Abstract
Perceptual learning is usually stimulus specific and, therefore, assumed to occur within the sensory areas or when mapping sensory evidence onto decisions. The motor responses, involving all perceptual learning experiments, are thought to play no role in the learning process. Here, we show that this is not true. Perceptual learning is specific for the stimuli, the task and even the type of motor response. In the first experiment, observers trained with a standard three-line bisection task and indicated the offset direction of the central line by pushing either the left or the right button. Before and after training, observers adjusted the central line of the same bisection stimulus using a computer mouse. They were asked to adjust the line to the smallest visible offset. As expected, performance improved through training. Surprisingly, learning did not transfer to the untrained mouse adjustment condition, even though the visual stimulus was almost the same as during training. The second experiment was the same as experiment 1 except that response types were reversed, i.e., the training was performed with the mouse adjustment task and pre- and post-tests with button presses. As in the first experiment, performance improved trough training and learning did not transfer to the untrained button presses condition. In the third experiment, we repeated the second experiment and recorded the 5600 mouse adjustment traces of each observer during training. The traces were played back to new observers, i.e., observers saw how other participants adjusted the central line. Observers indicated the offset direction of the last position of the central line by button press. Training led to significant learning. There was no transfer to the untrained button presses or mouse adjustments as determined in pre- and post-tests. Our results support theories where stimuli are coded together with the corresponding actions.
Meeting abstract presented at VSS 2016