Heiko Maurer | Justus-Liebig-University of Giessen (original) (raw)

Papers by Heiko Maurer

Zeitschrift Fur Sportpsychologie, Mar 6, 2015

Im Wettkampfsport ist immer wieder zu beobachten, dass Athleten in besonders wichtigen Situatione... more Im Wettkampfsport ist immer wieder zu beobachten, dass Athleten in besonders wichtigen Situationen nur mäßige Leistungen erzielen. Dieses ‚Versagen unter Druck’ oder ‚choking under pressure’ ist häufig bei solchen Fertigkeiten zu beobachten, die durch hohe koordinative Anforderungen geprägt sind. Im Rahmen der Arbeit wird den Fragen nachgegangen, welche Ursachen Leistungseinbußen in Drucksituationen zu Grunde liegen und welche kinematischen Veränderungen der Bewegungsausführung daraus resultieren. Auf der Ebene motorische Kontrollprozesse werden drei plausible Erklärungsansätze für das Phänomen diskutiert. Empirische Belege anhand sportmotorischer Fertigkeiten liegen jedoch nur für eine Erklärungsrichtung vor, die in den letzten Jahren von verschiedenen Autoren mit ähnlichen Annahmen bearbeitet wurde und die unter dem Label ‚Explicit Monitoring Theories’ zusammengefasst wird. Die Grundannahme besteht darin, dass in wichtigen Situationen eine Lenkung der Aufmerksamkeit auf den Ausfüh...

Einleitung. Im Wettkampfsport ist die Leistungserbringung in wichtigen Situationen von entschei- ... more Einleitung. Im Wettkampfsport ist die Leistungserbringung in wichtigen Situationen von entschei- dender Bedeutung, so dass großes Interesse an den Ursachen von Leistungseinbußen in Drucksitu- ationen besteht. Viele Studien unterliegen jedoch zwei Einschränkungen. Zum einen werden wenig geübte Aufgaben genutzt, so dass eine Übertragung auf den Wettkampfsport nur bedingt möglich ist. Zum anderen wird meist nur das Bewegungsergebnis, nicht aber die Ausführung untersucht, was ei- nen wichtigen Beitrag zum Verständnis der Ursachen leisten kann. Diese Aspekte werden in der vor- liegenden feldnahen Untersuchung aufgegriffen. Untersuchung. Die Untersuchung wurde im Rahmen einer Kadersichtungsmaßnahme des Deut- schen Pétanque Verbandes durchgeführt, an der 36 Personen mit mehrjähriger Wettkampferfahrung teilnahmen. Genutzt wurde der in diesem Rahmen vorgesehene "Schusstest". Die Aufgabe bestand darin, eine neun Meter entfernte Zielkugel mit der im Pétanque üblichen Schusstechnik zu...

Zeitschrift für Sportpsychologie, 2005

Http Dx Doi Org 10 1080 00222895 2014 912197, May 23, 2014

The authors examined how varying the content of verbal-motor instructions and requesting an inter... more The authors examined how varying the content of verbal-motor instructions and requesting an internal versus external focus influenced the kinematics and outcome of a golf putting task. On Day 1, 30 novices performed 120 trials with the instruction to focus attention either on performing a pendulum-like movement (internal) or on the desired ball path (external). After 20 retention trials on Day 2, they performed 20 transfer trials with the opposite instruction. Group differences for retention and a group by block interaction showed that external instruction enhanced movement outcome. Kinematic data indicated that specific instruction content influenced outcomes by eliciting changes in movement execution. Switching from the external to the internal focus instruction resulted in a more pendulum-like movement.

