bluuebunny/crossref_metadata_2025 huggingface dataset:
Shock on T Versus Direct Current Voltage for Induction of Ventricular Fibrillation:
Authors: SHARMA ARJUN D. , FAIN ERIC , O'NEILL P. GEAROID , SKADSEN ANNE , DAMLE ROGER , BAKER JIM , CHAUHAN VINOD , MAZUZ MEIR , ROSS TERRANCE , ZHANG XIAOZHENG
Published: January 2004

VF is induced during ICD implantation to determine efficacy of therapy. Establishing the best clinical method of induction of VF would potentially be beneficial in reducing the number of induction attempts and reducing the frequency of inadvertent induction of VT. Commonly used methods to induce VF include shock in the T wave vulnerable period (T shock) and high frequency stimulation. This study compared the efficacy of T shock with a new induction method using a 9‐V DC pulse. The study was a randomized, prospective, case crossover trial in patients receiving ICDs. VF was induced by T shock and DC in a randomized sequence during an ICD implant. VF was induced at least four times in each patient (two T shocks and two DC inductions) and with each induction; attempts were continued with modifications until successful. A paired evaluation between the T shock/DC induction was performed in 37 patients (28 men, age 64 ± 12 years) with a left ventricular ejection fraction of 0.40 ± 0.20. Arrhythmia indications were VT (n = 23), VF (n = 10), and VT/VF (n = 4). Drug therapy included amiodarone (n = 10), metoprolol (n = 6), digoxin (n = 1), and lidocaine (n = 1). The average T shock voltage was 207.0 ± 16.1 V. The S1 cycle drive length was consistently 400 ms, and the mean S2 coupling interval was 317.8 ± 19.6 ms. The length of time DC applied averaged 3.8 ± 1.4 seconds. A total of 148 episodes of VF were included in the analysis. T shock induced VF with a cycle length of 213.5 ± 35.1 ms, and DC induced VF with a cycle length of 214.6 ± 34.5 ms (P = 0.86). Although VF was eventually induced for each randomization, the number of attempts required were dependent on the method of induction. The successful DC first attempt VF induction rate was 96%, with three patients requiring two attempts during one of the DC inductions. T shock had a 68% first attempt success rate with 21 patients requiring multiple T shocks to induce VF. All nine female patients had at least one unsuccessful first attempt T shock, which contributed to an overall unsuccessful first attempt induction rate significantly higher in women then men (36.1% vs 12.5%, P = 0.001). A constant DC voltage induction of VF may be more effective than T shock for induction of VF in a clinical setting because it reduces the number of attempts required to induce VF. By either method, VF appears to be more difficult to induce in women. DC induction has the advantage of simple programming of only duration of stimulation. These findings have implications particularly for ICD implantation with conscious sedation. (PACE 2004; 27:89–94)
Perceived parental beliefs about the causes of success in sport: relationship to athletes' achievement goals and personal beliefs
Authors: White Sally A. , Kavussanu Maria , Tank Kari M. , Wingate Jason M.
Published: January 2004

This study examined the relationship between perceived parental beliefs and young athletes' achievement goal orientations and personal beliefs about the causes of success in sport. Participants were 183 male and female athletes, 11–18 years old, involved in team sports. Athletes completed the Task and Ego Orientation in Sport Questionnaire, the Beliefs about the Causes of Sport Success Questionnaire, and two modified versions of the latter inventory to assess their perceptions of their parents' beliefs. Canonical correlation analysis revealed that perceived parental beliefs were related to goal orientations and personal beliefs in a conceptually coherent fashion. Thus, the perceived parental belief that effort leads to success in sport was related to athletes' task orientation and personal belief that effort causes sport success. In contrast, the perceived parental beliefs that superior ability, external factors, and using deceptive tactics are precursors to success in sport corresponded to athletes' ego orientation and the same personal beliefs. The findings are discussed in terms of their implications for understanding the socialization experiences of young athletes.
Has exercise an antifracture efficacy in women?
Authors: Karlsson Magnus
Published: January 2004

Exercise in girls during growth seems to confer a high peak bone mineral density (BMD). Exercise in adulthood, in the peri‐ and postmenopausal period, and in old age prevents bone loss or increases BMD with a magnitude of minor biological significance. However, these changes must be regarded as beneficial compared to the age‐related bone loss, which inevitably will occur if no interventions are implemented. Prospective intervention studies also suggest that exercise improves muscle strength, coordination and balance, even in elderly women, all of which are improvements with a potential of reducing the number of falls. A randomised, controlled, prospective, blinded study (the only study design that tests a hypothesis) of exercise with fracture as end point is extremely difficult to conduct, due to the large sample sizes needed. At present, no such studies exist. Retrospective and prospective observational and case–control studies suggest that physical activity in women is associated with reduced fracture risk. This may be correct, but we must never forget that a consistently replicated sampling bias may produce the same outcome.

