Innate and learned perceptual abilities in the newborn infant

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Exp Brain Res (1998) 123:90–94
© Springer-Verlag 1998
Alan Slater · Rachel Kirby
Innate and learned perceptual abilities in the newborn infant
Abstract From research carried out over the last few
years, it has become apparent that the visual world of the
newborn baby (0–7 days from birth) is highly organised.
It is also clear that the newborn infant is an extremely
competent learner. These themes are illustrated with respect to two areas of research, face perception and intermodal learning. Evidence is presented suggesting that
the human face is “special” in that newborns respond to
them as faces, rather than merely collections of stimulus
elements. Additional evidence is presented which demonstrates that newborns can form auditory-visual associations after only a short exposure to the stimulation.
These lines of evidence suggest that innate capacities, or
modules, facilitate and direct early learning in order to
allow newborn infants to understand their newly encountered world.
Key words Innate perceptual abilities ·
Learned perceptual abilities ·
Newborn perceptual abilities
Introduction
Research carried out over the last 30 years has changed
the traditional view of the young infant’s perceptual
world from one of “incompetence” to one of “competence”. While experience is of great importance, infants
display considerable perceptual competence at an early
age, and even the newborn baby perceives an organised
and structured world. Several organisational principles,
such as size and shape constancy, the ability to distinguish between 2- and 3-dimensional stimulation and to
detect motion, and rudimentary form perception, are innately provided to newborn infants. These help them to
parse the visual world and help them to create order out
of what would otherwise be chaos (Slater 1995 gives a
detailed account of visual perception and memory at
A. Slater (‚úČ) · R. Kirby
Department of Psychology, Washington Singer Laboratories,
University of Exeter, UK
birth). In addition to these inborn abilities, it has been
suggested that newborn infants have innate representational abilities, and it is also apparent that they engage in
very rapid learning about the visual world. This article
presents evidence relating to these topics with respect to
two areas of research, face perception and intermodal
learning.
Innate representations and early learning:
the case of face perception
The human face is one of the most complex visual stimuli encountered by the human infant. It moves, is three-dimensional, has areas of both high and low contrast, and
contains features that can appear both in changing (perhaps with changes of expression) and invariant (the positions of eyes, mouth, nose, hair, etc.) relationships. In
addition, individual faces are all unique and differ from
one another often in subtle ways. A major task confronting the newborn infant, therefore, is to make sense of
“faces in general” and also to distinguish between different individual faces. We know that a considerable period
of learning is required in order to achieve some degree
of competence in these areas. However, it is clear that
the newborn infant has something of a “head start”, as
shown both by rapid learning about faces and by the
likelihood of an innately provided representation of the
human face.
Early learning about faces
The visual information detected by newborn infants is
poor, but Hainline and Abramov (1992) point out that,
“while infants may not, indeed, see as well as adults do,
they normally see well enough to function effectively in
their role as infants” (p. 40). For newborn infants, the visual stimuli likely to be of most relevance are people
who interact with them and are therefore likely to be
close to them. Figure 1 gives an indication of how a face
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Fig. 1 A face as it might
appear to us (right), and to a
newborn infant (left)
might look to newborn infants at a distance of about a
foot from their eyes and how it would look to us. Although the image is degraded and unfocused for the
newborn, enough information is potentially available for
the infant to learn to recognise the mother’s face and to
discriminate her from others. Indeed, it seems that newborns quickly learn about, and show a preference for,
their mother’s face (Bushnell et al. 1989; Field et al.
1984; Pascalis et al. 1995; Walton et al. 1992).
We do not know precisely what aspects of the face
newborn (and older) infants use in making these discriminations. However, it seems that they are attending both
to external and internal aspects of the face. Pascalis et al.
