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Antiferromagnetic magnetization dynamics is more effective than ferromagnetic magnetization; however, it is extremely complex. Rare earth (RE) ferrimagnets, on the other hand, have tunable magnetization with associated negative exchange interaction in sublattices. Here, we study different RE-Fe ferrimagnets while changing the RE-content. We obtain various magnetic properties like saturation magnetization MS, coercivity HC, magnetic anisotropy energy constant Ku, exchange coupling constant λ, and compensation temperature Tcomp for different RE compositions. We suggest that along with MS and HC, λ is another important parameter that is easy to measure and has information that is similar to that in the spin-orbit torque effective field and the canting angle. [ABSTRACT FROM AUTHOR]

Interlayer dipolar coupling is an important aspect in magnetic switching devices from the application point of view. Here, we identify various sources affecting the interlayer dipolar coupling in CoFeB-based perpendicular magnetic tunnel junctions (pMTJs). By changing the MgO tunnel barrier layer thickness, we show that it plays a crucial role in controlling the dipolar coupling between the CoFeB reference and free layers and affects the magnetic properties of pMTJ. Moreover, changes in thickness of the bottom electrode layer affect the interlayer coupling strength and change the magnetic anisotropy of the free layer from perpendicular to in-plane direction. Furthermore, it is observed that the smaller the cell size of such MTJs, the more dominating the coupling strength which is formed by stray fields. These are some of the crucial parameters which need to be investigated during the device fabrication process for optimum device performance. [ABSTRACT FROM AUTHOR]

• Gd-content gradients influence PMA in both "+δ" and "−δ" samples. • "+δ" has lower H C due to closer T comp , suggesting different Gd-content. • Reversal of AHE loop near T comp indicates sublattice dominance shift. • Decrease in H SF suggests weakened exchange interaction near T comp. • Strong ΔR XY at ± 4 kOe and ± 30 kOe for "−δ" indicates enhanced PMA. Ferrimagnetic rare-earth (RE) – transition-metal (TM) alloys are considered small ferromagnets with antiferromagnetic exchange in sublattices, which makes them a preferable choice for future ultrafast memory-related applications. Here, we explore the magnetic properties of two GdFeCo thin films with tailored vertical composition gradients, achieved by gradually varying Gd concentration across the film thickness. The temperature-dependent magnetic behavior of these films is investigated using anomalous Hall effect (AHE) measurements and SQUID magnetometry. Both films exhibit perpendicular magnetic anisotropy with distinct coercivities, indicating variations in their magnetic properties. The films show RE-dominant behavior at 300 K. Moreover, for the positive composition gradient (+δ) film, the compensation temperature is around 350 K, while the film with a negative gradient (−δ) exhibits a compensation temperature above 400 K. Furthermore, the spin-flop behavior and AHE sign reversal provide insights into the sublattice dominance and exchange interactions within the films. The magnitude of ΔR XY (the difference in AHE resistance at different magnetic fields) is shown to be sensitive to the composition gradient, indicating stronger perpendicular magnetic anisotropy for the "−δ" sample. This study demonstrates the potential of composition engineering to tailor the magnetic characteristics of ferrimagnetic materials for specific spintronics applications. [ABSTRACT FROM AUTHOR]

Among various perpendicularly anisotropic magnetic materials, amorphous rare earth-transition metal RE-TM alloys have attracted much interest due to the advantages of tunable magnetic properties and suitable perpendicular magnetic anisotropy (PMA) strength. In this study, the magnetic properties of the Ta/TbFeCo/MgO structure with various Tb-contents are investigated under different annealing conditions like heating rate and annealing temperature. The samples were annealed at heating rate from 10 °C/min to 50 °C/min and holding time was varied from 10 min to 30 min with annealing temperatures ranging from 100 to 150 °C. We found that fast heating rate and low holding temperature help to improve PMA and significantly increase the saturation magnetization and squareness of the TbFeCo films. [ABSTRACT FROM AUTHOR]

• Investigate the temperature-dependent AHE in sandwich structures composed of two RE-TM FIM layers. • Complex AHE phenomena explained by the magnetization reversal of individual layers, Hall sign reversal, and the SF transition in the GdFeCo layer. • A model is developed to provide a simplified explanation of the origin of these complex AHE loops. • The model unravels the complexity in AHE loops near and far from the T comp. • The model fits well with the experimental results. The anomalous Hall effect (AHE) has been a remarkable tool for characterizing the magnetic properties of thin films with perpendicular magnetic anisotropy. In this study, we investigate the temperature-dependent AHE in sandwich structures composed of two ferrimagnetic (FIM) layers with different coercivities, using rare-earth-transition-metal (RE-TM) materials. Complex triple AHE loops are obtained near the compensation temperature of GdFeCo, and these loops are explained by considering the magnetization reversal of the individual layers, Hall sign reversal, and the spin-flop transition in the GdFeCo layer. A model is developed to provide a simplified explanation of the origin of these complex AHE loops. This study elucidates the mechanism behind the unusual temperature-dependent AHE response of the technologically important RE-TM FIM films for spintronics applications. [ABSTRACT FROM AUTHOR]