The Achilles heel of exercise is the reduction or the cessation of physical activity, which commonly occurs among middle‐aged women when family and work demands reduce the time available for exercise. A higher BMD or improvement in muscle size and muscle strength achieved by exercise during adolescence seems to be eroded on retirement, leaving virtually no remaining benefits in old age, the period when fragility fractures begin to be a problem of increasing magnitude. However, recreational activities seem to maintain some of the musculo‐skeletal benefits, but to date we do not know the level of activity needed to retain these benefits. Dose–response relationships need to be quantified, as also the effects on bone size, shape and architecture. Another essential question that we must address is how many fewer fractures will be the result of a community‐based exercise campaign. Will efforts by the community to encourage a higher level of physical exercise, with the aim of reducing bone fractures, be cost‐effective? The higher level of proof, suggesting that exercise does reduce fragility fractures and thus reduces the total cost for the society, must come from well‐designed and well‐executed, prospective, randomised, controlled trials. The responsibility of executing these studies lies in the hands of both researchers and the community.
Power toothbrushes: a critical review
Authors: Penick Catherine
Published: January 2004

Abstract:  Although the first toothbrush is thought to have been used in about 1000 ad, tooth brushing in America did not gain popularity until after 1945. The introduction of the powered toothbrush in 1960 has led to a large number of studies comparing the safety and efficacy of powered toothbrushes to manual toothbrushes. There is a general agreement that powered toothbrushes are as safe as manual toothbrushes; however, studies show significantly differing conclusions regarding the efficacy of power toothbrushes for the removal of plaque. The recent amendment of the Cochrane report on this subject concluded that the only type of powered toothbrush that removes more plaque than a manual toothbrush is one with rotational oscillation movement. Their conclusion was based on the review of 29 published studies, conducted between 1964 and 2001, with a total of 2547 participants. All these studies used similar research design criteria. The Cochrane conclusion is in agreement with a 1996 study carried out in the Netherlands. Many of the conflicting study conclusions, to date, on powered toothbrushes, are the result of using differing study design criteria. While the dental profession desires evidence‐based research, it is clear that dental schools will need to increase the level of attention in their curriculum to address disciplined techniques for research design in order to reconcile the large variances in reported research results.
Oral microflora on the tongue and tooth surfaces in subjects with hyposalivation because of radiation therapy
Authors: Almståhl A , Wikström M
Published: January 2004

Objective: To study the microflora on the tongue and tooth surfaces in subjects with hyposalivation because of radiation therapy in the head and neck region (RT). Material and methods: The RT subjects (≥16 teeth, an unstimulated secretion rate of ≤0.1 ml min−1, 6 months after completed radiation therapy) were matched with controls with normal salivary secretion rates according to age, sex and number of teeth. A clinical examination was performed, and samples for microbial analysis were taken. Results: The RT group (n = 16) had a mean age of 53 ± 8 years and 28 ± 2 teeth. The unstimulated secretion rate was 0.02 ± 0.04 ml min−1 and the stimulated 0.4 ± 0.2 ml min−1. On the tongue, Fusobacterium nucleatum and Prevotella intermedia, associated with gingivitis, were found in low numbers in almost all RT subjects. Candida albicans and enterococci, associated with mucosal infections, were frequently found in high numbers. On the tooth surfaces, the number of C. albicans was increased. Lactobacillus species, indicating an acidic environment, were generally found in very high numbers in the RT subjects. Mutans streptococci, strongly associated with the development of caries, showed a different pattern. In 44% of the RT subjects, mutans streptococci could not be detected; 38% of the subjects showed very high numbers. Conclusions: Although high numbers of microorganisms associated with the development of mucosal infections and caries were frequently found in RT subjects, there were differences between subjects, especially for mutans streptococci. Microbial analysis might therefore be a helpful tool to identify RT subjects with an increased risk of oral disorders.
Near Earth Objects: A brief review and a student project
Authors: Smallwood Lee M. , Katz Debora M. , Richmond Michael W.
Published: January 2004

We provide a general overview of asteroids which pass close to the Earth: Near Earth Objects (NEOs). NEOs provide information on the formation of the solar system, and may have played an important role in the history of life on Earth. They are easy targets for future space missions. We also describe how to measure the distance to an NEO: an observational exercise for undergraduates which is pedagogically rich, exciting, and requires only modest equipment. We use our own recent data to compute the distances to two objects: 2002 NY40 and 2002 HK12.
Perturbations of the excited quantum oscillator: From number states to statistical distributions
Authors: Sunko D. K. , Gumhalter B.
Published: January 2004

We discuss the transitions that an external time-dependent perturbation can induce upon a quantum harmonic oscillator in an excited initial state. In particular, we show how to describe transitions of the oscillator from initial states characterized by statistical distributions. These results should be useful for interpretations of the properties of weakly dispersive bosonic excitations in quantum systems whose dynamics is investigated by time or energy resolved spectroscopies.
Why does a cylindrical permanent magnet rotate when levitated above a superconducting plate?
Authors: Schreiner Michael , Palmy Claudio
Published: January 2004

