Rate of Change of Angular Bearing as the Relevant Property in a Horizontal Interception Task During Locomotion

The authors ran 3 experiments to investigate how catchers deal with the horizontal component of the ball's trajectory in an interception task during locomotion. The experiments were built upon the finding that velocity adaptations are based upon changes in the horizontal angular position or velocity of the ball with respect to the observer (M. Lenoir, M. Janssens, E. Musch, E. Thiery, & J. Uyttenhove, 1999); a potential underlying information source for that strategy is described. In Experiment 1, actor (N = 10 participants) and ball approached each other along the legs of a V-shaped track. When the velocity and the initial angular bearing of the ball were varied, the observed behavior fitted with nulling the horizontal angular velocity of the ball: A positive or negative angular velocity was compensated by a velocity change. Evidence was obtained that those adaptations are modulated by a critical change in, rather than by a critical state of, the environment-actor system. In Experiment 2, the distance between the head and an artificial end-effector was varied. Irrespective of that distance, participants (N = 7) accelerated and decelerated in order to keep the angular velocity of the ball with respect to the end-effector close to constant. The ecological relevance of that constant bearing angle strategy was confirmed in Experiment 3: Participants (N = 7) in that experiment freely ran to catch fly balls. The present results support the concept that one can explain with a limited number of control variables an actor's behavior in an interception task during self-motion.     

Reaction time measures in deception research: Comparing the effects of irrelevant and relevant stimulus–response compatibility

Evidence regarding the validity of reaction time (RT) measures in deception research is mixed. One possible reason for this inconsistency is that structurally different RT paradigms have been used. The aim of this study was to experimentally investigate whether structural differences between RT tasks are related to how effective those tasks are for capturing deception. We achieved this aim by comparing the effectiveness of relevant and irrelevant stimulus–response compatibility (SRC) tasks. We also investigated whether an intended but not yet completed mock crime could be assessed with both tasks. Results showed (1) a larger compatibility effect in the relevant SRC task compared to the irrelevant SRC task, (2) for both the completed and the intended crime. These results were replicated in a second experiment in which a semantic feature (instead of color) was used as critical response feature in the irrelevant SRC task. The findings support the idea that a structural analysis of deception tasks helps to identify RT measures that produce robust group effects, and that strong compatibility effects for both enacted crimes as well as merely intended crimes can be found with RT measures that are based on the manipulation of relevant SRC.     

Getting the closer object? An information‐based dissociation between vision for perception and vision for movement in early infancy

In human adults two functionally and neuro‐anatomically separate systems exist for the use of visual information in perception and the use of visual information to control movements (Milner & Goodale, 1995 , 2008 ). We investigated whether this separation is already functioning in the early stages of the development of reaching. To this end, 6‐ and 7‐month‐old infants were presented with two identical objects at identical distances in front of an illusory Ponzo‐like background that made them appear to be located at different distances. In two further conditions without the illusory background, the two objects were presented at physically different distances. Preferential reaching outcomes indicated that the allocentric distance information contained in the illusory background affected the perception of object distance. Yet, infants' reaching kinematics were only affected by the objects' physical distance and not by the perceptual distance manipulation. These findings were taken as evidence for the two‐visual systems, as proposed by Milner and Goodale ( 2008 ), being functional in early infancy. We discuss the wider implications of this early dissociation.     

Disability Cosmology: The Practice of Making Disability Worlds

The practice of making disability worlds is investigated both theoretically, in the context of developments in disability studies, in particular in the cultural model of disability, and practically in two examples, namely inclusive education environments and public environments. Theoretically, we argue that disability worlds can be better understood by introducing the notion of disability cosmology as the largest possible perspective on the making of disability worlds. A cultural model research perspective of disability consists then of the complementary study of disability identity, culture and cosmology. The practical examples work out the particularities of making and understanding disability worlds. In the making of disability worlds, much attention goes to the ways in which disability worlds relate to the normative world; for example in the formation of boundaries and transgressions, but also fundamentally how disability adds to becoming human.     