Abstract The superconductor (SC)/ferromagnetic (FM) systems have shown tremendous attention due to their amazing phenomena at the SC/FM interfaces such as the inverse proximity effect, triplet superconducting pair generation and the non-dissipation spintronics, which exhibit a great potential on scientific development and applications. To explore these unique characteristics, possible unknown effect and seeking for potential capabilities in bulk SC/FM systems, this study focuses on the bulk composites made of the high -T C superconductor YBa 2 Cu 3 O 7-δ (YBCO) and the highly spin-polarized La 2/3 Sr 1/3 MnO 3 (LSMO). The (YBCO) 0.9 /(LSMO) 0.1 composites were annealed at short (Comp_2hr) and longer (Comp_18hr) annealing time. We found that the composites form a distinct core-shell structure. The LSMO grains and the outer layer of YBCO interdiffuse into each other and reconstruct in a way to form off-stoichiometric thin shells. Due to the limited interdiffusion speed, a clear white diffusion-limited-boundary separates the shell and core and protects the pure YBCO phase. This core-shell structure modifies the superconducting behavior to appear complex resistivity and magnetization with temperature such as a second transition due to the tunneling of Cooper pairs at low temperature. Graphical abstract Image 1 Highlights • YBCO-LSMO composite is studied in association with microstructure. • System forms a distinct core-shell structure due to interdiffusion. • Diffusion-limited boundary protects the inner-grain maintaining pure YBCO phase. • Core-shell structure modifies superconducting behavior as complex transport property. [ABSTRACT FROM AUTHOR]

Abstract A systematic study on the thermal conductivity, Seebeck coefficient and specific heat of La 0.7 Ca 0.2 Sr 0.1 MnO 3 :PdO composites is presented. Solid state reaction procedure was employed to synthesis the samples. It is seen from thermal conductivity (κ(T)) studies that the samples exhibit a slope change nature close to their corresponding magnetic phase transition temperature, T C. The overall magnitude of κ is observed to decrease with increasing Pd concentration. The analysis of Seebeck coefficient data, S(T) versus temperature, T was done using Mott's polaron hopping model reveals that the electron-magnon scattering is governing the low temperature region. The temperature dependent specific heat C P (T) is analyzed to determine the entropy change (Δ S) during the magnetic phase transition. Highlights • Thermal conductivity deceases with increase in Pd content. • Mott's polaron hopping mechanism is operative at high temperatures. • Change in entropy ΔS decreases with Pd content. [ABSTRACT FROM AUTHOR]

Abstract We present temperature-dependent studies on electrical and thermal properties of bulk samples of Pr 2/3 Sr 1/3 MnO 3-δ synthesized at different sintering temperatures (T S). It is established that these properties intensely influenced by the sintering temperatures. Analysis of electrical resistivity data ρ (T) by means of standard models, demonstrated that electron-electron scattering processes play a key role in the conduction process in the low-temperature region. At high temperatures, the ρ (T) follows the small polaron hopping (SPH) model. Analyses of the Seebeck coefficient data S (T) in the low temperature regime illustrates that electron-magnon scattering governs the thermoelectric transport, on contrary, the high-temperature S (T) follows the SPH model. The low-temperature phonon peak in thermal conductivity κ (T) increases with increasing T S , demonstrating that a better crystallinity of Pr 2/3 Sr 1/3 MnO 3 samples was obtained at higher sintering temperatures. Magnetic transitions are observed to increase with a higher T S , and the entropy change associated with the transition also increases with T S. Highlights • Small polaron hopping model is operative in high temperature regime. • Thermal conductivity increases with increasing sintering temperature. • The entropy change around transition temperature increases with sintering temperature. [ABSTRACT FROM AUTHOR]

Adult perceivers segregate figure from ground based on image cues such as small size and main axis orientation. The current study examined whether infants can use such cues to perceive figure-ground segregation. Three- to 7-month-olds were familiarized with a pie-shaped stimulus in which some pieces formed a + and other pieces formed an x. The infants were then presented with a novelty preference test pairing the + and x. The bases for the pieces forming the + or x were size and orientation (Experiment 1), size (Experiment 2), and orientation (Experiment 3). In each experiment, infants responded as if they recognized as familiar the shape specified by small size, main axis orientation, or their combination. Control conditions showed that infant performance could not be attributed to spontaneous preference. The findings suggest that infants can achieve figure-ground segregation based on some of the same cues used by adults. [ABSTRACT FROM AUTHOR]

• Identification of Hall-contributor from TEM analysis and AHE measurements in RE-TM FIMs. • Novel sandwich structure of FeCo-compensated GdFeCo and TbFeCo. • ΔR AHE drops towards zero when FeCo-content compensate in the two layers. • FeCo is the major contributor of the anomalous Hall signal. • Temperature dependence of ΔR AHE further supports the claim. The contribution of magnetic sublattices in rare-earth-transition-metal (RE-TM) ferrimagnets (FIMs) has long been debated and is still unclear. The spin-split of 3d conducting electrons in TMs has been known for the anomalous Hall effect (AHE) response, yet in FIMs the contribution from RE is unclear. Here we try to solve the problem by applying a novel sandwich structure of TbFeCo and GdFeCo using Ta spacer. FeCo-content in the two layers is changed from unequal to equal and the AHE resistance (R AHE) of the structure is studied. The difference in R AHE of the two layers is compared with their FeCo-content ratio. This study shows that when the FeCo-content of the two magnetic layers is close, the ΔR AHE is greatly reduced. The results indicate that the AHE signal is majorly contributed by the FeCo-sublattices. The novel approach followed here adds crucial information to the ongoing debate on Hall-contribution in RE-TM FIMs. [ABSTRACT FROM AUTHOR]

