339 results on '"Y. Yeshurun"'
Search Results
152. Magnetic relaxation and critical current in an YBaCuO crystal
- Author
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F. Holtzberg, A. P. Malozemoff, and Y. Yeshurun
- Subjects
Crystal ,Superconductivity ,Magnetization ,Materials science ,Yield (engineering) ,Condensed matter physics ,Electrical resistivity and conductivity ,Condensed Matter::Superconductivity ,Inorganic chemistry ,General Physics and Astronomy ,Electric current ,Type-II superconductor ,Single crystal - Abstract
We have measured the temperature dependence of magnetic relaxation and critical current in an YBaCuO single crystal. Unusually strong time‐logarithmic magnetic relaxation is observed. The relaxation rate increases initially with temperature, peaks at ≂25 K and slows down at higher temperatures. The results, interpreted with a thermally activated flux model, yield a low‐temperature pinning energy U0≂0.02 eV. This low pinning energy results in an unusually rapid decrease of the critical current as temperature is increased.
- Published
- 1988
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153. Shear strength of shock‐loaded alumina as determined with longitudinal and transverse manganin gauges
- Author
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D. Yaziv, Y. Yeshurun, Stephan Bless, and Zvi Rosenberg
- Subjects
Transverse plane ,Amplitude ,Materials science ,Shear (geology) ,visual_art ,visual_art.visual_art_medium ,General Physics and Astronomy ,Ceramic ,Composite material ,Manganin ,Shock (mechanics) - Abstract
The shear strength of shock‐loaded commercial alumina (AD‐85 manufactured by Coors) is determined in the 0–140‐kbar range of shock stresses. Longitudinal and transverse manganin gauges were used to determine the principal stresses in the shocked specimens. Shear strengths were determined from the difference between the longitudinal and lateral stresses. It was found that the shear strength remains essentially constant at about 27 kbar for shock stresses between 60 kbar (the Hugoniot elastic limit) and the maximum shock amplitude tested in this series (142 kbar). The source for the high shear strength is attributed to the confining pressures that strengthen the comminuted ceramic. Evidence for this interpretation is obtained by considering the release profiles as recorded by the longitudinal gauges when the free‐surface rarefactions reach gauge location.
- Published
- 1987
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154. Release behavior of shock loaded commercial alumina
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Z. Rosenberg and Y. Yeshurun
- Subjects
Aluminium oxides ,Dilatant ,Shock wave ,Materials science ,General Physics and Astronomy ,chemistry.chemical_element ,equipment and supplies ,Copper ,Shock (mechanics) ,Stress (mechanics) ,chemistry ,Composite material ,Manganin ,Longitudinal wave - Abstract
Plate impact experiments were conducted on AD‐85 alumina specimens (manufactured by Coors) in the low shock stress region. The experimental configuration consisted of impacting a thin flyer disc (either copper or alumina) on a relatively thick specimen disc (the target). A thin manganin stress gauge was placed at the back face of the specimen supported by a thick polymethylmethacrylate disc. After recording the initial shock at the specimen‐PMMA interface, the gauge showed an unusually fast compressional wave preceding the main release wave which originates at the flyer’s back surface. This wave appeared for all the shots with copper flyers and impact velocities resulting shock stresses in the 0–30 kb range. They did not appear when alumina flyers were used. Our explanation for the origin of this fast compressional wave is based on the possible occurrence of dilatancy in the specimen upon stress unloading.
- Published
- 1986
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155. Magnetic properties of a high-TcsuperconductorYBa2Cu3O7: Reentry-like features, paramagnetism, and glassy behavior
- Author
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Y. Yeshurun, Haim Sompolinsky, and Israel Felner
- Subjects
Superconductivity ,Magnetization ,Paramagnetism ,Spin glass ,Materials science ,Condensed matter physics ,Electrical resistivity and conductivity ,Magnetism ,Condensed Matter::Superconductivity ,Transition temperature ,Diamagnetism - Abstract
Magnetic measurements on a high-T/sub c/ superconductor YBa/sub 2/Cu/sub 3/O/sub 7/ are reported. Diamagnetism sets in, at low fields, below a temperature Tapprox. =90 K. At low T the field-cooled magnetization becomes positive again. We show that the low-T phase is still superconducting and the apparent reentry behavior is due to strong paramagnetic contributions. Glassy features appear below a temperature whose field dependence differs substantially from that observed in spin glasses.
- Published
- 1987
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156. Crystallization, magnetization and scaling: Study of magnetic relaxation in amorphous Fe83B12Si5
- Author
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Israel Felner, Y. Yeshurun, J. Wolny, and Y. Wolfus
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Materials science ,Amorphous metal ,Condensed matter physics ,Nucleation ,Time evolution ,General Chemistry ,Condensed Matter Physics ,Amorphous solid ,law.invention ,Crystallography ,Magnetization ,law ,Phase (matter) ,Materials Chemistry ,Crystallization ,Scaling - Abstract
We have investigated the crystallization of amorphous Fe 83 B 12 Si 5 by measuring the time evolution of the magnetization for isotherms 634 K ⩽ T ⩽ 666 K. The rate of growth of the crystalline phase increases with increasing temperature but all growth curves collapse to a universal function when the time is scaled by a factor τ(T). The shape of the universal curve, which is consistent with the Kolmogorov-Johnson-Mehl-Avrami model for nucleation and growth, suggests a diffusion-controlled growth mechanism for this amorphous system.
- Published
- 1987
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157. Nonlinear susceptibility and relaxation in the XY spin glass Y Tb
- Author
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M. B. Salamon, Y. Yeshurun, and L. J. P. Ketelsen
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Physics ,Phase transition ,Magnetization ,Spin glass ,Condensed matter physics ,Remanence ,Relaxation (NMR) ,Anisotropy ,Condensed Matter::Disordered Systems and Neural Networks ,Magnetic susceptibility ,Spin-½ - Abstract
Measurements of the nonlinear susceptibility, irreversibility onset, and relaxation of the remanent magnetization are reported for a single-crystal sample of YTbat. %. The data give strong support for the existence of a spin-glass phase transition for spin components in the basal plane, but not for those along the c axis. A scaling analysis of the nonlinear susceptibility leads to the values delta = 3.2 +- 0.2 and phi = 3.0 +- 0.2 for the field and cross-over exponents, respectively. These values are consistent with the position of the de Almeida--Thouless line observed below the freezing temperature.
- Published
- 1985
158. Measurements of Compressive and Tensile Wave in a Shock Loaded Pyrex Glass
- Author
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Y. Yeshurun, G. Rosenberg, and Z. Rosenberg
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Shock wave ,chemistry.chemical_compound ,Materials science ,chemistry ,Ultimate tensile strength ,Composite material ,Silicate ,Shock (mechanics) ,BORO - Abstract
Shock loading experiments were conducted in order to determine failure modes of Boro silicate (Pyrex) glass under impact.
