Chapter 2. Prehension

398 Appendices
only sense is vision and there are only three objects that you know
about: mug, pen, and key. Suppose the only action you are capable of
doing is grasping, and the only oppositions you can form are: palm
opposition, pad opposition, and side opposition. Assume the inputs
can be identified by the firing rates of three ‘visual’ neurons and your
postures as the firing rates of three motor neurons. We can represent
the three input objects as transposed vectors:
mug = [0.6, 0, 0.81
pen = [0, 1, 01
key = [0.8, 0, -0.61
And the outputs as:
palm= [l, 2, 31
pad = [O, 5, 41
side = [l, 0, 01
Seeing Grasping
Figure C.9 Heteroassociative memory (of linear units) that
associates patterns impinging on seeing receptors to patterns of
motor activity for grasping. The set of weights learned for the
three objects in the example are seen.
In order to associate a word that you see (the inputs) with one of
the postures you can form (the outputs), you would need a set of
weights on the connecting network as seen in Figure C.9. If the