Stable levitation of a permanent magnet above a superconducting plate is a popular demonstration in physics lectures. If the magnet has a cylindrical shape and is axially magnetized, it can start to oscillate along the horizontal axis with increasing amplitude and might eventually rotate continuously. We present a mathematical model based on physical considerations and simulations of the stationary and transient rotation using a finite element method.
Determining a force law from a scattering experiment
Authors: Blackburn James A. , Smith H. J. T.
Published: January 2004

An experiment is described in which a small permanent magnet is scattered by a second identical fixed magnet. The apparatus sits on an air table, so the scattered object can move with negligible friction. A ring of Hall effect switches surrounding the fixed magnet is used to determine the scattering angle. The experimental data are compared with numerical simulations and the form of the repulsive force between the two magnets is determined.
Physical time and physical space in general relativity
Authors: Cook Richard J.
Published: January 2004

This paper comments on the physical meaning of the line element in general relativity. We emphasize that, generally speaking, physical spatial and temporal coordinates (those with direct metrical significance) exist only in the immediate neighborhood of a given observer, and that the physical coordinates in different reference frames are related by Lorentz transformations (as in special relativity) even though those frames are accelerating or exist in strong gravitational fields.
A simple electronic system for demonstrating chaos control
Authors: Corron Ned J. , Pethel Shawn D. , Hopper Buckley A.
Published: January 2004

In this note, we describe a simple electronic oscillator and controller for demonstrating chaos control. The oscillator is built using a LC tank circuit tuned near 1 kHz, and the controller is an active limiter. Both circuits can be constructed using common, inexpensive parts. As such, this system is well suited for laboratory demonstrations of chaos control, thereby providing students with valuable exposure to the emerging field of chaos engineering.
Operator domains and self-adjoint operators
Authors: Araujo Vanilse S. , Coutinho F. A. B. , Fernando Perez J.
Published: January 2004

To construct a self-adjoint operator the domain of the operator has to be specified by imposing an appropriate boundary condition or conditions on the wave functions on which the operator acts. We illustrate situations for which different boundary conditions lead to different operators and hence to different physics.
A demonstration of phonons that implements the linear theory
Authors: Lüerßen Dietrich , Easwar Nalini , Malhotra Ayesha , Hutchins Libby , Schulze Kim , Wilcox Brandi
Published: January 2004

Beads on a vibrating wire are used to simulate the discrete structure of a solid-state material. The novel idea of the experiment is to use very small oscillation amplitudes of the wire to avoid nonlinearities in the interaction. We achieve a good signal-to-noise ratio using a lock-in technique. We find quantitative agreement between theory and experiment for not only a mono- and a diatomic chain, but also for the bare wire. The latter agreement is the crucial aspect that distinguishes our experiment from previous ones. This agreement assures that the fundamental assumption of the theory (Hooke’s law) is satisfied. We show that the properties of phonon dispersion curves are not special, and that the same band structures occur when the wavelength of any wave becomes comparable to the length scale of a discrete periodicity.
Resource Letter PBGP-1: Physics books for the general public
Authors: von Baeyer Hans Christian , Bowers Edith V.
Published: January 2004

This Resource Letter is a checklist of popular books about physics and some of its allied sciences, grouped by subject and genre. Its principal purpose is to help physics teachers provide advice and guidance to their students and to the lay public.
Blueschist and eclogite in tectonic melange, Port Macquarie, New South Wales, Australia
Authors: Och D. J. , Leitch E. C. , Caprarelli G. , Watanabe T.
Published: January 2004

The Rocky Beach Metamorphic Melange contains metre-scale phacoids of high-Plow-Tmetamorphic rocks embedded in chlorite-actinolite schist. The phacoids include eclogite, glaucophane schist and omphacitite and provide evidence for four episodes of metamorphism with mineral assemblages: M1= actinolite-glaucophane-titanite-apaite, M2= almandine-omphacite-lawsonite ±quartz, M3= phengite- glaucophane-K-feldspar-quartz, and M4= chlorite-actinolite-calcite-quartz-titanite-white mica ± albite ± talc. M1-M3occurred at a Neoproterozoic-Early Palaeozoic convergent plate boundary close to the eastern margin of Gondwana. Peak metamorphic conditions were attained during the static phase M2, with temperatures of ~560°C and pressures in excess of 1.8 GPa, equivalent to a depth of burial of at least 54 km.
Al-rich diopside in alluvial ruby and corundum-bearing xenoliths, Australian and SE Asian basalt fields
Authors: Sutherland F. L. , Coenraads R. R. , Schwarz D. , Raynor L. R. , Barron B. J. , Webb G. B.
Published: January 2004