- Published
- 1986
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159. Effect of Ga substitution on the superconducting properties of the electron-doped system: Nd-Ce-Cu-O
- Author
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E. R. Yacoby, Y. Wolfus, Y. Yeshurun, U. Yaron, and Israel Felner
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Superconductivity ,Physics ,chemistry.chemical_classification ,Condensed matter physics ,Transition temperature ,Substitution (algebra) ,Magnetic hysteresis ,Magnetization ,Crystallography ,chemistry ,Meissner effect ,Condensed Matter::Superconductivity ,Inorganic compound ,Type-II superconductor - Abstract
We are reporting on results of dc magnetization measurements of the new electron-doped ${\mathrm{Nd}}_{2\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{Ce}}_{\mathrm{x}}$${\mathrm{Cu}}_{1\mathrm{\ensuremath{-}}\mathit{y}}$${\mathrm{Ga}}_{\mathit{y}}$${\mathrm{O}}_{4}$ superconductors. The effect of ${\mathrm{Ga}}^{3+}$ on ${T}_{c}$ is similar to that of ${\mathrm{Ce}}^{4+}$, although the extra electron of the former comes from the Cu-O planes. For example, for x=0.12 the undoped compound (y=0) is not superconducting; but by the addition of Ga (y=0.03), the material becomes superconducting at ${T}_{c}$=20 K, and the Meissner fraction and the critical current density are improved compared to ${\mathrm{Nd}}_{1.85}$${\mathrm{Ce}}_{0.15}$${\mathrm{CuO}}_{4}$. The irreversibility line ${T}_{\mathrm{irr}(\mathrm{H})}$ for doped and undoped samples scales with the applied field as ${H}^{p}$, with p\ensuremath{\simeq}0.6, but for the Ga-doped sample it is pushed to higher temperatures.
- Published
- 1989
160. Mechanisms of Dynamic Failure in Debased Alumina
- Author
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Y. Yeshurun and D. G. Brandon
- Subjects
Impact pressure ,Materials science ,Projectile ,Damage zone ,Ultimate tensile strength ,Fracture (geology) ,Compressive pressure ,Strain rate ,Composite material ,Kinetic energy - Abstract
Regimes of dynamic fracture have been analysed in terms of four interconnected parameters: the imposed strain rate\(\dot \varepsilon \), the compressive pressure generated by an impact P, the rate of tensile loading of a preexisting crack \(\dot K\) and the “damage number” D. This last parameter is the ratio of the kinetic energy density in a projectile to the failure strength of the target [1]. Large values of D imply that inertial effects dominate the failure process.
- Published
- 1987
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161. Micromechanisms of Impact Failure in Engineering Ceramics
- Author
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David Brandon, Zvi Rosenberg, Y. Ozeri, and Y. Yeshurun
- Subjects
Shock wave ,Materials science ,business.industry ,Structural engineering ,Plasticity ,Shock (mechanics) ,Impact velocity ,stomatognathic system ,Engineering ceramics ,Jump ,Shear strength ,Composite material ,Adiabatic process ,business - Abstract
The dynamic response of commercial alumina was determined in the 3.0 to 10.0 GPa range. The shock wave was composed of an initial elastic jump to about 6.0 GPa and a subsequent dispersive rise to the final shock level. Three alternative models for this behavior have been proposed: adiabatic melting, shock-induced plastic flow and multiple micro-cracking.
- Published
- 1987
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162. Strengthening of Alumina by Heat Treatment
- Author
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J. Ozeri, Z. Nissenholz, David Brandon, N. Travitzki, D. Shechtman, Y. Yeshurun, and E.Y. Gutmanas
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Fracture toughness ,Materials science ,Ceramic tiles ,Flexural strength ,technology, industry, and agriculture ,Composite material ,equipment and supplies - Abstract
Ceramic tiles of a commercial alumina were subjected to post-sintering heat-treatment. Marked increases in both fracture strength and fracture toughness were observed, independent of surface strengthening.
- Published
- 1982
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163. Effect of magnetic sheath on filament AC losses and current distribution in MgB2 superconducting wires: numerical analysis.
- Author
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Y Nikulshin, Y Yeshurun, and S Wolfus
- Abstract
Finite element method (FEM) analysis is employed to study and compare AC losses in a wide frequency range in two MgB2 superconducting wires in self-field and in the presence of external AC field. The modelled wires, of the same external dimensions, are mono- and 36-superconducting filaments embedded in either magnetic Monel or a nonmagnetic metallic wire sheath. We demonstrate that in a multifilamentary wire in self-field the Monel sheath serves as a ‘pole piece’ at the filament outer surface and alters local magnetic fields, current flow and AC losses distribution within the filament. In comparison with the nonmagnetic sheath with the same electrical conductivity, AC current in the wire with the magnetic sheath penetrates significantly deeper into the filaments and AC losses in the filament and in the magnetic sheath increase significantly. In contrast, the symmetry of the monofilament wire makes the current and loss distributions in the filament practically indifferent to the sheath composition. Still, losses in the magnetic sheath are much higher than in the nonmagnetic sheath due to increased flux dynamics. The application of DC current, on which the AC current is superimposed, sharply reduces the AC losses in the magnetic sheath material due to the drop in its permeability. Filament losses are also reduced in the presence of DC current, but to a much lesser extent. Results also show that in the kHz frequency range, the magnetic permeability of the sheath increases the skin effect in both the wire and filaments complex. As a result, at such frequencies, a significant portion of the current is carried by the metallic part of the wire instead of the superconductor, contributing to a further increase in losses. The analysis also shows that in the presence of external AC magnetic field, the Monel can provide magnetic shielding for inner filaments, thus reducing coupling effects between filaments. However, if magnetically saturated by the DC current, the Monel behaves quite similarly to a nonmagnetic sheath. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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164. Scaling of the irreversible magnetization curves of YBaCuO
- Author
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Haim Sompolinsky, Y. Yeshurun, Y. Wolfus, E. R. Yacoby, and Israel Felner
- Subjects
Superconductivity ,Physics ,Magnetization ,Condensed matter physics ,Feature (computer vision) ,Condensed Matter::Superconductivity ,Energy Engineering and Power Technology ,Collapse (topology) ,Electrical and Electronic Engineering ,Condensed Matter Physics ,Scaling ,Electronic, Optical and Magnetic Materials - Abstract
A one-parameter scaling of the magnetization curves of the high-temperature superconductor YBaCuO cause all data points in the irreversible regime to collapse into a single curve. We show that this scaling feature is predicted by the Bean model.
