Theodora Chaspari

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Embodied conversational agents (ECA) offer platforms for the collection of structured interaction and communication data. This paper discusses the data collected from the Rachel system, an ECA developed at the University of Southern California, for interactions with children with autism. Two dyads each composed of a child with autism and his parent(More)
Impaired social communication and social reciprocity are the primary phenotypic distinctions between autism spectrum disorders (ASD) and other developmental disorders. We investigate quantitative conversational cues in child-psychologist interactions using acoustic-prosodic, turn-taking, and language features. Results indicate the conversational quality(More)
In this paper, we propose robust features for the problem of voice activity detection (VAD). In particular, we extend the long term signal variability (LTSV) feature to accommodate multiple spectral bands. The motivation of the multi-band approach stems from the non-uniform frequency scale of speech phonemes and noise characteristics. Our analysis shows(More)
Signal-derived measures can provide effective ways towards quantifying human behavior. Verbal Response Latencies (VRLs) of children with Autism Spectrum Disorders (ASD) during conversational interactions are able to convey valuable information about their cognitive and social skills. Motivated by the inherent gap between the external behavior and inner(More)
Biometric sensors and portable devices are being increasingly embedded into our everyday life, creating the need for robust physiological models that efficiently represent, analyze, and interpret the acquired signals. We propose a knowledge-driven method to represent electrodermal activity (EDA), a psychophysiological signal linked to stress, affect, and(More)
Speech and spoken language cues offer a valuable means to measure and model human behavior. Computational models of speech behavior have the potential to support health care through assistive technologies, informed intervention, and efficient long-term monitoring. The Interspeech 2013 Autism SubChallenge addresses two developmental disorders that manifest(More)
The affective state of children with autism is not always expressed or discernible through observational cues, a phenomenon which is further confounded by vast variability across individuals on the autism spectrum. Electrodermal Activity (EDA) is a physiological signal indicative of a person’s arousal and thus affording us new insights into a child’s inner(More)
The quality of shared enjoyment in interactions is a key aspect related to Autism Spectrum Disorders (ASD). This paper discusses two types of enjoyment: the first refers to humorous events and is associated with one's positive affective state and the second is used to facilitate social interactions between people. These types of shared enjoyment are(More)
Parametric dictionaries can increase the ability of sparse representations to meaningfully capture and interpret the underlying signal information, such as encountered in biomedical problems. Given a mapping function from the atom parameter space to the actual atoms, we propose a sparse Bayesian framework for learning the atom parameters, because of its(More)
Children's interpersonal synchrony has been related to various benefits in social, mental and emotional development. We explore verbal and acoustic synchrony patterns between pairs of children playing a speech-controlled video game. Verbal features include word timing and duration patterns, while acoustic cues contain prosodic information. Synchrony is(More)