The role of vowel formant frequencies and duration in the perception of foreign accent

ABSTRACT

This study used synthesis to manipulate vowel formant frequencies and durations to evaluate their role on foreign accent perception. Formant frequencies and durations for the vowels /æ/, /?/, and /a/ were manipulated with changes toward and away from the mean native English and Spanish-accented values from Sidaras, S. K., Alexander, J. E. D., & Nygaard, L. C. (2009. Perceptual learning of systematic variation in Spanish-accented speech. The Journal of the Acoustical Society of America, 125, 3306–3316). Native listeners rated these stimuli on degree of accentedness and comprehensibility. Gradual changes in formant frequencies from native to non-native values impacted /a/ negatively, /?/ positively, and /æ/ minimally. Effects of vowel duration on either type of ratings were small and restricted to vowel-specific interactions. The current findings suggest that vowel formant frequencies are primary cues to foreign accent. Their influence depends upon whether or not frequencies could reflect alternative vowel categories.     

A Meta-Analysis of Working Memory Impairments in Autism Spectrum Disorders

Autism spectrum disorders (ASD) are characterized by executive dysfunction, and working memory (WM) comprises one core component of executive function. Many studies have investigated WM impairments in individuals with ASD, however, a conclusive agreement has not been reached. The present study provided a meta-analytic review of WM impairments in individuals with ASD and evaluated potential moderating variables of this problem. Twenty-eight studies were included in this study, and the participants comprised 819 individuals with ASD and 875 healthy controls. A significant WM impairment (Cohen’s d?=??0.61) was identified in the individuals with ASD, however, this impairment was not associated with age. Results of moderation analyses showed that (a) spatial WM was more severely impaired than verbal WM and (b) the component of cognitive processing (maintenance vs. maintenance plus manipulation) did not affect the severity of WM impairments. These findings suggest that WM is impaired in individuals with ASD and may have implications for interventions related to WM impairments in these individuals.     

Decoding dyadic interactive nonverbal behaviour in Chinese and Australian cohorts: A novel dyadic puzzle‐solving task

The current study used a novel problem‐solving task in which the solution could only be reached via interactions between members of dyads. The study aimed to systematically examine how nonverbal interactive behaviour was related to the cultural background of the dyads, the participant's role in the dyad (viz., instructor, problem solver) and task repetition. Twenty‐one Australian dyads and 32 Chinese dyads performed the dyadic puzzle‐solving task while their interactions were video‐recorded. In each dyad, one instructor and one problem solver worked together to solve a seven‐piece puzzle. Six trials, each comprising a different puzzle, were completed. Results indicate that the Australian instructors engaged in significantly more eye gazing and displayed more hand gestures but smiled less than the Chinese instructors. The Australian problem solvers maintained longer eye gazing, displayed more hand gestures and more echoing than their Chinese counterparts. Over trials, the Chinese instructors reduced their total talking time, hand gestures, nodding behaviour and smiling during self‐talking more than the Australian instructors. Moreover, the problem solvers in the dyads from both countries significantly reduced their smiling across trials. The current study shows that nonverbal behaviours during dyadic interactions are related to one's cultural background, role in the task and task repetition.     

An experimentally confirmed statistical model on arm movement

The purpose of this research work was to develop a methodology to model arm movement in normal subjects and neurologically impaired individuals through the application of a statistical modelling method. Thirteen subjects with Parkinson's disease and 29 normal controls were recruited to participate in an arm motor task. An infrared optoelectronic kinematic movement analysis system was employed to record arm movement at 50 times per second. This study identified the modified extended Freundlich model as one that could be used to describe this task. Results showed that this model fit the data well and that it has a good correspondence between the observed and the predicted data. However, verification of the model showed that the residuals contained a sizeable autocorrelation factor. The Cochrane and Orcutt method was applied to remove this factor, which improved the fit of the model. Results showed that Parkinson's disease subjects had a higher autocorrelation coefficient than the normal subjects for this task. A positive correlation (r(s) = 0.72, p < 0.001) was found between the Langton-Hewer stage and the autocorrelation coefficient of PD subjects. This finding suggests that if autocorrelation is positively correlated with disease progression, clinicians in their clinical practice might use the autocorrelation value as a useful indicator to quantify the progression of a subjects' disease. Significant differences in model parameters were seen between normal and Parkinson's disease subjects. The use of such a model to represent and quantify movement patterns provides an important base for future study.     