- Published
- 1989
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165. A theory of the electric field gradient in KH2PO4-type crystals, based on the protonic E-mode
- Author
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S. Havlin and Y. Yeshurun
- Subjects
Materials science ,Condensed matter physics ,Mode (statistics) ,Electric potential ,Type (model theory) ,Condensed Matter Physics ,Electric field gradient ,Electronic, Optical and Magnetic Materials - Abstract
The temperature dependence of the Electric Field Gradient in KH2PO4-type crystals is explained in terms of the E-mode fluctuations. Calculations based on the q-dependence of this mode alone lead to good agreement with the experimental data.
- Published
- 1976
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166. Spin dynamics and low temperature properties of the anisotropic spin glass Fe2TiO5
- Author
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B. Wanklyn, J.L. Tholence, Y. Yeshurun, and J.K. Kjems
- Subjects
Cusp (singularity) ,Physics ,Magnetic anisotropy ,Spin glass ,Spin polarization ,Condensed matter physics ,Spins ,Neutron diffraction ,Condensed Matter Physics ,Anisotropy ,Condensed Matter::Disordered Systems and Neural Networks ,Power law ,Electronic, Optical and Magnetic Materials - Abstract
Fe 2 TiO 5 is an anisotropic spin glass with a cusp temperature T g 50 K observed only along the “easy” magnetic axis. “Loose spins” are observed in all directions at low temperature. The frequency dependence of T g , as determined by ac or dc susceptibility and by neutron diffraction, can be well fitted by a Vogel-Fulcher or by a power law which characterize the spin-glass transition along the easy axis.
- Published
- 1986
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167. Magnetic flux instability in NbN films exposed to fast field sweep rates.
- Author
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E Baruch-El, M Baziljevich, T H Johansen, X Y Zhou, X Q Jia, B B Jin, A Shaulov, and Y Yeshurun
- Subjects
MAGNETIC flux ,SUPERCONDUCTING films - Abstract
Magneto-optical imaging of dendritic flux instability is reported for NbN films exposed to magnetic fields ramped at a fast rate (0.1–3.2 kT s
−1 ). The results show that as the magnetic ramp rate increases, the temperature and field range of the instability extends significantly. In particular, the lower and upper threshold fields ( and respectively) that bound the field range for dendritic instability are affected. The upper field is found to increase linearly with the applied field sweep rate, a behavior which is discussed in terms of a recent theoretical work (Vestgarden et al 2016 Phys. Rev. B 73 174511). The extended instability range should be taken into account in applications in which the superconducting films are exposed to rapid changes in the magnetic field. [ABSTRACT FROM AUTHOR]- Published
- 2018
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168. Thickness dependence of dendritic flux avalanches in YBa2Cu3O7-x films.
- Author
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E. Baruch-El, M. Baziljevich, T.H. Johansen, A. Shaulov, and Y. Yeshurun
- Published
- 2018
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169. Effect of carbon coating on the superconducting properties of Pb and Sn nano-spheres.
- Author
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L. Shani, V. B. Kumar, A. Gedanken, I. Shapiro, B.Y. Shapiro, A. Shaulov, and Y. Yeshurun
- Published
- 2018
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170. Flux-periodicity crossover from h/2e to h/e in aluminium nano-loops.
- Author
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C. Espy, O. J. Sharon, J. Braun, R. Garreis, F. Strigl, A. Shaulov, P. Leiderer, E. Scheer, and Y. Yeshurun
- Published
- 2018
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171. Dendritic flux instability in MgB2 films above liquid hydrogen temperature.
- Author
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E Baruch-El, M Baziljevich, T H Johansen, J Albrecht, A Shaulov, and Y Yeshurun
- Subjects
MAGNETIC properties of superconductors ,LIQUID hydrogen - Abstract
Magnetic flux instability limits potential applications of superconductors such as MgB
2 in practical devices. Previous studies in MgB2 films exposed to magnetic fields revealed the occurrence of dendritic flux avalanches at temperatures below T ∼ 10 K. In the present work it is shown that films of MgB2 exposed to a fast-ramped magnetic field display a dendritic flux instability at elevated temperatures, up to 23 K. Such instability can therefore cause malfunctioning of practical devices based on MgB2 films even when operating at liquid hydrogen temperature. [ABSTRACT FROM AUTHOR]- Published
- 2018
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172. Relaxation in a spin glass system with competing magnetic interactions: Fe0.16Cr0.84
- Author
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A C Palumbo, R D Parks, and Y Yeshurun
- Subjects
General Engineering ,General Physics and Astronomy ,Condensed Matter Physics - Published
- 1982
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173. Effect of shock wave on the dislocation density in pure copper
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D.G. Brandon, Y. Partom, and Y. Yeshurun
- Subjects
Shock wave ,Materials science ,Condensed matter physics ,chemistry ,chemistry.chemical_element ,Dislocation ,Instrumentation ,Copper ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials - Published
- 1985
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174. The many faces of mimicry depend on the social context.
- Author
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Ravreby I, Navon M, Pinhas E, Lerer J, Bar-Anan Y, and Yeshurun Y
- Abstract
One of the richest and most powerful tools in social communication is the face. Facial expressions are a prominent way to convey high-dimensional, dynamic information, such as emotion, motivation, and intentions. Previous research has linked mimicry of facial expressions to positive human interaction (e.g., mutual agreement). In this study, we investigated in a real-world setting whether the mimicry pattern of multiple affective facial expressions depends on the interpersonal attitudinal agreement between interlocutors. We analyzed video clips of Democratic or Republican American politicians being interviewed by either a political ally or an opponent ( N
total = 150 videos). The interviews showed either agreement between two Republicans or two Democrats, or disagreement between members of each affiliation. Using image processing tools, we extracted the intensity of the facial action units for each timepoint. In contrast to the prevalent notion that positive social interaction, such as agreement, fosters mimicry, we found mimicry of all facial expressions in both agreement and disagreement. Moreover, the pattern of the facial expressions mimicry depended on the agreement condition such that an artificial classifier could successfully discriminate between the agreement conditions. Our results suggest that not only positive interpersonal communication is characterized by mimicry but also negative one. This implies that in real-life interactions, mimicry may be a tool to understand others and thus successfully communicate, regardless of the positivity of the social interaction. Whereas the existence of mimicry may be indispensable for social communication, the specific pattern of facial expressions mimicry depends on the social context. (PsycInfo Database Record (c) 2024 APA, all rights reserved).- Published
- 2024
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175. Suppression of magnetic vortex losses in submicron NbN coplanar waveguide resonators.
- Author
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Roitman A, Burlachkov L, Sharoni A, Shaulov A, and Yeshurun Y
- Abstract
We present a method for improving the performance of microwave coplanar resonators in magnetic fields, by using narrow superconducting strips of width close to the London penetration depth. In a range of low fields, the narrow strips inhibit the presence of magnetic vortices, thus preventing the generation of losses caused by their motion, leading to enhanced resistance to magnetic fields. Our method provides a more straightforward solution compared to previously proposed techniques designed to restrict vortex motion, holding potential for the development of improved devices based on microwave resonators., (© 2024. The Author(s).)
