The attentional blink: Invreasing target salience provides no evidence for resource depletion. A commentary on Dux, Asplund and Marois

The authors have argued elsewhere that the attentional blink (AB; i.e., reduced target detection shortly after presentation of an earlier target) arises from blocked or disrupted perceptual input in response to distractors presented between the targets. When targets replace the intervening distractors, so that three targets (T1, T2, and T3) are presented sequentially, performance on T2 and T3 improves. Dux, Asplund, and Marois (2008) argued that T3 performance improves at the expense of T1, and thus provides evidence for resource depletion. They showed that when T1 is made more salient (and presumably draws more resources), an AB for T3 appears to reemerge. These findings can be better explained, however, by (1) the relationship between T1 and T2 (not T1 and T3) and (2) differential salience for T3 in the long-lag condition of Dux et al.'s study. In conclusion, the Dux et al. study does not present a severe challenge to input control theories of the AB. © 2009 The Psychonomic Society, Inc

Pitch contours of Northern Vietnamese tones vary with focus marking

Intonation is a means of structuring discourse and one of its functions is to highlight new or contrasting information, i.e., focus. Speakers of different languages use a range of prosodic cues to mark focus. Compared to non-tonal languages such as English, tonal languages use pitch to distinguish lexical tones and focus marking. Determining the interplay between intonation and lexical tone is therefore important. Previous studies found that tonal languages use different strategies to mark focus. For example, some use an increase (e.g., Mandarin Chinese), others a decrease in pitch (e.g., Kammu). The Vietnamese language has six lexical tones and is particularly interesting for examining pitch contours in focus marking. In this article, we present a production study with 70 Northern Vietnamese speakers. Participants read six sentences aloud under two different conditions (narrow/wide focus). In each sentence, focus marked a single noun (‘focus item’) which occurred in the final position of the sentence and carried one of the six tones. Acoustic analyses of the focus item showed that Vietnamese speakers realized focus with significant differences in pitch at the beginning of the word, but the strategies to increase or decrease pitch varied across tones. Our findings add important insights to the discussion about Information Structure and the role of intonation in tonal languages by analyzing the use of prosodic cues in a complex tone system. The large number of speakers in our study also adds further methodological rigor compared to other studies, which often rely on a few speakers.1 Introduction 2 Using intonation for focus marking 2.1 Focus marking with intonation in tonal languages 2.2 Using intonation to mark pragmatic functions and focus in Vietnamese 3 Method 3.1 Participants 3.3 Material 3.2 Procedure 3.3 Pitch Analysis 4 Results 5 Discussio

Intrinsic Structural Disorder and the Magnetic Ground State in Bulk EuTiO3

The magnetic properties of single-crystal EuTiO3 are suggestive of nanoscale disorder below its cubic-tetragonal phase transition. We demonstrate that electric field cooling acts to restore monocrystallinity, thus confirming that emergent structural disorder is an intrinsic low-temperature property of this material. Using torque magnetometry, we deduce that tetragonal EuTiO3 enters an easy-axis antiferromagnetic phase at 5.6 K, with a first-order transition to an easy-plane ground state below 3 K. Our data is reproduced by a 3D anisotropic Heisenberg spin model.Comment: 5 pages, 4 figure

On the role of intrinsic disorder in the structural phase transition of magnetoelectric EuTiO3

Up to now the crystallographic structure of the magnetoelectric perovskite EuTiO3 was considered to remain cubic down to low temperature. Here we present high resolution synchrotron X-ray powder diffraction data showing the existence of a structural phase transition, from cubic Pm-3m to tetragonal I4/mcm, involving TiO6 octahedra tilting, in analogy to the case of SrTiO3. The temperature evolution of the tilting angle indicates a second-order phase transition with an estimated Tc=235K. This critical temperature is well below the recent anomaly reported by specific heat measurement at TA\sim282K. By performing atomic pair distribution function analysis on diffraction data we provide evidence of a mismatch between the local (short-range) and the average crystallographic structures in this material. Below the estimated Tc, the average model symmetry is fully compatible with the local environment distortion but the former is characterized by a reduced value of the tilting angle compared to the latter. At T=240K data show the presence of local octahedra tilting identical to the low temperature one, while the average crystallographic structure remains cubic. On this basis, we propose intrinsic lattice disorder to be of fundamental importance in the understanding of EuTiO3 properties.Comment: 13 pages, 8 figures, 2 table

