We compared electrical brain responses to fearful vs. neutral facial expressions in healthy volunteers while they performed an orthogonal gender decision task. Face stimuli either had a broadband spatial-frequency content, or were filtered to create either low spatial-frequency (LSF) or high spatial-frequency (HSF) faces, always overlapped with their complementary SF content in upside-down orie...

the neural net for pattern p and output neuron k. This process has a similar minimization objective to that used in the well known least squares fitting method (LSF), where we normally would have k = 1 for the least squares curve fit. The difference between fitting data points with a neural net and fitting with the LSF technique is that with a neural net the fitted function is represented by th...

Abnormal facial emotion recognition is considered as one of the key symptoms of schizophrenia. Only few studies have considered deficits in the spatial frequency (SF)-dependent visual pathway leading to abnormal facial emotion recognition in schizophrenia. Twenty-one patients with schizophrenia and 19 matched healthy controls (HC) were recruited for this study. Event-related potentials (ERP) we...

In two experiments we measured object recognition performance as a function of delay. In Experiment 1 we presented half of an image of an object, and then the other half after a variable delay. Objects were subdivided into top versus bottom halves, left versus right halves, or vertical strips. In Experiment 2 we separated the low (LSF) and high spatial frequency (HSF) components of an image, an...

In this work, a switched lattice-based quantizer for the quantization of speech LSF parameters is presented. LSF di erence values are rst quantized using a scalar quantizer, as well as a two dimensional vector quantizer, and subsequently adjusted for a lower bit-rate using a lattice. A Euclidean distance measure is used as the distortion measure for the design, while a spectral distortion measu...

Low spatial frequency (LSF) visual information is extracted rapidly from fearful faces, suggesting magnocellular involvement. Autistic phenotypes demonstrate altered magnocellular processing, which we propose contributes to a decreased P100 evoked response to LSF fearful faces. Here, we investigated whether rapid processing of fearful facial expressions differs for groups of neurotypical adults...

An original technique to incorporate random fields non-intrusively in probabilistic design is presented. The approach is based on the extraction of the main features of a random field using a limited number of experimental observations (snapshots). An approximation of the random field is obtained using proper orthogonal decomposition (POD). For a given failure criterion, an explicit limit state...

In this paper, we present a dynamic programming approach to voice transformation (VT). The goal of VT is to modify the speech of a source speaker such that it is perceived as if spoken by a target speaker. The speech model used in this work is based on MELP (Mixed Excitation Linear Prediction) speech coding algorithm. The designed system obtains speaker−specific codebooks of line spectral frequ...

Individuals form first impressions of others all the time, which affects their social functioning. Typical adults form threat impressions in faces with neutral expressions quickly, requiring less than 40 ms. These impressions appear to be mediated by low spatial frequency (LSF) content in the images. Little is known, however, about mechanisms of first impression formation in schizophrenia. The ...

Lipid-induced insulin resistance is associated with intracellular accumulation of inhibitory intermediates depending on the prevalent fatty acid (FA) species. In cultured myotubes, ceramide and phosphatidic acid (PA) mediate the effects of the saturated FA palmitate and the unsaturated FA linoleate, respectively. We hypothesized that myriocin (MYR), an inhibitor of de novo ceramide synthesis, w...