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In social interactions, humans tend to naturally synchronize their body movement, a process thought to reflect individual differences such as personality and to influence the way those encounters are appraised. In a 15-minute semi-structured conversation 56 previously-unfamiliar dyads introduced themselves, followed by self-disclosing and argumentative conversations, while their bodily movements were video-recorded in a standardized room (112 young adults, aged 18-33, mean= 20.54, SD= 2.74; 58% Dutch, 31% German, 11% other). Interpersonal bodily synchronization was estimated as (a) synchronization strength using Windowed Lagged Cross-Correlations and (b) Dynamic Organization (Determinism/Entropy/Laminarity/Mean Line) using Cross-Recurrence Quantification Analysis. Bodily synchronization was associated with differences in Agreeableness and Extraversion (IPIP-NEO-120) and post-conversational appraisals (affect/closeness/enjoyment) in mixed-effects models. Agreeable participants exhibited higher complexity in bodily synchronization dynamics (higher Entropy) than disagreeable individuals, who also reported more negative affect afterward. Interpersonal synchronization was stronger among extraverts than among introverts, and extraverts appraised conversations as more positive and enjoyable. Bodily synchronization strength and dynamic organization were related to the type of conversation (self-disclosing or argumentative). Interpersonal dynamics were intimately connected to differences in Agreeableness and Extraversion, varied across situations, and these parameters affected how pleasant, close, and enjoyable each conversation felt.

In this paper we investigated if keeping the driver in the perception–action loop during automated driving can improve take-over behavior from conditionally automated driving. To meet this aim, we designed an experiment in which visual exposure (perception) and manual control exposure (action) were manipulated. In a dynamic driving simulator experiment, participants (n = 88) performed a non-driving related task either in a head-up display in the windshield (high visual exposure) or on a head-down display near the gear shift (low visual exposure). While driving, participants were either in an intermittent control-mode with four noncritical take-over situations (high manual control exposure), or in a continuous automation-mode throughout the ride (low manual control exposure). In all conditions, a critical take-over had to be carried out after an approximately 13 min ride. Measurements of take-over behavior showed that only high visual exposure had an effect on hands-on reaction time measurements. Both visual exposure and manual control exposure had small to medium sized main effects on time to system deactivation, the maximum velocity of the steering wheel, and the standard deviation of the steering wheel angle. The combined high visual – and high manual control exposure condition led to 0.55 s faster reaction time and 37% less steering variability in comparison to the worst case low visual – and low manual control exposure condition. Together, results corroborate that maintaining visual exposure and manual control exposure during automated driving can be efficacious and suggest that their positive effects are additive.

In the current study we investigated if drivers of conditionally automated vehicles can be kept in the loop through lane change maneuvers. More specifically, we examined whether involving drivers in lane-changes during a conditionally automated ride can influence critical take-over behavior and keep drivers' gaze on the road. In a repeated measures driving simulator study (n = 85), drivers drove the same route three times, each trial containing four lane changes that were all either (1) automated, (2) semi-automated or (3) manual. Each ride ended with a critical take-over situation that could be solved by braking and/or steering. Critical take-over reactions were analyzed with a linear mixed model and parametric accelerated failure time survival analysis. As expected, semi-automated and manual lane changes throughout the ride led to 13.5% and 17.0% faster maximum deceleration compared to automated lane changes. Additionally, semi-automated and manual lane changes improved the quality of the take-over by significantly decreasing standard deviation of the steering wheel angle. Unexpectedly, drivers in the semi-automated condition were slowest to start the braking maneuver. This may have been caused by the drivers' confusion as to how the semi-automated system would react. Additionally, the percentage gaze off-the-road was significantly decreased by the semi-automated (6.0%) and manual (6.6%) lane changes. Taken together, the results suggest that semi-automated and manual transitions may be an alarm-free instrument which developers could use to help maintain drivers' perception-action loop and improve automated driving safety.

Art is known to give rise to a large range of emotions in people. These emotions are associated with bodily sensations felt in various regions of the body and subjective feelings. The current study applies Bodily Sensation Maps (BSMs, Nummenmaa et al., 2014) as a tool to measure art-elicited emotions by charting bodily sensations onto a body map. Through a web survey, 90 participants viewed 36 digital artworks. After each artwork, they were asked (1) to point out the regions of their body in which they felt strong or weak activity, (2) to select, if appropriate, up to two primary emotional words being anger, disgust, fear, happiness, sadness or surprise, and (3) to rate the intensity of the subjective feeling on a continuous scale. By allowing two primary emotional words for each artwork, participants could report more complex emotions. Results show that BSMs are a resourceful method to investigate simple and complex emotions elicited by art in terms of bodily sensations and subjective feelings. Interestingly, we found that art-elicited emotions were always characterized by increased activity in the head area. This might indicate a cognitive effort which is typically associated with artistic encounters. This study provides novel insights into the nature of art-elicited emotions and how they are experienced in the body, as well as how they are related to emotions in everyday life.