- Published
- 2024
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176. Microwave Kinetic Inductance Detector Made of Molecular Beam Epitaxy (MBE)-Grown MgB2 Film.
- Author
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Roitman A, Pfaff C, Hauet T, Shaulov A, and Yeshurun Y
- Abstract
We present a MgB
2 -based Microwave Kinetic Inductance Detector (MKID) featuring a quality factor Qi ~ 105 and noise equivalent power NEP ~ 10-14 W/Hz at 2 K. In comparison to YBCO-based MKIDs, the MgB2 detector shows greater sensitivity to both temperature and magnetic field, a result of its two-gap nature and relatively low critical Hc2 field. Our data indicate that MgB2 is more advantageous for MKID applications at temperatures lower than 3 K.- Published
- 2024
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177. Interference across time: dissociating short from long temporal interference.
- Author
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Hochmitz I, Abu-Akel A, and Yeshurun Y
- Abstract
Our ability to identify an object is often impaired by the presence of preceding and/or succeeding task-irrelevant items. Understanding this temporal interference is critical for any theoretical account of interference across time and for minimizing its detrimental effects. Therefore, we used the same sequences of 3 orientation items, orientation estimation task, and computational models, to examine temporal interference over both short (<150 ms; visual masking) and long (175-475 ms; temporal crowding) intervals. We further examined how inter-item similarity modifies these different instances of temporal interference. Qualitatively different results emerged for interference of different scales. Interference over long intervals mainly degraded the precision of the target encoding while interference over short intervals mainly affected the signal-to-noise ratio. Although both interference instances modulated substitution errors (reporting a wrong item) and were alleviated with dissimilar items, their characteristics were markedly disparate. These findings suggest that different mechanisms mediate temporal interference of different scales., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Hochmitz, Abu-Akel and Yeshurun.)
- Published
- 2024
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178. Reward-related regions play a role in natural story comprehension.
- Author
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Kobo O, Yeshurun Y, and Schonberg T
- Abstract
The reward system was shown to be involved in a wide array of processes. Nevertheless, the exploration of the involvement of the reward system during language processing has not yet been directly tested. We investigated the role of reward-processing regions while listening to a natural story. We utilized a published dataset in which half of the participants listened to a natural story and the others listened to a scrambled version of it to compare the functional MRI signals in the reward system between these conditions and discovered a distinct pattern between conditions. This suggests that the reward system is activated during the comprehension of natural stories. We also show evidence that the fMRI signals in reward-related areas might potentially correlate with the predictability level of processed sentences. Further research is needed to determine the nature of the involvement and the way the activity interacts with various aspects of the sentences., Competing Interests: The authors declare no competing interests., (© 2024 The Authors.)
- Published
- 2024
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179. Temporal crowding with central vision reveals the fragility of visual representations.
- Author
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Sahar T and Yeshurun Y
- Subjects
- Humans, Fovea Centralis, Pattern Recognition, Visual physiology, Vision, Ocular, Crowding
- Abstract
This study examined whether temporal crowding-the impaired object identification when distracting objects precede and succeed it-occurs at the fovea and if so whether its magnitude is reduced. We presented a central sequence of three oriented items separated by relatively long intervals (200/400 ms) and used an orientation estimation task with mixture-model analyses. We found clear evidence of temporal crowding with central vision, even with 400 ms intervals. Critically, reduced encoding precision surfaced as a robust and unique characteristic of temporal crowding. The magnitude of central and peripheral temporal crowding was similar suggesting the involvement of higher visual areas. Precision impairment emerged even when only the target contained orientation information, excluding "response competition" as the sole interference mechanism; yet it was larger when all items included orientation information, underscoring the importance of orientation-selective mechanisms. Overall, we show that even with central simple stimuli, the formation of a stable visual representation is surprisingly slow. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
- Published
- 2024
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180. Attachment Reminders Trigger Widespread Synchrony across Multiple Brains.
- Author
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Shimon-Raz O, Yeshurun Y, Ulmer-Yaniv A, Levinkron A, Salomon R, and Feldman R
- Subjects
- Infant, Adult, Animals, Humans, Female, Temporal Lobe, Prefrontal Cortex, Mother-Child Relations psychology, Mothers, Mammals, Brain physiology, Maternal Behavior physiology
- Abstract
Infant stimuli elicit widespread neural and behavioral response in human adults, and such massive allocation of resources attests to the evolutionary significance of the primary attachment. Here, we examined whether attachment reminders also trigger cross-brain concordance and generate greater neural uniformity, as indicated by intersubject correlation. Human mothers were imaged twice in oxytocin/placebo administration design, and stimuli included four ecological videos of a standard unfamiliar mother and infant: two infant/mother alone ( Alone ) and two mother-infant dyadic contexts ( Social ). Theory-driven analysis measured cross-brain synchrony in preregistered nodes of the parental caregiving network (PCN), which integrates subcortical structures underpinning mammalian mothering with cortical areas implicated in simulation, mentalization, and emotion regulation, and data-driven analysis assessed brain-wide concordance using whole-brain parcellation. Results demonstrated widespread cross-brain synchrony in both the PCN and across the neuroaxis, from primary sensory/somatosensory areas, through insular-cingulate regions, to temporal and prefrontal cortices. The Social context yielded significantly more cross-brain concordance, with PCNs striatum, parahippocampal gyrus, superior temporal sulcus, ACC, and PFC displaying cross-brain synchrony only to mother-infant social cues. Moment-by-moment fluctuations in mother-infant social synchrony, ranging from episodes of low synchrony to tightly coordinated positive bouts, were tracked online by cross-brain concordance in the preregistered ACC. Findings indicate that social attachment stimuli, representing evolutionary-salient universal cues that require no verbal narrative, trigger substantial interbrain concordance and suggest that the mother-infant bond, an icon standing at the heart of human civilization, may function to glue brains into a unified experience and bind humans into social groups. SIGNIFICANCE STATEMENT Infant stimuli elicit widespread neural response in human adults, attesting to their evolutionary significance, but do they also trigger cross-brain concordance and induce neural uniformity among perceivers? We measured cross-brain synchrony to ecological mother-infant videos. We used theory-driven analysis, measuring cross-brain concordance in the parenting network, and data-driven analysis, assessing brain-wide concordance using whole-brain parcellation. Attachment cues triggered widespread cross-brain concordance in both the parenting network and across the neuroaxis. Moment-by-moment fluctuations in behavioral synchrony were tracked online by cross-brain variability in ACC. Attachment reminders bind humans' brains into a unitary experience and stimuli characterized by social synchrony enhance neural similarity among participants, describing one mechanism by which attachment bonds provide the neural template for the consolidation of social groups., (Copyright © 2023 Shimon-Raz et al.)
- Published
- 2023
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181. Neural synchronization as a function of engagement with the narrative.