Zeitschrift Fur Sportpsychologie, Mar 6, 2015

Frontiers in Behavioral Neuroscience, 2015

The goal of the study was to quantify error prediction processes via neural correlates in the Ele... more The goal of the study was to quantify error prediction processes via neural correlates in the Electroencephalogram (EEG). Access to such a neural signal will allow to gain insights into functional and temporal aspects of error perception in the course of learning. We focused on the error negativity (Ne) or error-related negativity (ERN) as a candidate index for the prediction processes. We have used a virtual goal-oriented throwing task where participants used a lever to throw a virtual ball displayed on a computer monitor with the goal of hitting a virtual target as often as possible. After one day of practice with 400 trials, participants performed another 400 trials on a second day with EEG measurement. After error trials (i.e., when the ball missed the target), we found a sharp negative deflection in the EEG peaking 250 ms after ball release (mean amplitude: t = -2.5, df = 20, p = 0.02) and another broader negative deflection following the first, reaching from about 300 ms after release until unambiguous visual knowledge of results (KR; hitting or passing by the target; mean amplitude: t = -7.5, df = 20, p < 0.001). According to shape and timing of the two deflections, we assume that the first deflection represents a predictive Ne/ERN (prediction based on efferent commands and proprioceptive feedback) while the second deflection might have arisen from action monitoring.

1 Problem Das vorliegende Forschungsprojekt widmet sich dem Einfluss von Aufmerksamkeitsprozessen... more 1 Problem Das vorliegende Forschungsprojekt widmet sich dem Einfluss von Aufmerksamkeitsprozessen auf die Erbringung optimaler sportlicher Leistungen. Dabei wird insbesondere der Frage nachgegangen, inwieweit in der Sportpraxis häufig zu beobachtende Leistungseinbußen in wichtigen Wettkampfsituationen durch unfunktionale Aufmerksamkeitsprozesse erklärt werden können. Obwohl in den letzten Jahrzehnten viele Untersuchungen den Zusammenhang von psychischem Druck und motorischer Leistung belegen, sind die genauen Mechanismen dafür nicht bekannt. In den letzten Jahren wird vermehrt ein von Baumeister (1984) vorgeschlagener Erklärungsansatz aus dem Bereich der Aufmerksamkeitstheorien diskutiert. Dabei wird angenommen, dass es in Situationen, denen eine hohe Bedeutung zugemessen wird, zu einer Lenkung der Aufmerksamkeit auf den Ausführungsprozess der Bewegung kommt und dies bei hoch geübten Fertigkeiten eine Störung der automatisierten Ausführung bewirkt. Dieser Erklärungsansatz wurde in einigen neueren Arbeiten aufgegriffen und erhält Unterstützung aus empirischer und theoretischer Richtung. So konnte entsprechend der Annahmen gezeigt werden, dass automatisierte motorische Fertigkeiten auch ohne Aufmerksamkeitszuwendung ausgeführt werden können und sich schlechtere Leistungen ergeben, wenn eine Zuwendung zum Ausführungsprozess provoziert wird (z. B. Beilock et al., 2004). Ergebnisse von Gray (2004) stützen die Annahme, dass es in Drucksituationen zu einer Hinwendung zum Ausführungsprozess und zu damit verbundenen Leistungseinbußen kommt. Auch aus dem Blickwinkel aktueller Theorien zur motorischen Kontrolle lässt sich die Forderung ableiten, die Aufmerksamkeit bei automatisierten Fertigkeiten nicht auf die Bewegungsausführung (internaler Fokus), sondern die damit verbundenen Effekte in der Umwelt (externaler Fokus) zu lenken (vgl. Hossner, 2004). In einem vorangegangenen Projekt (Maurer & Munzert, 2005) wurden die Vorhersagen des von Baumeister (1984) vorgeschlagenen Erklärungsansatzes unter feldnahen Bedingungen beim Basketball-Freiwurf überprüft. Die Untersuchung wurde mit Spielerinnen der U16/U18-Bundeskader durchgeführt. Im Vergleich zu einer Baselinebedingung er-

