The role of perceptual salience during the segmentation of connected speech

Statistical learning allows listeners to track transitional probabilities among syllable sequences and use these probabilities for subsequent speech segmentation. Recent studies have shown that other sources of information, such as rhythmic cues, can modulate the dependencies extracted via statistical computation. In this study, we explored how syllables made salient by a pitch rise affect the segmentation of trisyllabic words from an artificial speech stream by native speakers of three different languages (Spanish, English, and French). Results showed that, whereas performance of French participants did not significantly vary across stress positions (likely due to language-specific rhythmic characteristics), the segmentation performance of Spanish and English listeners was unaltered when syllables in word-initial and word-final positions were salient, but it dropped to chance level when salience was on the medial syllable. We argue that pitch rise in word-medial syllables draws attentional resources away from word boundaries, thus decreasing segmentation effectiveness.     

Qualitative differences between implicit and explicit sequence learning

Four experiments investigate the differences between implicit and explicit sequence learning concerning their resilience to structural and superficial task changes. A superficial change that embedded the SRT task in the context of a selection task, while maintaining the sequence, did selectively hinder the expression of implicit learning. In contrast, a manipulation that maintained the task surface, but decreased the sequence validity, affected the expression of learning specifically when it was explicit. These results are discussed in the context of a dynamic framework (Cleeremans & Jiménez, 2002), which assumes that implicit knowledge is specially affected by contextual factors and that, as knowledge becomes explicit, it allows for the development of relevant metaknowledge that modulates the expression of explicit knowledge.     

Sexual attraction: its dimensionality

The purpose of this research was to develop a new Sexual Attraction Questionnaire (SAQ) [Cuestionario de Atracción Sexual, CAS]. The goal was to determine whether sexual attraction could be represented as two different clusters (Attraction to men and Attraction to women), which would imply two negatively correlated factors or a bipolar one. Three studies were carried out with 182, 118, and 425 participants, respectively. Cluster and exploratory factor analyses were performed. The results obtained show satisfactory psychometric properties for the SAQ, the two clusters, and the two predicted negatively related factors or the bipolar factor. Results are discussed in the context of the different conceptions of sexual attraction and the fourfold typology: attracted to both sexes, to men, to women, or to neither sex.     

Item selection rules in a Computerized Adaptive Test for the assessment of written English

Item selection rules in a Computerized Adaptive Test for the assessment of written English. e-CAT is a Computerized Adaptive Test for the evaluation of written English knowledge, using the item selection rule most commonly employed: the maximum Fisher information criterion. Some of the problems of this criterion have a negative impact in the estimation accuracy and in the item bank security. In this study, the performance of this item selection rule is compared, by means of simulation, with two other rules: selecting the item with maximum Fisher information in an interval (Veerkamp y Berger, 1997) and a new criterion, called "maximum Fisher information in an interval with geometric mean". In general, this new rule shows smaller measurement error and smaller item overlap rates. It seems, thus, recommendable, as it allows the simultaneous improvement of estimation accuracy and the maintenance of the item bank security of e-CAT.     

Third International Conference on Spatial Cognition: “Dynamics in Spatial Interactions”. Rome - Perugia, Italy: September 12th–15th 2006. www.icsc2006.org - committee@icsc2006.org

Call for Papers

Third International Conference on Spatial Cognition: “Dynamics in Spatial Interactions”. Rome - Perugia, Italy: September 12th–15th 2006. www.icsc2006.org - committee@icsc2006.org     

Learning processes in matching and oddity: the oddity preference effect and sample reinforcement

Eight pigeons learned either matching (to sample) or oddity (from sample) with or without reward for sample responding. The training stimuli were coarse-white, fine-black, or smooth-mauve gravels in pots with buried grain as the reinforcer. Oddity without sample reward was learned most rapidly, followed by matching with sample reward, oddity with sample reward, and matching without sample reward. Transfer was related to acquisition rate: The oddity group without sample reward showed full (equal to baseline) color and texture transfer; the matching group with sample reward showed partial texture transfer; other groups showed no transfer. Sample reward was shown to determine rate of acquisition of matching and oddity and the oddity preference effect. The results are discussed in terms of item-specific associations operating early in learning prior to any relational learning between sample and comparison stimuli.     

Unsafe Knowledge

Ernest Sosa has argued that if someone knows that p, then his belief that p is “safe”. and Timothy Williamson has agreed. In this paper I argue that safety, as defined by Sosa, is not a necessary condition on knowledge – that we can have unsafe knowledge. I present Sosa’s definition of safety and a counterexample to it as a necessary condition on knowledge. I also argue that Sosa’s most recent refinements to the notion of safety don’t help him to avoid the counterexample. I consider three replies on behalf of the defender of safety, and find them all wanting. Finally, I offer a tentative diagnosis of my counterexample.     

The influence of violent behavior and victimization at school on psychological distress: the role of parents and teachers

This study examined the role of adolescents' interactions with both parents and teachers in the relationship between violent behavior/victimization at school and adolescent psychological distresss (depression and stress). Participants were 983 Spanish adolescents (mean age 13.7 years) from four public schools in the Valencian Community. Statistical analyses were carried out using structural equation modeling. Results showed victimization to be directly and positively related to psychological distress. Moreover, victimization was associated with negative father-adolescent communication, which mediated a part of the influence of victimization on distress. Regarding school-based violent behavior, no direct effect on psychological adjustment was found. Results showed, however, an indirect effect: violent behavior negatively influenced communication with parents and interaction with teachers which, in turn, was related to poor psychological adjustment. This model accounted for 47.7% of the variance in psychological distress. Findings are discussed in relation to previous research on adolescent psychosocial adjustment, and directions for future research are suggested.     

Speech segmentation by statistical learning depends on attention

We addressed the hypothesis that word segmentation based on statistical regularities occurs without the need of attention. Participants were presented with a stream of artificial speech in which the only cue to extract the words was the presence of statistical regularities between syllables. Half of the participants were asked to passively listen to the speech stream, while the other half were asked to perform a concurrent task. In Experiment 1, the concurrent task was performed on a separate auditory stream (noises), in Experiment 2 it was performed on a visual stream (pictures), and in Experiment 3 it was performed on pitch changes in the speech stream itself. Invariably, passive listening to the speech stream led to successful word extraction (as measured by a recognition test presented after the exposure phase), whereas diverted attention led to a dramatic impairment in word segmentation performance. These findings demonstrate that when attentional resources are depleted, word segmentation based on statistical regularities is seriously compromised.