Categorical perception of intonation contrasts: effects of listeners' language background

Intonation perception of English speech was examined for English- and Chinese-native listeners. F0 contour was manipulated from falling to rising patterns for the final words of three sentences. Listener's task was to identify and discriminate the intonation of each sentence (question versus statement). English and Chinese listeners had significant differences in the identification functions such as the categorical boundary and the slope. In the discrimination functions, Chinese listeners showed greater peakedness than English peers. The cross-linguistic differences in intonation perception were similar to the previous findings in perception of lexical tones, likely due to listeners' language background differences.     

Functional subconformations in protein folding: evidence from single-channel experiments

We study fluctuations in ion conductance and enzymatic rates of the sugar-specific channel-forming membrane protein, Maltoporin, at the single-molecule level. Specifically, we analyze time-persistent deviations in the transport parameters of individual channels from the multichannel averages and discuss our findings in the context of static disorder in protein folding. We show that the disorder responsible for variations in ion conductance does not affect sugar binding, suggesting that Maltoporin can exist in a wide set of fully functional, yet distinctly different, subconformations.     

The influence of musical training on the perception of sequentially presented mistuned harmonics

The question of whether musical scales have developed from a processing advantage for frequency ratios based on small integers, i.e., ratios derived from relationships among harmonically related tones, is widely debated in musicology and music perception. In the extreme position, this processing advantage for these so-called "natural intervals" is assumed to be inherent, and to apply to sequentially presented tones. If this is the case, evidence for this processing advantage should show up in psychoacoustic experiments using listeners from the general population. This paper reports on replications and extensions of two studies from the literature. One [Lee and Green, J. Acoust. Soc. Am. 96, 716-725 (1994)] suggests that listeners from the general population can in fact determine whether sequentially presented tones are harmonically related. The other study [Houtgast, J. Acoust. Soc. Am. 60, 405-409 (1976)] is interpreted in different terms, but could be confounded by such an ability. The results of the replications and extensions, using listeners of known relative pitch proficiency, are consistent with the idea that only trained musicians can reliably determine whether sequentially presented tones are harmonically related.     

Some experiments on the sound of silence in phonetic perception.

The results of several experiments demonstrate that silence is an important cue for the perception of stop-consonant and affricate manner. In some circumstances, silence is necessary; in others, it is sufficient. But silence is not the only cue to these manners. There are other cues that are more or less equivalent in their perceptual effects, though they are quite different acoustically. Finally, silence is effective as a cue when it separates utterances produced by male and female speakers. These findings are taken to imply that, in these instances, perception is constrained as if by some abstract conception of what vocal tracts do when they make linguistically significant gestures.     

Possible evidence for a time variation of the weak-interaction constant from double-beta-decay experiments

The probabilities of the two-neutrino double-beta decay of ⁸²Se and ⁹⁶Zr in direct (counter) and geochemical experiments are compared. Relevant experimental data on ¹³⁰Te are also analyzed. It is shown that the probability is systematically lower in geochemical experiments, which characterize the probability of ββ(2ν) decay about 10⁹ yr ago. It is assumed that this can be due to a change in the weak-interaction constant with time. A series of new, precise measurements with the aid of counters and geochemical experiments is proposed.     

Possible evidence for coherence of hadronic fields from Bose-Einstein correlation experiments

The Hanbury-Brown and Twiss effect in particle physics is used to infer information about the amount of coherence of mesonic fields by using recent theoretical results of quantum optics. The two-particle correlation data suggests that an appreciable coherent (classical) contribution is present.     

New evidence for the Soret effect in pulsed laser experiments

The impurity profile evolution occurring in laser irradiated metals is shown to be governed by ordinary and thermal diffusion in two new cases. Soret coefficients are found in a dilute impurity case (Zn implanted Al) and in a more complex situation (NiAu mixing in a Ni matrix).     

