Van Geert Research Articles

An efficient Bayesian observer model of attractive and repulsive temporal context effects when perceiving multistable dot lattices.

In multistable dot lattices, the orientation we perceive is attracted toward the orientation we perceived in the immediately preceding stimulus and repelled from the orientation for which most evidence was present previously (Van Geert, Moors, Haaf, & Wagemans, 2022). Theoretically-inspired models have been proposed to explain the co-occurrence of attractive and repulsive context effects in multistable dot lattice tasks, but these models artificially induced an influence of the previous trial on the current one without detailing the process underlying such an influence (Gepshtein & Kubovy, 2005; Schwiedrzik etal., 2014). We conducted a simulation study to test whether the observed attractive and repulsive context effects could be explained with an efficient Bayesian observer model (Wei & Stocker, 2015). This model assumes variable encoding precision of orientations in line with their frequency of occurrence (i.e., efficient encoding) and takes the dissimilarity between stimulus space and sensory space into account. An efficient Bayesian observer model including both a stimulus and a perceptual level was needed to explain the co-occurrence of both attractive and repulsive temporal context effects. Furthermore, this model could reproduce the empirically observed strong positive correlation between individuals' attractive and repulsive effects (Van Geert etal., 2022), by assuming a positive correlation between temporal integration constants at the stimulus and the perceptual level. To conclude, the study brings evidence that efficient encoding and likelihood repulsion on the stimulus level can explain the repulsive context effect, whereas perceptual prior attraction can explain the attractive temporal context effect when perceiving multistable dot lattices.

Attractor States in Second Language Development

Identifying changing patterns of stability and variability is crucial when examining second language development (SLD) from a complex dynamic systems theory (CDST) perspective (Larsen-Freeman, 2020). By studying attractor states, or recurrent patterns of stability, light can be shed on the underlying dynamics of a complex dynamic system (van Geert & Verspoor, 2015). In the context of SLD, attractor states can be observed in individuals’ linguistic behaviors, as well as learners’ interactions with others (Hiver, 2014; van Geert & Verspoor, 2015). As such, attractor states have been cited in recent SLD literature (e.g., Amerstorfer, 2020; Evans & Larsen-Freeman, 2020; Syed et al., 2021; Gillies & Roger, 2022). The conceptual unpacking of attractor states can therefore be invaluable for SLD scholars seeking to enter the realm of CDST. Accordingly, serving as a stepping stone for those looking to foray into the CDST paradigm, this forum piece offers a definition of attractor state, identifies and describes different types of attractor states, clarifies some possible misconceptions about attractor states, and provides a few examples of attractor states in SLD.

The development of intra-individual variability in academic writing: A study on lexical diversity and lexical sophistication

This study is aimed at finding out (1) whether Lexical Diversity (LD) and Lexical Sophistication (LS) can provide useful insights into the development of academic writing by tracing the interaction between the intra-individual variability in relation to a Dynamic Systems perspective, and (2) whether the supportive interaction between LD and LS can be recognized from the writing development. Twelve academic writing samples written over a 5-year period (2010-2015) by an Indonesian learner of English were employed as longitudinal data. Several tools designed by van Geert and van Dijk (2002), Peltier (2009), and Steinkrauss (2016) were used to analyze the dynamic patterns of language development. The results showed that the development of intra-individual variability in academic writing is in line with the Dynamic Systems Theory as it indicates that the developmental process between the two growers is complex, non-linear, self-organized, unpredictable, revealing attractor states, and constantly changing. The supportive growth movement emerges as the result of the interaction between variables. Finally, it can be concluded that variability is a source of development. Learners might need to be aware of their unique learning trajectory in order to maintain a more stable linguistic development.

Performance Management for Learning, Reform, and Change: A Review of Three Recent Books

ABSTRACTA review essay of Performance Management in the Public Sector, by Wouter Van Dooren, Geert Bouckaert, and John Halligan; Government Performance and Results: An Evaluation of GPRA’s First Decade, by Jerry Ellig, Maurice McTigue, and Henry Wray; and The PerformanceStat Potential: A leadership strategy for producing results, by Robert D. Behn.