We have synthesized a nominal composition of NiMnSn alloy using arc melting technique. Rietveld refinement confirms the austenite L2 structure in the Fm-3m space group. Electrical resistivity has been found to be clearly exhibiting two different phenomena viz a magnetic transition from paramagnetic to ferromagnetic and a structural transition from austenite to martensite phase. Thermo-magnetization measurements M(T) confirms ferromagnetic transition temperature T at 222 K and martensitic transition starting at 127 K (M). Magnetization measurement M(H) at 10 K confirms the ferromagnetic state. Frequency dependence of AC susceptibility χ' at low temperature suggests spin glass behavior in the system. The isothermal magnetic entropy change values have been found to be 1.14, 2.69, and 3.9 J/Kg.K, with refrigeration capacities of 19.6, 37.8, and 54.6 J/Kg for the field change of 1, 2, and 3 T respectively at 227 K. [ABSTRACT FROM AUTHOR]

• Magnetization relaxation in Hf/GdFeCo/SiN as a function of current polarity, probe widths, and notch in the device. • In notched Hall bar, the smaller H C for positive current seems due to valve-like behavior from notch. • Notch provides smaller delays for nucleation and switching compared to the no-notch Hall bar. • Narrow probe shows the advantage of comparatively faster and less stochastic switching. • Sense current is another important key to controlling the nucleation delay. The race-track memory concept relies on domain wall propagation through a magnetic track, which has the potential to change the future course of memory-related applications. Therefore, the materials where one can control the propagation of domain walls are crucial. Further, the stochastic nature of magnetization switching has potential applications in neuromorphic computing. Here we study the propagation of magnetic domains and the stochastic magnetization relaxation in the Gd-Fe-Co Hall bar. The magnetic relaxation of Hall bar devices is studied using anomalous Hall resistance measurements. This study highlights the behavior of magnetization relaxation under various parameters viz., at different magnitudes and directions of sensing currents, Hall probe aspect ratios, and the presence of a notch in the Hall bar. This study shows that the stochastic nature and delay in magnetization relaxation can be controlled by the sensing currents and the Hall bar geometry, which is crucial for magnetization switching-based applications. [ABSTRACT FROM AUTHOR]

Introduction Face processing undergoes significant developmental change with age. Two kinds of developmental changes in face specialization were examined in this study: specialized maturation, or the continued tuning of a region to faces but little change in the tuning to other categories; and competitive interactions, or the continued tuning to faces accompanied by decreased tuning to nonfaces (i.e., pruning). Methods Using fMRI, in regions where adults showed a face preference, a face- and object-specialization index were computed for younger children (5-8 years), older children (9-12 years) and adults (18-45 years). The specialization index was scaled to each subject's maximum activation magnitude in each region to control for overall age differences in the activation level. Results Although no regions showed significant face specialization in the younger age group, regions strongly associated with social cognition (e.g., right posterior superior temporal sulcus, right inferior orbital cortex) showed specialized maturation, in which tuning to faces increased with age but there was no pruning of nonface responses. Conversely, regions that are associated with more basic perceptual processing or motor mirroring (right middle temporal cortex, right inferior occipital cortex, right inferior frontal opercular cortex) showed competitive interactions in which tuning to faces was accompanied by pruning of object responses with age. Conclusions The overall findings suggest that cortical maturation for face processing is regional-specific and involves both increased tuning to faces and diminished response to nonfaces. Regions that show competitive interactions likely support a more generalized function that is co-opted for face processing with development, whereas regions that show specialized maturation increase their tuning to faces, potentially in an activity-dependent, experience-driven manner. [ABSTRACT FROM AUTHOR]

Although we know much about the development of face processing, we know considerably less about the development of body knowledge-despite bodies also being significant sources of social information. One set of studies indicated that body structure knowledge is poor during the 1st year of life and spawned a model that posits that, unlike the development of face knowledge, which benefits from innate propensities and dedicated learning mechanisms, the development of body knowledge relies on general learning mechanisms and develops slowly. In this article, we review studies on infants' knowledge about the structure of bodies and their processing of gender and emotion that paint a different picture. Although questions remain, a general social cognition system likely engenders similar trajectories of development of knowledge about faces and bodies, and may equip developing infants with the capacity to obtain socially critical information from many sources. [ABSTRACT FROM AUTHOR]

The magneto-transport and magnetocaloric effect in Pr 2/3 Sr 1/3 MnO 3 :Ag 2 O (PSMO:Ag) with Ag 2 O (10–30 mol%) have been studied by resistivity and magnetization measurements. Temperature coefficient of resistance (TCR), magneto-resistance (MR) and magnetocaloric properties of the composite have shown different responses to Ag addition. Rietveld refinement confirms single phase crystalline structure with orthorhombic Pbnm space group and presence of silver metal as well. TCR changes randomly with Ag, increasing initially to 7.8% K −1 for PSMO:Ag10 composite which then decreases marginally with increasing Ag content. MR has been found to reach a maximum value of 30.5% at 1 T applied field for PSMO:Ag10 composite. Magnetic entropy change (Δ S M ) increases with increasing Ag content and is found to be 3.5 J kg −1 K −1 (1 T), 6.1 J kg −1 K −1 (2 T) and 8.4 J kg −1 K −1 (3 T) for PSMO:Ag30 composite at 285 K. The maximum refrigeration capacity of 39.5 J kg −1 (1 T), 91.0 J kg −1 (2 T) and 107.7 J kg −1 (3 T) has been found for the PSMO:Ag20 composite. PSMO:Ag composite exhibits potential for bolometric, magnetic sensing and magnetic refrigerating applications near room temperature. [ABSTRACT FROM AUTHOR]

