**3.1 Method**

The learning phase again consisted of a series of four 4 study-test trials with corrective feedback. On each learning trial, the participant visually perceived an object of a category (e.g., A1) and at the same time haptically explored, under an opaque black foam board, another object of the same category (e.g., A15). Presentation order for the systematic training condition again presented the objects blocked by category; in the random condition, category pairing was maintained but randomly selected in terms of the category presented. Following a given study block, the objects were randomly presented and the subject was asked to identify the category. In the visual condition, the objects were presented visually but could not be touched; in the haptic condition, each object could be manipulated but not seen. In the visual + haptic condition, the objects could be inspected both visually and haptically. Following each response, corrective feedback was provided. This procedure was repeated 3 additional study/test times. Participants were only informed of a category label and told to form each category by using both the appearance and felt conformations of each presented object. Participants were instructed to haptically explore and visually perceive the two conflicting stimuli simultaneously.

The transfer phase began either immediately or one week after completion of the learning phase. Participants were instructed to classify each object to its appropriate category learned during training (A, B, or C), and recognize whether this object was old or new using vision only, touch only, or both vision and touch. To each randomly presented object, participants gave a double-response after each presentation, recognition (Old or New) followed by classification (A, B, or C). Response time was self-spaced but restricted to 15 sec and feedback was not given during transfer test.
