Between 6 and 10 months of age, the infant's ability to discriminate among native speech sounds improves, whereas the same ability to discriminate among foreign speech sounds decreases. Our study aimed to determine whether this perceptual narrowing is unique to language or might also apply to face processing. We tested discrimination of human and monkey faces by 6-month-olds, 9-month-olds, and adults, using the visual paired-comparison procedure. Only the youngest group showed discrimination between individuals of both species; older infants and adults only showed evidence of discrimination of their own species. These results suggest that the "perceptual narrowing" phenomenon may represent a more general change in neural networks involved in early cognition.

Newborn infants respond preferentially to simple face-like patterns, raising the possibility that the face-specific regions identified in the adult cortex are functioning from birth. We sought to evaluate this hypothesis by characterizing the specificity of infants' electrocortical responses to faces in two ways: (1) comparing responses to faces of humans with those to faces of nonhuman primates; and 2) comparing responses to upright and inverted faces. Adults' face-responsive N170 event-related potential (ERP) component showed specificity to upright human faces that was not observable at any point in the ERPs of infants. A putative "infant N170" did show sensitivity to the species of the face, but the orientation of the face did not influence processing until a later stage. These findings suggest a process of gradual specialization of cortical face processing systems during postnatal development.

Event-related potentials were used to determine whether infants, like adults, show differences in spatial and temporal characteristics of brain activation during face and object recognition. Three aspects of visual processing were identified: (a) differentiation of face vs. object (P400 at occipital electrode was shorter latency for faces), (b) recognition of familiar identity (Nc, or negative component, at fronto-temporal electrodes [FTEs] was of larger amplitude for familiar stimuli), and (c) encoding novelty (slow wave at FTEs was larger for unfamiliar stimuli). The topography of the Nc was influenced by category type: Effects of familiarity were limited to the midline and right anterior temporal electrodes for faces but extended to all temporal electrodes for objects. Results show that infants' experience with specific examples within categories and their general category knowledge influence the neural correlates of visual processing.

No abstract

No abstract

Event-related potentials (ERPs) were recorded from 6-month-olds as each watched pictures of the mother's face and a stranger's face. The ERPs differed for the 2 faces, but the pattern of neural activity elicited depended on whether the mother and stranger looked different (Experiment 1, n = 22) or alike (Experiment 3, n = 22). In contrast, when different 6-month-olds were each shown 1 of these 44 pairs of faces their ERPs did not differ between the 2 faces (Experiment 2, n = 22, and Experiment 4, n = 22). In a visual preference test of recognition, infants showed no evidence of recognizing the mother's face (Experiment 5, n = 32). Together, these results suggest that infants are able to recognize their mothers' faces but (1) the neural processes accompanying recognition depend on the difficulty with which mother can be discriminated from stranger and (2) under the conditions investigated in this study, ERPs are a more sensitive measure of recognition than is looking time.

Event-related potentials (ERPs) were recorded from 6-month-olds as each watched pictures of the mother's face and a stranger's face. The ERPs differed for the 2 faces, but the pattern of neural activity elicited depended on whether the mother and stranger looked different (Experiment 1, n = 22) or alike (Experiment 3, n = 22). In contrast, when different 6-month-olds were each shown 1 of these 44 pairs of faces their ERPs did not differ between the 2 faces (Experiment 2, n = 22, and Experiment 4, n = 22). In a visual preference test of recognition, infants showed no evidence of recognizing the mother's face (Experiment 5, n = 32). Together, these results suggest that infants are able to recognize their mothers' faces but (1) the neural processes accompanying recognition depend on the difficulty with which mother can be discriminated from stranger and (2) under the conditions investigated in this study, ERPs are a more sensitive measure of recognition than is looking time.

After questioning the practical significance of evidence that parenting influences brain development - while highlighting the scientific importance of such work for understanding how family experience shapes human development - this paper reviews evidence suggesting that brain structure and function are 'chiselled' by parenting. Although the generalisability of most findings is limited due to a disproportionate, but understandable focus on clinical samples (e.g., maltreated children with post-traumatic stress disorder (PTSD)) and causal inferences are difficult to draw because of the observational nature of most of the evidence, it is noteworthy that some work with community samples and very new experimental work (e.g., parent training) suggests that tentative conclusions regarding effects of parenting on the developing brain may well be substantiated in future research. Such efforts should focus on parenting in the normal range, experimental manipulations of parenting, differential susceptibility to parenting effects and pathway models linking parenting to brain development and, thereby, to behavioural development. Research on parenting and children's brain development may be regarded as at 'the end of the beginning'.