Alluvial rubies and sapphires are found in palaeodrainage deposits along the Cudgegong-Macquarie River system, central eastern New South Wales, Australia. A pink to red suite contains Cr (up to 0.6 wt.% Cr2O3) as the main chromophore, exceeding Fe (up to 0.5 wt.%Fe2O3). Corrosive etching suggests a prior xenocrystic Mesozoic-Cenozoic basaltic transport, while Cr2O3/Ga2O3 to Fe2O3/TiO2 ratios indicate an original metamorphic source. Syngenetic mineral inclusions include Al-rich diopside, meionite and anatase. The Al-rich diopside (‘fassaite’) contains extremely high Al2O3 (20–21 wt.%). A blue-green suite contains Fe (up to 0.8 wt.% Fe2O3) as a dominant chromophore, while a rare nepheline-anorthoclase composite inclusion supports a magmatic phonolitic origin. The Cudgegong- Macquarie ruby formation is compared with a garnet granulite origin proposed for Thailand rubies and a xenolith of corundum-bearing garnet granulite from Ruby Hill, Bingara, Australia. Clinopyroxenecorundum thermometry suggests the Cudgegong-Macquarie rubies formed at T >1000–1300ºC, a high equilibration T for proposed lithospheric granulites. These rubies form a distinctive suite compared to other rubies from Australian and SE Asian basalt fields, but have some similarities with eastern Thailand rubies.
Fluoronyböite from Jianchang (Su-Lu, China) and nyböite from Nybö (Nordfjord, Norway): a petrological and crystal-chemical comparison of these two high-pressure amphiboles
Authors: Oberti R. , Boiocchi M. , Smith D. C.
Published: January 2004

Fluoronyböite, ideally NaNa2(Al2Mg3)(Si7Al)O22F2, has been found in the Jianchang eclogite pod, Su-Lu coesite-eclogite province, China. It has been approved as a new mineral by the IMA. Single-crystal structure refinement and electron microprobe analysis were used for characterization: C2/m, with a = 9.666(4), b = 17.799(6), c = 5.311(2) Å, β = 104.10(3)º, V = 886.2(8) Å3, Z = 2, formula: A(Na0.78K0.06)Σ0.84B(Na1.53Ca0.47)Σ2.00C(Fe2+0.89Mg2.55Mn0.01Zn0.01Fe3+0.32Al1.21Ti0.01)Σ5.00T(Si7.14Al0.86)Σ8.00O22X(OH0.84F1.16)Σ2.00.

Fluoronyböite formed during UHPM conditions, and is preserved in the retrograded kyanite-bearing eclogite sample DJ102 together with clinopyroxene (Jd70Ae20Di10), garnet (Alm60Prp21Grs17Sps02), and rutile. Lower-pressure minerals are also present (fluoro-alumino-magnesiotaramite, apatite, paragonite), and symplectitic rims were also developed around clinopyroxene crystals. Cation ordering and the structural and physical properties of fluoronyböite are reported and discussed with reference to those of F-free nyböite from the type locality at Nyböin Norway, for which some as yet unpublished mineral data are also reported. Relations between composition and petrogenetic conditions of these rare high-pressure amphiboles are discussed.
Delayed Saccades, but Not Delayed Manual Aiming Movements, Require Visual Attention Shifts
Authors: DEUBEL HEINER , SCHNEIDER WERNER X.
Published: January 2004

Several studies have shown that during the preparation of a goal‐directed movement, perceptual selection (i.e., visual attention) and action selection (the selection of the movement target) are closely coupled. Here, we study attentional selection in situations in which delayed saccadic eye movements and delayed manual movements are prepared. A dual‐task paradigm was used which combined the movement preparation with a perceptual discrimination task. The results demonstrate a fundamental difference between the preparation of saccades and of manual reaching. For delayed saccades, attention is pinned to the saccade target until the onset of the response. This does not hold for manual reaching, however. Although fast reaching movements require attention, reaches delayed more than 300 ms after movement cue onset can be already performed “off‐line” that is, attention can be withdrawn from the movement target.
Grounded in the World: Developmental Origins of the Embodied Mind
Authors: Thelen Esther
Published: January 2004

Piaget's (1952) question of how the adult mind emerges from the sensorimotor infant is still the framing issue for developmental psychology. Here I suggest that real‐life skill is better understood if the sensorimotor origins of cognition are not abandoned. Skilled people are not only better at both abstract and logical thinking but also at processing the world “online” and, most important, seamlessly and rapidly shifting between the two modes. I illustrate the tight coupling between action, perception, and cognition in early life and propose that this coupling remains but becomes more flexibly adaptive. Further, I show that the language of dynamics is appropriate to capture these mind‐body‐world interconnections.
Global‐Before‐Basic Object Categorization in Connectionist Networks and 2‐Month‐Old Infants
Authors: Quinn Paul C. , Johnson Mark H.
Published: January 2004

A 3‐layered backpropagation connectionist network, configured as an autoassociator, learned to form global (e.g.,mammal)before basic‐level (e.g.,cat)category representations from perceptual input. To test the predicted global‐to‐basic order of category learning of the network, 2‐month‐olds were administered the familiarization/novelty‐preference procedure and examined for representation of global and basic‐level categories. Infants formed a global category representation for mammals that excluded furniture but not a basic‐level representation for cats that excluded elephants, rabbits, or dogs. The empirical results are consistent with the global‐to‐basic learning sequence observed in the network simulations.
Mechanisms of Categorization in Infancy
Authors: Mareschal Denis , French Robert
Published: January 2004