Two experiments and a model on limb selection are reported. In Experiment 1 left-handed and right-handed participants (N = 36) repeatedly used one hand for grasping a small cube. After a clear switch in the cube’s location, perseverative limb selection was revealed in both handedness groups. In Experiment 2 the cubes were presented in a clockwise and counter-clockwise sequence to right-handed participant (N = 15). A spatial delay in the switch point between right-hand use and left-hand use was observed. The model simulates the experiments, by implementing the multiple-timescale dynamics of the action-selection process underlying limb selection. It integrates two mechanisms that were earlier proposed to underlie this selection aspect of manual activity: limb dominance and attentional information. Finally, the model is used to simulate Gabbard et al.’s (1997) experiment, offering a concise coupling of strength and direction of handedness.

The psychophysical description of one of the pillars of color science, the color-matching paradigm, forms the basis of the representation theory of colors. This description entails the weighted integration of a spectral distribution of radiant energy (i.e. a light ray) with three color-matching functions. Here these color-matching functions are conceptualized as a vector-valued measure , which grounds the representation theory of colors in the mathematical frameworks of measure theory and functional analysis. Properties like the convexity and compactness of the tristimulus space follow readily from this color-matching measure model. Notably, the model quite naturally encapsulates metamerism as -equivalence classes of spectral distributions. A subsequent extension of the model to object colors results in similar properties for the object color solid. Also following from this extension is a novel expression for optimal colors. This entails both a comprehensive mathematical formulation of these colors as well as a practical calculation tool for their reflection coefficients.

Item does not contain fulltext This study investigated the developing ability of children to identify emotional facial expressions in terms of the contexts in which they generally occur. We presented Dutch 6- to 9-year-old primary school children (N = 164, 98 girls) prototypical contexts for different emotion categories and asked them whether different kinds of facial expressions belonged to those contexts or not, using a 2-alternative forced-choice task. Correct and incorrect responses were quantified into a single index using signal detection theory, representing children's sensitivity to perceive each facial expression as categorically different from each of the others in terms of their prototypical contexts. Results show age-related improvements in identifying facial expressions as belonging to their prototypical contexts. In addition, we found that older children not only made less misidentifications but also misidentified less kinds of facial expressions to the prototypical contexts. Furthermore, the kinds of misidentifications children made suggest that they do not identify facial expressions based on their conceptual emotional valence. Results were discussed from a perceptual learning account. 13 p.

In the current study, we applied the dynamical systems approach to obtain novel insights into resilience losses. Dyads (n = 42) performed a lateral rhythmical pointing (Fitts) task. To induce resilience losses and transitions in performance, dyads were exposed to ascending and descending scoring scenarios. To assess changes in the complexity of the dyadic pointing performance, reflecting their resilience, we performed cross-recurrence quantification analyses. Then, we tested for temporal patterns indicating resilience losses. We applied lag 1 autocorrelations to assess critical slowing down and mean squared successive differences (MSSD) to assess critical fluctuations. Although we did not find evidence that scoring scenarios produce performance transitions across individuals, we did observe transitions in each condition. Contrary to the lag 1 autocorrelations, our results suggest that transitions in human performance are signaled by increases in the MSSD. Specifically, both positive and negative performance transitions were accompanied with increased fluctuations in performance. Furthermore, negative performance transitions were accompanied with increased fluctuations of complexity, signaling resilience losses. On the other hand, complexity remained stable for positive performance transitions. Together, these results suggest that combining information of critical fluctuations in performance and complexity can predict both positive and negative transitions in dyadic team performance.

BACKGROUND: Dog-assisted therapy (DAT) is hypothesized to help children with autism spectrum disorder (ASD) and Down syndrome (DS).METHODS: The present authors compared synchronous movement patterns of these children (n = 10) and their therapy dogs during the first and last session of a DAT programme, and their post-therapy changes in emotional and behavioural problems.RESULTS: The present authors found a significant increase in synchrony between child and therapy dog over time. Exploratory analyses suggest more synchrony between children with ASD and their therapy dogs, compared to the children with DS.CONCLUSIONS: This study is the first to test the synchrony hypothesis, shedding light upon a mechanism that may underlie the effect of DAT and how this may be different for children with ASD and DS.