BIO Web of Conferences, 2011

Whenever high target accuracy is a limiting factor of motor performance, as in goal-oriented thro... more Whenever high target accuracy is a limiting factor of motor performance, as in goal-oriented throwing tasks, equifinal movement techniques can be used to reduce the influence of inherent biological variability on the task result. In throwing movements, for instance, these techniques are characterized by a specific spatio-temporal organization of the movement trajectory that allows several moments of release that lead to a target hit. Throwing experts (e.g. darts or boule players) with the experience of several ten thousand practice trials show equifinal movements, but also throwing novices can learn to use equifinality after at least 1000 trials of practice. Here, we present a study that aims to scrutinize how the acquisition of equifinal throwing movements can be improved and accelerated. Mechanical guidance was used as intervention method. Determination and mechanical implementation of an equifinal technique in a virtual goal-oriented throwing task as well as results of a four-day intervention experiment are presented. Results confirm that the approaches to compute an equifinal movement trajectory and to implement mechanical guidance are appropriate to support acquisition of error tolerant movement strategies.

Journal of motor behavior, 2014

The authors examined how varying the content of verbal-motor instructions and requesting an inter... more The authors examined how varying the content of verbal-motor instructions and requesting an internal versus external focus influenced the kinematics and outcome of a golf putting task. On Day 1, 30 novices performed 120 trials with the instruction to focus attention either on performing a pendulum-like movement (internal) or on the desired ball path (external). After 20 retention trials on Day 2, they performed 20 transfer trials with the opposite instruction. Group differences for retention and a group by block interaction showed that external instruction enhanced movement outcome. Kinematic data indicated that specific instruction content influenced outcomes by eliciting changes in movement execution. Switching from the external to the internal focus instruction resulted in a more pendulum-like movement.

Human Movement Science, 2014

journal hom ep ag e: www.elsevier.com/loc ate/humov by a short flattening of the BP curves prior ... more journal hom ep ag e: www.elsevier.com/loc ate/humov by a short flattening of the BP curves prior to release. Thus, temporal and shape deviations in the neural movement initiation are assumed to delay self-timed movements.

Frontiers in Human Neuroscience, 2012

In patients with an impaired motor system, like Parkinson's disease (PD), deficits in motor learn... more In patients with an impaired motor system, like Parkinson's disease (PD), deficits in motor learning are expected and results of various studies seem to confirm these expectations. However, most studies in this regard are behaviorally based and quantify learning by performance changes between at least two points in time, e.g., baseline and retention. But, performance in a retention test is also dependent on other factors than learning. Especially in patients, the functional capacity of the control system might be altered unspecific to a certain task and learning episode. The aim of the study is to test whether characteristic temporal deficits exist in PD patients that affect retention performance. We tested the confounding effects of typical PD motor control deficits, here movement initiation deficits, on retention performance in the motor learning process. 12 PD patients and 16 healthy control participants practiced a virtual throwing task over 3 days with 24 h rest between sessions. Retention was tested comparing performance before rest with performance after rest. Movement initiation deficits were quantified by the timing of throwing release that should be affected by impairments in movement initiation.To scrutinize the influence of the initiation deficits on retention performance we gave participants a specific initiation intervention prior to practice on one of the three practice days. We found that only for the PD patients, post-rest performance as well as release timing was better with intervention as compared to without intervention. Their performance could be enhanced through a tuning of release initiation. Thus, we suggest that in PD patients, performance decline after rest that might be easily interpreted as learning deficits could rather result from disease-related deficiencies in motor control.

BIO Web of Conferences, 2011

It is suggested that when learning a redundant goaloriented motor task, people explore and choose... more It is suggested that when learning a redundant goaloriented motor task, people explore and choose error tolerant solutions of the task to reduce result variability. This assumption was tested with a virtual throwing task where the error tolerant solutions were designed such that subjects needed to recurrently adapt to a new tolerant solution in order to achieve high performance. We tested 13 participants who practiced the task over six days. All of them adapted to changes in error tolerant solutions although the absolute number of adaptations as well as the rate of adaptation varied strongly between subjects. Results are discussed with reference to motor noise and the integration of practice trials according to error probability.

