Biomedical Engineering Reference
In-Depth Information
1.0
(a)
8000
-1.0
0.0
0.2
time (s)
1.8
0.2
time (s)
1.8
1.0
(b)
8000
-1.0
0.0
0.0
time (s)
2.0
0.0
time (s)
2.0
Fig. 5.7.
How good are models? The simple rules described in the text allow us
to reproduce the song of a chingolo sparrow (
Zonotrichia capensis
). The acoustic-
pressure amplitude and the sonograms of the recorded sounds are illustrated in (
a
),
while the synthetically generated sound is represented in (
b
)
was necessary to find the values of the parameters
k
and
p
, at successive
instants, that would drive the model in order to generate the song. With the
values displayed in Fig. 5.8, it was possible to generate a song remarkably
similar to the natural one [Laje et al. 2002].
It is tempting to try one more step. Where are these gestures generated?
Clearly, the activities of the muscles involved should vary in the precise way
that we have described. Therefore, some sets of neurons (dedicated to con-
veying the instructions to the muscles) should let a coordinated firing pattern
emerge. What neurons are these? Where are they located? How do they in-
terconnect? We shall address these issues in Chap. 8.
5.4 Experimental Support
In the model discussed in the preceding section, the main acoustic parame-
ters were correlated with the air sac pressure, the activity of the vS muscle
and the activity of the dTB. In order to build confidence in this model, Franz
Goller and Roderick Suthers recorded these variables. Then, these experi-
mental records were used to drive the model. In this way, one could compare
