Emotion lateralization in a graduated emotional chimeric face task: An online study

Objective: To resolve inconsistencies in the literature regarding the dominance of the right cerebral hemisphere (RH) in emotional face perception, specifically investigating the role of the intensity of emotional expressions, different emotions, and conscious perception. Method: The study used an online version of the well-established emotional chimeric face task (ECFT) in which participants judged which side of a chimeric face stimulus was more emotional. We tested the laterality bias in the ECFT across six basic emotions and experimentally modified the intensity of the emotional facial expression from neutral to fully emotional expressions, in incremental steps of 20%. Results: The results showed an overall left hemiface bias across all emotions, supporting the RH hypothesis of emotional lateralization. However, the left hemiface bias decreased with decreasing intensity of the emotional facial expression. Conclusions: The results provide further support for the RH hypothesis and suggest that the RH dominance in emotional face perception may be affected by task difficulty and visual perception strategy

Asymmetric interference between sex and emotion in face perception

Previous research with speeded-response interference tasks modeled on the Garner paradigm has demonstrated that task-irrelevant variations in either emotional expression or facial speech do not interfere with identity judgments, but irrelevant variations in identity do interfere with expression and facial speech judgments. Sex, like identity, is a relatively invariant aspect of faces. Drawing on a recent model of face processing according to which invariant and changeable aspects of faces are represented in separate neurological systems, we predicted asymmetric interference between sex and emotion classification. The results of Experiment 1, in which the Garner paradigm was employed, confirmed this prediction: Emotion classifications were influenced by the sex of the faces, but sex classifications remained relatively unaffected by facial expression. A second experiment, in which the difficulty of the tasks was equated, corroborated these findings, indicating that differences in processing speed cannot account for the asymmetric relationship between facial emotion and sex processing. A third experiment revealed the same pattern of asymmetric interference through the use of a variant of the Simon paradigm. To the extent that Garner interference and Simon interference indicate interactions at perceptual and response-selection stages of processing, respectively, a challenge for face processing models is to show how the same asymmetric pattern of interference could occur at these different stages. The implications of these findings for the functional independence of the different components of face processing are discussed

Developmental changes in children's facial preferences

Facial averageness, symmetry, health, and femininity are positively associated with adults' judgements of attractiveness, but little is known about the age at which preferences for individual facial traits develop. We investigated preferences for these facial traits and global attractiveness in 4- to 17-year-olds (N = 346). All age groups showed preferences for globally attractive faces. Preferences for averageness, symmetry, and health did not emerge until middle childhood and experienced apparent disruption or stasis around age 10- to 14-years; femininity was not preferred until early adulthood, and this preference was seen only in girls. Children's pubertal development was not clearly related to any facial preferences, but the results are consistent with the suggestion that early adrenal hormone release may play an activating role in mate preferences, while other constraints may delay further increases in preferences during later puberty

Facial masculinity is related to perceived age, but not perceived health

Variation in women's preferences for male facial masculinity may reflect variation in attraction to immunocompetence or to maturity. This paper reports two studies on (a) the interrelationships between women's preferences for masculinity, apparent health, and age in male faces and (b) the extent to which manipulating each of these characteristics affects women's attributions of the remaining characteristics. Both studies were carried out with a large sample of the general public (Studies 1a and 2a) and independently in a laboratory environment with smaller undergraduate samples (Studies 1b and 2b). In both samples, masculinity and age preferences were positively related, and masculinity preferences were not associated with preferences for apparent health. There was also a positive relationship between perceived age and perceived masculinity in both samples, but evidence for a link between perceptions of masculinity and health was equivocal. Collectively, these findings suggest that variation in women's preferences for masculine proportions in male faces reflect variation in attraction to male age and do not support a strict immunocompetence explanation of preferences for facial masculinity

Dispersion in dielectric-lined waveguides designed for terahertz-driven deflection of electron beams

We have developed dielectric-lined rectangular waveguide structures for terahertz (THz)-driven ultrafast deflection of 100 keV electron beams. The structures were designed to achieve THz phase velocity matching with co-propagating electron bunches. The phase-matching capability was experimentally confirmed through time-frequency analysis of the broadband coherent THz transmission measured by electro-optic sampling. The analysis determined both the frequency dependent propagation constants in the electron interaction region, and the propagation characteristics of the integrated THz tapered coupler