Item does not contain fulltext In the weaning period, infants are introduced to solid food after being fed solely on milk, which involves a deliberate reorganization of the infant-caregiver feeding interaction. This multiple case study, involving 5 dyads with 10 repeated observations, analyzed its dynamical structure using Cross-Recurrence Quantification Analysis. The results showed that an optimal interaction occurs when the caregiver is leading by roughly 1-2 seconds. During the weaning period, all dyads showed signs of increased synchronization, although there are interesting differences between dyads. These findings indicate that infant-caregiver dyads co-regulate their behavior within a relatively short period. 7 p.

Children move their hands to explore, learn and communicate about hands-on tasks. Their hand movements seem to be “learning” ahead of speech. Children shape their hand movements in accordance with spatial and temporal task properties, such as when they feel an object or simulate its movements. Their speech does not directly correspond to these spatial and temporal task properties, however. We aimed to understand whether and how hand movements' are leading cognitive development due to their ability to correspond to spatiotemporal task properties, while speech is unable to do so. We explored whether hand movements' and speech's variability changed with a change in spatiotemporal task properties, using two variability measures: Diversity indicates adaptation, while Complexity indicates flexibility to adapt. In two experiments, we asked children (4–7 years) to predict and explain about balance scale problems, whereby we either manipulated the length of the balance scale or the mass of the weights after half of the trials. In three out of four conditions, we found a change in Complexity for both hand movements and speech between first and second half of the task. In one of these conditions, we found a relation between the differences in Complexity and Diversity of hand movements and speech. Changes in spatiotemporal task properties thus often influenced both hand movements' and speech's flexibility, but there seem to be differences in how they did so. We provided many directions for future research, to further unravel the relations between hand movements, speech, task properties, variability, and cognitive development.

Researchers from the complex dynamical systems perspective seek their explanations of human behavior and development in the dynamical interactions across many levels in an active, situated individual. Tat is to say, behavior and development are both constraining and constrained by the continuous exchange between a myriad of processes distributed across brain, body, and environment. This fundamentally questions the more traditional rationale that behavior and development of any kind can be explained by targeting a low number of domain-specific, static components or environmental factors. In such a mechanistic approach, components are typically thought to exert their causal effects in a chain-like fashion, and development is explained by the function and place of the components in the chain. However, compiling evidence demonstrates that human behavior and development are dynamic, multi-scaled, and emergent phenomena. It is for this reason that they should be studied from a complex dynamical systems perspective.

Contains fulltext : 207431.pdf (Publisher’s version ) (Open Access) From a perceptual learning perspective, infants use social information (like gaze direction) in a similar way as other information in our physical environment (like object movements) to specify action possibilities. In the current study, we assumed that infants are able to learn an affordance upon observing an adult failing to act out that affordance, without appreciating object-directed intentions, or, communicative intent towards the infant. Using a variation of the Re-enactment procedure, we found that when the attention of infants (N = 46, Mage = 20 months) was drawn towards the eyes of the person before she acted out the failed attempt, either by ostensive cues or non-ostensive cues, infants achieved more affordances than 15 when their attention was not directed towards the eyes. As directing the attention of infants to the eyes of another person frequently results in gaze following, this suggests that infants use the gaze direction of another person in order to learn what affordance that other person is trying to realize. In addition, the results of a spatiotemporal analysis on the eye-movements of infants suggest that the gaze and the object movements of the person facilitate learning by directing the attention of infants towards important object-directed actions on crucial moments during the failed attempt demonstrations. These results are discussed in terms of perceptual attunement and affordance learning. 27 juni 2019 21 p.

This study presents an empirical test and dynamic model of perseverative limb selection in children of 14‐, 24‐, and 36‐months old (N = 66 in total). In the experiment, children repeatedly grasped a spoon with a single hand. In two separate conditions, the spoon was presented either four times on their right side or four times on their left side. In both conditions, following this training, the spoon was presented on midline for two more trials. This setup enabled us to determine whether children's limb selection was influenced by their prior choices in the task (i.e., perseveration). Individual children's handedness was determined in a third condition consisting of nine object presentations (laterally or on midline). A dynamic model for limb selection is presented combining external input, motor memory, and preferences. The model was used to simulate the experiment and reproduced the results, including the age‐related changes.

International audience; This study on psychological momentum (PM) in sports provides the first experimental test of an intercon-nection between short-term PM (during a match) and long-term PM (across a series of matches). Twenty-two competitive athletes were striving to win a prize during a rowing-ergometer tournament, consisting of manipulated races. As hypothesized, athletes who had developed long-term positive PM after two successful races were less sensitive to a negative momentum scenario in the third race, compared with athletes who had developed long-term negative PM after two unsuccessful races. More specifically, the exerted efforts, percep-tions of momentum, and self-efficacy were higher for participants who had developed long-term positive PM, and their perceptions of momentum and self-efficacy decreased less rapidly. These results illustrate a typical complex dynamical systems property, namely interconnected time scales, and provide deeper insights into the dynamical nature of PM.