Zeitschrift für Sportpsychologie, 2007

Human Movement Science, 2013

Recent studies have demonstrated that the direction of attentional focus exerts a substantial inf... more Recent studies have demonstrated that the direction of attentional focus exerts a substantial influence on motor performance. We argue that in well-learned skills, this variable might be confounded with athletes' familiarity with focus conditions. We studied the effect of familiarity and the direction of attentional focus on performance in two experiments using 2 (familiarity)×2 (direction) within-subject designs. A significant main effect of familiarity-that is, better performance under familiar compared with unfamiliar focus conditions-confirmed the influence of familiarity on motor performance. Results are consistent with existing concepts, but lead to different consequences when applied to sport and exercise.

The study of family factors that relate to diabetes management and metabolic control is crucial b... more The study of family factors that relate to diabetes management and metabolic control is crucial because of the family's central role in this management. Four sequential phases of diabetes management are specified in this review: (1) the pre-onset stage; (2) the onset, crisis stage; (3) the accommodation stage; and (4) the stabilization stage. Each stage can be expected to influence the following stage. Thus, each is important to later management of the condition. No theory of family functioning provides a satisfactory framework for understanding the complex relationships between family development and diabetes. The Peabody Family Development Model is introduced as a more complex and systematic way of understanding the stages of management and the long-term view of the individual and family development. Individual and family are acting and reacting, and at the same time, coping with outside influences while moving from one life stage to the other. Historic factors of family and community influence one's view of the world and, consequently, the way regular routines are carried out. Individual characteristics influence individual behavior at any given point in time. The model has at its core a stress-support paradigm, and has an ecologic frame of reference. Behavior is a result of all preceding factors, and information processed is fed back into the system. The Peabody Family Development Model is a way to organize a variety of information on family functioning and to specify how it might relate to the control of diabetes in children.

Zeitschrift Fur Sportpsychologie, Mar 6, 2015

Im Wettkampfsport ist immer wieder zu beobachten, dass Athleten in besonders wichtigen Situatione... more Im Wettkampfsport ist immer wieder zu beobachten, dass Athleten in besonders wichtigen Situationen nur mäßige Leistungen erzielen. Dieses ‚Versagen unter Druck’ oder ‚choking under pressure’ ist häufig bei solchen Fertigkeiten zu beobachten, die durch hohe koordinative Anforderungen geprägt sind. Im Rahmen der Arbeit wird den Fragen nachgegangen, welche Ursachen Leistungseinbußen in Drucksituationen zu Grunde liegen und welche kinematischen Veränderungen der Bewegungsausführung daraus resultieren. Auf der Ebene motorische Kontrollprozesse werden drei plausible Erklärungsansätze für das Phänomen diskutiert. Empirische Belege anhand sportmotorischer Fertigkeiten liegen jedoch nur für eine Erklärungsrichtung vor, die in den letzten Jahren von verschiedenen Autoren mit ähnlichen Annahmen bearbeitet wurde und die unter dem Label ‚Explicit Monitoring Theories’ zusammengefasst wird. Die Grundannahme besteht darin, dass in wichtigen Situationen eine Lenkung der Aufmerksamkeit auf den Ausfüh...