Magneto-resistive and magneto-caloric properties of polycrystalline La(CaSr)MnO (LCSMO) and La(CaSr)MnO:10 %PdO (LCSMO:Pd10) composites sintered at 1400 C have been investigated. Rietveld refinement of their X-ray diffraction ( XRD) patterns confirms the single-phase crystalline structure with orthorhombic Pbnm space group, showing no significant change in their lattice parameters with Pd addition. Disappearance of the low temperature resistivity hump in the Pd composite has been attributed to the suppression of the grain boundary effect and the conducting channels due to the presence of metallic Pd. While the Curie temperature T remained nearly unchanged, the peak value of the temperature coefficient of resistance ( TCR) increased in the composite. $\mathit{TCR}_{\operatorname{MAX}}$ increased to 6.4 % (at 308 K) in the composite from 2 % (at 305 K) for the pristine LCSMO. Magneto-resistance ( MR) and magnetic entropy change (Δ S) also increased markedly in the composite material. This could be ascribed to the observed sharpness of both the magnetic and resistive transitions resulting from better grain connectivity. Maximum MR of 12.9 % (1 T) and 19.6 % (2 T) has been observed close to its T (309 K) in the pristine LCSMO. These values increased to 24.1 % (1 T) and 33.9 % (2 T) with the addition of PdO. The maximum values of |Δ S| are found to be 4.4, 8.2 and 11.7 J kg K at field values of 1, 2 and 3 T, respectively, for LCSMO:Pd10 composite, which are far better than those reported for LCSMO:Ag10 composite. [ABSTRACT FROM AUTHOR]

Highlights: [•] Sintering temperature (Ts ) dependent MR and MCE properties of Pr2/3Sr1/3MnO3. [•] Better grain connectivity results in improved MR and TCR with Ts . [•] The MR at Tc is 32% at 1T and 58% at 5T magnetic field for the optimized sample. [•] Maximum entropy change (ΔSMmax) is 7.8Jkg−1 K−1 upon the field change of 5 Tesla. [•] Obtained results suggest that it can be a potential magnetic refrigerant material. [ABSTRACT FROM AUTHOR]

• Temperature dependent anomalous Hall effect (AHE) in GdFeCo. • Magnetic compensation temperature for sheet film ~240 K and device ~118 K. • In sheet film, spin-flopping is witnessed at 0.6 Tesla close to compensation temperature. • Triple loops are observed in AHE hysteresis for the device. • The zero-field and 3 Tesla R AHE scan suggests the Hall signal generates solely from the FeCo moment. • Drop in the 3Tesla R AHE near the compensation is explained by considering the low field spin-flopping. Here we investigate the temperature dependence of anomalous Hall effect in Hf/GdFeCo/MgO sheet film and Hall bar device. The magnetic compensation temperature (T comp) for the sheet film and device is found to be ~240 K and ~118 K, respectively. In sheet film, spin-flopping is witnessed at a considerably lower field, 0.6 T, close to T comp. The AHE hysteresis loops in the sheet film have a single loop whereas in the Hall bar device, hystereses consist of triple loops are observed just above the T comp. Moreover, the temperature-dependent anomalous Hall resistance (R AHE) responds unusually when a perpendicular magnetic field is applied while recording the R AHE. The zero-field R AHE scan suggests the Hall signal generates solely from the FeCo moment. However, the behavior of 3T-field R AHE scan in which the R AHE drops close to zero near the T comp seems to be following the net magnetization response of the device, is explained by considering the low field spin-flopping around the compensation temperature. The results presented here give important insight to understand the complex AHE behavior of ferrimagnets for their spintronic applications. [ABSTRACT FROM AUTHOR]

Infants do not readily organize visual pattern information using form similarity: 3 to 4 month olds familiarized with arrays consisting of alternating columns or rows of a given element contrast do not display a subsequent preference for a novel organization of horizontal versus vertical bars. However, when array types composed of different element contrasts are presented during familiarization, infants perform successfully, indicating that variability in pattern information depicting an invariant structure promotes perceptual learning. In the current investigation, we examined whether the type of variability (relevant versus irrelevant) impacts this learning, as a way to understand the specificity and mechanism underlying the learning. In experiment 1, one group of infants (relevant variability) was familiarized with three element contrasts forming column-row arrays on different trials, and a fourth element contrast that formed an outer enclosing context on all trials. For the other group (irrelevant variability), the column-row array was composed of the same element contrast across trials, while the outer context differed across trials by being composed of three different element contrasts. Only the relevant variability group performed successfully. Experiment 2 showed that the failure of irrelevant variation to facilitate organization was not due to insensitivity to the variation among elements in the outer context. The findings suggest that variation which emphasizes global structure and deemphasizes local element information is a significant factor in facilitating perceptual learning. [ABSTRACT FROM AUTHOR]