(1995), in their experiment 1, confirmed earlier findings
that newborn infants (their babies averaged 4 days from
birth) reliably discriminate and prefer their mother’s face
to that of a stranger, when all the facial information is
present. However, when mother and stranger both wore
scarves around their heads (in experiment 2), the babies
were no longer able to make the discrimination. Their interpretation of this is “that what (newborns) have learned
has to do with the external features of the face rather
than the inner features” (1995, p. 84). However, Walton
and Bower (1993) demonstrated that newborns also detect internal facial features. In their experiment, newborn
infants who were shown four faces for a total looking
time of less than 1 min extracted a facial prototype, or
averaged version, of the four in that they subsequently
looked more at a composite of the previously seen faces
than at a composite of four faces that had not been seen
earlier: it would be difficult for the newborns to make
these discriminations without attending to the internal
features of the faces.
In a more recent study (Walton et al. 1997), newborn
infants (averaging just over 1 day from birth) recognised
a face to which they had previously been trained or familiarised across three facial transformations: (1) a photonegative transformation; (2) a size change (the transformed face was smaller than the original); (3) rotation
in the third dimension (the training face was facing
straight ahead and the transformed one was half profile).
Newborns succeeded with all three transformations in
that they sucked more to see the transformed familiar
face.
These preferences for a “familiar” composite of faces
(Walton and Bower 1993) and for the “familiar” transformation (Walton et al. 1997) are further evidence that
learning about faces, and the formation of a representation of faces, can be extremely rapid in the newborn period and that what is learned is robust in that it holds
across transformations of the original.
Is there an innate representation of the human face?
Several lines of evidence converge to suggest that newborn infants come into the world with some innately
specified representation of faces. Goren et al. (1975) reported that their newborn subjects, who averaged 9 min
from birth at the time of testing and had never seen a human face, turned their heads more to follow (i.e., track) a
two-dimensional schematic face-like pattern than either
of two patterns consisting of the same facial features in
different arrangements. A replication of Goren et al.’s
study was reported by Johnson and Morton (1991): the
stimuli they used were three of those used by Goren et
al. and are shown in Fig. 2. Johnson and Morton use
these findings and other evidence to argue for the existence of an innate face-detecting device they call “Conspec” (short for conspecifics), which “perhaps comprises
just three dark patches in a triangle, corresponding to
eyes and mouth” (Pascalis et al. 1995, p. 80) and which
serves to direct the newborn infant’s visual attention to
faces.
Imitation
Other evidence suggests that the hypothesized innate facial representation might be more detailed than simply a
template that matches three dots. In particular, it has
been demonstrated that newborn (and older) infants will
imitate a variety of facial gestures they see an adult model performing (e.g., Field et al. 1982; Maratos 1973;
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Fig. 2 The three stimuli used by Johnson and Morton (1991) in
their replication of Goren et al. (1975): newborn infants tracked
the Face in preference to Scrambled and Blank
Meltzoff and Moore 1977, 1984, 1992, 1994, 1997; Reissland 1988). Meltzoff (1995) suggests that “newborns
begin life with some grasp of people” (p. 43) and that
their ability to recognise when their facial behaviour is
being copied implies that “there is some representation
of their own bodies” (p. 53).
Infants prefer attractive faces
It has been known for some time that infants 2 months
and older will spend more time looking at attractive faces, when these are shown paired with less attractive
ones. In the studies reported to date, the face pairings
have been equated for age, gender, and ethnicity, and the
“attractiveness effect” seems to be robust in that it is
found for stimulus faces that are infant, adult, male, female, and of two races (African-American and Caucasian) (Langlois et al. 1987, 1991; Samuels and Ewy
1985; Samuels et al. 1994).
In two recent experiments (Slater et al. 1998), pairings of attractive and unattractive female faces (as
judged by adult raters) were shown to newborn infants
(in the age range 14–151 h from birth), and in both the
infants looked longer at the attractive faces. The findings
from these studies show that newborn infants, less than 1
week from birth, can discriminate attractive from unattractive faces and that, like older infants, they prefer attractive faces. A frequently expressed interpretation of
the attractiveness effect in older infants is in terms of
prototype formation and a cognitive averaging process.