- Author
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Ohad T and Yeshurun Y
- Subjects
- Humans, Memory, Short-Term physiology, Prefrontal Cortex physiology, Auditory Perception physiology, Magnetic Resonance Imaging methods, Neural Pathways physiology, Brain Mapping, Brain physiology
- Abstract
We can all agree that a good story engages us, however, agreeing which story is good is far more debatable. In this study, we explored whether engagement with a narrative synchronizes listeners' brain responses, by examining individual differences in engagement to the same story. To do so, we pre-registered and re-analyzed a previously collected dataset by Chang et al. (2021) of functional Magnetic Resonance Imaging (fMRI) scans of 25 participants who listened to a one-hour story and answered questionnaires. We assessed the degree of their overall engagement with the story and their engagement with the main characters. The questionnaires revealed individual differences in engagement with the story, as well as different valence towards specific characters. Neuroimaging data showed that the auditory cortex, the default mode network (DMN) and language regions were involved in processing the story. Increased engagement with the story was correlated with increased neural synchronization within regions in the DMN (especially the medial prefrontal cortex), as well as regions outside the DMN such as the dorso-lateral prefrontal cortex and the reward system. Interestingly, positively and negatively engaging characters elicited different patterns of neural synchronization. Finally, engagement increased functional connectivity within and between the DMN, the ventral attention network and the control network. Taken together, these findings suggest that engagement with a narrative synchronizes listeners' responses in regions involved in mentalizing, reward, working memory and attention. By examining individual differences in engagement, we revealed that these synchronization patterns are due to engagement, and not due to differences in the narrative's content., Competing Interests: Declaration of Competing Interest The authors state that they have no competing financial interests or personal relationships that could have affected the work disclosed in this study., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
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182. Attention does not spread automatically along objects: Evidence from the pupillary light response.
- Author
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Luzardo F, Einhäuser W, Michl M, and Yeshurun Y
- Subjects
- Humans, Reaction Time physiology, Cues, Pupil, Attention physiology
- Abstract
Objects influence attention allocation; when a location within an object is cued, participants react faster to targets appearing in a different location within this object than on a different object. Despite consistent demonstrations of this object-based effect, there is no agreement regarding its underlying mechanisms. To test the most common hypothesis that attention spreads automatically along the cued object, we utilized a continuous, response-free measurement of attentional allocation that relies on the modulation of the pupillary light response. In Experiments 1 and 2, attentional spreading was not encouraged because the target appeared often (60%) at the cued location and considerably less often at other locations (20% within the same object and 20% on another object). In Experiment 3, spreading was encouraged because the target appeared equally often in one of the three possible locations within the cued object (cued end, middle, uncued end). In all experiments, we added gray-to-black and gray-to-white luminance gradients to the objects. By cueing the gray ends of the objects, we could track attention. If attention indeed spreads automatically along objects, then pupil size should be greater after the gray-to-dark object is cued because attention spreads toward darker areas of the object than when the gray-to-white object is cued, regardless of the target location probability. However, unequivocal evidence of attentional spreading was only found when spreading was encouraged. These findings do not support an automatic spreading of attention. Instead, they suggest that attentional spreading along the object is guided by cue-target contingencies. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
- Published
- 2023
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183. Perspective changes in human listeners are aligned with the contextual transformation of the word embedding space.
- Author
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Tikochinski R, Goldstein A, Yeshurun Y, Hasson U, and Reichart R
- Subjects
- Humans, Auditory Perception, Speech Perception physiology
- Abstract
Word embedding representations have been shown to be effective in predicting human neural responses to lingual stimuli. While these representations are sensitive to the textual context, they lack the extratextual sources of context such as prior knowledge, thoughts, and beliefs, all of which constitute the listener's perspective. In this study, we propose conceptualizing the listeners' perspective as a source that induces changes in the embedding space. We relied on functional magnetic resonance imaging data collected by Yeshurun Y, Swanson S, Simony E, Chen J, Lazaridi C, Honey CJ, Hasson U. Same story, different story: the neural representation of interpretive frameworks. Psychol Sci. 2017:28(3):307-319, in which two groups of human listeners (n = 40) were listening to the same story but with different perspectives. Using a dedicated fine-tuning process, we created two modified versions of a word embedding space, corresponding to the two groups of listeners. We found that each transformed space was better fitted with neural responses of the corresponding group, and that the spatial distances between these spaces reflect both interpretational differences between the perspectives and the group-level neural differences. Together, our results demonstrate how aligning a continuous embedding space to a specific context can provide a novel way of modeling listeners' intrinsic perspectives., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.)
- Published
- 2023
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184. Deeper Than You Think: Partisanship-Dependent Brain Responses in Early Sensory and Motor Brain Regions.
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Katabi N, Simon H, Yakim S, Ravreby I, Ohad T, and Yeshurun Y
- Subjects
- Female, Humans, Male, Speech physiology, Brain Mapping, Magnetic Resonance Imaging methods, Auditory Cortex physiology, Sensorimotor Cortex
- Abstract
Recent political polarization has illustrated how individuals with opposing political views often experience ongoing events in markedly different ways. In this study, we explored the neural mechanisms underpinning this phenomenon. We conducted fMRI scanning of 34 right- and left-wing participants (45% females) watching political videos (e.g., campaign ads and political speeches) just before the elections in Israel. As expected, we observed significant differences between left- and right-wing participants in their interpretation of the videos' content. Furthermore, neuroimaging results revealed partisanship-dependent differences in activation and synchronization in higher-order regions. Surprisingly, such differences were also revealed in early sensory, motor, and somatosensory regions. We found that the political content synchronized the responses of primary visual and auditory cortices in a partisanship-dependent manner. Moreover, right-wing (and not left-wing) individuals' sensorimotor cortex was involved in processing right-wing (and not left-wing) political content. These differences were pronounced to the extent that we could predict political orientation from the early brain-response alone. Importantly, no such differences were found with respect to neutral content. Therefore, these results uncover more fundamental neural mechanisms underlying processes of political polarization. SIGNIFICANCE STATEMENT The political sphere has become highly polarized in recent years. Would it be possible to identify the neural mechanisms underpinning such processes? In our study, left- and right-wing participants were scanned in fMRI while watching political video clips just before the elections in Israel. We found that political content was potent in synchronizing the brain responses of individuals holding similar views. This was far more pronounced in individuals holding right-wing views. Moreover, partisan-dependent differences in neural responses were identified already in early sensory, somatosensory, and motor regions, and only for political content. These results suggest that individuals' political views shape their neural responses at a very basic level., (Copyright © 2023 the authors.)
- Published
- 2023
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185. Current dependence of the negative magnetoresistance in superconducting NbN nanowires.
