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In simple tests of preference, infants as young as newborns prefer faces and face-like stimuli over distractors. Little is known, however, about the development of attention to faces in complex scenes. We recorded eye-movements of 3-, 6-, and 9-month-old infants and adults during free-viewing of clips from A Charlie Brown Christmas (an animated film). The tendency to look at faces increased with age. Using novel computational tools, we found that 3-month-olds were less consistent (across individuals) in where they looked than were older infants. Moreover, younger infants' fixations were best predicted by low-level image salience, rather than the locations of faces. Between 3 and 9 months of age, infants gradually focus their attention on faces. We discuss several possible interpretations of this shift in terms of social development, cross-modal integration, and attentional/executive control.A lot can be learned about our social world from the faces of others. Faces provide information about age, race, gender, physical health, emotional state, and focus of attention, giving observers a window into the mental states of other human beings. During the first year after birth, infants begin to extract a large amount of information from faces: they begin to recognize identities (Pascalis, De Haan, Nelson, & De Schonen, 1998), recognize and prefer faces from their own race , detect affect (Cohn & Tronick, 1983;Tronick, 1989), and follow gaze (Corkum & Moore, 1998;Scaife & Bruner, 1975). However, these sophisticated abilities are of little use if infants don't look at faces to begin with. Put another way, to extract information from faces, infants must first attend to them.Although there is a large literature on the origins and development of infants' face representations during infancy, far less research has examined the behavior of infants outside of controlled laboratory settings. In particular, both the extent to which infants attend to faces when other objects are present-as in most real-world situations-and the extent to which this behavior changes across development are still largely unknown. The reasons for this gap in the literature may be both methodological and theoretical. Methodologically, standard lookingtime paradigms used in infant research typically produce only qualitative evidence and do not make sense in older populations; hence it is difficult to design experimental paradigms whose results can be compared across wide age ranges. Theoretically, many researchers have been interested primarily in the question of innateness: whether human infants are predisposed to treat human faces as "special" relative to other objects and whether the representations underlying these judgments are qualitatively similar to those used by adults. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the result...

How do infants learn to perceive the backs of objects that they see only from a limited viewpoint? Infants' 3D object completion abilities emerge in conjunction with developing motor skillsindependent sitting and visual-manual exploration. Twenty-eight 4.5-to 7.5-month-old infants were habituated to a limited-view object and tested with volumetrically complete and incomplete (hollow) versions of the same object. Parents reported infants' sitting experience, and infants' visual-manual exploration of objects was observed in a structured play session. Infants' self-sitting experience and visual-manual exploratory skills predicted looking to the novel, incomplete object on the habituation task. Further analyses revealed that self-sitting facilitated infants' visual inspection of objects while they manipulated them. The results are framed within a developmental systems approach, wherein infants' sitting skill, multimodal object exploration, and object knowledge are linked in developmental time.Keywords perceptual development; 3D object perception; exploration; object manipulation; sitting Developmental psychology has a long history of linking achievements in infants' motor skills with improvements in perceptual and cognitive abilities. Piaget (1954), for example, proposed that infants' developing motor actions and subsequent exploration of the world are critical for learning and development. Likewise, E. J. Gibson (1988) argued that infants learn about the properties of the world through exploration and that developing motor skills constrain and guide how infants pick up information about objects, surfaces, and events. Piaget viewed motor skill acquisition as a launching point for perceptual and cognitive skills. In contrast, Gibson took seriously the proposition that motor action, perception, and cognition are linked in real time and throughout development: Perception and cognition remain inextricably grounded in the body and its actions (e.g., E. J. Gibson & Pick, 2000;Thelen & Smith, 1994). The current work was motivated by a developmental systems approach, which emphasizes the developmental processes that facilitate acquisition of new skills, even when the developmental history grows from non-obvious causal factors (e.g., Gottlieb, 2007; Spencer et al., in press). The present study examined how developmental changes in motor skills-sitting and manual exploration-affect three-dimensional (3D) object completion, that is, perceiving an object as a complete volume in visual space despite only seeing it from a limited viewpoint (Soska & Johnson, 2008).Correspondence should be addressed to: Kasey C. Soska, Department of Psychology, New York University, 6 Washington Place, Rm. 458, New York, NY 10003, Tel: (212) Object Exploration Facilitates Object PerceptionManual exploration provides information about objects in the environment-object properties, such as weight, shape, and surface texture, and affordances for action, such as grasping, banging, sliding, and rolling (Lockman, 2000). Different exploratory pr...

Stimulation of one sensory modality can induce perceptual experiences in another modality that reflect synaesthetic correspondences among different dimensions of sensory experience. In visual-hearing synaesthesia, for example, higher pitched sounds induce visual images that are brighter, smaller, higher in space, and sharper than those induced by lower pitched sounds. Claims that neonatal perception is synaesthetic imply that such correspondences are an unlearned aspect of perception. To date, the youngest children in whom such correspondences have been confirmed with any certainty were 2- to 3-year-olds. We examined preferential looking to assess 3- to 4-month-old preverbal infants' sensitivity to the correspondences linking auditory pitch to visuospatial height and visual sharpness. The infants looked longer at a changing visual display when this was accompanied by a sound whose changing pitch was congruent, rather than incongruent, with these correspondences. This is the strongest indication to date that synaesthetic cross-modality correspondences are an unlearned aspect of perception.