Contains fulltext : 168142.pdf (Publisher’s version ) (Closed access) PURPOSE: This study aimed to examine the controllability of cylinder-shaped and dome-shaped magnifiers in young children with visual impairment. METHODS: This study investigates goal-directed arm movements in low-vision aid use (stand and dome magnifier-like object) in a group of young children with visual impairment (n = 56) compared to a group of children with normal sight (n = 66). Children with visual impairment and children with normal sight aged 4-8 years executed two types of movements (cyclic and discrete) in two orientations (vertical or horizontal) over two distances (10 cm and 20 cm) with two objects resembling the size and shape of regularly prescribed stand and dome magnifiers. RESULTS: The visually impaired children performed slower movements than the normally sighted children. In both groups, the accuracy and speed of the reciprocal aiming movements improved significantly with age. Surprisingly, in both groups, the performance with the dome-shaped object was significantly faster (in the 10 cm condition and 20 cm condition with discrete movements) and more accurate (in the 20 cm condition) than with the stand-shaped object. CONCLUSION: From a controllability perspective, this study suggests that it is better to prescribe dome-shaped than cylinder-shaped magnifiers to young children with visual impairment. 7 p.

The aim of this study was to examine (1) the temporal structures of variation in rowers’ (natural) ergometer strokes to make inferences about the underlying motor organization, and (2) the relation between these temporal structures and skill level. Four high-skilled and five lower-skilled rowers completed 550 strokes on a rowing ergometer. Detrended Fluctuation Analysis was used to quantify the temporal structure of the intervals between force peaks. Results showed that the temporal structure differed from random, and revealed prominent patterns of pink noise for each rower. Furthermore, the high-skilled rowers demonstrated more pink noise than the lower-skilled rowers. The presence of pink noise suggests that rowing performance emerges from the coordination among interacting component processes across multiple time scales. The difference in noise pattern between high-skilled and lower-skilled athletes indicates that the complexity of athletes’ motor organization is a potential key characteristic of elite performance.

Insight into the typical motor development of children with visual impairment (VI) is necessary in order to recognise whether children with VI are at risk of motor developmental problems, and to evaluate the effectiveness of exercise interventions. In 2003 the ManuVis was published with reference values for children with VI of ages from 6 to 11 years. This paper reports on a follow-up study of the ManuVis focused on: a) comparison of fine motor skills between children with VI and normal sighted (NS) children; b) sampling norm-references for children with VI in the 4-11 years age range to increase validity; and c) test-retest and inter-rater reliability. In total 256 children with VI and 162 NS children were included in the study. The results demonstrated that children with VI needed significantly more time than NS children to perform all test items, especially at younger ages. Performance time decreased in both children with VI and NS children from the younger to the older age groups, but NS children reached their minimum at a younger age. Test-retest reliability on the items varied from moderate to excellent and inter-rater reliability was excellent. The results suggest that children with VI have slower and more prolonged motor learning than NS children. The ManuVis differentiates between typical and atypical fine-motor performance of children with VI between 4 and 9 years of age, and is useful for monitoring fine-motor skills in children with VI from 4 years to (at least) 11 years.

Cooperation with peers is challenging for young children, and there are large individual differences in the development of cooperation. The roles of child characteristics and peer experiences for peer interaction during free play have been studied extensively, but it is unclear which factors predict young children's successful cooperation at different points in development. In this study, 2-, 3-, and 4-year-old children were observed during a peer cooperation task. Both their interactive behavior and cooperation success were examined, and the association of these variables with child characteristics and peer experiences was explored. Results showed that successful peer cooperation increased with age. Moreover, early individual differences in peer cooperation were related to temperamental characteristics, and, among older children, the rate of cooperation was related to prior peer experience.

The aim of this study was to investigate interpersonal coordination in young children during dyadic problem solving, by using Cross-Recurrence Quantification Analysis (CRQA). We examined the interactions of seven dyads of children (Mage= 5.1 years) in a longitudinal design (6 sessions) with a sequence of problem-solving tasks increasing in difficulty. An innovative implementation of CRQA is presented in order to study the attractor dynamics of dyadic coordination. The analysis consisted of distinguishing two recurrent states in the relationship between children and the task. In other words, the analysis is focused on how the dyadic interaction oscillates between two stable states that for their recurrent presence are considered to be attractors. The distributed dyadic interaction (DDI) state indicates that both children contribute equally to the solution of the task. The unequal dyadic interaction (UDI) state indicating that only one of the children contributes actively to the solution of the task. Results showed that the DDI was more frequent than the UDI but that the dynamics of these two attractor states were quite similar. The behaviors within these states increased in complexity over time, although they did so in DDI more strongly than UDI. The overall recurrence, which indicates the global level of coordination between the individuals in the dyad across all time points, was moderately correlated with the performance of the children.

