and character and furthermore are instruments of sensibility and of expression'. 18 Surgical tools are divided in two categories, the ones that need to be guided specifically from the left or right hemisphere of the brain (hence, they are designed for being used by one hand) and the ones that can be guided from either hemisphere. When a surgeon holds a scalpel, the index finger is placed along the edge while the object in turn is grasped by the other fingers within the palm.19 Depending on its function, the surgical instrument is held differently. Similarly, the architect reaches out the index finger and then the rest of the fingers, to grasp the pen to start observing the image rendered in his/her mind. The architect becomes the doctor and the pencil becomes the lancet; the drawing then becomes a surgery. In both cases, the practitioner's hand is controlled by the brain and the tool has become a part of the body. The difference however, is that the surgeon's movements have to be done consciously, while the architect can go free hand; which is why drawing tools are not specifically designed for use with one hand.
1.6 Time Between the visual touch with an object until the actual grasp with the hand, a delay is observed. What is happening during that time? This is the time required for the brain to absorb and manipulate all the information and plan the most efficient strategy to shape and orientate the hand. A cost-efficient plan is when fewer or easier movements in less time are to be followed. The process, according to Mackenzie and Iberall is as follows: 1.
Perceiving task specific object properties
18
Norman Capener, 'The hand in surgery', The Journal of Bone and Joint Surgery, 38 B, (1956), 128-151 (p. 128) 19 Christine L MacKenzie, Thea Iberall, The Grasping Hand, (Amsterdam: North-Holland, 1994), p. 30
18
