were normal,
healthy and full-term infants (37 weeks gestation) with no complications during
delivery. The infants were primarily from middle class and diverse ethnic
backgrounds of Malaysia (Malay, Chinese and Hindou). They were volunteered
by their mothers on the wards of the University Hospital, Kuala Lumpur where
they were born. The data of ten additional infants were discarded from the study:
four for side bias in their looking behaviour (see procedure section for details
regarding criteria for side bias), three for excessive fussiness, two for persistent
sleeping and one because the mother made sounds during the testing.
Stimuli and Apparatus
The stimulus faces for each participant in this experiment were the live face of
the participant’s mother and that of a female stranger. This was another mother
Copyright # 2004 John Wiley & Sons, Ltd. Inf. Child Dev. 14: 29–50 (2005)