Einleitung. Im Wettkampfsport ist die Leistungserbringung in wichtigen Situationen von entschei- ... more Einleitung. Im Wettkampfsport ist die Leistungserbringung in wichtigen Situationen von entschei- dender Bedeutung, so dass großes Interesse an den Ursachen von Leistungseinbußen in Drucksitu- ationen besteht. Viele Studien unterliegen jedoch zwei Einschränkungen. Zum einen werden wenig geübte Aufgaben genutzt, so dass eine Übertragung auf den Wettkampfsport nur bedingt möglich ist. Zum anderen wird meist nur das Bewegungsergebnis, nicht aber die Ausführung untersucht, was ei- nen wichtigen Beitrag zum Verständnis der Ursachen leisten kann. Diese Aspekte werden in der vor- liegenden feldnahen Untersuchung aufgegriffen. Untersuchung. Die Untersuchung wurde im Rahmen einer Kadersichtungsmaßnahme des Deut- schen Pétanque Verbandes durchgeführt, an der 36 Personen mit mehrjähriger Wettkampferfahrung teilnahmen. Genutzt wurde der in diesem Rahmen vorgesehene "Schusstest". Die Aufgabe bestand darin, eine neun Meter entfernte Zielkugel mit der im Pétanque üblichen Schusstechnik zu...

Zeitschrift für Sportpsychologie, 2005

Http Dx Doi Org 10 1080 00222895 2014 912197, May 23, 2014

The authors examined how varying the content of verbal-motor instructions and requesting an inter... more The authors examined how varying the content of verbal-motor instructions and requesting an internal versus external focus influenced the kinematics and outcome of a golf putting task. On Day 1, 30 novices performed 120 trials with the instruction to focus attention either on performing a pendulum-like movement (internal) or on the desired ball path (external). After 20 retention trials on Day 2, they performed 20 transfer trials with the opposite instruction. Group differences for retention and a group by block interaction showed that external instruction enhanced movement outcome. Kinematic data indicated that specific instruction content influenced outcomes by eliciting changes in movement execution. Switching from the external to the internal focus instruction resulted in a more pendulum-like movement.

Zeitschrift Fur Sportpsychologie, Mar 6, 2015

Frontiers in Behavioral Neuroscience, 2015

The goal of the study was to quantify error prediction processes via neural correlates in the Ele... more The goal of the study was to quantify error prediction processes via neural correlates in the Electroencephalogram (EEG). Access to such a neural signal will allow to gain insights into functional and temporal aspects of error perception in the course of learning. We focused on the error negativity (Ne) or error-related negativity (ERN) as a candidate index for the prediction processes. We have used a virtual goal-oriented throwing task where participants used a lever to throw a virtual ball displayed on a computer monitor with the goal of hitting a virtual target as often as possible. After one day of practice with 400 trials, participants performed another 400 trials on a second day with EEG measurement. After error trials (i.e., when the ball missed the target), we found a sharp negative deflection in the EEG peaking 250 ms after ball release (mean amplitude: t = -2.5, df = 20, p = 0.02) and another broader negative deflection following the first, reaching from about 300 ms after release until unambiguous visual knowledge of results (KR; hitting or passing by the target; mean amplitude: t = -7.5, df = 20, p < 0.001). According to shape and timing of the two deflections, we assume that the first deflection represents a predictive Ne/ERN (prediction based on efferent commands and proprioceptive feedback) while the second deflection might have arisen from action monitoring.