Research regarding the variability of state self-esteem (SSE) commonly focuses on the magnitude of variability. In this article we provide the first empirical test of the temporalstructure of SSE as a real-time process during parent-adolescent interactions. We adopt a qualitative phenomenological approach, whereby moment-to-moment emotional and behavioral indicators of SSE are measured as they emerged during the interactions, resulting in SSE time series. We conducted detrended fluctuation analyses (DFA) on the SSE time series and found that they exhibited a form of structured variability, called pink noise. The mean DFA exponent differed significantly from that of randomized surrogate data (p.01), which revealed uncorrelated random variability, called white noise. This finding shows that the temporal structure of SSE variability exhibits self-similarity and is not random. In addition, a weak positive relationship was found between the DFA and context-independent autonomy levels.

We investigated 20-month-olds' (N = 56) gaze following by presenting toddlers with a female model that displayed either ostensive or no ostensive cues before shifting her gaze laterally toward an object. The results indicated that toddlers reliably followed the model's gaze redirection after mutual eye contact was established but did so equally reliably after the model's eyes had been made salient nonostensively. Moreover, both conditions elicited gaze following more prominently than when children's attention was initially directed away from the eyes either by specifically accentuating the mouth or by covering the entire face before the model redirected her eyes laterally. These findings suggest that gaze following by toddlers is more likely to be driven by general attention mechanisms than by their appreciation of somebody else's communicative intent through perceiving eye contact. (C) 2012 Elsevier Inc. All rights reserved.

In previous studies we demonstrated that the speech of a language-acquiring child and that of her parent can be characterized as a transactional process of dynamic adaptation. We reported a striking attunement between child and parent in the global development of mean length of utterance and utterance length between the ages of 1.5 and 2.5 years. Here we present a reanalysis of these data, focusing on the utilization of different categories of utterance length. In particular we analyzed the temporal structure of the dialogue on the linguistic level using the technique of cross-recurrence quantification. This type of analysis enabled us to study the interaction between interlocutors at the microlevel, revealing the dynamics of child-parent conversation and how this changes over time. Results showed decreasing values for measures quantifying the vertical line structures as well as an increasing average length of the diagonal lines in the recurrence plot. This was interpreted as indicating an increasing flexibility in the patterns of parent-child dialogue over the period of 1 year.

Complex systems applications in human movement sciences have increased our understanding of emergent coordination patterns between athletes. In the current study, we take a novel step and propose that movement coordination between athletes is a multiscale phenomenon. Specifically, we investigated so-called "complexity matching" of performance measured in the context of rowing. Sixteen rowers participated in two sessions on rowing ergometers: One individual session of 550 strokes and one dyadic session of 550 strokes side-by-side with a team member. We used evenly-spaced detrended fluctuation analysis (DFA) to calculate the complexity indices (DFA exponents) of the force-peak interval series for each rower in each session. The DFA exponents between team members were uncorrelated in the individual sessions (r = 0.06), but were strongly and significantly correlated when team members rowed together (r = 0.87). Furthermore, we found that complexity matching could not be attributed to the rowers mimicking or locally adapting to each other. These findings contribute to the current theoretical understanding of coordination dynamics in sports.

AIM: To compare fine motor performance of 3-year-old children with visual impairment with peers having normal vision, to provide reference scores for 3-year-old children with visual impairment on the ManuVis, and to assess inter-rater reliability.METHOD: 26 children with visual impairment (mean age: 3 years 7 months (SD 3 months); 17 boys) and 28 children with normal vision (mean age: 3 years 7 months (SD 4 months); 14 boys) participated in the study. The ManuVis age band for 3-year-old children comprised two one-handed tasks, two two-handed tasks, and a pre-writing task.RESULTS: Children with visual impairment needed more time on all tasks (p < .01) and performed the pre-writing task less accurately than children with normal vision (p < .001). Children aged 42-47 months performed significantly faster on two tasks and had better total scores than children aged 36-41 months (p < .05). Inter-rater reliability was excellent (Intra-class Correlation Coefficient = 0.96-0.99).CONCLUSIONS: The ManuVis age band for 3-year-old children is appropriate to assess fine motor skills, and is sensitive to differences between children with visual impairment and normal vision and between half-year age groups. Reference scores are provided for 3-year-old children with visual impairment to identify delayed fine motor development.

