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Abstract A striking demonstration that sound–object correspondences are not completely arbitrary is that adults map nonsense words with rounded vowels (e.g. bouba) to rounded shapes and nonsense words with unrounded vowels (e.g. kiki) to angular shapes (Köhler, 1947; Ramachandran & Hubbard, 2001). Here we tested the bouba/kiki phenomenon in 2.5‐year‐old children and a control group of adults (n =20 per age), using four pairs of rounded versus pointed shapes and four contrasting pairs of nonsense words differing in vowel sound. Overall, participants at both ages matched words with rounded vowels to the rounder shapes and words with unrounded vowels to the pointed shapes (both ps < .0005), with no significant difference between the two ages (p > .10). Such naturally biased correspondences between sound and shape may influence the development of language.

Abstract Early experience preserves and refines many capabilities that emerge prenatally. Here we describe another role that it plays – establishing the neural substrate for capabilities that emerge at a much later point in development. The evidence comes from sleeper effects: permanent deficits when early experience was absent in capabilities that normally emerge long after birth. We provide evidence of sleeper effects for three aspects of vision, based on our research with children who were deprived of early visual input by congenital cataracts: contrast sensitivity for mid and high spatial frequencies, holistic face processing, and the ability to recognize the identity of faces based on small differences in the spacing among facial features.

Abstract In three experiments, we traced the development of the adult pattern of judgments of attractiveness for faces that have been altered to have internal features in low, average, or high positions. Twelve‐year‐olds and adults demonstrated identical patterns of results: they rated faces with features in an average location as significantly more attractive than faces with either low or high features. Although both 4‐year‐olds and 9‐year‐olds rated faces with high features as least attractive, unlike adults and 12‐year‐olds, they rated faces with low and average features as equally attractive. Three‐year‐olds with high levels of peer interaction, but not those with low levels of peer interaction, chose faces with low features as significantly more attractive than those with high‐placed features, possibly as a result of their increased experience with the proportions of the faces of peers. Overall, the pattern of results is consistent with the hypothesis that experience influences perceptions of attractiveness, with the proportions of the faces participants see in their everyday lives influencing their perceptions of attractiveness.

AbstractWe used opposing figural aftereffects to investigate whether there are at least partially separable representations of upright and inverted faces in patients who missed early visual experience because of bilateral congenital cataracts (mean age at test 19.5 years). Visually normal adults and 10‐year‐olds were tested for comparison. Adults showed the expected opposing aftereffects for upright and inverted faces. Ten‐year‐olds showed an adultlike aftereffect for upright faces but, unlike the adult group, no aftereffect for inverted faces. Patients failed to show an aftereffect for either upright or inverted faces. Overall, the results suggest that early visual input is necessary for the later development of (at least partially) separable representations of upright and inverted faces, a developmental process that takes many years to reach an adult‐like refinement.

We evaluated the importance of early visual input for the later development of expertise in face processing by studying 17 patients, aged 10 to 38 years, treated for bilateral congenital cataracts that deprived them of patterned visual input for the first 7 weeks or more after birth. We administered five computerized tasks that required matching faces on the basis of identity (with changed facial expression or head orientation), facial expression, gaze direction and lip reading. Compared to an age–matched control group, patients' recognition of facial identity was impaired significantly when there was a change in head orientation (e.g. from frontal to tilted up), and tended to be impaired when there was a change in facial expression (e.g. from happy to surprised). Patients performed normally when matching facial expression and direction of gaze (e.g. looking left or right), and in reading lips (e.g. pronouncing 'u' or 'a'). The results indicate that visual input during early infancy is necessary for the normal development of some aspects of face processing, and are consistent with theories postulating the importance of early visual experience (de Schonen & Mathivet, 1989; Johnson & Morton, 1991) and separate neural mediation of different components of face processing (Bruce & Young, 1986).

AbstractBeing born at extremely low birth weight (ELBW; ≤1,000 g) is associated with enduring visual impairments. We tested for long‐term, higher order visual processing problems in the oldest known prospectively followed cohort of ELBW survivors. Configural processing (spacing among features of an object) was examined in 62 adults born at ELBW (Mage = 31.9 years) and 82 adults born at normal birth weight (NBW; ≥2,500 g: Mage = 32.5 years). Pairs of human faces, monkey faces, or houses were presented in a delayed match‐to‐sample task, where non‐matching stimuli differed only in the spacing of their features. Discrimination accuracy for each stimulus type was compared between birth weight groups, adjusting for neurosensory impairment, visual acuity, binocular fusion ability, IQ, and sex. Both groups were better able to discriminate human faces than monkey faces (p < .001). However, the ELBW group discriminated between human faces (p < .001), between monkey faces (p < .001), and to some degree, between houses (p < .06), more poorly than NBW control participants, suggesting a general deficit in perceptual processing. Human face discrimination was related to performance IQ (PIQ) across groups, but especially among ELBW survivors. Coding (a PIQ subtest) also predicted human face discrimination in ELBW survivors, consistent with previously reported links between visuo‐perceptive difficulties and regional slowing of cortical activity in individuals born preterm. Correlations with Coding suggested ELBW survivors may have used a feature‐matching approach to processing human faces. Future studies could examine brain‐based anatomical and functional evidence for altered face processing, as well as the social and memory consequences of face‐processing deficits in ELBW survivors.

AbstractThe expertise of adults in face perception is facilitated by their ability to rapidly detect that a stimulus is a face. In two experiments, we examined the role of early visual input in the development of face detection by testing patients who had been treated as infants for bilateral congenital cataract. Experiment 1 indicated that, at age 9 to 20, patients' accuracy and response times on a Mooney face detection task were normal. Experiment 2 revealed that the neural mechanisms underlying face detection in a similar group of adult patients are abnormal: the amplitude of both the P100 and N170 event‐related potential were larger in patients than in visually normal controls, and the extent of augmentation was related to the duration of deprivation. Thus, early visual experience is necessary for the establishment of normal neural networks for face detection; abnormalities at these early processing stages may contribute to the deficits we previously reported in configural face processing for this patient cohort.