Perceptual scaling of voice identity: common dimensions for different vowels and speakers

The aims of our study were: (1) to determine if the acoustical parameters used by normal subjects to discriminate between different speakers vary when comparisons are made between pairs of two of the same or different vowels, and if they are different for male and female voices; (2) to ask whether individual voices can reasonably be represented as points in a low-dimensional perceptual space such that similarly sounding voices are located close to one another. Subjects were presented with pairs of voices from 16 male and 16 female speakers uttering the three French vowels “a”, “i” and “u” and asked to give speaker similarity judgments. Multidimensional analyses of the similarity matrices were performed separately for male and female voices and for three types of comparisons: same vowels, different vowels and overall average. The resulting dimensions were then interpreted a posteriori in terms of relevant acoustical measures. For both male and female voices, a two-dimensional perceptual space was found to be most appropriate, with axes largely corresponding to contributions of the larynx (pitch) and supra-laryngeal vocal tract (formants), mirroring the two largely independent components of source and filter in voice production. These perceptual spaces of male and female voices and their corresponding voice samples are available at: section Resources.     

A new look at sensory attenuation. Action-effect anticipation affects sensitivity, not response bias

The systematic association of an action that a person performs with its sensory effects is thought to attenuate that person's perception of the effect of the action. However, whether learned sensorimotor contingencies truly affect perception, rather than just inducing a response bias, has yet to be determined. The experiment presented in this article comprised two parts: an action-effect association phase and a test phase, during which the actions' perceptual effects were tested. During the association phase, specific actions (left-key and right-key presses) were associated with specific visual effects (tilted Gabor patches). In the test phase, participants' left-key presses and right-key presses triggered the onset of a low-contrast tilted Gabor patch in 50% of trials (no stimulus was presented on the remaining 50% of trials). Participants were required to report the presence or absence of this tilted Gabor patch. Our results showed that participants' sensitivity (d') to the Gabor patches was reduced by 10% when the patches were triggered by the action they had previously been associated with. This finding indicates that a person's action does not induce a response bias (c), but changes the perception (d') of the learned action effect.     

Keeping the vermin out: Perceived disease threat and ideological orientations as predictors of exclusionary immigration attitudes

Integrating evolutionary and social representations theories, the current study examines the relationship between perceived disease threat and exclusionary immigration attitudes in the context of a potential avian influenza pandemic. This large‐scale disease provides a realistic context for investigating the link between disease threat and immigration attitudes. The main aim of this cross‐sectional study (N = 412) was to explore mechanisms through which perceived chronic and contextual disease threats operate on immigration attitudes. Structural equation models show that the relationship between chronic disease threat (germ aversion) and exclusionary immigration attitudes (assimilationist immigration criteria, health‐based immigration criteria and desire to reduce the proportion of foreigners) was mediated by ideological and normative beliefs (social dominance orientation, belief in a dangerous world), but not by contextual disease threat (appraisal of avian influenza pandemic threat). Contextual disease threat only predicted support for health‐based immigration criteria. The conditions under which real‐life disease threats influence intergroup attitudes are scrutinized. Convergence and dissimilarity of evolutionary and social representational approaches in accounting for the link between disease threat and immigration attitudes are discussed. Copyright © 2010 John Wiley & Sons, Ltd.     

Exploring the temporal dynamics of social facilitation in the Stroop task

The importance of social context in affecting attention has recently been highlighted by the finding that the presence of a passive, nonevaluative confederate can improve selective attention. The underlying mechanism, however, remains unclear. In this paper, we argue that social facilitation can be caused by distractor inhibition. Two distinct sources of evidence are provided from an experiment employing the Stroop task with and without social presence. First, analysis of the response time (RT) distribution indicates that interference is reduced at relatively long RTs. This is consistent with an inhibitory mechanism, whose effects build up slowly. Further support is provided by showing that social facilitation is prevented by using short response-to-stimulus intervals that are thought to reduce cognitive control processes.     

Cross-modal facilitation in speech prosody

Speech prosody has traditionally been considered solely in terms of its auditory features, yet correlated visual features exist, such as head and eyebrow movements. This study investigated the extent to which visual prosodic features are able to affect the perception of the auditory features. Participants were presented with videos of a speaker pronouncing two words, with visual features of emphasis on one of these words. For each trial, participants saw one video where the two words were identical in both pitch and amplitude, and another video where there was a difference in either pitch or amplitude that was congruent or incongruent with the visual changes. Participants were asked to decide which video contained the sound difference. Thresholds were obtained for the congruent and incongruent videos, and for an auditory-alone condition. It was found that the congruent thresholds were better than the incongruent thresholds for both pitch and amplitude changes. Interestingly, the congruent thresholds for amplitude were better than for the auditory-alone condition, which implies that the visual features improve sensitivity to loudness changes. These results demonstrate that visual stimuli can affect auditory thresholds for changes in pitch and amplitude, and furthermore support the view that visual prosodic features enhance speech processing.     

A two-dimensional model of social representations

This paper reports a series of four experiments conducted to gain insight into students' social representations of the firm. The results suggested a possible revision of the central core theory. They showed that the central elements of the representation were treated differently by the subjects. More specifically, the notion of Profit and Hierarchy, both central, did not play the same role in the representation. The subjects were found to grant evaluative power to the notion of Profit but not to the notion of Hierarchy. This differentiation by evaluative potential was also found for two peripheral elements. These differences suggest that independently of their central or peripheral nature, the various elements of a representation can be placed along an evaluative continuum. By combining the evaluative dimension and the central or peripheral dimension of the elements, we obtain a two-dimensional model of representations which divides discourse and cognition into four fields.     

The influence of social comparison with less fortunate others on task performance: The role of gender motivations or appropriate norms

French male and female children performed a cognitive-perceptual task while anticipating or not public comparisons of their score with probably less fortunate others at a time when concerns about fitting in to social expectations were maximized. As predicted, boys performed better and girls poorer when social comparison was anticipated than when it was not. This suggested that task performance can depend on the compatibility of the social context of cognition with gender motivations or appropriate norms.     

Generalized Processing Tree Models: Jointly Modeling Discrete and Continuous Variables

Multinomial processing tree models assume that discrete cognitive states determine observed response frequencies. Generalized processing tree (GPT) models extend this conceptual framework to continuous variables such as response times, process-tracing measures, or neurophysiological variables. GPT models assume finite-mixture distributions, with weights determined by a processing tree structure, and continuous components modeled by parameterized distributions such as Gaussians with separate or shared parameters across states. We discuss identifiability, parameter estimation, model testing, a modeling syntax, and the improved precision of GPT estimates. Finally, a GPT version of the feature comparison model of semantic categorization is applied to computer-mouse trajectories.     

N. R. Hanson and von Uexküll: A Biosemiotic and Evolutionary Account of Theories

Journal for General Philosophy of Science - This paper proposes a biosemiotic conception of theories, as non-intentional organic theories, which is based on an analysis and comparison of...