Past research has shown that rapport and cooperation between individuals is related to the level of nonverbal synchrony they achieve in their interactions. This study investigates the extent to which staff and clients with mild to borderline intellectual disability achieve interactional synchrony in daily social interactions. Whilst there has been work examining how staff can adapt their verbal communication to help achieve better mutual understanding, there has been an absence of work concerning the responsiveness of staff and clients regarding their nonverbal behavior. Nineteen staff members video-recorded a social interaction with one of their clients in which the client had a need for support. The recordings were analyzed using cross recurrence quantification analysis. In addition, fifteen staff members as well as clients with an intellectual disability completed a questionnaire on the quality of the nineteen video-recorded interactions. Analysis of the nonverbal patterns of interaction showed that the staff–client dyads achieved interactional synchrony, but that this synchrony is not pervasive to all nonverbal behaviors. The client observers appeared to be more sensitive to this synchrony or to value it more highly than the staff raters. Staff observers were sensitive to quantitative measures of talking. The more staff in the interactions talked, the lower the quality rating of the interaction. The more the clients talked, the more positively the staff observers rated the interactions. These findings have implications for how collaborative relationships between clients and support workers should be understood.Keywords: Staff–client interactions, Collaborative relationship, Intellectual disabilities, Interactional patterns, Social interactions, Nonverbal communication

Contains fulltext : 116604.pdf (Publisher’s version ) (Open Access) PURPOSE. This study investigated whether visual perceptual learning can improve near visual acuity and reduce foveal crowding effects in four-to nine-year-old children with visual impairment. METHODS. Participants were 45 children with visual impairment and 29 children with normal vision. Children with visual impairment were divided into three groups: a magnifier group (n = 12), a crowded perceptual learning group (n = 18), and an uncrowded perceptual learning group (n = 15). Children with normal vision also were divided in three groups, but were measured only at baseline. Dependent variables were single near visual acuity (NVA), crowded NVA, LH line 50% crowding NVA, number of trials, accuracy, performance time, amount of small errors, and amount of large errors. Children with visual impairment trained during six weeks, two times per week, for 30 minutes (12 training sessions). RESULTS. After training, children showed significant improvement of NVA in addition to specific improvements on the training task. The crowded perceptual learning group showed the largest acuity improvements (1.7 logMAR lines on the crowded chart, P < 0.001). Only the children in the crowded perceptual learning group showed improvements on all NVA charts. CONCLUSIONS. Children with visual impairment benefit from perceptual training. While task-specific improvements were observed in all training groups, transfer to crowded NVA was largest in the crowded perceptual learning group. To our knowledge, this is the first study to provide evidence for the improvement of NVA by perceptual learning in children with visual impairment. 9 p.

The current study focuses on one child's (male, 3 years old) learning behaviors in an English as a Foreign Language classroom, and explores the coordination and developmental patterns of his nonverbal (gestures and body language) and verbal (verbal repetition and verbal responses) learning behaviors over time. Guided by the principles of the theory of Complex Dynamical Systems, the child's learning behaviors were analyzed over the course of four months, using (Cross) Recurrence Quantification Analysis and Monte Carlo permutation tests. The results show that the coordination between the child's nonverbal and verbal behaviors exhibited a rigid pattern at the beginning but got loosened over time, allowing the child to respond more flexibly to the teachers' instructions and to alternate more freely between his verbal and nonverbal learning behaviors. When focusing on the child's verbal learning behaviors only, we found that patterns of the verbal responses seemed to be more predictable than those of verbal repetitions, which suggests the varied influence of internal and external factors on these verbal learning behaviors.

Item does not contain fulltext BACKGROUND/AIMS: To investigate crowding ratios in children with a visual impairment due to ocular disease (n = 58) and normally sighted children (n = 75) aged 4 to 8 years using several variants of two clinically available tests with different optotype spacing (fixed or proportional to the optotype size). METHODS: Crowding ratios, calculated by dividing the single acuity by the linear acuity, were measured binocularly with the C-test and the LH line chart. Ratios >1.00 indicate crowding. RESULTS: The charts with fixed spacing revealed significantly higher crowding ratios for visually impaired children than normally sighted children (both for measurements at 40 cm and 5 m). The age-related reduction of the crowding ratios seen in normally sighted children when tested with near-vision charts with fixed spacing was not present in the visually impaired group. Visually impaired children with nystagmus showed higher crowding ratios than visually impaired children without nystagmus. The chart with proportional intersymbol spacing (ISS) did not reveal differences between the normally sighted and visually impaired children; nor did it show group, age, or nystagmus effects. CONCLUSION: Visually impaired children showed higher crowding ratios than normally sighted children when measured with charts with fixed ISS. This study illustrates that test design and target/flanker interference as a manifestation of crowding are critical issues to bear in mind when assessing crowding ratios in children. 01 juni 2012

