Investigating speech motor practice and learning in people who stutter

In this exploratory study, we investigated whether or not people who stutter (PWS) show motor practice and learning changes similar to those of people who do not stutter (PNS). To this end, five PWS and five PNS repeated a set of non-words at two different rates (normal and fast) across three test sessions (T1, T2 on the same day and T3 on a separate day, at least 1 week apart). The results indicated that PWS and PNS may resemble each other on a number of performance variables (such as movement amplitude and duration), but they differ in terms of practice and learning on variables that relate to movement stability and strength of coordination patterns. These findings are interpreted in support of recent claims about speech motor skill limitations in PWS.

Educational objectives: The reader will be able to: (1) define oral articulatory changes associated with motor practice and learning and their measurement; (2) summarize findings from previous studies examining motor practice and learning in PWS; and (3) discuss hypotheses that could account for the present findings that suggest PWS and PNS differ in their speech motor learning abilities.     

Modelling relations between sensory processing, speech perception, orthographic and phonological ability, and literacy achievement

The general magnocellular theory postulates that dyslexia is the consequence of a multimodal deficit in the processing of transient and dynamic stimuli. In the auditory modality, this deficit has been hypothesized to interfere with accurate speech perception, and subsequently disrupt the development of phonological and later reading and spelling skills. In the visual modality, an analogous problem might interfere with literacy development by affecting orthographic skills. In this prospective longitudinal study, we tested dynamic auditory and visual processing, speech-in-noise perception, phonological ability and orthographic ability in 62 five-year-old preschool children. Predictive relations towards first grade reading and spelling measures were explored and the validity of the global magnocellular model was evaluated using causal path analysis. In particular, we demonstrated that dynamic auditory processing was related to speech perception, which itself was related to phonological awareness. Similarly, dynamic visual processing was related to orthographic ability. Subsequently, phonological awareness, orthographic ability and verbal short-term memory were unique predictors of reading and spelling development.     

Substantive and procedural norms in normative multiagent systems

Procedural norms are instrumental norms addressed to agents playing a role in the normative system, for example to motivate these role playing agents to recognize violations or to apply sanctions. Procedural norms have first been discussed in law, where they address legal practitioners such as legislators, lawyers and policemen, but they are discussed now too in normative multiagent systems to motivate software agents. Procedural norms aim to achieve the social order specified using regulative norms like obligations and permissions, and constitutive norms like counts-as obligations. In this paper we formalize procedural, regulative and constitutive norms using input/output logic enriched with an agent ontology and an abstraction hierarchy. We show how our formalization explains Castelfranchi's notion of mutual empowerment, stating that not only the agents playing a role in a normative system are empowered by the normative system, but the normative system itself is also empowered by the agents playing a role in it. In our terminology, the agents are not only institutionally empowered, but they are also delegated normative goals from the system. Together, institutional empowerment and normative goal delegation constitute a mechanism which we call delegation of power, where agents acting on behalf of the normative system become in charge of recognizing which institutional facts follow from brute facts.     

How Should We Do Nanoethics? A Network Approach for Discerning Ethical Issues in Nanotechnology

There is no agreement on how nanoethics should proceed. In this article I focus on approaches for discerning ethical issues in nanotechnology, which is as of yet one of the most difficult and urging tasks for nanoethics. I discuss and criticize two existing approaches for discerning ethical issues in nanotechnology and propose a network approach as alternative. I discuss debates in nanoethics about the desirable role of ethics in nanotechnological development and about the newness of ethical issues in nanotechnology. On basis of a critical analysis of both debates, I formulate a number of desiderata for a method for discerning ethical issues in nanotechnology and argue that the network approach that my colleagues and I have developed for ethical issues in research and development networks is also appropriate in nanotechnology.

“When Strangers Meet”: John Bowlby and Harry Harlow on Attachment Behavior

From 1957 through the mid-1970s, John Bowlby, one of the founders of attachment theory, was in close personal and scientific contact with Harry Harlow. In constructing his new theory on the nature of the bond between children and their caregivers, Bowlby profited highly from Harlow’s experimental work with rhesus monkeys. Harlow in his turn was influenced and inspired by Bowlby’s new thinking. On the basis of the correspondence between Harlow and Bowlby, their mutual participation in scientific meetings, archival materials, and an analysis of their scholarly writings, both the personal relationship between John Bowlby and Harry Harlow and the cross-fertilization of their work are described.

Rigorous Experiments on Monkey Love: An Account of Harry F. Harlow’s Role in the History of Attachment Theory

On the basis of personal reminiscences an account is given of Harlow’s role in the development of attachment theory and key notions of attachment theory are being discussed. Among other things, it is related how Harlow arrived at his famous research with rhesus monkeys and how this made Harlow a highly relevant figure for attachment theorist Bowlby.

Interactive effects of work group and organizational identification on job satisfaction and extra-role behavior

Past research has focused on the differential relationships of organizational and work group identification with attitudes and behavior. However, no systematic effort has been undertaken yet to explore interactive effects between these foci of identification. We predicted that in cases of positive overlap of identifications (i.e. high work group and organizational identification) identifications are more strongly associated with employee job satisfaction and extra-role behavior than when only one of the identifications is high—that is, the one identification augments the influence of the other. These hypotheses were tested and supported with data from two samples of bank employees (N = 358) and travel agency employees (N = 308).     

Positive and negative effects of family involvement on work-related burnout

We aimed to explain the influence of family involvement on feelings of burnout among employees who combine work and family tasks. As proxies for family involvement, we used the family structure (partner, number and age of children) and family tasks (e.g. hours spent on household chores). We compared conflict theory and enrichment theory, and investigated how well they explain the relationship between family involvement and feelings of burnout. Based on a sample of 1046 employees at 30 Dutch organizations, the results showed that the presence of young children and doing more household chores were positively related to feelings of burnout, whereas having children reduced employees’ feelings of burnout. We also investigated interaction effects of gender and gender-role norms. We conclude that family life can reduce work-related burnout and that for men, the relationship between family involvement and feelings of burnout differs depending on whether they have traditional or modern gender-role norms.     

An information-based approach to action understanding

It has been proposed that the ability to make sense of other agents' behavior relies on the activation of internal mechanisms that map action perception onto action execution. In this study we explored the constraints on this ability introduced by eyeheight-scaled information in the optic array. Short and tall participants provided maximum overhead reaching judgments for themselves and another participant. Perceptual information was manipulated by changing the participants' optically specified eyeheight. Observers were modestly accurate in perceiving maximum overhead reach for themselves and for another actor whose action capabilities differed. Perceived maximum overhead reach increased for both self- and other-judgments when the perceiver's eyeheight was increased. The results suggest an important role of perceptual information that has gone unrecognized in existing accounts of action understanding and prediction.     

A computational model of spatial visualization capacity

Visualizing spatial material is a cornerstone of human problem solving, but human visualization capacity is sharply limited. To investigate the sources of this limit, we developed a new task to measure visualization accuracy for verbally-described spatial paths (similar to street directions), and implemented a computational process model to perform it. In this model, developed within the Adaptive Control of Thought-Rational (ACT-R) architecture, visualization capacity is limited by three mechanisms. Two of these (associative interference and decay) are longstanding characteristics of ACT-R’s declarative memory. A third (spatial interference) is a new mechanism motivated by spatial proximity effects in our data. We tested the model in two experiments, one with parameter-value fitting, and a replication without further fitting. Correspondence between model and data was close in both experiments, suggesting that the model may be useful for understanding why visualizing new, complex spatial material is so difficult.