This article presents a connectionist model of correlation‐based categorization by 10‐month‐old infants (Younger, 1985). Simple autoencoder networks were exposed to the same stimuli used to test 10‐month‐olds. The familiarization regime was kept as close as possible to that used with the infants. The performance of the model matched that of the infants. Both infants and networks used covariation information (when available) to segregate items into separate categories. The model provides a mechanistic account of category learning within a test session. It demonstrates how categorization arises as the product of an inextricable interaction between the subject (the infant) and the environment (the stimuli). The computational characteristics of both subject and environment must be considered in conjunction to understand the observed behaviors.
When a Rose Is Just a Rose: The Illusion of Taxonomies in Infant Categorization
Authors: Rakison David H.
Published: January 2004

The termsbasic, superordinate, subordinate, andglobalare often used to describe the categories formed by infants. However, although infants' categories appear externally to match those formed by adults, it is not clear that they are grounded in an organized hierarchical system that embodies relations within and between domains; that is, a taxonomy. To assess whether it is appropriate to consider infants' categories as taxonomies, 3 criteria are examined: (a) similarity to adults' choice of category members, (b) hierarchical understanding, and (c) agreement with adults' bases for classification. It is argued that infants' categories do not meet these criteria and that it may be erroneous to apply the same labels to categories formed in the first 2 years as those in later life. To do so may be to hold an illusion of taxonomies about infants' categories.
Emergence of Selective Social Referencing in Infancy
Authors: Striano Tricia , Rochat Philippe
Published: January 2004

Seven and 10‐month‐old infants were presented with a remote‐controlled toy dog that intermittently barked at 30‐sec intervals as they faced an experimenter who either attended to them (look toward condition) or looked away (look away condition). Seven‐month‐old infants' looking toward the experimenter was significantly greater after the dog barking events compared to before regardless of experimental condition. In contrast, 10‐month‐old infants' looks were significantly greater after the barking events compared to before only when the experimenter was attending to them. These results suggest that by 10 months infants monitor and refer to people in an ambiguous situation depending on their attention toward them. This development is viewed as indexing the emergence of an intentional stance in social referencing by 10 months of age.
Newborn Infants' Preference for Attractive Faces: The Role of Internal and External Facial Features
Authors: Slater Alan , Bremner Gavin , Johnson Scott P. , Sherwood Penny , Hayes Rachel , Brown Elizabeth
Published: January 2004

Several previous experiments have found that newborn and young infants will spend more time looking at attractive faces when these are shown paired with faces judged by adults to be unattractive. Two experimental conditions are described with the aim of finding whether the “attractiveness effect” results from attention to internal or external facial features, or both. Pairs of attractive and less attractive faces (as judged by adults) were shown to newborn infants (mean age 2 days, 9 hours), where each pair had either identical internal features (and different external features) or identical external features (and different internal features). In the latter, but not the former, condition the infants looked longer at the attractive faces. These findings are clear evidence that newborn infants use information about internal facial features in making preferences based on attractiveness. It is suggested that when newborn (and older) infants are presented with facial stimuli, whether dynamic or static, they are able to attend both to internal and external facial features.
The Effects of Graded Occlusion on Manual Search and Visual Attention in 5‐ to 8‐Month‐Old Infants
Authors: Shinskey Jeanne L. , Bogartz Richard S. , Poirier Christopher R.
Published: January 2004

Young infants may be limited in searching for hidden objects because they lack the means‐end motor skill to lift occluders from objects. This account was investigated by presenting 5‐ to 8‐month‐old infants with objects hidden behind transparent, semitransparent, and opaque curtains. If a means—end deficit explains search limitations, then infants should search no more for an object behind a transparent curtain than for objects behind semitransparent or opaque curtains. However, level of occlusion had a significant effect on manual search and visual attention. Infants retrieved and contacted the object more, contacted the curtain more, and looked away less with the transparent curtain than with the semi transparent or opaque curtains. Adding a time delay before allowing search and presenting a distraction after occlusion further depressed infants' behavior. The findings fail to support the means—end deficit hypothesis, but are consistent with the account that young infants lack object permanence.
Social and Didactic Parenting Behaviors and Beliefs Among Japanese American and South American Mothers of Infants
Authors: Cote Linda R. , Bornstein Marc H.
Published: January 2004

Mothers of Japanese or South American ancestry living in the United States participated. Similarities and differences in mothers' social and didactic parenting behaviors and beliefs, and direct relations between behaviors and beliefs in these 2 domains of interaction, are reported. In accordance with a common collectivist orientation, Japanese American and South American mothers reported that they engaged in more social than didactic interactions with their infants, and South American mothers more than Japanese American mothers. However, in actuality, both of these acculturating groups engaged in more didactic than social behaviors with their infants and did so for longer periods of time. Not surprisingly, no belief‐behavior relations emerged in either group.
Temporal Sequence of Global‐Local Processing in 3‐Month‐Old Infants
Authors: Frick Janet E. , Colombo John , Allen Jennifer Ryther
Published: January 2004