When faces are computer-averaged, the resulting prototype is typically seen as more attractive than the individual faces that are averaged together. Therefore, averageness has been claimed to be an important ingredient of
attractiveness (Langlois and Roggman 1990), although it
has been claimed that “very attractive faces are not average” (Alley and Cunningham 1991, p. 123). According
to this interpretation, attractive faces are seen as more
“face-like”, because they match more closely the prototype that infants have formed from their experience of
seeing faces. As was mentioned earlier, it is known that
newborn infants can form prototypes of faces they have
seen in the laboratory in less than 1 min (Walton and
Bower 1993), and that they recognise a learned face over
transformations (Walton et al. 1997). One interpretation
of the present findings, therefore, is that the newborns’
preference for attractive faces is a preference for an image similar to a composite of the faces they have seen in
the few hours from birth prior to testing: thus, “infants
may prefer attractive or prototypical faces because prototypes are easier to classify as a face” (Langlois and
Roggmann 1990, p. 119).
An alternative interpretation of the findings is in
terms of an innate perceptual mechanism, which detects
and responds specifically to faces. According to this interpretation, the newborns look more at the attractive
faces because they most closely match the innately provided face template. Several authors have speculated that
infants may be born with an innate built-in specification
of the face or face module (e.g., Johnson and Morton
1991; Meltzoff 1995; Walton et al. 1997), and Langlois
and Roggman (1990) discuss the possibility of an innate
account for attractiveness preferences.
The results from these studies do not allow us to rule
out either of these alternative interpretations. We do not
know precisely what features, or combination of features, the newborns (or the older infants of other studies)
were using in order to make their preferential choices.
Nevertheless, the findings strongly suggest that preferences for attractive faces are present soon after birth and
are not the result of a long period of observing faces.
Overview
It seems now to be reasonably well agreed that “there
does seem to be some representational bias... that the
neonate brings to the learning situation for faces” (Karmiloff-Smith 1996, p. 10). This representational bias (resulting perhaps from a “face module”) might simply be a
tendency to attend to stimuli that possess three blobs in
the location of eyes and mouth, or it might be something
more elaborate: it is possible that evolution has provided
the infant with a more detailed blueprint of the human
face. The latter possibility is suggested by newborn infants’ ability to imitate the facial gestures produced by
the first face they have ever seen (Reissland 1988) and
also, perhaps, by newborn infants’ preferences for attractive faces.
The roles of experience and learning:
the case of intermodal learning
While the newborn and young infant display competence
in face perception, their world is very different from
ours: “It must certainly lack associations, meaning and
familiarity...: (they) see everything, but nothing makes
sense” (Gordon 1997, pp. 82–83). Nevertheless, the
newborn infant’s ability to learn about the visual world is
remarkable, and, in this section, rapid learning by the
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newborn infant is illustrated by an experiment on intermodal learning.
Most of the objects and events we experience are intermodal, in that they provide information to more than
one sensory modality. Such intermodal information can
be broadly categorised into two types of relation, amodal
and arbitrary. Amodal perception is where two (or more)
senses provide information that is equivalent in one or
more respects, and many types of amodal perception
have been demonstrated in early infancy. Newborn infants reliably turn their heads and eyes in the direction of
a sound source, indicating that spatial location is given
by both visual and auditory information (Butterworth
1983; Muir and Clifton 1985; Wertheimer 1961). One
month olds demonstrate cross-modal matching by recognising a visual shape (a pacifier) that had previously
been experienced tactually by sucking, indicating that
the shape is coded both tactually and visually (Meltzoff
and Borton 1979). By 4 months, infants are sensitive to
temporal synchrony specified intermodally, in that they
detect the common rhythm and duration of tones and
flashing lights (Lewkowicz 1986). Four month olds also
detect and appropriately match the sounds made either
by a single unitary element or by a cluster of smaller elements (Bahrick 1987, 1988). Thus, there is evidence that
infants, from birth, perceive a wide range of invariant
amodal relations.
It is quite likely that the ability to detect amodal relations is innately given to the infant, and, hence, minimal
learning is required in their detection. However, many of
the intermodal relationships that we perceive appear to
be quite arbitrary. For example, there is no information
specifying a priori that a particular voice has to be associated with a particular face, that a particular animal
makes a certain sound, or that an object makes a certain
sound on making contact with a certain surface. Research suggests that many arbitrary intermodal relations
are learned in infancy: Spelke and Owsley (1979) found
that 31/2 month olds had learned to associate the sound
of their mother’s voice with the sight of her face, and
Hernandez-Reif et al. (1994) reported that 6 month olds
learned the face-voice pairings of same-sex female
strangers; Reardon and Bushnell (1988) reported that 7
month olds were able to learn the association between
the colour of a container and the taste of the food it contained.