Adults' processing of own-race faces differs from that of other-race faces. The presence of an 'other-race' feature (ORF) has been proposed as a mechanism underlying this specialization. We examined whether this mechanism, which was previously identified in adults and in 9-month-olds, is evident at 3.5 months. Caucasian 3.5-month-olds looked longer at a pattern containing a single Asian face among seven Caucasian faces than at a pattern containing a single Caucasian face among seven Asian faces. Homogenous and inverted face control conditions indicated that infants' preference was not driven by the majority of faces in arrays or by low-level features. Thus, 3.5-month-olds found the presence of an other-race face among own-race faces to be more salient than the reverse configuration. This asymmetry suggests sensitivity to an ORF at 3.5 months. Thus, a key mechanism of race-based processing in adults has an early onset, indicating rapid development of specialization early in life. [ABSTRACT FROM AUTHOR]

Part representation is not only critical to object perception but also plays a key role in a number of basic visual cognition functions, such as figure-ground segregation, allocation of attention, and memory for shapes. Yet, virtually nothing is known about the development of part representation. If parts are fundamental components of object shape representation early in life, then the infant visual system should give priority to parts over other aspects of objects. We tested this hypothesis by examining whether part shapes are more salient than cavity shapes to infants. Five-month-olds were habituated to a stimulus that contained a part and a cavity. In a subsequent novelty preference test, 5-month-olds exhibited a preference for the cavity shape, indicating that part shapes were more salient than cavity shapes during habituation. The differential processing of part versus cavity contours in infancy is consistent with theory and empirical findings in the literature on adult figure-ground perception and indicates that basic aspects of part-based object processing are evident early in life. [ABSTRACT FROM AUTHOR]

The article discusses the article "How Does Learning Impact Development in Infancy? The Case of Perceptual Organization," by Ramesh S. Bhatt and Paul C. Quinn. In the article Bhatt and Quinn offer a response to criticisms which were offered in response to their article and discuss different approaches which can be used to study early perceptual learning in infants.

Pattern perception and organization are critical functions of the visual cognition system. Many organizational processes are available early in life, such that infants as young 3 months of age are able to readily utilize a variety of cues to organize visual patterns. However, other processes are not readily evident in young infants, and their development involves perceptual learning. We describe a theoretical framework that addresses perceptual learning in infancy and the manner in which it affects visual organization and development. It identifies five kinds of experiences that induce learning, and suggests that they work via attentional and unitization mechanisms to modify visual organization. In addition, the framework proposes that this kind of learning is abstract, domain general, functional at different ages in a qualitatively similar manner, and has a long-term impact on development through a memory reactivation process. Although most models of development assume that experience is fundamental to development, very little is actually known about the process by which experience affects development. The proposed framework is an attempt to account for this process in the domain of perception. [ABSTRACT FROM AUTHOR]

Like faces, bodies are significant sources of social information. However, research suggests that infants do not develop body representation (i.e., knowledge about typical human bodies) until the second year of life, although they are sensitive to facial information much earlier. Yet, previous research only examined whether infants are sensitive to the typical arrangement of body parts. We examined whether younger infants have body knowledge of a different kind, namely the relative size of body parts. Five- and 9-month-old infants were tested for their preference between a normal versus a proportionally distorted body. Nine-month-olds exhibited a preference for the normal body when images were presented upright but not when they were inverted. Five-month-olds failed to exhibit a preference in either condition. These results indicate that infants have knowledge about human bodies by the second half of the first year of life. Moreover, given that better performance on upright than on inverted stimuli has been tied to expertise, the fact that older infants exhibited an inversion effect with body images indicates that at least some level of expertise in body processing develops by 9 months of age. [ABSTRACT FROM AUTHOR]

Infants do not readily organize using form similarity: 6- to 7-month-olds familiarized with horizontal or vertical bars (filled rectangles) do not display a subsequent preference for a novel column versus row organization of X–O elements (Quinn and Bhatt, 2006 Journal of Experimental Psychology: Human Perception and Performance 32 1221–1230). In experiment 1, infants were familiarized with more complex bars composed of beads or crosshatches, and performance was again unsuccessful. In experiment 2, all three bar types were presented during familiarization and infants performed successfully, indicating that variability in pattern information depicting an invariant structure enhances the learning of perceptual organization. In experiment 3, we examined whether the manner in which variability is experienced (simultaneous versus sequential contrast) impacts this learning. One group of infants was familiarized with a single pattern containing the three different bar types (within-trial variability), and another was presented with the same three bar types, but with each appearing on a different trial (across-trial variability). Only the across-trial variability group performed successfully, suggesting that trial-to-trial change in local element information induced by sequential presentation is a significant factor in facilitating the learning of perceptual organization. [ABSTRACT FROM AUTHOR]

Research indicates that object perception involves the decomposition of images into parts. A critical principle that governs part decomposition by adults is the short-cut rule, which states that, all else being equal, the visual system parses objects using the shortest possible cuts. We examined whether 6.5-month-olds' parsing of images also follows the short-cut rule. Infants in the experimental conditions were habituated to cross shapes and then tested for their preference between segregated patterns produced using long cuts versus short cuts. Infants in the control conditions were directly tested with the segregated patterns. Infants in the experimental conditions exhibited a greater novelty preference for the long-cut over the short-cut patterns than did those in the control conditions, thereby indicating that they are more likely to segregate cross shapes using short cuts rather than long cuts. This sensitivity to the short-cut rule was evident when two alternative parameters, part area and protrusion, were controlled in Experiments 1 and 2, respectively. Thus, a critical principle that governs part segregation in adulthood is operational by 6.5 months of age. [ABSTRACT FROM AUTHOR]