In 3 experiments, the temporal processing sequence of local and global visual properties was investigated with 3‐month‐old infants. Across the experiments, a global pattern was discriminated under conditions of less familiarization than was necessary for local elements to be discriminated, thus indicating a global precedence in the sequence of visual processing at 3 months of age. Patterns of discrimination were also observed to vary as a function of individual differences in infants' look duration. Furthermore, the pattern of novelty and familiarity preferences for short‐looking infants varied in complex ways as a function of familiarization time: Preferences for novel global properties were supplanted by familiarity preferences at the point in familiarization at which infants first became sensitive to local properties.
Object Permanence in Five‐and‐a‐Half‐Month‐Old Infants?
Authors: Bogartz Richard S. , Shinskey Jeanne L. , Schilling Thomas H.
Published: January 2004

Event Set × Event Set designs were used to study the rotating screen paradigm introduced by Baillargeon, Spelke, and Wasserman (1985). In Experiment 1, 36 5 1/2‐month‐old infants were habituated to a screen rotating 180° with no block, a screen rotating 120° up to a block, or a screen rotating 180° up to and seemingly through a block. All infants were then tested on the same 3 events and also a screen rotating 120° with no block. The results indicate that infants are using novelty and familiarity preference to determine their looking times. To confirm this, in Experiment 2, 52 5 1/2‐month‐old infants were familiarized on either 3 or 7 trials to a screen rotating 180° with no block or a screen rotating 120° with no block. All infants were then tested on the same test events as in Experiment 1. Infants with fewer familiarization trials were more likely to prefer the familiar rotation event. The results of these 2 experiments indicate that infants did not use the possibility or impossibility of events but instead used familiarity or novelty relations between the habituation events and the test events to determine their looking times, and suggest that the Baillargeon et al. study should not be interpreted as indicating object permanence or solidity knowledge in young infants.
Eight‐Month‐Old Infants' Perception of Possible and Impossible Events
Authors: Cashon Cara H. , Cohen Leslie B.
Published: January 2004

This study investigated 8‐month‐old infants' perception of object permanence in an extension of the rotating screen studies by Baillargeon (1987) and Baillargeon, Spelke, and Wasserman (1985). Using computer‐animated stimuli similar to the “live” stimuli used by Baillargeon and her colleagues (Baillargeon, 1987; Baillargeon et al., 1985), 48 8‐month‐old infants were habituated to 1 of 4 computer‐animated events and then tested on all 4 events. The events involved a screen that rotated in either a 180° or 120° arc*** and a block that either was sitting in the path of the rotating screen or absent from the event. The results provided no evidence that infants responded on the basis of the possibility or impossibility of the events as claimed by Baillargeon and her colleagues, but instead indicated that the infants responded on the basis of perceptual novelty. These results are consistent with the findings of Schilling (this issue) and Bogartz, Shinskey, and Schilling (this issue). Taken together, along with the findings of Rivera, Wakeley, and Langer (1999), these more recent findings suggest that Baillargeon's (1987; Baillargeon et al., 1985) results should not be interpreted as definitive evidence of object permanence in very young infants.
Infants' Preferences for Familiarity and Novelty During the Course of Visual Processing
Authors: Roder Beverly J. , Bushneil Emily W. , Sasseville Anne Marie
Published: January 2004

At 4 1/2 months, infants were shown a series of brief choice trials between a stimulus that always remained the same and another that was different on every trial. The point when a consistent preference for the novel stimulus commenced was identified for each infant, and their preferences for the familiar and novel stimuli in trials preceding that point were examined. Infants who saw objects or faces as stimuli both exhibited selective attention to the familiar stimulus prior to preferring novel stimuli, although infants shown kaleidoscope patterns did not. These results document a preference for familiarity early in processing with a procedure that is not subject to ambiguities due to individual differences in processing speed or to collapsing data across infants. The results support a nonlinear model for memory formation during infancy and underscore recently voiced concerns that in research on cognitive development, infants' attention to perceptual familiarity‐novelty must be carefully disentangled from conceptual knowledge.
What's in a Name When It Isn't a Word? 17‐Month‐Olds' Mapping of Nonverbal Symbols to Object Categories
Authors: Namy Laura L.
Published: January 2004

Infants begin acquiring object labels as early as 12 months of age. Recent research has indicated that the ability to acquire object names extends beyond verbal labels to other symbolic forms, such as gestures. This experiment examines the latitude of infants' early naming abilities. We tested 17‐month‐olds' ability to map gestures, nonverbal sounds, and pictograms to object categories using a forced‐choice triad task. Results indicated that infants accept a wide range of symbolic forms as object names when they are embedded in familiar referential naming routines. These data suggest that infants may initially have no priority for words over other symbolic forms as object names, although the relative status of words appears to change with development. The implications of these findings for the development of criteria for determining whether a symbol constitutes an object name early in development are considered.
No Compelling Evidence That Newborns Imitate Oral Gestures
Authors: Anisfeld Moshe , Turkewitz Gerald , Rose Susan A. , Rosenberg Faigi R. , Sheiber Faith J. , Couturier‐Fagan Deborah A. , Ger Joseph S. , Sommer Iris
Published: January 2004