Contains fulltext : 102560.pdf (Publisher’s version ) (Closed access) The aim of this study was to investigate the coupling of the biological system of infant sleep and the social system of mother–infant synchrony. Before birth and shortly after birth the systems appear to be connected, but it is unclear whether this remains the case over time. This study therefore examined whether infant sleep measured at 6 weeks and 5 months could predict mother–infant gaze synchrony after a social challenge at 5 months (N = 84). Infant sleep was measured in terms of sleep bout duration, which normally increases during this period. Gaze was defined in terms of looking at each other's head simultaneously, known as gaze synchrony, or looking elsewhere. Results showed that infant sleep could predict the temporal dynamics of the mother–infant interaction in terms of flexibility of gaze pattern shifts. The larger the increase in sleep bout duration over age, the more flexible the interaction appeared to be. Maternal Age, type of feeding and change of feeding appeared to function as confounding variables in this relation. Infant sleep could not predict percentage of synchrony (central tendency measure) or the average sequence length of gaze patterns (temporal dynamic measure). 12 p.

Contains fulltext : 102865.pdf (Publisher’s version ) (Closed access) The background noise of response times is often overlooked in scientific inquiries of cognitive performances. However, it is becoming widely acknowledged in psychology, medicine, physiology, physics, and beyond that temporal patterns of variability constitute a rich source of information. Here, we introduce two complexity measures (1/f scaling and recurrence quantification analysis) that employ background noise as metrics of reading fluency. These measures gauge the extent of interdependence across, rather than within, cognitive components. In this study, we investigated dyslexic and non-dyslexic word-naming performance in beginning readers and observed that these complexity metrics differentiate reliably between dyslexic and average response times and correlate strongly with the severity of the reading impairment. The direction of change in the introduced metrics suggests that developmental dyslexia resides from dynamical instabilities in the coordination among the many components necessary to read, which could explain why dyslexic readers score below average on so many distinct tasks and modalities. 20 p.

1/f noise has been discovered in a number of time series collected in psychological and behavioral experiments. This ubiquitous phenomenon has been ignored for a long time and classical models were not designed for accounting for these long-range correlations. The aim of this paper is to present and discuss contrasted theoretical perspectives on 1/f noise, in order to provide a comprehensive overview of current debates in this domain. In a first part, we pro pose a formal definition of the phenomenon of 1/f noise, and we present some commonly used methods for measuring long-range correlations in time series. In a second part, we develop a theoretiical position that considers 1/f noise as the hallmark of system complexity. From this point of view, 1/f noise emerges from the coordination of the many elements that compose the system. In a third part, we present a theoretical counterpoint suggesting that 1/f noise could emerge from localized sources within the system. In conclusion, we try to draw some lines of reasoning for going beyond the opposition between these two approaches. info:eu-repo/semantics/publishedVersion

It is a widely accepted belief in clinical practice that children with a visual impairment can profit from the use of a low vision aid (LVA). However, we found a considerable gap in our scientific understanding of LVA use, particularly in young children. This is the reason for the analysis presented in this paper. A selected overview of LVA use in adults is given, from which valuable insights are taken. Additionally, an action perspective for analysing LVA use is discussed as well as the results of tool-use studies in children. Mainly based on these three ingredients, we developed a conceptual framework for LVA use. The framework consists of three interacting relations between LVA, child and task. Performance of a particular child on a specific task with a certain LVA is constrained by the following three reciprocal and dynamic relations: the Child-to-Task relation (related to goal-information), the Child-to-LVA relation (related to control-information), and the LVA-to-Task relation (related to topology information).

Contains fulltext : 77136.pdf (Publisher’s version ) (Closed access) We report an experiment concerning the use of a stand magnifier by young children with visual impairments (21 males, 12 females; mean age 4y 8mo [SD 11mo]). Children had a normative developmental level and a visual acuity of 0.4 or less (

This paper discusses both a dissociation view and a dynamic view with respect to the study of voluntary, goal-directed behavior. The dissociation view builds on the recently reintroduced ideomotor principle, and conceives of clearly dissociated and hierarchical roles for the planning and control of action. The dynamic view has a more integral and dynamic conception of how planning, control, and timing merge in the guidance of behavior. This view, however, lacks a clear way of encompassing the goaldirectedness of behavior. For behavior to be effective and efficient, sensory information has to play an equally important role in guiding action as goal-related information does. As a third view, a dynamic action-selection approach is introduced by combining aspects of the former two. This model is able to merge ideomotor and sensorimotor processes continuously and in real time. In discussing the action-selection approach, a special emphasis is given to the role of long-term influences like preferences and goals.