Previous research has demonstrated that organizational principles become functional over different time courses of development: Lightness similarity is available at 3 months of age, but form similarity is not readily in evidence until 6 months of age. We investigated whether organization would transfer across principles and whether perceptual scaffolding can occur from an already functional principle to a not-yet-operational principle. Six- to 7-month-old infants (Experiment 1) and 3- to 4-month-old infants (Experiment 2) who were familiarized with arrays of elements organized by lightness similarity displayed a subsequent visual preference for a novel organization defined by form similarity. Results with the older infants demonstrate transfer in perceptual grouping: The organization defined by one grouping principle can direct a visual preference for a novel organization defined by a different grouping principle. Findings with the younger infants suggest that learning based on an already functional organizational process enables an organizational process that is not yet functional through perceptual scaffolding. [ABSTRACT FROM AUTHOR]

lthough several studies have examined infants' sensitivity to perceptual organizational cues, few have examined the functional relations among these cues. We examined how uniform connectedness (UC) functions in relation to shape and luminance similarity. UC has been characterized as the entry-level mechanism of perceptual organization and would therefore be predicted to be more salient than the other two cues. We found that UC was more salient than shape similarity organization was, to the point that 6- to 7-month-old infants failed to even organize on the basis of shape in the presence of UC. Luminance similarity, however, was more salient than UC, even though UC was detected by infants in the presence of luminance cues. We conclude that UC is not necessarily the most salient mechanism of perceptual organization in infancy. Moreover, the luminance-UC-shape salience hierarchy exhibited by 6- to 7-month-olds in the present study is consistent with the order of development of sensitivity to these organizational cues. [ABSTRACT FROM AUTHOR]

Prior research indicates that, like adults, infants use enclosed regions to group elements. It is not clear whether infants or adults can use regions that have to be inferred from illusory contours to group elements. We examined whether 3- to 4-month-olds use illusory regions to group elements and generalize this organization to novel regions. Infants habituated to pairs of shapes in illusory vertical or horizontal regions subsequently discriminated, in novel regions, pairs of elements that had previously shared a region from pairs of elements that had been in different regions. A control group of infants, who had experienced the same stimuli except for the presence of illusory regions, failed to discriminate between within-region and between-region pairs of stimuli. These results reveal that (1) illusory regions can be used to group elements, (2) perceptual organization is sufficiently developed early in life for 3- to 4-month-olds to group on the basis of ecologically relevant illusory contours, and (3) such grouping in infancy generalizes to novel regions. [ABSTRACT FROM AUTHOR]

Abstract: Four experiments relying on novelty and spontaneous preference procedures were performed to determine whether 3–4-month-old infants utilize the Gestalt principle of proximity to organize visual pattern information. In Experiment 1, infants familiarized with arrays of elements that could be organized into either columns or rows were tested for their preference between vertical and horizontal bars. The infants preferred the novel organization of bars. Experiments 2 and 3 showed that the novelty preference could not be attributed to an a priori preference or an inability to discriminate between the elements comprising the patterns. Experiment 4 replicated the results of Experiment 1 in a bars → elements version of the task, indicating that extended exposure is not necessary for infants to organize based on proximity. The results suggest that infants readily organize visual pattern information in accord with proximity. Implications of this finding for models of the ontogenesis and microgenesis of object perception in infants and adults are discussed. [Copyright &y& Elsevier]

We examined whether infants organize information according to the newly proposed principle of common region, which states that elements within a region are grouped together and separated from those of other regions. In Experiment 1, 6- to 7-month-olds exhibited sensitivity to regions by discriminating between the displacement of an element within a region versus across regions. In Experiments 2 (6- to 7-month-olds) and 3 (3- to 4-month-olds), infants who were habituated to 2 elements in each of 2 regions subsequently discriminated between a familiar and novel grouping in familiar and novel regions. Thus, infants as young as 3 to 4 months of age are not only sensitive to regions in visual images, but also use these regions to group elements in accord with the principle of common region. Because common region analysis is critical to such basic visual functions as figure-ground and object segregation, these results suggest that the organizational mechanism that underlies many vital visual functions is already operational by 3 to 4 months of age. [ABSTRACT FROM AUTHOR]

Human adults are more accurate at discriminating faces from their own race than faces from another race. This other-race effect (ORE) has been characterized as a reflection of face processing specialization arising from differential experience with own-race faces. We examined whether 3.5-month-old infants exhibit ORE using morphed faces on which adults had displayed a crossover ORE (i.e., Caucasians performed better on Caucasian faces and Asians performed better on Asian faces). In this experiment, Caucasian infants who had grown up in a predominantly Caucasian environment discriminated 100% Caucasian faces from 70% Caucasian/30% Asian morphed faces but failed to discriminate between the corresponding 100% Asian and 70% Asian/30% Caucasian faces. Thus, 3.5-month-olds exhibited evidence of ORE. These results indicate that at least by 3.5 months of age, infants have attained enough face processing expertise to process familiar-race faces in a different manner than unfamiliar-race faces. [ABSTRACT FROM AUTHOR]