Newborns (N = 83) were presented with 3 conditions, each for 160 sec: tongue protrusion (TP), mouth opening (MO), and control (CO). In TP and MO, a female model alternated between demonstrating the gesture for 20 sec and presenting a passive, motionless face for 20 sec. In CO, she presented a passive face in both the “demonstration” and “passive” intervals. The participants' eyes were more widely open in the demonstration intervals of TP and MO than in the passive intervals, indicating that they were attending to the gestures. In TP, the participants produced more TP responses than MO responses, but in MO there was no effect, undermining the neonatal imitation hypothesis.
Cortical Indexes of Saccade Planning Following Covert Orienting in 20‐Week‐Old Infants
Authors: Richards John E.
Published: January 2004

This study examined scalp‐recorded, event‐related potential (ERP) indexes of saccade planning in 20‐week‐old infants. A spatial cuing procedure was used in which the infants were presented with a central fixation stimulus and a peripheral cue. A peripheral target followed the cue on the ipsilateral or contralateral side of the cue. The procedure resulted in covert orienting of attention in these participants, reflected in behavioral (e.g., response facilitation or inhibition of return depending on cue‐target stimulus‐onset asynchrony) and ERP (P1 facilitation to ipsilateral target) indexes of covert orienting of attention. A presaccadic ERP that occurred over the frontal cortex about 50 msec before the saccade onset was largest when the saccade was to a target in a cued location. A presaccadic ERP potential that occurred about 300 msec before the saccade onset was largest for the saccades toward the cued location whether the target was present or not. These results suggest that saccade planning occurs in infants at this age and that infant saccade planning is controlled by cortical systems.
Differential Frontal Cortex Activation Before Anticipatory and Reactive Saccades in Infants
Authors: Csibra Gergely , Tucker Leslie A. , Johnson Mark H.
Published: January 2004

Neural correlates of anticipatory and reactive saccades were studied in 4‐month‐old infants by recording high‐density event‐related potentials. Infants were presented with a fixed sequence of stimulus presentation to which they rapidly showed anticipatory saccades, as well as continuing with some reactive (stimulus‐driven) saccades. As in a previous study, no clear evidence was found for adultlike, saccade‐related potentials, although some presaccadic differences between reactive and anticipatory saccades were observed. Infants also showed different stimulus offset‐related effects preceding the 2 types of trials with a right‐frontal positivity when an anticipatory look follows, but only left‐frontal positivity when a reactive saccade follows.
Lessons From Infants: 1960–2000
Authors: Clifton Rachel Keen
Published: January 2004

Our image of the infant as an organism interacting with the environment has changed dramatically in the past 40 years. A new surge of infancy research began in the 1960s and continues unabated today. The view of the infant has been transformed from that of a primarily reflexive organism to a highly competent being, exquisitely sensitive to sensory and perceptual information. Controversy still swirls around the issue of when infants acquire specific knowledge about objects and events. New work is reviewed on how infants and toddlers use knowledge to guide their behavior in challenging situations. Despite the tremendous growth of knowledge about infant development over the past 40 years, it seems that we are on the threshold of even more exciting discoveries.
Onset of Voluntary Communication: Smiling Looks to Mother
Authors: Jones Susan S. , Hong Hye‐Won
Published: January 2004

Playing infants often direct smiling looks toward social partners. In some cases the smile begins before the look, so it cannot be a response to the sight or behavior of the social partner. In this study we asked whether smiles that anticipate social contact are used by 8‐ to 12‐month‐old infants as voluntary social signals. Eighty infants—20 at each of 8, 9, 10, and 12 months of age—completed 5 tasks. The tasks assessed anticipatory smiling during toy play, means‐end understanding (2 tasks), intentional communication via gesture and vocalizations, and memory for mother's location. Across all ages, anticipatory smiling was strongly predicted by intentional gestural and vocal communication and by means‐end understanding. The findings are discussed in terms of the nature and origins of infants' voluntary communications.
Relation Between Maternal Cigarette Smoking During Pregnancy and Behavioral and Physiological Measures of Autonomic Regulation in Neonates
Authors: Schuetze Pamela , Zeskind Philip Sanford
Published: January 2004

The effects of maternal cigarette smoking during pregnancy on behavioral and physiological measures of arousal were examined in a sample of 50 neonates. After the effects of alcohol, caffeine, and maternal demographic variables were statistically controlled, regression analyses showed that maternal smoking during pregnancy was predictive of higher heart rates overall and during quiet and active sleep. Maternal smoking during pregnancy was also predictive of lower heart rate variability and an increased number of tremors and changes in behavioral state. These findings suggest that maternal cigarette smoking during pregnancy affects the regulation of spontaneous autonomic activity in neonates.
Perception of Prosodic Boundary Correlates by Newborn Infants
Authors: Christophe Anne , Mehler Jacques , Sebastián‐Gallés Núria
Published: January 2004

French newborn infants were shown to perceive acoustic correlates of phonological phrase boundaries in Spanish, with stress‐controlled stimuli. Access to phonological phrase boundaries may facilitate the acquisition of a lexicon, as well as some aspects of phonology and even syntax.
Detecting Transparent Barriers: Clear Evidence Against the Means‐End Deficit Account of Search Failures
Authors: Shinskey Jeanne L. , Munakata Yuko
Published: January 2004