Contains fulltext : 72871.pdf (Publisher’s version ) (Open Access) Two experiments investigated how 3-year-old children select a tool to perform a manual task, with a focus on their perseverative parameter choices for the various relationships involved in handling a tool: the actor-to-tool relation and the tool-to-target relation (topology). The first study concerned the parameter value for the tool-to-target relation by asking how children use a cane for either pushing an object further away (exclosure; outside the hook) or pulling an object nearby (enclosure; inside the hook). The second study concerned the parameter value for the hand-to-tool relation by assessing the hand used for grasping a spoon to feed a puppet. Results from both studies showed that on the first trial, choices were driven by task information. However, when the task switched from pulling to pushing or from left hand to right hand, or vice versa, children persevered with the choice they made during the 4 previous trials. Results are discussed in terms of the dynamical field modeling work of Esther Thelen and her colleagues. Our findings underscore Thelen's hypotheses that: (a) the action-selection process is a dynamic affair, affected by multiple influences at different time scales and its own intrinsic dynamics; and (b) that perseverative behavior is a general phenomenon that is neither indicative for a specific period in the development, nor for a particular task. Similarly, we argue that the presence (or absence) of causal understanding emerges from the action-selection process, rather than determining this process.

Contains fulltext : 167758.pdf (Publisher’s version ) (Open Access) PURPOSE: The main objective of this study was to analyze the effectiveness and efficiency of magnifier use in children with visual impairment who did not use a low vision aid earlier, in an ecologically valid goal-directed perceptuomotor task. METHODS: Participants were twenty-nine 4- to 8-year-old children with visual impairment and 47 age-matched children with normal vision. After seeing a first symbol (an Lea Hyvarinen [LH] symbol), children were instructed to (1) move the stand magnifier as quickly as possible toward a small target symbol (another LH symbol that could only be seen by using the magnifier), (2) compare the two symbols, and (3) move the magnifier to one of two response areas to indicate whether the two symbols were identical. Performance was measured in terms of accuracy, response time, identification time, and movement time. Viewing distance, as well as hand and eye dominance while using the magnifier was assessed. RESULTS: There were no significant differences between the two groups in accuracy, reaction time, and movement time. Contrary to the prediction, children with visual impairment required less time to identify small symbols than children with normal vision. Both within-subject and between-subject variability in viewing distance were smaller in the visually impaired group than in the normally sighted group. In the visually impaired group, a larger viewing distance was associated with shorter identification time, which in turn was associated with higher accuracy. In the normally sighted group, a faster movement with the magnifier and a faster identification were associated with increasing age. CONCLUSION: The findings indicate that children with visual impairment can use the stand magnifier adequately and efficiently. The normally sighted children show an age-related development in movement time and identification time and show more variability in viewing distance, which is not found in visually impaired children. Visually impaired children seem to choose a standard but less adaptive strategy in which they primarily used their preferred hand to manipulate the magnifier and their preferred eye to identify the symbol. TRIAL REGISTRATION: Registered at http://www.trialregister.nl; NTR2380. 11 p.

Cross-recurrence quantification analysis (CRQA) is a powerful nonlinear time-series method to study coordination and cooperation between people. This chapter concentrates on two methodological issues related to CRQA on categorical data streams, which are commonly encountered in the behavioral sciences . Firstly, we introduce a more general definition of recurrence as ‘behavioral matching ’, which can be applied to several kinds of matches simultaneously, visualized by a color coding. We will refer to this as cross -matching, and to the resulting quantification procedure as Chromatic CRQA . Secondly, cross-recurrence plots of categorical data often prominently consists of rectangular structures. This calls for a differential analysis of vertical and horizontal lines, rather than of diagonal lines. We introduce a simple procedure for this, referred to as Anisotropic CRQA . Both procedures are demonstrated with empirical studies on children’s problem-solving behavior and by means of a model simulation. The authors hope that the ideas presented here increase the power and applicability of CRQA in the behavioral sciences, and that this chapter serves as a stepping stone for their mathematical and methodological development.

The aim of this study was to examine (1) the temporal structures of variation in rowers’ (natural) ergometer strokes to make inferences about the underlying motor organization, and (2) the relation between these temporal structures and skill level. Four high-skilled and five lower-skilled rowers completed 550 strokes on a rowing ergometer. Detrended Fluctuation Analysis was used to quantify the temporal structure of the intervals between force peaks. Results showed that the temporal structure differed from random, and revealed prominent patterns of pink noise for each rower. Furthermore, the high-skilled rowers demonstrated more pink noise than the lower-skilled rowers. The presence of pink noise suggeststhat rowing performance emerges from the coordination among interacting component processes across multiple time scales. The difference in noise pattern between high-skilled and lower-skilled athletes indicates that the complexity of athletes’ motor organization is a potential key characteristic of elite performance.