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Sofer Z, Shaulov A, and Yeshurun Y
- Abstract
Magnetoresistance measurements in amorphous NbN nanowires show that transport current affects their negative magnetoresistance (nMR) in a manner qualitatively similar to temperature. In particular, the current suppresses the nMR and, beyond a certain level it eliminates the effect altogether. As the temperature dependence of the nMR effect is more pronounced at low currents, similarly the current dependence of the effect is more pronounced at low temperatures. These results are discussed in terms of the phenomenological model which attributes the nMR to the interplay between the resistance originating from the rate of phase slips via the Josephson relation and the Ohmic contribution from quasiparticles charge imbalance that accompany fluctuations of the order parameter in the nanowire., (© 2022. The Author(s).)
- Published
- 2022
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186. Real-time neurofeedback to alter interpretations of a naturalistic narrative.
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Mennen AC, Nastase SA, Yeshurun Y, Hasson U, and Norman KA
- Abstract
We explored the potential of using real-time fMRI (rt-fMRI) neurofeedback training to bias interpretations of naturalistic narrative stimuli. Participants were randomly assigned to one of two possible conditions, each corresponding to a different interpretation of an ambiguous spoken story. While participants listened to the story in the scanner, neurofeedback was used to reward neural activity corresponding to the assigned interpretation. After scanning, final interpretations were assessed. While neurofeedback did not change story interpretations on average, participants with higher levels of decoding accuracy during the neurofeedback procedure were more likely to adopt the assigned interpretation; additional control conditions are needed to establish the role of individualized feedback in driving this result. While naturalistic stimuli introduce a unique set of challenges in providing effective and individualized neurofeedback, we believe that this technique holds promise for individualized cognitive therapy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
- Published
- 2022
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187. Fear of being near: Fear supersedes sociability when interacting amid a pandemic.
- Author
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Amram R, Ravreby I, Trainin N, and Yeshurun Y
- Abstract
In the COVID-19 era, physical interactions ubiquitously pose a disease threat. Using a novel online paradigm, this study tested whether under such unique circumstances, the fundamental motivation to avoid disease-related threats interacts with individual differences in sociability, such that: (i) responses to others are slowed down, particularly among sociable individuals, reflecting motivational tension; (ii) the role of sociability in predicting interaction likelihood is diminished. Participants (Israeli young adults, N = 207) listened to auditory descriptions of everyday social situations, taking place in either the physical or virtual space, and decided quickly whether to interact. Participants also completed the Sociability Scale (Cheek & Buss, 1981). Responses were slower in the physical compared to virtual space, regardless of sociability. The association between interaction likelihood and sociability was stronger in the virtual space, with sociability mirrored by self-reported fear of COVID-19 in predicting interaction likelihood. We propose that when physical contact with others poses a threat to safety, fear supersedes sociability in guiding behavior in physical interactions., Competing Interests: None., (© 2021 Elsevier Ltd. All rights reserved.)
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- 2022
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188. Liking as a balance between synchronization, complexity and novelty.
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Ravreby I, Shilat Y, and Yeshurun Y
- Abstract
Synchronization has been identified as a key aspect in social bonding. While synchronization could be maximized by increasing the predictability of an interaction, such predictability is in tension with individuals' level of interest, which is tied to the interaction's complexity and novelty. In this study, we tested the interplay between synchronization and interest. We asked 104 female dyads to play the Mirror Game, in which they had to move their hands as coordinately as possible, and then report how much they liked each other. Utilizing information theory and video processing tools, we found that a combination of movement synchronization and complexity explained liking almost two times better than movement synchronization alone. Moreover, we found that people initiated novel and challenging interactions, even though they paid a price-being less synchronized. Examining the interactions' dynamics, we found that people who liked each other moved in a more synchronized, complex, and novel manner during most of the interaction. This suggests that in addition to synchronization, maintaining interest may be critical for positive social bonding. Thus, we propose a new framework in which balancing synchronization and interest, rather than merely maximizing synchronization, optimizes the interaction quality., (© 2022. The Author(s).)
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- 2022
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189. Reading the mind with a mask? Improvement in reading the mind in the eyes during the COVID-19 pandemic.
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Trainin N and Yeshurun Y
- Subjects
- Emotions, Eye, Humans, Pandemics, SARS-CoV-2, COVID-19
- Abstract
The necessity to wear facial masks in public during the COVID-19 pandemic generated a unique situation where the eyes' importance as a visual source of information about individuals' mental and emotional states greatly increased. In this study, we tested the hypothesis that experience in looking in interlocutor's eyes (as a result of mask-wearing) will be correlated with enhanced performance on "reading the mind in the eyes test" (RMET). To test this, 87 participants performed an online version of the RMET at 2 different timepoints: when the mandatory mask wearing rules were put in place and a month later. We found that reported tendency to look at interlocutors' eyes, combined with experience in interacting with other people wearing masks, explained individual differences in RMET performance. Moreover, we found that individual's tendency to look at interlocutors' eyes was correlated with change in performance in reading the mind in the eyes over this month. These results suggest that in addition to individual's interest and motivation in understanding other's mental state, continuous everyday experiences can result in an improved capacity for reading mental and emotional states by looking into individuals' eyes. (PsycInfo Database Record (c) 2022 APA, all rights reserved).
- Published
- 2021
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190. Inter-individual variations in internal noise predict the effects of spatial attention.
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Luzardo F and Yeshurun Y
- Subjects
- Cues, Humans, Noise, Visual Perception, Attention, Space Perception
- Abstract
Individuals differ considerably in the degree to which they benefit from attention allocation. Thus far, such individual differences were attributed to post-perceptual factors such as working-memory capacity. This study examined whether a perceptual factor - the level of internal noise - also contributes to this inter-individual variability in attentional effects. To that end, we estimated individual levels of internal noise from behavioral variability in an orientation discrimination task (with tilted gratings) using the double-pass procedure and the perceptual-template model. We also measured the effects of spatial attention in an acuity task: the participants reported the side of a square on which a small aperture appeared. Central arrows were used to engage sustained attention and peripheral cues to engage transient attention. We found reliable correlations between individual levels of internal noise and the effects of both types of attention, albeit of opposite directions: positive correlation with sustained attention and negative correlation with transient attention. These findings demonstrate that internal noise - a fundamental characteristic of visual perception - can predict individual differences in the effects of spatial attention, highlighting the intricate relations between perception and attention., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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191. Temporal crowding is a unique phenomenon reflecting impaired target encoding over large temporal intervals.