The standard explanation of infants' search failures with hidden objects, despite an apparent sensitivity to them, is a deficit in the means‐end skill for retrieving objects from occluders. Studies equating means‐end demands for retrieving toys from transparent and opaque barriers challenge this account by showing that infants succeed more with visible objects. However, they suffer from a critical limitation: Infants may retrieve visible objects without noticing the transparent barriers in front of them. We addressed this concern by requiring infants to notice a barrier to retrieve a toy and specifically to pull down a rotating screen to retrieve a toy from behind it. Seven‐month‐olds used this means‐end skill more often with a transparent barrier than an opaque one. Thus, neither a means‐end deficit nor an ability to ignore transparent barriers fully accounts for search failures. Relations to other findings challenging the means‐end deficit account and implications for approaches to studying cognitive development are discussed.
Decalage in Infants' Search for Mothers Versus Toys Demonstrated With a Delayed Response Task
Authors: Slaughter Virginia , Boh Wai
Published: January 2004

Thirty‐one infants, 7 to 14 months of age, were tested on object and mother permanence using a delayed response task (Diamond, 1985), in which a delay period is enforced before infants are allowed to search for hidden objects. Infants were tested in 2 separate conditions in which they searched for their mothers and a large toy, both of which were hidden under curtained tables. The delay period before search was allowed was incremented after each successful trial until infants either failed to search or searched in the wrong location. Infants were scored for the maximum delay preceding a successful search. The results from 17 infants showed that infants were able to withstand significantly longer delays before successful search for the mother than for the toy. These results support previous studies showing that mother permanence precedes object permanence in infants older than 8 months.
Neural Network Simulation of Infant Familiarization to Artificial Sentences: Rule‐Like Behavior Without Explicit Rules and Variables
Authors: Shultz Thomas R. , Bale Alan C.
Published: January 2004

A fundamental issue in cognitive science is whether human cognitive processing is better explained by symbolic rules or by subsymbolic neural networks. A recent study of infant familiarization to sentences in an artificial language seems to have produced data that can only be explained by symbolic rule learning and not by unstructured neural networks (Marcus, Vijayan, Bandi Rao, & Vishton, 1999). Here we present successful unstructured neural network simulations of the infant data, showing that these data do not uniquely support a rule‐based account. In contrast to other simulations of these data, these simulations cover more aspects of the data with fewer assumptions about prior knowledge and training, using a more realistic coding scheme based on sonority of phonemes. The networks show exponential decreases in attention to a repeated sentence pattern, more recovery to novel sentences inconsistent with the familiar pattern than to novel sentences consistent with the familiar pattern, occasional familiarity preferences, more recovery to consistent novel sentences than to familiarized sentences, and extrapolative generalization outside the range of the training patterns. A variety of predictions suggest the utility of the model in guiding future psychological work. The evidence, from these and other simulations, supports the view that unstructured neural networks can account for the existing infant data.
Role of Clinical Diagnosis and Medication Use in Effects of Maternal Depression on Infant‐Directed Speech
Authors: Kaplan Peter S. , Bachorowski Jo‐Anne , Smoski Moria J. , Zinser Michael
Published: January 2004

Infant‐directed (ID) speech was recorded from mothers as they interacted with their 4‐ to 12‐month‐old infants. Hierarchical regression analyses revealed that two variables, age of the mother and mother's diagnosed depression, independently accounted for significant proportions of the variance in the extent of change in fundamental frequency (ΔF0). Specifically, depressed mothers produced ID speech with smaller ΔF0 than did nondepressed mothers, and older mothers produced ID speech with larger ΔF0 than did younger mothers. Mothers who were taking antidepressant medication and who were diagnosed as being in at least partial remission produced ID speech with mean ΔF0 values that were comparable to those of nondepressed mothers. These results demonstrate explicit associations between major depressive disorder and an acoustic attribute of ID speech that is highly salient to young infants.
Infants' Ability to Learn Phonetically Similar Words: Effects of Age and Vocabulary Size
Authors: Werker Janet F. , Fennell Christopher T. , Corcoran Kathleen M. , Stager Christine L.
Published: January 2004

What do novice word learners know about the sound of words? Word‐learning tasks suggest that young infants (14 months old) confuse similar‐sounding words, whereas mispronunciation detection tasks suggest that slightly older infants (18–24 months old) correctly distinguish similar words. Here we explore whether the difficulty at 14 months stems from infants' novice status as word learners or whether it is inherent in the task demands of learning new words. Results from 3 experiments support a developmental explanation. In Experiment 1, infants of 20 months learned to pair 2 phonetically similar words to 2 different objects under precisely the same conditions that infants of 14 months (Experiment 2) failed. In Experiment 3, infants of 17 months showed intermediate, but still successful, performance in the task. Vocabulary size predicted word‐learning performance, but only in the younger, less experienced word learners. The implications of these results for theories of word learning and lexical representation are discussed.