The contributions of static visual cues, nonvisual cues, and optic flow in distance estimation

By systematically varying cue availability in the stimulus and response phases of a series of same-modality and cross-modality distance matching tasks, we examined the contributions of static visual information, idiothetic information, and optic flow information. The experiment was conducted in a large-scale, open, outdoor environment. Subjects were presented with information about a distance and were then required to turn 180 before producing a distance estimate. Distance encoding and responding occurred via: (i) visually perceived target distance, or (ii) traversed distance through either blindfolded locomotion or during sighted locomotion. The results demonstrated that subjects performed with similar accuracy across all conditions. In conditions in which the stimulus and the response were delivered in the same mode, when visual information was absent, constant error was minimal; whereas, when visual information was present, overestimation was observed. In conditions in which the stimulus and response modes differed, a consistent error pattern was observed. By systematically comparing complementary conditions, we found that the availability of visual information during locomotion (particularly optic flow) led to an 'under-perception' of movement relative to conditions in which visual information was absent during locomotion.     

When children ask, "What is it?" what do they want to know about artifacts?

When children ask, "What is it?" are they seeking information about what something is called or what kind of thing it is? To find out, we gave 2-, 3-, and 4-year-olds (32 at each age) the opportunity to inquire about unfamiliar artifacts. An ambiguous question was answered with a name or with functional information, depending on the group to which the children were assigned. Children were inclined to follow up with additional questions about the object when they had been told its name, but seemed satisfied with the answer when they had been told the object's function. Moreover, children in the name condition tended to substitute questions about function for ambiguous questions over the course of the session. These results indicate that children are motivated to discover what kinds of things novel artifacts are, and that young children, like adults, conceive of artifact kinds in terms of their functions.     

A brief version of the geriatric depression scale for the chinese

Elderly persons (N=310) attending outpatient psychiatric clinics were given an interview on the 30-item Geriatric Depression Scale (T. L. Brink et al., 1982; J. A. Yesavage et al., 1983) and received an independent psychiatric evaluation. A 3-step binary logistic regression showed that 2 items measuring positive affect and 2 others measuring negative affect combined to produce diagnostic performance comparable with the full scale. This result was cross-validated on a different sample (N=134). A hierarchical measurement model in which the 4 items tapped 2 first-order factors (positive and negative affect), which in turn tapped a higher order construct of depression, provided excellent fit to the data.     

Factors associated with college student intent to engage in community service

Many universities in the United States highlight service as an integral component to their mission. Additionally, a growing pedagogical focus highlights the importance of community service as an integral component of student development. The current study was an investigation of the factors associated with college student intentions to engage in volunteer community service. University students (N = 403) at a comprehensive university located in the southern plains completed an anonymous Web-based questionnaire to assess community service attitudes and intentions. Subsequent to testing for statistical assumptions, results from multiple regression analysis suggest that a sense of community connectedness, cost and benefit considerations, and the seriousness of community needs are significant variables in explaining variance in the intent to engage in community service.     

Binocular shape constancy from novel views: the role of a priori constraints

We tested shape constancy from novel views in the case of binocular viewing, using a variety of stimuli, including polyhedra, polygonal lines, and points in 3-D. The results of the psychophysical experiments show that constraints such as planarity of surface contours and symmetry are critical for reliable shape constancy. These results are consistent with the results obtained in our previous psychophysical experiments on shape constancy from novel views in the presence of a kinetic depth effect (Pizlo & Stevenson, 1999). On the basis of these results, we developed a new model of binocular shape reconstruction. The model is based on the assumption that binocular reconstruction is a difficult inverse problem, whose solution requires imposing a priori constraints on the family of possible interpretations. In the model, binocular disparity is used to correct monocularly reconstructed shape. The new model was tested on the same shapes as those used in the psychophysical experiments. The reconstructions produced by this model are substantially more reliable than the reconstructions produced by models that do not use constraints. Interestingly, monocular (but not binocular) reconstructions produced by this model correlate well with both monocular and binocular performance of human subjects. This fact suggests that binocular and monocular reconstructions of shapes in the human visual system involve similar mechanisms based on monocular shape constraints.