Abstract: Sensitivity to second-order relational information (i.e., spatial relations among features such as the distance between eyes) is a vital part of achieving expertise with face processing. Prior research is unclear on whether infants are sensitive to second-order differences seen in typical human populations. In the current experiments, we examined whether infants are sensitive to changes in the space between the eyes and between the nose and the mouth that are within the normal range of variability in Caucasian female faces. In Experiment 1, 7-month-olds detected these changes in second-order relational information. Experiment 2 extended this finding to 5-month-olds and also found that infants detect second-order relations in upright faces but not in inverted faces, thereby exhibiting an inversion effect that has been considered to be a hallmark of second-order relational processing during adulthood. These results suggest that infants as young as 5 months are sensitive to second-order relational changes that are within the normal range of human variability. They also indicate that at least rudimentary aspects of face processing expertise are available early in life. [Copyright &y& Elsevier]

Four experiments investigated how readily infants achieve perceptual organization by lightness and form similarity. Infants were (a) familiarized with elements that could be organized into rows or columns on the basis of lightness or form similarity and tested with vertical versus horizontal bars depicting the familiar versus novel organization or (b) familiarized with bars and tested with elements. For lightness similarity, generalization occurred in both tasks; however, for form similarity, generalization occurred only in the elements → bars task. The findings indicate that lightness similarity is more readily deployed than form similarity and are discussed in the context of (a) whether the difference reflects speed of application or experience-based learning, (b) evidence from visual agnosic patients and the time course of application of the principles in healthy adults, and (c) development of dorsal and ventral visual processing streams. [ABSTRACT FROM AUTHOR]

Abstract: Object parts are signaled by concave discontinuities in shape contours. In seven experiments, we examined whether 5- and 6-month-olds are sensitive to concavities as special aspects of contours. Infants of both ages detected discrepant concave elements amid convex distractors but failed to discriminate convex elements among concave distractors. This discrimination asymmetry is analogous to the finding that concave targets among convex distractors pop out for adults, whereas convex targets among concave distractors do not. Thus, during infancy, as during adulthood, concavities appear to be salient regions of shape contours. The current study also found that infants’ detection of concavity is impaired if the contours that define concavity and convexity are not part of closed shapes. Thus, for infants, as for adults, concavities and convexities are defined more readily in the contours of closed shapes. Taken together, the results suggest that some basic aspects of part perception from shape contours are available by at least 5 months of age. [Copyright &y& Elsevier]

Abstract: Three-month-olds are sensitive to orientation changes of line drawings when they have a three-dimensional (3-D) interpretation and when the changes are defined by both 3-D depth and two-dimensional (2-D) picture plane cues [Bhatt, R. S., & Bertin, E. (2001). Pictorial cues and three-dimensional information processing in early infancy. Journal of Experimental Child Psychology, 80, 315–332]. In the current study, we examined whether 3-month-olds are sensitive to pictorial line junction cues that signal orientation changes solely in the 3-D depth plane. The results revealed that infants discriminated a misoriented elongated cube in an array when the stimuli contained both shading and lines (Experiment 2) but not when only lines depicted the elongated cubes (Experiment 1). Testing with comparable 2-D images revealed that, even in the presence of shading information, detection of orientation changes is specific to images that have a 3-D interpretation. Together, the results suggest that 3-month-olds are sensitive to pictorial line junction cues that signal orientation changes in the 3-D depth plane to adults provided that shading information is available and the images have a 3-D interpretation. [Copyright &y& Elsevier]

It has been demonstrated that older infants (6- to 7-month-olds), but not younger infants (3- to 4-month-olds), use form similarity to organize stimuli consisting of X and O elements. We investigated whether utilization of form similarity is governed by maturation or experience by contrasting how infants perform when familiarized with a single exemplar versus multiple exemplars depicting a particular organization. In Experiment 1, 3- to 4-month-olds failed to organize alternating columns or rows of squares and diamonds or Hs and Is, respectively. In Experiment 2, same-aged infants familiarized with all three patterns ( X- O, square-diamond, H- I) displayed evidence of organization. The results suggest that 3- to 4-month-olds can use form similarity to organize visual patterns in a concept-formation task. The findings imply that perceptual organization based on form similarity is learned through experience with multiple patterns depicting a common arrangement, rather than immediately apprehended in an individual pattern. [ABSTRACT FROM AUTHOR]

Adults use both first-order, or categorical, relations among features (e.g., the nose is above the mouth), and second-order, or fine spatial relations (e.g., the space between eyes), to process faces. Adults' expertise in face processing is thought to be based on the use of second-order relations. In the current study, 5-month-olds detected second-order changes, but 3-month-olds failed to detect second-order changes induced by 2 different manipulations. Three-month-olds did detect first-order changes, however. Also, inversion affected 5-month-olds' processing of second-order but not first-order information. These results suggest that, although sensitivity to first-order relations is available by 3 months or earlier, sensitivity to second-order information may not develop until sometime between 3 and 5 months of age. [ABSTRACT FROM AUTHOR]

Adults readily detect changes in face patterns brought about by the inversion of eyes and mouth when the faces are viewed upright but not when they are viewed upside down. Research suggests that this illusion (the Thatcher illusion) is caused by the interfering effects of face inversion on the processing of second-order relational information (fine spatial information such as the distance between the eyes). In the current study, 6-month-olds discriminated ‘thatcherized’ faces when they were viewed upright but not when they were viewed upside down. These results are consistent with the notion that 6-month-olds are sensitive to second-order relational information while processing faces. [ABSTRACT FROM AUTHOR]

Investigates the pictorial cues and three-dimensional information processing in early infancy in Kentucky. Sensitivity of three months old to 3-D structure; Assessment whether infants are sensitive to holistic combinations of line junctions; Process of the experiment.

