How do people make decisions about motor activities? The Chair of Human Movement Science at the Technical University of Munich (TUM) has published an essay in the specialized journal "Frontiers in Psychology" (Impact Factor 2.089). In an experiment, Dr. Melanie Krueger together with Full Prof. Dr. Joachim Hermsdörfer studied the influence of various uncertainties on motor activities. "The topic of 'Motor Decision Making' is currently a top topic in our field both nationally and internationally," says Prof. Hermsdörfer.
Experiment with 66 movement tasks in three blocks
Precisely examined was the extent to which various causes and levels of uncertainty during motoric decision-making influence the execution of targeted pointing movements. To do this, 10 subjects had to perform 66 movement tasks in one experiment with three blocks each. From a starting point, you should point a finger at a point on a screen. In the first block, the point appeared before the movement was completed so that there was no uncertainty about the target point.
In the second block, two dots were shown, one of which became colored after the movement had begun and then had to be touched. This process created a high uncertainty about the target during the planning of the movement. In the third situation, both points became colored after the start of the movement. The participants had to choose one of the two points during the execution. In order to measure the movements of the test subject, the position of their fingertip was recorded via 3D motion capture throughout the process. "The experimental design is naturally very broken down and abstracted from everyday life. This consequently enables us to gather objective knowledge in a targeted manner," explains Hermsdörfer.
The brain plans different actions in the event of target ambiguity
The primary result is that different potential actions in target ambiguity are planned simultaneously. "The decision to take a specific action is only made during execution. The brain not only prefers a single serial movement in its
planning, but also considers other alternatives," explains Prof. Hermsdörfer. This, for example, enables one to deal with varying and unforeseen environmental situations that people frequently encounter in practice. For instance, if you want to grab one of several nearby handgrips which wobble spontaneously in the subway while the train is moving.
In the future, further studies on this subject field with other subject collectives will be conducted at the chair. "For example, we know very little about the decision-making behavior of elderly individuals, since this group has hardly been explored at all," says Hermsdörfer.
To the Paper in the Journal Frontiers in Psychology
To the Homepage of the Chair of Human Movement Science
Contact:
Prof. Dr. Joachim Hermsdörfer
Chair of Movement Science
Georg-Brauchle-Ring 60/62
80992 Munich
Tel.: 089 289 24551
E-mail: joachim.hermsdoerfer(at)tum.de
Text: Dr. Fabian Kautz
Photo: TUI