Elastic and anelastic relaxations associated with phase transitions in EuTiO3

Elastic and anelastic properties of single crystal samples of EuTiO3 have been measured between 10 and 300 K by Resonant Ultrasound Spectroscopy at frequencies in the vicinity of 1 MHz. Softening of the shear elastic constants C44 and by ~20-30% occurs with falling temperature in a narrow interval through the transition point, Tc = 284 K, for the cubic - tetragonal transition. This is accounted for by classical coupling of macroscopic spontaneous strains with the tilt order parameter, in the same manner as occurs in SrTiO3. A peak in the acoustic loss occurs a few degrees below Tc and is interpreted in terms of initially mobile ferroelastic twin walls which rapidly become pinned with further lowering of temperature. This contrasts with the properties of twin walls in SrTiO3 which remain mobile down to at least 15 K. No further anomalies were observed that might be indicative of strain coupling to any additional phase transitions above 10 K. A slight anomaly in the shear elastic constants, independent of frequency and without any associated acoustic loss, was found at ~140 K. It marks a change from elastic stiffening to softening with falling temperature and perhaps provides evidence for coupling between strain and local fluctuations of dipoles related to the incipient ferroelectric transition. An increase in acoustic loss below ~80 K is attributed to the development of dynamical magnetic clustering ahead of the known antiferromagnetic ordering transition at ~5.5 K. Detection of these elastic anomalies serves to emphasise that coupling of strain with tilting, ferroelectric and magnetic order parameters is likely to be a permeating influence in determining the structure, stability, properties and behaviour of EuTiO3.RUS facilities were established in Cambridge through a grant from the Natural Environment Research Council of Great Britain to MAC, which is gratefully acknowledged (NE/B505738/1). LJS acknowledges the support of the National Science Centre (NCN) through Grant MAESTRO No. DEC-2012/04/A/ST3/00342. CP acknowledges Financial support in Greece through grants EURYI and MEXT-CT-2006-039047 grants, and in Singapore through Award No. NRF-CRP-4-2008-04 of the Competitive Research Programme.This is the accepted version. The final version is published of the final version by APS here: http://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.054119

Mass enhancement and magnetic order at the Mott-Hubbard transition

We study the evolution with pressure P and band filling y of the heat capacity, Hall coefficient, and resistivity at the approach to the T→0 Mott-Hubbard metal-insulator transition (MIT) in highly correlated V_(2-y)O_3. Under P, the electronic effective mass m* diverges at the MIT with a negligible change in carrier concentration n away from half-filling. Conversely, in the doped system m* actually decreases as the MIT is approached, while n increases linearly with y. The low-T magnetic order in the metal helps us deconvolute contributions from charge correlations and spin fluctuations

Effect of correlations and disorder on electron states in the Mott-Hubbard insulator V_2O_3

We compare vanadium-deficient (nonstoichiometric) and titanium-doped vanadium sesquioxide through measurements of the electrical resistivity at a series of hydrostatic pressures, the magnetic susceptibility, and the low-temperature specific heat: all as a function of T. The pressure dependence of the critical temperature for this discontinuous metal-antiferromagnetic-insulator transition as well as the temperature dependence of the magnetic susceptibility track in the two cases. However, the pressure dependence of the Hubbard gap, the slower than exponential form of the low-temperature resistivity, and the concentration of two-level systems are markedly different for V_(1.9967)O_3 and (V_(0.99)Ti_(0.01))_2O_3. We discuss our results in terms of the intra-atomic Coulomb repulsion, which is of comparable magnitude to the bare bandwidth of the vanadium 3d states. The band splitting in the antiferromagnetic insulating state is argued to cross over to a Slater-type splitting between the subbands narrowed by correlations with a sufficient degree of oxygen nonstoichiometry or Ti doping

Verwey transition in Fe3_{3}O4_{4} at high pressure: quantum critical behavior at the onset of metallization

We provide evidence for the existence of a {\em quantum critical point} at the metallization of magnetite Fe$_{3}$O$_{4}$ at an applied pressure of $p_{c} \approx 8$ GPa. We show that the present ac magnetic susceptibility data support earlier resistivity data. The Verwey temperature scales with pressure $T_{V}\sim (1-p/p_{c})^{\nu}$, with $\nu\sim 1/3$. The resistivity data shows a temperature dependence $\rho(T)=\rho_{0}+AT^{n}$, with $n\simeq 3$ above and 2.5 at the critical pressure, respectively. This difference in $n$ with pressure is a sign of critical behavior at $p_{c}$. The magnetic susceptibility is smooth near the critical pressure, both at the Verwey transition and near the ferroelectric anomaly. A comparison with the critical behavior observed in the Mott-Hubbard and related systems is made.Comment: 5 pages, 5 figure