Gestural channel and the function of gesture

Claude Cadoz defines the gestural channel as a means of action on the physical world as well as communication means in a double sense: emission and reception of information.

Cadoz proposes three hand actions (or hand gesture functions):

• Ergotic : the action of modifying and transforming the environment. There's energy transfer in this action.
• Epistemic : the action of getting knowledge from the environment. E.g. the information received by the tactile sense.
• Semiotic : the action of conveying information to the environment.

We can see from the above that both ergotic and epistemic functions need some kind of physical contact with a device. On the other hand, the conductor's gestures [8] have only a semiotic function - the information is conveyed to the visual sense of the musicians in the orchestra. There's no ergotic or epistemic function in these gestures.

From this classification, one can start discussing the different gestures depending or not on the need of physical contact with a device [9], what can be called free (or empty-handed) gestures in opposition to instrumental [10] or ergotic [7] gestures. Mulder, for example, divides hand movements into two groups, one involving communication and the other manipulation and prehension.
 

Wed Feb 10 10:07:20 MET 1999