1 Problem Das vorliegende Forschungsprojekt widmet sich dem Einfluss von Aufmerksamkeitsprozessen... more 1 Problem Das vorliegende Forschungsprojekt widmet sich dem Einfluss von Aufmerksamkeitsprozessen auf die Erbringung optimaler sportlicher Leistungen. Dabei wird insbesondere der Frage nachgegangen, inwieweit in der Sportpraxis häufig zu beobachtende Leistungseinbußen in wichtigen Wettkampfsituationen durch unfunktionale Aufmerksamkeitsprozesse erklärt werden können. Obwohl in den letzten Jahrzehnten viele Untersuchungen den Zusammenhang von psychischem Druck und motorischer Leistung belegen, sind die genauen Mechanismen dafür nicht bekannt. In den letzten Jahren wird vermehrt ein von Baumeister (1984) vorgeschlagener Erklärungsansatz aus dem Bereich der Aufmerksamkeitstheorien diskutiert. Dabei wird angenommen, dass es in Situationen, denen eine hohe Bedeutung zugemessen wird, zu einer Lenkung der Aufmerksamkeit auf den Ausführungsprozess der Bewegung kommt und dies bei hoch geübten Fertigkeiten eine Störung der automatisierten Ausführung bewirkt. Dieser Erklärungsansatz wurde in einigen neueren Arbeiten aufgegriffen und erhält Unterstützung aus empirischer und theoretischer Richtung. So konnte entsprechend der Annahmen gezeigt werden, dass automatisierte motorische Fertigkeiten auch ohne Aufmerksamkeitszuwendung ausgeführt werden können und sich schlechtere Leistungen ergeben, wenn eine Zuwendung zum Ausführungsprozess provoziert wird (z. B. Beilock et al., 2004). Ergebnisse von Gray (2004) stützen die Annahme, dass es in Drucksituationen zu einer Hinwendung zum Ausführungsprozess und zu damit verbundenen Leistungseinbußen kommt. Auch aus dem Blickwinkel aktueller Theorien zur motorischen Kontrolle lässt sich die Forderung ableiten, die Aufmerksamkeit bei automatisierten Fertigkeiten nicht auf die Bewegungsausführung (internaler Fokus), sondern die damit verbundenen Effekte in der Umwelt (externaler Fokus) zu lenken (vgl. Hossner, 2004). In einem vorangegangenen Projekt (Maurer & Munzert, 2005) wurden die Vorhersagen des von Baumeister (1984) vorgeschlagenen Erklärungsansatzes unter feldnahen Bedingungen beim Basketball-Freiwurf überprüft. Die Untersuchung wurde mit Spielerinnen der U16/U18-Bundeskader durchgeführt. Im Vergleich zu einer Baselinebedingung er-

BIO Web of Conferences, 2011

Whenever high target accuracy is a limiting factor of motor performance, as in goal-oriented thro... more Whenever high target accuracy is a limiting factor of motor performance, as in goal-oriented throwing tasks, equifinal movement techniques can be used to reduce the influence of inherent biological variability on the task result. In throwing movements, for instance, these techniques are characterized by a specific spatio-temporal organization of the movement trajectory that allows several moments of release that lead to a target hit. Throwing experts (e.g. darts or boule players) with the experience of several ten thousand practice trials show equifinal movements, but also throwing novices can learn to use equifinality after at least 1000 trials of practice. Here, we present a study that aims to scrutinize how the acquisition of equifinal throwing movements can be improved and accelerated. Mechanical guidance was used as intervention method. Determination and mechanical implementation of an equifinal technique in a virtual goal-oriented throwing task as well as results of a four-day intervention experiment are presented. Results confirm that the approaches to compute an equifinal movement trajectory and to implement mechanical guidance are appropriate to support acquisition of error tolerant movement strategies.

Journal of motor behavior, 2014

The authors examined how varying the content of verbal-motor instructions and requesting an inter... more The authors examined how varying the content of verbal-motor instructions and requesting an internal versus external focus influenced the kinematics and outcome of a golf putting task. On Day 1, 30 novices performed 120 trials with the instruction to focus attention either on performing a pendulum-like movement (internal) or on the desired ball path (external). After 20 retention trials on Day 2, they performed 20 transfer trials with the opposite instruction. Group differences for retention and a group by block interaction showed that external instruction enhanced movement outcome. Kinematic data indicated that specific instruction content influenced outcomes by eliciting changes in movement execution. Switching from the external to the internal focus instruction resulted in a more pendulum-like movement.

Human Movement Science, 2014

journal hom ep ag e: www.elsevier.com/loc ate/humov by a short flattening of the BP curves prior ... more journal hom ep ag e: www.elsevier.com/loc ate/humov by a short flattening of the BP curves prior to release. Thus, temporal and shape deviations in the neural movement initiation are assumed to delay self-timed movements.