Weakly bound atomic trimers in ultracold traps

The experimental three-atom recombination coefficients of the atomic states $^{23}$Na$|F=1,m_F=-1>$, $^{87}$Rb$|F=1,m_F=-1>$ and $^{85}$Rb$|F=2,m_F=-2>$, together with the corresponding two-body scattering lengths, allow predictions of the trimer bound state energies for such systems in a trap. The recombination parameter is given as a function of the weakly bound trimer energies, which are in the interval $1<m(a/\hbar)^2 E_3< 6.9$ for large positive scattering lengths, $a$. The contribution of a deep-bound state to our prediction, in the case of $^{85}$Rb$|F=2,m_F=-2>$, for a particular trap, is shown to be relatively small.Comment: 5 pages, 1 figur

Mean-field analysis of collapsing and exploding Bose-Einstein condensates

The dynamics of collapsing and exploding trapped Bose-Einstein condensat es caused by a sudden switch of interactions from repulsive to attractive a re studied by numerically integrating the Gross-Pitaevskii equation with atomic loss for an axially symmetric trap. We investigate the decay rate of condensates and the phenomena of bursts and jets of atoms, and compare our results with those of the experiments performed by E. A. Donley {\it et al.} [Nature {\bf 412}, 295 (2001)]. Our study suggests that the condensate decay and the burst production is due to local intermittent implosions in the condensate, and that atomic clouds of bursts and jets are coherent. We also predict nonlinear pattern formation caused by the density instability of attractive condensates.Comment: 7 pages, 8 figures, axi-symmetric results are adde

Mean-field description of collapsing and exploding Bose-Einstein condensates

We perform numerical simulation based on the time-dependent mean-field Gross-Pitaevskii equation to understand some aspects of a recent experiment by Donley et al. on the dynamics of collapsing and exploding Bose-Einstein condensates of $^{85}$Rb atoms. They manipulated the atomic interaction by an external magnetic field via a Feshbach resonance, thus changing the repulsive condensate into an attractive one and vice versa. In the actual experiment they changed suddenly the scattering length of atomic interaction from positive to a large negative value on a pre-formed condensate in an axially symmetric trap. Consequently, the condensate collapses and ejects atoms via explosion. We find that the present mean-field analysis can explain some aspects of the dynamics of the collapsing and exploding Bose-Einstein condensates.Comment: 9 Latex pages, 10 ps and eps files, version accepted in Physical Review A, minor changes mad

Dental Caries, Fluorosis, and Fluoride Exposure in Michigan Schoolchildren

This study relates the prevalence of caries and fluorosis among Michigan children, residing in four different areas, to the various concentrations of F in the communities' water supplies. Demographic information, details of F history, and dental attendance data were collected by a questionnaire form filled out by parents. Children ages six to 12 were screened for caries by means of the NIDR criteria and for fluorosis by means of the TSIF index. Results pertain only to continuous residents and the permanent dentition. The prevalence of both caries and fluorosis was significantly associated with the F concentration in the community water supply. Approximately 65% of all children were caries-free, ranging from 55.1 % in fluoride-deficient Cadillac to 73.7% in Redford (1. 0 ppm F). About 36% of all children had dental fluorosis, ranging from 12.2 in Cadillac to 51.2 in Richmond (1.2 ppm). All of the fluorosis was very mild. From logistic regression, the prevalence of caries was significantly associated with age, dental attendance, and the use of a water supply fluoridated at 1.0 ppm. The odds of experiencing fluorosis increased at every F level above the baseline (Cadillac), with the use of topical F rinses, and with age. Results suggest that children in the four communities may be ingesting a similar level of F from sources such as dentifrices, dietary supplements, and professional applications, but the factor that differentiates them with respect to the prevalence of caries and fluorosis is the F concentration in the community water supply.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66926/2/10.1177_00220345880670050101.pd

Non-standard embedding and five-branes in heterotic M-Theory

We construct vacua of M-theory on S^1/Z_2 associated with Calabi-Yau three-folds. These vacua are appropriate for compactification to N=1 supersymmetry theories in both four and five dimensions. We allow for general E_8 x E_8 gauge bundles and for the presence of five-branes. The five-branes span the four-dimensional uncompactified space and are wrapped on holomorphic curves in the Calabi-Yau space. Properties of these vacua, as well as of the resulting low-energy theories, are discussed. We find that the low-energy gauge group is enlarged by gauge fields that originate on the five-brane world-volumes. In addition, the five-branes increase the types of new E_8 x E_8 breaking patterns allowed by the non-standard embedding. Characteristic features of the low-energy theory, such as the threshold corrections to the gauge kinetic functions, are significantly modified due to the presence of the five-branes, as compared to the case of standard or non-standard embeddings without five-branes.Comment: 34 pages, Latex 2e with amsmath, typos removed, factors corrected, refs improve