A longitudinal study of basal cortisol in infants: Intra-individual variability, circadian rhythm and developmental trends

Mothers with normally developing babies were visited in their homes during 13 consecutive weeks, when the babies were around 5–8 months of age. Basal salival cortisol measures were taken for both the baby and the mother on arrival.The infants’ basal cortisol decreased linearly with age, was negatively related to sleep, and did not show adult-like circadian declines from morning to mid-afternoon. Furthermore, while the infants showed relative stability across individuals, they displayed great intra-individual variability across assessments. Contrarily, the mothers displayed important inter-individual variability, together with a relative stability across assessments. The infants’ important intra-individual variability was not affected by gender, nor time of visit, nor was it related to the mothers’ basal cortisol. Daily measures of basal cortisol taken in a subgroup of infants indicated the day-to-day intra-individual variability to be of the same magnitude as the week-to-week variability.The question of how the intra-individual variability in basal cortisol affects assessments of cortisol in infancy is addressed. The aggregation of data with the goal of increasing the reliability of the assessments is shown to be inadequate for infant basal cortisol.     

Explaining after by before: Basic aspects of a dynamic systems approach to the study of development

The basic properties of a dynamic systems approach of development are illustrated by contrasting two simple equations. One, y_t+1 = f (y_t), is characteristic of dynamic systems models. The other, y_i = f (x_i), refers to what, for the sake of simplicity, is referred to as the standard developmental approach. We give illustrations from cognitive, language and social development to show the characteristic differences of these two types of models and show their complementarity. The article further compares the “Bloomington” with the “Groningen” approach to dynamic systems theorizing in developmental psychology. It continues with a discussion of two important questions. One involves the issue of measurement and the nature of developmental variables from the viewpoint of dynamic systems. The second concerns the question of short- and long-term time scales in developmental models, which is discussed on the basis of an example, namely dyadic interaction of young children in the context of different social statuses.     

Signals of threat do not capture, but prioritize, attention: a conditioning approach

Research suggests that threatening information captures attention more rapidly than neutral information. However, in most studies threat stimuli differ perceptually from neutral stimuli and are instrumental to perform the task, leaving the question unanswered whether threat is sufficient to capture attention. In experiment 1, we designed a visual search task with stimuli of equal salience (colored circles) that have the potential to lead to efficient search (10 ms/item). In experiment 2, one of the colors (conditioned stimulus, CS+) was made threatening by means of fear conditioning. Participants responded to a target presented in one of the circles. Overall, the search was faster on congruent trials (where the target was presented in the CS+) than on baseline trials (where the CS + was absent). Furthermore, the search was slower on incongruent trials (where the target was presented in another color than the CS+) than on baseline trials. The search on congruent trials was affected by set size (90 ms/item), but to a lesser extent than on baseline trials (105 ms/item). We conclude that threat prioritizes, but does not capture attention.     

Modeling the role of emotions in viewing oneself maturely

Adolescents develop a mature view on themselves: they view positive as well as negative self-attributes, but they hold a positive stance toward themselves. The literatures on identity, the self, parent-offspring relationships, and friendships provide hints on how such a view may develop. This article integrates this literature into an emotion-based dynamic systems mathematical model built to explain the development of maturity of such views. An innovative methodological design was used to collect empirical data: four students daily reported their experiences and emotions for a period of 5 months, while they temporarily studied abroad. At the beginning and end of this period, they were interviewed on their views on themselves. These mostly qualitative data were used to provide support to the suggested mathematical model. The usefulness, weaknesses, and strengths of such a methodological design and mathematical modeling are discussed.     

Two instructional designs for dialogic citizenship education: An effect study

Background Despite the renewed interest in citizenship education, relatively little is known about effective ways to realize citizenship education in the classroom. In the literature on citizenship education, dialogue is considered to be a crucial element. However, there is very little, if any, empirical research into the different ways to stimulate dialogue. Aim The main aim of this study is to arrive at an understanding of how citizenship education can be integrated in history classes. The focus is on the effect of a dialogic approach to citizenship education on students' ability to justify an opinion on moral issues. Sample Four hundred and eighty‐two students in the eighth grade of secondary education. Methods Two curriculum units for dialogic citizenship education were developed and implemented. The two curriculum units differed in the balance between group work and whole‐class teaching. Students' ability to justify an opinion was assessed by means of short essays written by students on a moral issue. The effectiveness of both curriculum units was compared with regular history classes. Results Students who participated in the lessons for dialogic citizenship education were able to justify their opinion better than students who participated in regular history lessons. The results further show a positive effect of the amount of group work involved. Conclusion The results of this study indicate that a dialogic approach to citizenship education as an integral part of history classes helps students to form a more profound opinion about moral issues in the subject matter. In addition, group work seems to be a more effective method to implement dialogue in the classroom than whole‐class teaching.