Integral processing of phonemes: evidence for a phonetic mode of perception

To investigate the extent and locus of integral processing in speech perception, a speeded classification task was utilized with a set of noise-tone analogs of the fricative-vowel syllables (fae), (integral of ae), (fu), and (integral of u). Unlike the stimuli used in previous studies of selective perception of syllables, these stimuli did not contain consonant-vowel transitions. Subjects were asked to classify on the basis of one of the two syllable components. Some subjects were told that the stimuli were computer generated noise-tone sequences. These subjects processed the noise and tone separably. Irrelevant variation of the noise did not affect reaction times (RTs) for the classification of the tone, and vice versa. Other subjects were instructed to treat the stimuli as speech. For these subjects, irrelevant variation of the fricative increased RTs for the classification of the vowel, and vice versa. A second experiment employed naturally spoken fricative-vowel syllables with the same task. Classification RTs showed a pattern of integrality in that irrelevant variation of either component increased RTs to the other. These results indicate that knowledge of coarticulation (or its acoustic consequences) is a basic element of speech perception. Furthermore, the use of this knowledge in phonetic coding is mandatory, even in situations where the stimuli do not contain coarticulatory information.     

Infant pitch perception: evidence for responding to pitch categories and the missing fundamental

While numerous studies on infant perception have demonstrated the infant's ability to discriminate sounds having different frequencies, little research has evaluated more sophisticated pitch perception abilities such as perceptual constancy and perception of the missing fundamental. In the present study 7-8-month-old infants demonstrated the ability to discriminate harmonic complexes from two pitch categories that differed in pitch by approximately 20% (e.g., 160 vs 200 Hz). Using a visually reinforced conditioned head-turning paradigm, a number of spectrally different tonal complexes that contained varying harmonic components but signaled the same two pitch categories were presented. After learning the basic pitch discrimination, the same infants learned to categorize spectrally different tonal complexes according to the pitches signaled by their fundamental frequencies. That is, the infants showed evidence of perceptual constancy for the pitch of harmonic complexes. Finally, infants heard tonal complexes that signaled the same pitch categories but for which the fundamental frequency was removed. Infants were still able to categorize the harmonic complexes according to their pitch categories. These results suggest that by 7 months of age infants show fairly sophisticated pitch perception abilities similar to those demonstrated by adults.     

A new version of duplex perception: evidence for phonetic and nonphonetic fusion

In a series of experiments, a variant of duplex perception was investigated. In its original form, duplex perception is created by presenting an isolated transition to one ear and the remainder of the syllable, the standard base, to the other ear. Listeners hear a chirp at the ear receiving the isolated transition, and a full syllable at the ear receiving the base. The new version of duplex perception was created by presenting a third-formant transition in isolation to one ear and the same transition electronically mixed with the base to the other ear; the modified base now has all the information necessary for syllabic perception. With the new procedure, listeners reported hearing a chirp centered in the middle of their head and a syllable in the ear presented the modified base that was clearer than that produced by the isolated transition and standard base. They could also reliably choose the patterns that contained the additional transition in the base when attending to either the phonetic or nonphonetic sides of the duplex percept. In addition, when the fundamental frequency, onset time, and intensity of the isolated third-formant transition were varied relative to the base, the phonetic and nonphonetic (lateralization) percepts were differentially affected, although not always reliably. In general, nonphonetic fusion was more affected by large differences in these variables than was phonetic fusion. However, when two isolated third-formant transitions were presented dichotically, fusion and the resulting central location of the chirp failed markedly with relatively small differences in each variable. The results were discussed in terms of the role of fusion in the new version of duplex perception and the nature of the information that undergoes both phonetic and nonphonetic fusion.     

Stop consonant place perception with single-formant stimuli: evidence for the role of the front-cavity resonance.

The third formant and the second formant were found on average to cue the place of articulation of intervocalic stop consonants equally well when the stop consonants occurred before the vowel/i/. This result and others provide some support for the notion that the fundamental resonance of the front cavity plays an important role in the perception of the phonetic dimension of place of articulation.     

Pentaquarks in high-energy colliding experiments: perspectives from HERA

Several issues related to pentaquark searches relevant for current and future high-energy colliding experiments are discussed. We make an attempt to explain why pentaquark candidates are not seen by some experiments, and what makes the HERA experiments so special in such searches. Received: 7 March 2005, Published online: 27 September 2005     

Categorical Smoothness of 4-Manifolds from Quantum Symmetries and the Information Loss Paradox

In this paper, we focus on some aspects of the relation of spacetime and quantum mechanics and the study counterparts (in Set) of the categorical local symmetries of smooth 4-manifolds. In the set-theoretic limit, there emerge some exotic smoothness structures on R4 (hence the Riemannian nonvanishing curvature), which fit well with the quantum mechanical lattice of projections on infinite-dimensional Hilbert spaces. The method we follow is formalization localized on the open covers of the spacetime manifold. We discuss our findings in the context of the information paradox assigned to evaporating black holes. A black hole can evaporate entirely, but the smoothness structure of spacetime will be altered and, in this way, the missing information about the initial states of matter forming the black hole will be encoded. Thus, the possible global geometric remnant of black holes in spacetime is recognized as exotic 4-smoothness. The full-fledged verification of this proposal will presumably be possible within the scope of future quantum gravity theory research.     

