Experience plays a crucial role in the development of face processing. In the study reported here, we investigated how faces observed within the visual environment affect the development of the face-processing system during the 1st year of life. We assessed 3-, 6-, and 9-month-old Caucasian infants' ability to discriminate faces within their own racial group and within three other-race groups (African, Middle Eastern, and Chinese). The 3-month-old infants demonstrated recognition in all conditions, the 6-month-old infants were able to recognize Caucasian and Chinese faces only, and the 9-month-old infants' recognition was restricted to own-race faces. The pattern of preferences indicates that the other-race effect is emerging by 6 months of age and is present at 9 months of age. The findings suggest that facial input from the infant's visual environment is crucial for shaping the face-processing system early in infancy, resulting in differential recognition accuracy for faces of different races in adulthood.Human adults are experts at recognizing faces of conspecifics and appear to perform this task effortlessly. Despite this impressive ability, however, adults are more susceptible to recognition errors when a target face is from an unfamiliar racial group, rather than their own racial group. This phenomenon is known as the other-race effect (ORE; see Meissner & Brigham, 2001, for a review). Although the ORE has been widely reported, the exact mechanisms that underlie reduced recognition accuracy for other-race faces, and precisely when this effect emerges during development, remain unclear.The ORE can be explained in terms of a modifiable face representation. The concept of a multidimensional face-space architecture, first proposed by Valentine (1991), has received much empirical support. According to the norm-based coding model, individual face exemplars are represented as vectors within face-space according to their deviation from a prototypical average. The prototype held by each person represents the average of all faces that person has ever encoded and is therefore unique. Although it is unclear which dimensions are most salient and used for recognition, it is likely that dimensions vary between individuals and possibly within each person over time. The prototype (and therefore

Adults are sensitive to the physical differences that define ethnic groups. However, the age at which we become sensitive to ethnic differences is currently unclear. Our study aimed to clarify this by testing newborns and young infants for sensitivity to ethnicity using a visual preference (VP) paradigm. While newborn infants demonstrated no spontaneous preference for faces from either their own- or other-ethnic groups, 3-month-old infants demonstrated a significant preference for faces from their own-ethnic group. These results suggest that preferential selectivity based on ethnic differences is not present in the first days of life, but is learned within the first 3 months of life. The findings imply that adults' perceptions of ethnic differences are learned and derived from differences in exposure to own- versus other-race faces during early development.

The other-race effect in face processing develops within the first year of life in Caucasian infants. It is currently unknown whether the developmental trajectory observed in Caucasian infants can be extended to other cultures. This is an important issue to investigate because recent findings from cross-cultural psychology have suggested that individuals from Eastern and Western backgrounds tend to perceive the world in fundamentally different ways. To this end, the current study investigated 3-, 6-, and 9-month-old Chinese infants’ ability to discriminate faces within their own racial group and within two other racial groups (African and Caucasian). The 3-month-olds demonstrated recognition in all conditions, whereas the 6-month-olds recognized Chinese faces and displayed marginal recognition for Caucasian faces but did not recognize African faces. The 9-month-olds’ recognition was limited to Chinese faces. This pattern of development is consistent with the perceptual narrowing hypothesis that our perceptual systems are shaped by experience to be optimally sensitive to stimuli most commonly encountered in one’s unique cultural environment.

Fixation duration for same-race (i.e., Asian) and other-race (i.e., Caucasian) female faces by Asian infant participants between 4 and 9 months of age was investigated with an eye-tracking procedure. The age range tested corresponded with prior reports of processing differences between same- and other-race faces observed in behavioral looking time studies, with preference for same-race faces apparent at 3 months of age and recognition memory differences in favor of same-race faces emerging between 3 and 9 months of age. The eye-tracking results revealed both similarity and difference in infants’ processing of own- and other-race faces. There was no overall fixation time difference between same race and other race for the whole face stimuli. In addition, although fixation time was greater for the upper half of the face than for the lower half of the face and trended higher on the right side of the face than on the left side of the face, face race did not impact these effects. However, over the age range tested, there was a gradual decrement in fixation time on the internal features of other-race faces and a maintenance of fixation time on the internal features of same-race faces. Moreover, the decrement in fixation time for the internal features of other-race faces was most prominent on the nose. The findings suggest that (a) same-race preferences may be more readily evidenced in paired comparison testing formats, (b) the behavioral decline in recognition memory for other-race faces corresponds in timing with a decline in fixation on the internal features of other-race faces, and (c) the center of the face (i.e., the nose) is a differential region for processing same-versus other-race faces by Asian infants.