Frontiers in Human Neuroscience, 2012

In patients with an impaired motor system, like Parkinson's disease (PD), deficits in motor learn... more In patients with an impaired motor system, like Parkinson's disease (PD), deficits in motor learning are expected and results of various studies seem to confirm these expectations. However, most studies in this regard are behaviorally based and quantify learning by performance changes between at least two points in time, e.g., baseline and retention. But, performance in a retention test is also dependent on other factors than learning. Especially in patients, the functional capacity of the control system might be altered unspecific to a certain task and learning episode. The aim of the study is to test whether characteristic temporal deficits exist in PD patients that affect retention performance. We tested the confounding effects of typical PD motor control deficits, here movement initiation deficits, on retention performance in the motor learning process. 12 PD patients and 16 healthy control participants practiced a virtual throwing task over 3 days with 24 h rest between sessions. Retention was tested comparing performance before rest with performance after rest. Movement initiation deficits were quantified by the timing of throwing release that should be affected by impairments in movement initiation.To scrutinize the influence of the initiation deficits on retention performance we gave participants a specific initiation intervention prior to practice on one of the three practice days. We found that only for the PD patients, post-rest performance as well as release timing was better with intervention as compared to without intervention. Their performance could be enhanced through a tuning of release initiation. Thus, we suggest that in PD patients, performance decline after rest that might be easily interpreted as learning deficits could rather result from disease-related deficiencies in motor control.

BIO Web of Conferences, 2011

It is suggested that when learning a redundant goaloriented motor task, people explore and choose... more It is suggested that when learning a redundant goaloriented motor task, people explore and choose error tolerant solutions of the task to reduce result variability. This assumption was tested with a virtual throwing task where the error tolerant solutions were designed such that subjects needed to recurrently adapt to a new tolerant solution in order to achieve high performance. We tested 13 participants who practiced the task over six days. All of them adapted to changes in error tolerant solutions although the absolute number of adaptations as well as the rate of adaptation varied strongly between subjects. Results are discussed with reference to motor noise and the integration of practice trials according to error probability.

Zeitschrift für Sportpsychologie, 2007

Human Movement Science, 2013

Recent studies have demonstrated that the direction of attentional focus exerts a substantial inf... more Recent studies have demonstrated that the direction of attentional focus exerts a substantial influence on motor performance. We argue that in well-learned skills, this variable might be confounded with athletes' familiarity with focus conditions. We studied the effect of familiarity and the direction of attentional focus on performance in two experiments using 2 (familiarity)×2 (direction) within-subject designs. A significant main effect of familiarity-that is, better performance under familiar compared with unfamiliar focus conditions-confirmed the influence of familiarity on motor performance. Results are consistent with existing concepts, but lead to different consequences when applied to sport and exercise.

The study of family factors that relate to diabetes management and metabolic control is crucial b... more The study of family factors that relate to diabetes management and metabolic control is crucial because of the family's central role in this management. Four sequential phases of diabetes management are specified in this review: (1) the pre-onset stage; (2) the onset, crisis stage; (3) the accommodation stage; and (4) the stabilization stage. Each stage can be expected to influence the following stage. Thus, each is important to later management of the condition. No theory of family functioning provides a satisfactory framework for understanding the complex relationships between family development and diabetes. The Peabody Family Development Model is introduced as a more complex and systematic way of understanding the stages of management and the long-term view of the individual and family development. Individual and family are acting and reacting, and at the same time, coping with outside influences while moving from one life stage to the other. Historic factors of family and community influence one's view of the world and, consequently, the way regular routines are carried out. Individual characteristics influence individual behavior at any given point in time. The model has at its core a stress-support paradigm, and has an ecologic frame of reference. Behavior is a result of all preceding factors, and information processed is fed back into the system. The Peabody Family Development Model is a way to organize a variety of information on family functioning and to specify how it might relate to the control of diabetes in children.