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Tkacz-Domb S and Yeshurun Y
- Subjects
- Humans, Perceptual Masking, Vision, Ocular, Visual Perception, Pattern Recognition, Visual, Space Perception
- Abstract
Crowding refers to impaired object identification when presented with other objects, and it is well established that spatial crowding-crowding from adjacent objects-affects many aspects of visual perception and cognition. A similar interference also occurs across time-the identification of a target object is impaired when distracting objects precede and succeed it. When such interference is observed with relatively long interitem intervals it is termed temporal crowding. Thus far, little was known about temporal crowding and its underlying processes. Particularly it was unknown which aspects of visual processing are impaired by temporal crowding, and the answer to this question bears critical theoretical implications. To reveal the nature of this impairment we used a continuous-report task and a mixture-model analysis. In three experiments, observers viewed sequences of three oriented items separated by relatively long intervals (170-475ms). The target was the second item in the sequence, and the task was to reproduce its orientation. The findings suggest that temporal crowding impairs target encoding and increases substitution errors, but there was no evidence of a reduced signal-to-noise ratio. This pattern of results was similar regardless of stimuli duration and target-distractor similarity. However, it differed considerably from the pattern found for ordinary masking and spatial crowding, indicating that temporal crowding is a unique phenomenon. Moreover, the finding that temporal crowding affected the precision of target encoding even when the items were separated by almost half a second suggests that visual processing requires a surprisingly long time to complete., (© 2021. The Psychonomic Society, Inc.)
- Published
- 2021
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192. The "Narratives" fMRI dataset for evaluating models of naturalistic language comprehension.
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Nastase SA, Liu YF, Hillman H, Zadbood A, Hasenfratz L, Keshavarzian N, Chen J, Honey CJ, Yeshurun Y, Regev M, Nguyen M, Chang CHC, Baldassano C, Lositsky O, Simony E, Chow MA, Leong YC, Brooks PP, Micciche E, Choe G, Goldstein A, Vanderwal T, Halchenko YO, Norman KA, and Hasson U
- Subjects
- Adolescent, Adult, Brain Mapping, Electronic Data Processing, Female, Humans, Male, Middle Aged, Narration, Young Adult, Comprehension, Language, Magnetic Resonance Imaging
- Abstract
The "Narratives" collection aggregates a variety of functional MRI datasets collected while human subjects listened to naturalistic spoken stories. The current release includes 345 subjects, 891 functional scans, and 27 diverse stories of varying duration totaling ~4.6 hours of unique stimuli (~43,000 words). This data collection is well-suited for naturalistic neuroimaging analysis, and is intended to serve as a benchmark for models of language and narrative comprehension. We provide standardized MRI data accompanied by rich metadata, preprocessed versions of the data ready for immediate use, and the spoken story stimuli with time-stamped phoneme- and word-level transcripts. All code and data are publicly available with full provenance in keeping with current best practices in transparent and reproducible neuroimaging., (© 2021. The Author(s).)
- Published
- 2021
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193. Relating the Past with the Present: Information Integration and Segregation during Ongoing Narrative Processing.
- Author
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Chang CHC, Lazaridi C, Yeshurun Y, Norman KA, and Hasson U
- Subjects
- Brain diagnostic imaging, Humans, Magnetic Resonance Imaging, Narration, Brain Mapping, Mental Recall
- Abstract
This study examined how the brain dynamically updates event representations by integrating new information over multiple minutes while segregating irrelevant input. A professional writer custom-designed a narrative with two independent storylines, interleaving across minute-long segments (ABAB). In the last (C) part, characters from the two storylines meet and their shared history is revealed. Part C is designed to induce the spontaneous recall of past events, upon the recurrence of narrative motifs from A/B, and to shed new light on them. Our fMRI results showed storyline-specific neural patterns, which were reinstated (i.e., became more active) during storyline transitions. This effect increased along the processing timescale hierarchy, peaking in the default mode network. Similarly, the neural reinstatement of motifs was found during Part C. Furthermore, participants showing stronger motif reinstatement performed better in integrating A/B and C events, demonstrating the role of memory reactivation in information integration over intervening irrelevant events., (© 2021 Massachusetts Institute of Technology.)
- Published
- 2021
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194. The effects of spatial attention on temporal integration measured with the ternus display.
- Author
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Hochmitz I, Hein E, and Yeshurun Y
- Subjects
- Attention, Humans, Motion, Photic Stimulation, Visual Perception, Motion Perception
- Abstract
While a large body of evidence has demonstrated the effects of attention on spatial processes, we know much less about attentional effects on the complementary temporal aspects of visual perception. To narrow this knowledge gap, we examined the effects of endogenous attention-the voluntary component of spatial attention-on temporal integration using the Ternus display. In a typical Ternus display, horizontally aligned discs shift by one position across alternating frames that are separated by a varying interframe interval. This display can induce two different motion percepts: all three discs moving together back and forth (group motion), or the two central discs seeming to remain static and the outer disk jumping across them (element motion). Several studies suggest that element motion reflects temporal integration. Thus, we used the rate of element motion percept to measure temporal integration. Attention was manipulated via the degree of certainty regarding the discs' location (Experiment 1), or with central informative arrows (Experiment 2). The pattern of results was similar in both experiments: The participants reported perceiving element motion more often when attention was allocated in advance to the discs' location. These results suggest that attention prolongs the period of time over which information is integrated. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
- Published
- 2021
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195. Mother brain is wired for social moments.
- Author
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Shimon-Raz O, Salomon R, Bloch M, Aisenberg Romano G, Yeshurun Y, Ulmer Yaniv A, Zagoory-Sharon O, and Feldman R
- Subjects
- Adult, Cross-Over Studies, Double-Blind Method, Female, Humans, Young Adult, Brain diagnostic imaging, Magnetic Resonance Imaging, Mothers psychology, Neuroimaging, Parent-Child Relations, Social Interaction
- Abstract
Reorganization of the maternal brain upon childbirth triggers the species-typical maternal social behavior. These brief social moments carry profound effects on the infant's brain and likely have a distinct signature in the maternal brain. Utilizing a double-blind, within-subject oxytocin/placebo administration crossover design, mothers' brain was imaged twice using fMRI while observing three naturalistic maternal-infant contexts in the home ecology; 'unavailable', 'unresponsive', and 'social', when mothers engaged in synchronous peek-a-boo play. The social condition elicited greater neural response across the human caregiving network, including amygdala, VTA, hippocampus, insula, ACC, and temporal cortex. Oxytocin impacted neural response primarily to the social condition and attenuated differences between social and non-social stimuli. Greater temporal consistency emerged in the 'social' condition across the two imaging sessions, particularly in insula, amygdala, and TP. Findings describe how mother's brain varies by caregiving experiences and gives salience to moments of social synchrony that support infant development and brain maturation., Competing Interests: OS, RS, MB, GA, YY, AU, OZ, RF No competing interests declared, (© 2021, Shimon-Raz et al.)
- Published
- 2021
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196. The default mode network: where the idiosyncratic self meets the shared social world.