Intrinsic dynamics of state self-esteem: The role of self-concept clarity

Change in self-esteem is commonly viewed as random variation or a response to external influence. The present research investigated whether changes in self-esteem are produced instead by the structure of the self-system and thus reflect intrinsic as opposed to extrinsic dynamics. In this view, temporal variability in self-esteem reflects the landscape of attractors and repellers in a person's self-concept. Using a computer mouse procedure (Vallacher, Van Geert, & Nowak, 2015), we recorded 3-min time series of participants' self-esteem and examined whether the temporal patterns stabilized on evaluative states (attractors) or converged on but departed from such states (repellers). We hypothesized and found that participants with higher self-concept clarity (signaling a well-integrated system) had positive self-esteem attractors and weaker self-esteem repellers, whereas those with lower clarity demonstrated less positive self-esteem attractors and stronger self-esteem repellers. Discussion centers on individual variation in self-esteem dynamics and the interplay of exogenous and endogenous sources of self-esteem.

Corporate Venturing: Organizing for Innovation by Jessica van den Bosch and Geert Duysters

<i>Corporate Venturing: Organizing for Innovation</i> by Jessica van den Bosch and Geert Duysters

‘Look closely at what I’m doing!’ Scaffolding in individual string lessons: Two case studies

In this article, we provide a process description of scaffolding in music lessons based on the scaffolding model of Van Geert and Steenbeek (2005). Scaffolding is a form of socially mediated learning in which teacher and student constantly adapt their behavior to one another in order to reach a goal. To illustrate this process, data from video-observations of two teacher-student dyads in Suzuki string lessons were analyzed to see how well this data fits the Van Geert and Steenbeek model. Results show the dynamic connection between amount of instruction and instruction type on the one hand and performance level of the student on the other hand. Results also show that the process of socially mediated learning takes the form of an increasing overlap between student and teacher actions, i.e. an increase of the joint action over time.

Variability in Second Language Development From a Dynamic Systems Perspective

This article illustrates that studying intra‐individual variability in Second Language Development can provide insight into the developmental dynamics of second language (L2) learners. Adopting a Dynamic Systems Theory framework (Thelen &amp; Smith, 1994; van Geert, 1994) and using insights from microgenetic variability studies in developmental psychology (Siegler, 2006), we focus on L2 systems during a time of rapid development, applying advanced visualization techniques. A reinterpretation of a longitudinal study by Cancino et al. (1978) on the use of negation shows nonlinear patterns and peaks of regression, and illustrates the relevance of regarding internal variability as a source of information in itself. A case study of an advanced learner reveals a general increase over time for the correlates included, but the development is nonlinear, showing moments of progress and regress. The case study also brings to light an interesting dynamic interaction of subsystems. In accordance with the assumption of a limitation of resources, the learner shows a variable development for some related measurements in the course of the trajectory.

Dynamic systems in second language learning: Some general methodological reflections

In this rich and provocative article, De Bot, Lowie and Verspoor provide a clear and informative description of the central tenets of dynamic systems theory and apply this to a number of theoretical and empirical issues in second language acquisition. The authors see dynamic systems theory as a promise for the future, an overarching theory in second language acquisition that takes into account the interconnectedness that is so characteristic of complex, developing systems, including the cognitive and social factors that help shape the process of second language acquisition. Having pioneered in dynamic systems for quite some time now (see Van Geert and Steenbeek, 2005, for a recent overview), I cannot be but supportive of their vision and their hope that this particular approach will lead to a fuller understanding of second language acquisition that is not only of theoretical but also of applied importance. However, the authors' remark about “some unresolved issues” in Dynamic Systems Theory may be somewhat over-optimistic. Nevertheless, I consider the dynamic systems approach as the quintessential future approach to human action, cognition and behavior, including language. All these phenomena are about change, about process in time. And this is exactly what dynamic systems approaches provide: an explicit model of change of some phenomenon of interest.