The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay -these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions.Experiments carried out over the past half century have revealed that neutrinos are found in three states, or flavors, and can transform from one flavor into another. These results indicate that each neutrino flavor state is a mixture of three different nonzero mass states, and to date offer the most compelling evidence for physics beyond the Standard Model. In a single experiment, LBNE will enable a broad exploration of the three-flavor model of neutrino physics with unprecedented detail. Chief among its potential discoveries is that of matter-antimatter asymmetries (through the mechanism of charge-parity violation) in neutrino flavor mixing -a step toward unraveling the mystery of matter generation in the early Universe. Independently, determination of the unknown neutrino mass ordering and precise measurement of neutrino mixing parameters by LBNE may reveal new fundamental symmetries of Nature.Grand Unified Theories, which attempt to describe the unification of the known forces, predict rates for proton decay that cover a range directly accessible with the next generation of large underground detectors such as LBNE's. The experiment's sensitivity to key proton decay channels will offer unique opportunities for the ground-breaking discovery of this phenomenon.Neutrinos emitted in the first few seconds of a core-collapse supernova carry with them the potential for great insight into the evolution of the Universe. LBNE's capability to collect and analyze this high-statistics neutrino signal from a supernova within our galaxy would provide a rare opportunity to peer inside a newly-formed neutron star and potentially witness the birth of a black hole.To achieve its goals, LBNE is conceived around three central components: (1) a new, highintensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a fine-grained near neutrino detector installed just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is ∼1,300 km from the neutrino source at Fermilab -a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions.With its exceptional combi...

A sex difference on mental-rotation tasks has been demonstrated repeatedly, but not in children less than 4 years of age. To demonstrate mental rotation in human infants, we habituated 5-monthold infants to an object revolving through a 240° angle. In successive test trials, infants saw the habituation object or its mirror image revolving through a previously unseen 120° angle. Only the male infants appeared to recognize the familiar object from the new perspective, a feat requiring mental rotation. These data provide evidence for a sex difference in mental rotation of an object through three-dimensional space, consistently seen in adult populations.Fifty years of research has confirmed that men typically outperform women in spatial-ability tests (Linn & Petersen, 1985;Voyer, Voyer, & Bryden, 1995). Such sex differences have been detected in 4-year-old children (Levine, Huttenlocher, Taylor, & Langrock, 1999); in children under 13, these differences are most often found on tasks requiring mental rotation (Voyer et al., 1995). Mental-rotation tasks revealing the largest sex differences require subjects to view a two-dimensional (2-D) representation of a three-dimensional (3-D) object, and to then recognize a novel 2-D representation of the same object rotated into a different orientation in 3-D space (Levine et al., 1999). Effect sizes for sex differences on such tasks are typically larger than the effects of sex on other behaviors (Collaer & Hines, 1995).The current study examined the origins of mental rotation in infancy. Early work revealed that 4-month-old infants can detect the 3-D form of objects moving around two axes of rotation (Kellman, 1984;Kellman & Short, 1987). More recent studies presented infants with kinetic random-dot displays that specified rotating 3-D cubes (Arterberry & Yonas, 2000) and with video displays of partially occluded 3-D shapes rotating around a vertical axis (Johnson, Cohen, Marks, & Johnson, 2003); in both cases, 2-month-old infants appeared to perceive the 3-D shape of rotating objects.Other studies found that 4-month-old infants form dynamic mental representations that allow them to both track the movement of a 2-D object rotating in the frontal plane and anticipate the object's ultimate orientation (Rochat & Hespos, 1996;Hespos & Rochat, 1997). These results were interpreted as tentative evidence for rudimentary mental rotation in infants; however, although these results suggest that infants can use exposure to a moving 2-D object to help them predict how that object will look when rotated in a 2-D plane, fullblown mental rotation has traditionally been tested by requiring observers to mentally rotate 3-D stimuli through 3-D space and to discriminate the rotated object from its mirror image (Shepard & Cooper, 1982). No studies have yet provided evidence that infants can recognize a particular 3-D object-as distinct from its mirror image-after it has been rotated through 3-D space into a previously unseen perspective; such an ability would be indicative of Address corr...

Objective This study had three goals, to examine: 1) the frequency of atypical development, consistent with the broader autism phenotype, in high-risk infant siblings of children with ASD, 2) the age at which atypical development is first evident, and 3) which developmental domains are affected. Method A prospective longitudinal design was used to compare 294 high-risk infants and 116 low-risk infants. Participants were tested at 6, 12, 18, 24, and 36 months of age. At the final visit, outcome was classified as ASD, Typical Development (TD), or Non-TD (defined as elevated ADOS score, low Mullen scores, or both). Results 28% of the high-risk group was classified as Non-TD at 36 months of age. Growth curve models demonstrated that the Non-TD group could not be distinguished from the other groups at 6 months of age, but differed significantly from the Low-Risk TD group by 12 months on multiple measures. The Non-TD group demonstrated atypical development in cognitive, motor, language, and social domains, with differences particularly prominent in social-communication. Conclusions These results demonstrate that features of atypical development, consistent with the broader autism phenotype, are detectable by the first birthday and affect development in multiple domains. This highlights the necessity for close developmental surveillance of infant siblings of children with ASD, along with implementation of appropriate interventions as needed.

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