Dynamical Patterns in the Development of Clapping

The development of a complex rhythmical behavior—clapping—is modeled using a formal, explicit model of coupled oscillator dynamics. Even though this behavior manifests a good deal of nonstationarity and high variability within and across subjects, results indicate that these properties may be dynamically modeled quantitatively as well as qualitatively. Results suggest that clapping goes through a less stable period of relative coordination between 3 and 7 years before more stable absolute coordination is achieved. Nevertheless, in that the clapping behavior is affected in highly predictable ways by inertial loading of the limbs, the same underlying dynamic seems responsible for the coordination of both the younger and older children. Developmentally, the behavior of the coordination variable (relative phase) changes from a nonconstant magnitude in younger clappers to a constant magnitude in older clappers. These results suggest that development of proficiency in rhythmic motor skills displays developmental changes that can be understood well in dynamical terms.     

The development of detour ability during infancy

3 longitudinal studies were conducted to examine the generalization of detour ability across motor responses and barrier types and the relationship between the development of object permanence and detour ability. In Experiment 1, 12 8-month-olds were tested every 3 weeks for 4 months on 4 different detour problems and Stage 4 and 6 object permanence tasks. In the detour problems, infants had to reach or move around a transparent or opaque barrier to obtain an object. The results indicated that infants made reaching detours before corresponding locomotor ones and generally made detours around opaque barriers before transparent ones. Infants also solved the Stage 4 task before the detour problems but failed to solve the Stage 6 task before testing ended. The results of Experiments 2 and 3 suggested that the difference in reaching and locomotor detour performance was not an artifact of barrier length or the infant's position relative to the barrier. The overall results are discussed in relation to issues of developmental synchrony and Piaget's theory of infant spatial development.     

The Human Face Becomes Mapped as a Sensorimotor Reaching Space During the First Year

Although recent behavioral and neural research indicates that infants represent the body’s structure, how they engage self-representations for action is little understood. This study addressed how the human face becomes a reaching space. Infants (N = 24; 2–11 months) were tested longitudinally approximately every 3 weeks on their ability to reach to a vibrating target placed at different locations on the face. Successful reaches required coordinating skin- and body-based codes for location, a problem known as tactile remapping. Findings suggest that a functional representation of the face is initially fragmented. Infants localized targets in the perioral region before other areas (ears/temples). Additionally, infants predominantly reached ipsilaterally to targets. Collectively, the findings illuminate how the face becomes an integrated sensorimotor space for self-reaching.     

When Does Tool Use Become Distinctively Human? Hammering in Young Children

This study examines the development of hammering within an ontogenetic and evolutionary framework using motion‐capture technology. Twenty‐four right‐handed toddlers (19–35 months) wore reflective markers while hammering a peg into a peg‐board. The study focuses on the motor characteristics that make tool use uniquely human: wrist involvement, lateralization, and handle use. Older children showed more distally controlled movements, characterized by relatively more reliance on the wrist, but only when hammering with their right hand. Greater age, use of the right hand, and more wrist involvement were associated with higher accuracy; handle use did not systematically change with age. Collectively, the results provide new insights about the emergence of hammering in young children and when hammering begins to manifest distinctively human characteristics.     

Improving Educational Outcomes of Hispanic Students in a Professional Degree Program

In an attempt to reduce the educational achievement gap of Hispanic students in a professional degree program, two courses grounded in the Keller method were implemented at a pharmacy school. The Keller method is characterized by breaking course content into modules, then allowing students to test and repeatedly remediate and retest until competency is achieved. Outcomes from this intervention-based cohort study suggest that the Keller method is effective in reducing the educational achievement gap of Hispanic students in a professional degree program.     

A perception--action perspective on tool use development

In this essay I argue for a new wave of research on tool use development. Advances in the literature on perception-action development hold important clues for how tool use unfolds in children. These advances suggest that tool use may be a more continuous developmental achievement than has been previously believed. On this view, tool use is rooted in the perception-action routines that infants employ to gain information about their environments. Although tools alter the properties of effector systems, children use tools to explore and change their environments, building on efforts that originate in infancy. Based on this approach, new research directions are suggested, including efforts designed to investigate the processes by which children detect and relate affordances between objects, coordinate spatial frames of reference, and incorporate early-appearing action patterns into instrumental behaviors.     

Motor Origins of Tool Use

The current study examines the developmental trajectory of banging movements and its implications for tool use development. Twenty (6‐ to 15‐month‐old) infants wore reflective markers while banging a handled cube; movements were recorded at 240 Hz. Results indicated that through the second half‐year, banging movements undergo developmental changes making them ideally suited for instrumental hammering and pounding. Younger infants were inefficient and variable when banging the object: Their hands followed circuitous paths of great lengths at high velocities. By 1 year, infants showed consistent and efficient straight up‐down hand trajectories of smaller magnitude and velocity, allowing for precise aiming and delivering dependable levels of force. The findings suggest that tool use develops gradually from infants' existing manual behaviors.     

Clinical Symptoms as a Function of Client Personality in College Students: Incorporating the Five‐Factor Model of Personality

In this study, the relationship between personality characteristics and presenting clinical symptoms of individuals at a college counseling center was examined. Analysis of assessments of personality ( Costa & McCrae, 1992 ) and mental health symptoms ( Farrell & McCullough, 1989 ) suggests that the personality characteristics of individuals presenting for assistance at a college counseling center systematically vary from those of a general college population. Furthermore, differing patterns of client personality characteristics were related to various symptom categories.     

Developmental Biodynamics: Brain, Body, Behavior Connections

This special section, Developmental Biodynamics: Brain, Body, Behavior Connections , celebrates a renewed and revitalized interest in the study of motor development. The renewed interest has been sparked by advances in the neurosciences, biomechanics, and behavioral sciences and, importantly, in the attempts to integrate theories and findings across these disciplines. In this introduction to the special section, we consider the contributions that have led to a reinvigorated field of motor development and to its new interdisciplinary look. We highlight the papers in the special section by discussing how they illustrate related advances across research in the neurosciences, biomechanics, and behavioral sciences and how progress across these domains has come to define and characterize the emerging field of developmental biodynamics.