Brief Report: A Theory-of-Mind-based Social-Cognition Training Program for School-Aged Children with Pervasive Developmental Disorders: An Open Study of its Effectiveness

Children with pervasive developmental disorders (PDD) are impaired by early onset difficulties in reciprocal social interaction. It has been proposed that this social impairment is the result of a lack of Theory of Mind (ToM): the ability to attribute mental states (e.g., beliefs, desires, intentions, and emotions) to others and to use these in predicting and explaining the behavior of others (Baron-Cohen, 1995; Serra et al., 1995). Research has shown that this ability is seriously impaired in autistic children (Baron-Cohen, Leslie, & Frith, 1985), and moderately impaired in children with Pervasive Developmental Disorders, Not Otherwise Specified (PDD-NOS) (Baron-Cohen & Swettenham, 1997; Happe, 1995; Perner & Wimmer, 1985). This impairment may limit PDD-NOS children in their understanding of humor and irony, and restrict their ability to take into account the interests and knowledge of a partner in social conversation (Serra, Loth, van Geert, Hurkens, & Minderaa, 2002). The hypothesis that an underdeveloped ToM underlies social impairment in PDD-children has led to the development of social skill interventions targeted at improving ToM-abilities. Ozonoff and Miller (1995) were the first to develop a group-based social-skills training, that has been evaluated in a controlled study with five adolescents (mean age: 13.8 [SD: 0.24]; Full Scale IQ scores above 70) participating in treatment and four adolescents in a no-treatment control group. Within two weeks, post intervention meaningful change was found in the treatment group’s performance on four false belief tasks (MM SecondOrder Belief Attribution Task, Baron-Cohen, 1989; Overcoat Story, Bowler, 1992; Prisoner Story, Happe, 1994), and no improvement in the control sample. No changes, however, were demonstrated on parent and teacher ratings of social competence for either group. Steerneman, Jackson, Pelzer, and Muris (1996) developed a program for children with social handicaps, including children with PDD (Steerneman et al., 1996). The program is developed for children with a range of social problems, but its effectiveness has only been examined in a study with eight children (age 6–8 years) with relatively mild social anxiety and social aggression (Steerneman et al., 1996). No children with PDD were involved in this study. Full scale IQ’s varied between 88 and 112. Before the training, directly after completion and four months after completion, emotion recognition (Test of perception of emotion from facial expression & Test of perception of emotion from posture cues, Spence, 1980) and ToM (Sally and Anne-test, Wimmer & Perner, 1983; pencil and Smarties box-task, Perner & Wimmer, 1985) were assessed in the children. At the same times social skills as reported by teachers and parents were evaluated. Compared to controls 1 Department of Child and Adolescent Psychiatry, Academic Medical Centre, Amsterdam, The Netherlands. 2 de Bascule, Academic Centre for Child and Adolescent Psychiatry, Amsterdam, The Netherlands. 3 Correspondence should be addressed to: Carolien Gevers, AMC – Dept Child Adol Psychiat./de Bascule, P.O. Box 12474, 1100 AL, Amsterdam, The Netherlands; Tel: +31-20-6501500; E-mail: c.gevers@debascule.com

Growth of Cognitive Abilities: Dynamic Models and Scaling

A dynamic model of cognitive growth, proposed by van Geert, has been extended in three different directions. (A) A term has been added to take into account external driving forces, that is, exposure to material to be learned. (B) A method has been developed to apply the model to cross-sectional studies. (C) Using ideas of Item Response Theory, a procedure has been developed to use the model to scale tests of cognitive abilities that consist of questions of varying difficulty. The model we use is an attempt to understand cognitive growth as the result of two driving forces: namely, the autocatalytic force proposed by van Geert that is due to processes internal to the person, while the other force is an external force and due to exposure to the material to be learned. Using the model, it is possible to derive a distribution function, g(d;t), that gives the fraction of correct responses by examinees of age t to questions of difficulty d. The model is tested by fitting the theoretical distribution function with the observed distribution of scores obtained by the testing of a large group of children ages 2 to 15 years on a Stanford–Binet test.