In response to insect attack, plants release complex blends of volatile compounds. These volatiles serve as foraging cues for herbivores, predators and parasitoids, leading to plant-mediated interactions within and between trophic levels. Hence, plant volatiles may be important determinants of insect community composition. To test this, we created rice lines that are impaired in the emission of two major signals, S-linalool and (E)-β-caryophyllene. We found that inducible S-linalool attracted predators and parasitoids as well as chewing herbivores, but repelled the rice brown planthopper Nilaparvata lugens, a major pest. The constitutively produced (E)-β-caryophyllene on the other hand attracted both parasitoids and planthoppers, resulting in an increased herbivore load. Thus, silencing either signal resulted in specific insect assemblages in the field, highlighting the importance of plant volatiles in determining insect community structures. Moreover, the results imply that the manipulation of volatile emissions in crops has great potential for the control of pest populations.

A visual preference procedure was used to examine preferences among faces of different ethnicities (African, Asian, Caucasian, and Middle Eastern) in Chinese 3-month-old infants exposed only to Chinese faces. The infants demonstrated a preference for faces from their own ethnic group. Alongside previous results showing that Caucasian infants exposed only to Caucasian faces prefer same-race faces and that Caucasian and African infants exposed only to native faces prefer the same over the other-race faces (Bar-Haim, Ziv, Lamy, & Hodes, 2006), the findings reported here (a) extend the same-race preference observed in young infants to a new race of infants (Chinese), and (b) show that cross-race preferences for same-race faces extend beyond the perceptually robust contrast between African and Caucasian faces.It has been reported recently in two separate studies that 3-month-old infants demonstrate a visual preference for faces from their own ethnic group when paired with faces from other ethnic groups. Using a standard visual preference task, Kelly et al. (2005) found that English Caucasian infants preferred to look at Caucasian faces when paired with African, Chinese, or Middle Eastern faces. Using the same paradigm, Bar-Haim, Ziv, Lamy, and Hodes (2006) found a cross-race visual preference in Israeli and Ethiopian infants with Israeli infants showing a visual preference for Caucasian faces and Ethiopian infants preferring to look at the faces from their own racial group. Crucially, Bar-Haim et al. (2006) also tested a population of Israeli-born infants of Ethiopian parentage recruited from an absorption center

The other-race effect is a collection of phenomena whereby faces of one's own race are processed differently from those of other races. Previous studies have revealed a paradoxical mirror pattern of an own-race advantage in face recognition and an other-race advantage in race-based categorisation. With a well-controlled design, we compared recognition and categorisation of own-race and other-race faces in both Caucasian and Chinese participants. Compared with own-race faces, other-race faces were less accurately and more slowly recognised, whereas they were more rapidly categorised by race. The mirror pattern was confirmed by a unique negative correlation between the two effects in terms of reaction time with a hierarchical regression analysis. This finding suggests an antagonistic interaction between the processing of face identity and that of face category, and a common underlying processing mechanism.

Previous research has shown that 3-month-olds prefer own- over other-race faces. The current study used eye-tracking methodology to examine how this visual preference develops with age beyond 3 months and how infants differentially scan between own- and other-race faces when presented simultaneously. We showed own- versus other-race face pairs to 3-, 6-, and 9-month-old Chinese infants. In contrast with 3-month-olds' visual preference for own-race faces, 9-month-olds preferentially looked more at other-race faces. Analyses of eye-tracking data revealed that Chinese infants processed own- and other-race faces differentially. These findings shed important light on the role of visual experience in the development of visual preference and its relation to perceptual narrowing.