- Author
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Yeshurun Y, Nguyen M, and Hasson U
- Subjects
- Animals, Cognition physiology, Communication, Humans, Nervous System Physiological Phenomena, Neural Pathways physiology, Default Mode Network physiology, Ego, Nerve Net physiology
- Abstract
The default mode network (DMN) is classically considered an 'intrinsic' system, specializing in internally oriented cognitive processes such as daydreaming, reminiscing and future planning. In this Perspective, we suggest that the DMN is an active and dynamic 'sense-making' network that integrates incoming extrinsic information with prior intrinsic information to form rich, context-dependent models of situations as they unfold over time. We review studies that relied on naturalistic stimuli, such as stories and movies, to demonstrate how an individual's DMN neural responses are influenced both by external information accumulated as events unfold over time and by the individual's idiosyncratic past memories and knowledge. The integration of extrinsic and intrinsic information over long timescales provides a space for negotiating a shared neural code, which is necessary for establishing shared meaning, shared communication tools, shared narratives and, above all, shared communities and social networks.
- Published
- 2021
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197. Superior Parietal Lobule: A Role in Relative Localization of Multiple Different Elements.
- Author
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Vialatte A, Yeshurun Y, Khan AZ, Rosenholtz R, and Pisella L
- Subjects
- Adult, Agnosia physiopathology, Female, Humans, Neuroimaging methods, Attention physiology, Cognition physiology, Parietal Lobe pathology, Visual Perception physiology
- Abstract
Simultanagnosia is an impairment in processing multiple visual elements simultaneously consecutive to bilateral posterior parietal damage, and neuroimaging data have specifically implicated the superior parietal lobule (SPL) in multiple element processing. We previously reported that a patient with focal and bilateral lesions of the SPL performed slower than controls in visual search but only for stimuli consisting of separable lines. Here, we further explored this patient's visual processing of plain object (colored disk) versus object consisting of separable lines (letter), presented in isolation (single object) versus in triplets. Identification of objects was normal in isolation but dropped to chance level when surrounded by distracters, irrespective of eccentricity and spacing. We speculate that this poor performance reflects a deficit in processing objects' relative locations within the triplet (for colored disks), aggravated by a deficit in processing the relative location of each separable line (for letters). Confirming this, performance improved when the patient just had to detect the presence of a specific colored disk within the triplets (visual search instruction), while the inability to identify the middle letter was alleviated when the distracters were identical letters that could be grouped, thereby reducing the number of ways individual lines could be bound., (© The Author(s) 2020. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2021
- Full Text
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198. The time-course of endogenous temporal attention - Super fast voluntary allocation of attention.
- Author
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Yeshurun Y and Tkacz-Domb S
- Subjects
- Humans, Reaction Time, Cues, Space Perception
- Abstract
It is widely accepted that voluntary spatial attention is slow - it can only affect performance with medium and long cue-target intervals. Here, we examined whether this also holds for voluntary temporal attention. We performed a rigorous examination of the time-course of attention allocation to a point in time using two common paradigms for studying endogenous temporal attention: 'constant foreperiod' and 'temporal orienting'. With both paradigms, the task required non-speeded identification of a letter, whose presentation was preceded by a warning cue. This cue was either auditory or visual, and it was either informative or uninformative. Critically, to avoid exogenous attention, the cues did not involve an intensity change. We found significantly higher identification accuracy when the cue was informative than uninformative, suggesting that temporal attention improved perceptual processing. Importantly, reliable effects of temporal attention on perceptual processing were found with as little as 150 ms from cue onset and up to 2400 ms. Hence, measuring endogenous attention in the temporal domain revealed a twofold faster mechanism than what was believed based on measurements in the spatial domain. These findings challenge the common assumption that voluntary processes are inherently slow. Instead, they portray voluntary mechanisms as considerably more flexible and dynamic, and they further underscore the importance of incorporating the temporal domain into the study of human perception., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2021
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199. DNA-assembled superconducting 3D nanoscale architectures.
- Author
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Shani L, Michelson AN, Minevich B, Fleger Y, Stern M, Shaulov A, Yeshurun Y, and Gang O
- Subjects
- Information Systems, Magnetic Fields, Metal Nanoparticles chemistry, Niobium, Quantum Theory, Silicon Dioxide, DNA chemistry, Nanostructures chemistry, Superconductivity
- Abstract
Studies of nanoscale superconducting structures have revealed various physical phenomena and led to the development of a wide range of applications. Most of these studies concentrated on one- and two-dimensional structures due to the lack of approaches for creation of fully engineered three-dimensional (3D) nanostructures. Here, we present a 'bottom-up' method to create 3D superconducting nanostructures with prescribed multiscale organization using DNA-based self-assembly methods. We assemble 3D DNA superlattices from octahedral DNA frames with incorporated nanoparticles, through connecting frames at their vertices, which result in cubic superlattices with a 48 nm unit cell. The superconductive superlattice is formed by converting a DNA superlattice first into highly-structured 3D silica scaffold, to turn it from a soft and liquid-environment dependent macromolecular construction into a solid structure, following by its coating with superconducting niobium (Nb). Through low-temperature electrical characterization we demonstrate that this process creates 3D arrays of Josephson junctions. This approach may be utilized in development of a variety of applications such as 3D Superconducting Quantum interference Devices (SQUIDs) for measurement of the magnetic field vector, highly sensitive Superconducting Quantum Interference Filters (SQIFs), and parametric amplifiers for quantum information systems.
- Published
- 2020
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200. Can rhythm-induced attention improve the perceptual representation?
- Author
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Elbaz A and Yeshurun Y
- Subjects
- Algorithms, Humans, Normal Distribution, Periodicity, Reaction Time, Signal-To-Noise Ratio, Students, Acoustic Stimulation, Attention, Auditory Perception, Time Perception
- Abstract
Temporal attention can be entrained exogenously to rhythms. Indeed, faster and more accurate responses were previously found when the target appeared in-phase with a preceding rhythm in comparison to when it was out of phase. However, the nature of this rhythm-induced attentional effect is not well understood. To better understand the processes underlying rhythm-induced attention, we employed a continuous measure of perceived orientation and a mixture-model analysis. A trial in our study started with a sequence of auditory beeps separated by a fixed inter-beeps interval in the regular (rhythmic) condition or by variable inter-beeps intervals in the irregular condition. A visual target-a line embedded in a circle-followed the sequence. The 'critical' interval between the last beep and the target was chosen randomly from several possible Inter-Onset Intervals (IOIs), of which only one was in-phase with the rhythm. The target was followed by a probe line, and the participants were asked to rotate it to reproduce the target's orientation. The measure of performance for a given trial was the difference in degrees between the orientation of the target and that reproduced by the observer. We found that guessing rate was lower with regular than irregular rhythms. However, there was no effect of rhythm type (regular vs irregular) on the quality of representation (measured as the variability in reproducing the target). Furthermore, the rhythm effect was present only when rhythm type was fixed within a block, and it was found with all IOIs, not just the in-phase IOI. This lack of specificity suggests that these results reflect a general effect of rhythm on alertness., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2020
- Full Text
- View/download PDF
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