Biomedical subjects

Gert-Jan Pepping

Publications and source records attributed to Gert-Jan Pepping.

3 recordsLinked to original sources

PubMed2005

Intercepting beats in predesignated target zones.

Moving to a rhythm necessitates precise timing between the movement of the chosen limb and the timing imposed by the beats. However, the temporal information specifying the moment when a beat will sound (the moment onto which one must synchronise one's movement) is not continuously provided by the acoustic array. Because of this informational void, the actors need some form of prospective information that will allow them to act sufficiently ahead of time in order to get their hand in the right place at the right time. In this acoustic interception study, where participants were asked to move between two targets in such a way that they arrived and stopped in the target zone at the same time as a beat sounded, we tested a model derived from tau-coupling theory (Lee DN (1998) Ecol Psychol 10:221-250). This model attempts to explain the form of a potential timing guide that specifies the duration of the inter-beat intervals and also describes how this informational guide can be used in the timing and guidance of movements. The results of our first experiment show that, for inter-beat intervals of less than 3 s, a large proportion of the movement (over 70%) can be explained by the proposed model. However, a second experiment, which augments the time between beats so that it surpasses 3 s, shows a marked decline in the percentage of information/movement coupling. A close analysis of the movement kinematics indicates a lack of control and anticipation in the participants' movements. The implications of these findings, in light of other research studies, are discussed.

Acoustic Stimulation↗

PubMed2005

Effects of response task on reaction time and the detection of affordances.

Studies on affordance perception commonly report systematic errors; a finding that is at odds with the observation that everyday motor behavior is accurate. The present study investigated whether the means by which perceptual performance is measured could explain the reported errors. Perception of overhead reachability and reaction time were measured using a verbal and an actual reaching response in a standing reach, and a reach-and-jump. Results show that participants accurately perceived their action boundaries for both tasks and in both response conditions. A simple reach, however, took less time to initiate (1,094 ms) than a reach-and jump (1,214 ms). Interestingly, the verbal response took considerably more time to initiate (1,424 ms) than the actual reach (1,154 ms). These results suggest that making verbal judgments about affordances is a different task than actually acting on them. It is therefore concluded that the use of conscious judgments to measure perceptual performance should be considered with care.

Adult↗

PubMed2005

Unnatural selection: talent identification and development in sport.

The early identification of talented individuals has become increasingly important across many performance domains. Current talent identification (TI) schemes in sport typically select on the basis of discrete, unidimensional measures at unstable periods in the athlete's development. In this article, the concept of talent is revised as a complex, dynamical system in which future behaviors emerge from an interaction of key performance determinants such as psychological behaviors, motor abilities, and physical characteristics. Key nonlinear dynamics concepts are related to TI approaches such as sensitivity to initial conditions, transitions, and exponential behavioral distributions. It is concluded that many TI models place an overemphasis on early identification rather than the development of potentially talented performers. A generic model of talent identification and development is proposed that addresses these issues and provides direction for future research.

Achievement↗