There is evidence that newborn babies are also able to
learn arbitrary intermodal relations. Slater et al. (1997)
familiarised 2-day-old infants, on successive trials, to
two visual-auditory stimuli. One visual-auditory combination (“red-mum”) was a red vertical line, and when
presented it was accompanied by the sound “mum” spoken in a male voice at a rate of once per second; the other combination (“green-teat”) was a green diagonal line
accompanied by the sound “teat” in a female voice. One
important characteristic of the familiarisation trials is
that the sound was only presented when the infant was
judged to be looking at the visual stimulus, meaning that
the infants were provided with amodal information, in
that there was temporal synchrony of onset and offset of
both stimuli. On the post-familiarisation test trials, the
infants were presented with one familiar combination
(either “red-mum” or “green-teat”), which was alternately presented with a novel combination (“red-teat” or
“green-mum”). On the test trials, the infants gave a
strong preference for the novel combination, giving a
clear demonstration that newborn infants can learn arbitrary visual-auditory combinations. Note that these novelty preferences could not have resulted if the newborns
had processed the separate properties of the stimuli presented on the familiarisation trials, because the novel
pairings consisted of visual and auditory stimuli that had
been presented earlier.
Many intermodal events give both amodal and arbitrary information. For instance, when a person speaks,
the synchrony of voice and mouth provides amodal information, whereas the pairing of the face and the sound
of the voice is arbitrary. In several publications, Bahrick
(i.e., 1987, 1988, 1992; Bahrick and Pickens 1994) has
provided strong evidence that learning about arbitrary
intermodal relations is greatly assisted if there is accompanying amodal information: “detection of amodal invariants precedes and guides learning about arbitrary object-sound relations by directing infants’ attention to appropriate object-sound pairings and then promoting sustained attention and further differentiation” (Bahrick and
Pickens 1994, p. 226). In Slater et al.’s (1997) experiment, amodal information was present, and it is likely
that this facilitated the newborns’ learning of the arbitrary intermodal relations. It is of interest to note that,
when the mother speaks to her infant, the amodal information of temporal synchrony of voice and lips is quite
likely to facilitate learning the association of her face
and voice, and it seems likely that this learning occurs
very soon after birth.
Conclusions
The newborn baby enters the world visually naive, but
possesses a number of means with which to begin the
business of making sense of the visually perceived
world. Newborn babies have, literally, a head-start, in
that it is now clear that they have some innate representational bias to attend to human faces, and perhaps some
innate knowledge of the face. These conclusions result
from studies of newborn infants’ tracking of face-like
patterns and their ability to imitate adult facial gestures.
Perhaps, too, the newborn’s preference to look at attractive faces might be guided by an innate facial representation that matches the attractive faces. The nature of infants’ innate facial representation is not well understood
and is an intriguing area for future research.
It is reasonable to claim that the newborn and young
infant are “competent”, in that they perceive the world in
an organised manner. Thus, their world is not the
“blooming, buzzing confusion” described by William
James (1890, p. 488), but it is clearly not the same as
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ours. At birth, “visual processing begins with a vengeance” (Karmiloff-Smith 1996, p. 10), and this processing can be seen in the rapidity with which newborn infants learn about faces, about other types of stimuli and
events (which are not discussed here), and in their ability
to learn arbitrary intermodal relations.
Evolution has provided the newborn infant with the
means to organise and begin to make sense of the visual
world and with an innate representation of the human
face, which ensures that the infant attends to and learns
about faces. Clearly, as infants develop, their perception
of the world changes, and infants from birth onwards
possess considerable learning ability to ensure rapid
learning about the world.
Acknowledgements The author’s research reported in this chapter was supported by Research Grant R000235288 from Economic
and Social Research Council.
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