First one-dimensional stress-strain experiments inside an aperiodic inclusion compound: evidence of depinning effects

This Letter reports on the first observation of depinning under hydrostatic pressure of the guest and host sublattices inside the aperiodic nonadecane-urea inclusion compound. This leads to a unique way for a direct determination of the one-dimensional interguest interaction (1 N/m for nonadecane).     

Sexual dimorphism in the human brain: evidence from neuroimaging

In recent years, more and more emphasis has been placed on the investigation of sex differences in the human brain. Noninvasive neuroimaging techniques represent an essential tool in the effort to better understand the effects of sex on both brain structure and function. In this review, we provide a comprehensive summary of the findings that were collected in human neuroimaging studies in vivo thus far: we explore sexual dimorphism in the human brain at the level of (1) brain structure, in both gray and white matter, observed by voxel-based morphometry (VBM) and diffusion tensor imaging (DTI), respectively; (2) baseline neural activity, studied using resting-state functional magnetic resonance imaging (rs-fMRI) and positron emission tomography (PET); (3) neurochemistry, visualized by means of neuroreceptor ligand PET; and (4) task-related neural activation, investigated using fMRI. Functional MRI findings from the literature are complemented by our own meta-analysis of fMRI studies on sex-specific differences in human emotional processing. Specifically, we used activation likelihood estimation (ALE) to provide a quantitative approach to mapping the consistency of neural networks involved in emotional processing across studies. The presented evidence for sex-specific differences in neural structure and function highlights the importance of modeling sex as a contributing factor in the analysis of brain-related data.     

Ion irradiation of TNOs: from the fluxes measured in space to the laboratory experiments

Cosmic ion irradiation is believed to be one of the processes driving the evolution of the surface materials on TNOs. We review the laboratory simulations of radiation effects induced in likely TNO materials. In particular the production of new molecular species, the formation of refractory organics, and the spectral changes induced in icy targets and in natural bitumens are described. In order to establish if the effects seen in the laboratory are in fact responsible for the surface properties of the TNOs, the present knowledge of the ion fluxes is reviewed. For objects at selected solar distances, dosage time is given versus depth into the material. As suggested by recent experiments, the contribution of the electronic energy loss and that due to knock-on collisions are given separately. The relevance of ion-irradiation for the physico-chemical properties of TNOs is demonstrated, and the need for future investigations is outlined. To cite this article: G. Strazzulla et al., C. R. Physique 4 (2003).     

Universality in the tail of musical note rank distribution

Although power laws have been used to fit rank distributions in many different contexts, they usually fail at the tails. Languages as sequences of symbols have been a popular subject for ranking distributions, and for this purpose, music can be treated as such. Here we show that more than 1800 musical compositions are very well fitted by the first kind two parameter beta distribution, which arises in the ranking of multiplicative stochastic processes. The parameters a and b are obtained for classical, jazz and rock music, revealing interesting features. Specially, we have obtained a clear trend in the values of the parameters for major and minor tonal modes. Finally, we discuss the distribution of notes for each octave and its connection with the ranking of the notes.     

Mathematical simulation of few-nucleon experiments with three or more particles in the final state

A computer program for the kinematic simulation of nuclear reactions with three or more particles in the final state is described. Simulation results for the d + ²H → (nn)^S + (pp)^S → p + p + n + n reaction, which proceeds through the formation of a singlet dineutron and diproton in the intermediate state, are presented as an example. It is shown that the kinematic parameters of breakup particles depend on the parameters of the intermediate state. The results from simulating secondary neutron spectra are compared to an experimental neutron time-of-flight spectrum obtained in a kinematically complete experiment at a deuteron energy of 15 MeV. As a result of the comparison, the energy of the quasi-bound singlet ¹S₀ state of the ²n-system is determined.