A Dynamic Model of Cognitive Growth in a Population: Spatial Tasks and Conservation

A dynamic model of cognitive growth is developed that is applicable to cross-sectional studies of growth in a population, and that predicts the distribution of scores as a function of age. This model modifies the theory of P. van Geert (1991,Psychological Review,98, 3–53) for the cognitive growth of an individual under limited resources, by taking into account the effect of schooling or training. The modified theory provides an explanation for the puzzling effect reported by C. J. Brainerd (1977,Psychological Bulletin,84, 919–939), that the gain in scores obtained in concept training experiments is independent of the initial state of the learner. In developing the modified theory, it was found that the assumption of delayed feedback is unnecessary. To apply the model to populations, it was assumed that the ability parameters that appear in the growth function are distributed normally in the population. A distribution functionG(s;t) was derived that predicts the distributions of scoressat agetin terms of a small number of parameters. Although the abilities are assumed to be distributed normally, the score distributions are often bimodal. The model was applied to the studies of H. Thomas and A. Lohaus (1993,Monographs of the Society for Research in Child Development,58, 1–169) on the growth of the concepts of verticality and horizontality, and to the study of P. M. Bentler (1970,Perceptual and Motor Skills,31, 855–859) on the growth of the concept of conservation. In these applications the score distributions are clearly bimodal, but there is no evidence of abrupt transitions or catastrophes. This shows that the presence of a “catastrophe flag” (bimodal distributions) does not necessarily imply the presence of a catastrophe.

Modeling Historical Development: Fitting a Competing Practices System to Coded Archival Data

This project used curve fitting to refine an ecological model of historical development. Dirlam (1972, 1980, and 1996) constructed multidimensional classifiers for coding sociocultural practices by using theories of children's drawing, students' writing, and developmental researchers' methods. The last involved an eleven-dimensional classifier based mostly on Danziger's (1990) insights. An NDS analysis began with Van Geert's (1991) variant of the Lotka-Volterra two-species model, which was generalized by Dirlam (1997) to many competing species, each embodying an evolutionary strategy. Excellent fits to codings of research strategies in 599 articles from Child Development and Developmental Psychology, 1969-1992, revealed chaotic growth unless suppressed by new strategies. In this paper, coding was extended to 313 new articles published from 1930-1968. A refined model using Levins' (1969) “logistic weed” produced more meaningful parameter values and suggested dynamic differences between evolutionary strategies and sociocultural practices. Statistically adequate solutions with both low growth and high growth were found. To differentiate solutions, we proposed independent experimental testing and examining the scientific meaning of parameter values. The analysis identified two novel dynamic entities: default and polarized practices. Removing the person-practice link and coding many dimensions at once extends dynamic modeling to a greatly enriched variety of cultural and historical processes.

From pragmatics to syntax: Modality in second language acquisition Ed. by Anna Giacalone Ramat and Grazia Crocco Galeas (review)