The segregation of objects from other objects in visual arrays is a fundamental function of our visual system. Research suggests that adults’ detection of a target among nontargets is affected by the heterogeneity of array elements and the resulting changes in target–nontarget and nontarget–nontarget similarities. We examined the effects of heterogeneity and similarity on object segregation in infancy. In Experiment 1, 5.5-month-olds detected a misoriented element in an array when the array elements were spatially arranged in a ‘good’ configuration but not when they were arranged in a ‘poor’ configuration. In Experiment 2, infants detected a vertical line in a homogeneous array of 55° or 125° lines, but failed to do so in a heterogeneous array of 55° and 125° lines. Thus, heterogeneity in both the arrangement and identity of array elements affected infants’ discrepancy detection. Because the average target–nontarget similarity was the same in the two conditions of Experiment 2, the results also indicated that nontarget–nontarget similarity independently affects discrepancy detection in infancy. These results are consistent with models of object segregation by adults, and suggest that stimulus heterogeneity and similarity have analogous effects on object segregation at 5.5 months of age and in adulthood. [ABSTRACT FROM AUTHOR]

Investigates dissociation between featural and conjunction-based texture processing in infancy. Basis of textural discrepancies in infants; Differences between featural and conjunction processing; Dissociation of sensitivity to featural versus conjunction discrepancies; Qualitative difference in visual processing of features versus conjunction.

Reports that 4.5-month-old infants can use a short-term familiarization experience with a single object to facilitate the segregation of a visual display. Systematic research on the development of object perception; Integration by infants of cues to form interpretations of complex visual displays.

• Magnetization relaxation at different probe widths, sensing currents, and Hall geometries. • Current shunting, Joule heating, and current-induced SOT are responsible for coercivity response. • Dependence of domain wall propagation on probe widths. • Device behavior at different circumstances is crucial for practical use. The understanding of the characteristics of a magnetic layer in a different environment is crucial for any spintronics application. Before practical applications, thorough scrutiny of such devices is compulsory. Here we study such a potential Hall device of MgO-capped Hf/GdFeCo bilayer (FeCo-rich) for magnetization relaxation around nucleation fields at different voltage probe line widths and dc sensing currents. The device is characterized by anomalous Hall measurements in transverse and longitudinal Hall geometries for two different probe widths A (5 µ m) and B (1 µ m). The coercivities of the Hall loops (ρ xy - H and R xx - H) drop with increasing the sense current for both the probes. For probe B, the sharp and large drop in coercivity (ρ xy - H loops) at comparatively lower sensing currents is observed, which is attributed to the negligible current shunting and presence of pinning site at B caused by the patterning process. The average domain wall velocities at various sensing currents for probe B are found to be smaller than probe A, from the transverse and longitudinal Hall geometry magnetization relaxation measurements, which agrees with pinning sites and Joule heating effect at probe B. The notch position in the pattern and the longitudinal Hall resistance curve peak shape suggest the domain wall propagation direction from probe B to probe A in the current channel. This study highlights the domain wall propagation at different nucleation fields, sensing currents, and the Hall probe aspect ratios. [ABSTRACT FROM AUTHOR]

Examines how the cytostatic factor arrest induced by the persistent activation of p42 mitogen-activated protein kinase (p42 MAPK) during mitosis. Role of p90 Rsk in p42 MAPK-induced mitotic arrest; Presence of Rsk isoforms in Xenopus eggs; Importance of the Rsk-2 in the maintenance of mitotic arrest.

Presents a study in which infants' processing of three-dimensional (3-D) information in static images were examined in three experiments. What three-month-olds familiarized with; Question whether discrepancies in 3-D information attract and hold infants' attention; Use of a different approach to examine whether 3-month-olds are sensitive to 3D cues in static 2D images; In-depth look at the experiment; Results of the study.

Studies the forgetting functions of different feature correlations among infants and examines their relation to infant's memory for individual features. Object perception among infants; Dissociations in memory between features and feature relations; Correlated attributes of forgetting functions; Feature errors versus conjunction errors; Two stages in visual processing.

Examines the effects of the number of features and feature relations on learning and long-term memory in children. Assumption made by psychologists concerning the memory; Dissociations between the processing of featural and relational information; Details on the study.

Presents experiments which examine the role of global and local cues in memory retrieval in infancy. Training of infants to kick a mobile in a playpen with liners of different designs; Encoding and remembering of infants global and local component information for a substantial period of time.

Examines effects of set size and novelty in visual pop-outs in six month old infants through perceptual-identification memory. Effect of set size and novelty in long-term retention; Assessment of retention in two individual measures; Discriminatory ratio of visual pop-out on parallel processing; Difference between adult and infants in implicit perceptual identification tasks.