Virtual boat to explore Bimanual Adaptation סירת משוטים מדומה לבחינת פעולת המוח בלימוד תנועה מחזורית בשתי ידיים Written by: Tomer Shalev Dan Mor Supervisors: Dr. Amir Karniel Kobi Ben-Tzvi (Rafael) Project presentation

Motion Control The main functionality of the brain is motion control. Understanding the activity of the motion control system may help to build human–machine interfaces, to treat people with physical disabilities and to create intelligent robots.

Argument The basic argument of this project is that coordination between the right hand and the left hand, concerning the frequency and the way the motorized movement is done, is deduced from the visual way the in which the brain comprehends the movement.

The Common Argument The above argument is opposed to the alternative common argument, claiming that the functionality of the two hands is deduced from the muscles system and / or the reflexive nerves system.

Means In this project we will try to examine the claimed argument through a series of experiments, produced with special force-feedback joysticks.

Implementation The project’s code was written using Microsoft’s DirectX 7.0 in Visual Studio 6.0 environment. The main DirectX 7.0 libraries were DirectInput (used for controlling the joysticks) and Direct3D (used for displaying the river and the boat and for managing the boat’s movement).

Experiment Layout The experiments consist of a simulation of paddling a boat. The experimenters are introduced with visual effects, describing with real and false manners the movements of the boat, which are derived from the paddling with the hands. A computerized imaging for the movements of the hands, reacting to the effects, will be done (one damaged paddle, for example).

Experiment – detailed explanation The experimenter is introduced with a task that requires him to generate a routine and symmetric movement with his hands, using the model of paddling a boat in order to navigate it along a straight course in the middle of the river, with minimal deviations.

The Effects After a fixed time interval, the experimenter is introduced with an effect, both visual (boat drift) and mechanical (friction of paddles) that enforces him to change his movements, in order to keep the boat course aligned. That effect can be described using the model’s terminology as a sudden stream in the river or a shortening of one of the boat’s paddle, etc. The effect changes in fixed time intervals, when it switches between no-effect (symmetric movements), effect on the left handle and effect on the right handle.

Paddling Guidelines Rotate joysticks as equal as possible (i.e. same angle, angular velocity and radius for both), in order to keep the boat aligned and drive it in a straight line. In case of a boat shift, return it as soon as possible to the middle of the screen, where a helper vertical line is drawn. Be aware of changes to the friction of the handles that might cause the boat to drift, and correct it by applying more force on the stiffer handle. Be aware of changes to the effect of the handles on the boat movements that might cause the boat to drift, and avoid it by rotating the proper handle faster.

Parameters Recorded Time interval between the triggering of an effect and the correction applied by the experimenter (detection time). Total deviation of the boat from the center (integration of deviation along time), which can be modeled as the distance of the boat from the middle of the river. Time interval between the termination of an effect and the correction applied by the experimenter to the deviation caused by the ‘after effect’ (assuming it is present). Total deviation of the boat from the center because of the ‘after effect’.

Simulation

Results In the end of the project an analysis of the results will be done, in order to determine whether the argument, presented in the beginning of the project, is confirmed.