220 LANGUAGE, VOLUME 74, NUMBER 1 (1998) language. This volume is a collection of chapters on the application ofdynamics to various aspects ofcognition . In the introduction, the editors outline the approach , suggesting that its real strength lies in the ability to account for processes and contexts which unfold continuously and simultaneously in real time (1-43). Such an account lays the groundwork not only for the explanation ofcognitive phenomena, but also for their implementation in a dynamic neural substrate and for their embeddedness in human bodies and the physical environment. Language is the subject of many of the chapters. In 'Dynamics and coordinate systems in skilled sensorimotor activity', Elliot L. Saltzman explores task dynamics for speech production (149-73). The model he uses is integrated with the model ofCatherine P. Browman and Louis Goldstein in the following chapter, 'Dynamics and articulatory phonology' (175-93). Human natural language processing is the subject of a chapter by Jeffrey L. Elman entitled 'Language as a dynamical system' (195-225). Jean Petitot combines the perspective of cognitive grammar with work by René Thom in 'Morphodynamics and attractor syntax: Constituency in visual perception and cognitive grammar' (227-81). In a paper reprinted from Machine learning , Jordan B. Pollack investigates "The induction of dynamical recognizers' (283-312). In the following chapter, 'Growth dynamics in development', Paul van Geert models the child's lexicon (313-37). Finally, a paper by Robert F. Port, Fred Cummins, and J. Devin McAuley looks at temporal information in audition ('Naive time, temporal patterns , and human audition', 339-71). Many of the papers make use of mathematics beyond the level most linguists are comfortable with. A chapter by Alec Norton (45-68) sketches some of the background, but the serious reader will want to supplement this chapter with other books; Mind as motion has a guide to further reading at the end of each chapter. Recognizing the potential difficulty ofthe subject, the editors have also provided an introduction to each chapter and a glossary of terms (573-77). Contributions on other topics in cognition allow the reader to get a feeling for the scope and unity of the dynamical approach. These chapters are: Esther Thelen, 'Time-scale dynamics and the development of an embodied cognition' (69-100); James T. Townsend and Jerome Busemeyer, 'Dynamic representation of decision-making' (101-20); Randall D. Beer, 'Computational and dynamical languages for autonomous agents' (121-47); M. T. Turvey and Claudia Carello, 'Some dynamical themes in perception and action' (373-401); Geoffrey P. Bingham, 'Dynamics and the problem ofvisual event recognition' (403-48); Stephen Grossberg, 'Neural dynamics ofmotion perception, recognition learning, and spatial attention' (449-89); Mary Ann Metzger , 'Multiprocess models applied to cognitive and behavioral dynamics' (491-526); Steven P. Reidbord and Dana J. Redington, "The dynamics of mind and body during cUnical interviews: Research trends, potential, and future directions' (527-47); and Marco Giunti, 'Dynamical models of cognition ' (549-71). Mind as motion is a difficult but rewarding book which outlines and exemplifies a powerful alternative to the computational approach in cognitive science . It is highly recommended for anyone with an interest in language as a cognitive phenomenon. [William J. Turkel, University of British Columbia .] From pragmatics to syntax: Modality in second language acquisition. Ed. by Anna Giacalone Ramat and Grazia Crocco Galeas. (Tübinger Beiträge zur Linguistik.) Tübingen: Gunter Narr Verlag, 1995. Pp. vii, 440. This volume comprises papers presented at a conference held at the University ofPaviain 1993. It contains abriefintroductionbytheeditors, 21 articles, and asubjectindex. SixofthecontributionsareinEnglish, three in French, and thirteen in Italian (with no summary or abstract in another language provided). Most of the papers deal with modality in Italian, but other languages are also considered in the contributions by Grazia Crocco Galeas (Modern Greek), Daniel Véronique (French andFrench-basedcreóles), Monique Lambert (English, French), Mireille Prodeau (French, German), and Norbert Dittmar and Bernt Ahrenholz (German). As is often the case with a collection of conference papers, the content is not tightly coherent. The first ofthe three sections is mainly concerned with general theoretical and descriptive issues in the study of modality . The second is devoted to modality in first language acquisition and to the similarities and differences...

Childhood Stress and Family Environment

L'etude menee aupres des enfants d'un village rural sur la cote orientale de Dominique montre la relation entre le stress et la composition du groupe domestique (âge, sexe, relation intergenerationnelle, nombre de personnes). Les enfants vivant dans des foyers ou prendre soin d'eux est une attitude frequente et stable ont un niveau de cortisol modere contrairement aux enfants connaissant des evenements familiaux traumatiques

