Purchase this article with an account.
Cristina de la Malla, Joan López-Moliner; Distance-to-contact and not time-to-contact determines when a hitting movement is initiated. Journal of Vision 2011;11(11):947. doi: https://doi.org/10.1167/11.11.947.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
When hitting moving targets, the hand or the hitting object has to be in the correct place at the correct time. That means that action must be initiated taking into account the velocity at which the object moves and has to be continuously updated. There are then two possibilities to calculate when to start the action: a) relying on the remaining distance for the object to arrive to the position where one wants to hit it (distance-to-contact) or b) relying on the remaining time for the object to arrive to the hitting position (time-to-contact). In our experiment, in different sessions subjects had to hit moving targets under harmonic motion with either reliable displacement amplitude or reliable maximum velocity. Results indicate that initiation of the movement is based on distance-to-contact instead of time-to-contact information. In both conditions the action is initiated when the target is at a relative distance (which is slightly different between conditions) from the hitting place, independently of the target maximum velocity. However, the temporal uncertainty present at initiation time is reduced with movement time for both conditions.
This PDF is available to Subscribers Only