De Waarneming van Klemtoon bij NT2-Studenten

Recently several research groups that are concerned with language acquisition have claimed, that suprasegmental information contributes to the learnability of natural languages. Specifically, it is claimed, that suprasegmentals enable the language learner to perceive and distinguish linguistic patterns in the stream of speech (Morgan et al, 1987; Mehler et al, 1988; Hirsch-PAsek, 1987). It has been shown, that suprasegmentals are immediately accessable to babies and require no learning process. This finding is compatible with psychological research that has shown, that the sensoric system of babies structures perception immediately after birth (see Van Geert, 1983 for an overview). The present study deals with the use of suprasegmentals in adult second language learners. For several reasons it may be wondered whether adults have the same benefit from suprasegmentals like newborns. Therefore an experiment is conducted in order to investigate the ability of adult second language learners to distinguish several stress-patterns in Dutch. Several stress-patterns in two- and three syllabic words were investigated. The results indicate, that both groups of second language learners use a lexical and a perceptual strategy, that in the case of Level 1 students leads to a confusion of perceptual and lexical strategies, whereas Level Π students appear to seperate these strategies in a more appropriate way. The results are discussed in the perspective of language teaching. It is concluded, that the development of perceptual strategies need more attention in the classroom, since they might enable the student more effectively to explore a second language in communicative situations.

The Future of Dynamic Systems Models in Developmental Psychology in the Light of the Past

A compact glance at the history and impact of mathematical models in development provides background for predicting the fate of dynamical systems modeling in developmental psychology. Dynamic models are considered and the articles by Thelen and Ulrich (1991) and van Geert (1991) are summarized. Deterministic and probabilistic models are compared and some cautions are presented along with a consideration of forms that can be attained by linear models in comparison to those well known in logistic difference models. Reactions to the research by Rabinowitz, Grant, Howe, and Walsh; Kreindler and Lumsden; and Cooney and Troyer are given, with some concluding remarks on survival of dynamical systems modeling in developmental psychology.

Perceiving Objects Across Gaps in Space and Time

guage Development, N.A. Krasnegor, D.M. Rum baugh, M. Studdert-Kennedy, and R.L. Schiefel busch, Eds. (Erlbaum, Hillsdale, NJ, 1991). 5. E. Thelen, Dynamical systems and the gen eration of individual differences, in Individual Dif ferences in Infancy: Reliability, Stability, and Predic tion, J. Colombo and J.W. Fagen, Eds. (Erlbaum, Hillsdale, NJ, 1990). 6. E. Thelen and B.D. Ulrich, Hidden skills: A dynamic systems analysis of treadmill stepping dur ing the first year, Monographs of the Society for Re search in Child Development, 56(1, Serial No. 223, 1991). 7. E. Thelen, D. Corbetta, K. Kamm, J.P. Spen cer, K. Schneider, and R.F. Zernicke, The transition to reaching: Mapping intention and intrinsic dynam ics, Child Development (in press). 8. L.B. Smith and E. Thelen, Eds., Dynamic Sys tems in Development: Applications (MIT Press, Cambridge, MA, in press). 9. L.B. Smith and M.D. Sera, A developmental analysis of the polar structure of dimensions, Cog nitive Psychology, 24, 99-142 (1992). 10. P. van Geert, A dynamic systems model of cognitive and language growth, Psychological Re view, 98, 3-53 (1991). 11. S.S. Robertson, Behavioral chaos: Beyond the metaphor, in Dynamic Systems in Development: Applications, L.B. Smith and E. Thelen, Eds. (MIT Press, Cambridge, MA, in press).

The Structure of Gal’perin’s Model of the Formation of Mental Acts

An analysis of the underlying structure of Gal’perin’s model of the formation of mental acts is presented, based on a generative method developed by van Geert in 1987. First, an overview of Gal’perin’s five-stage model is given. Then, two analyses of the underlying state and sequence rules are presented, one according to a prospective, another according to a retrospective strategy. It is concluded that a retrospective strategy yields the best result. It is argued that the five-stage model should be viewed as a particular transformation of an underlying model of four main stages, each including four substages. Finally, an analysis of the transition rules is given. It includes a model of transitions and process components and a model of a transition topology. The topology is a structure of overlapping domains. The particular form of the overlap accounts for the stepwise and controlled character of the formation of a mental act.