Biomedical Engineering Reference
In-Depth Information
(a)
Trajectory
80
X
Y
Z
60
40
20
0
-20
-40
0
50
100
150
200
250
300
350
400
Summed Neuronal Activity
(b)
60
50
40
30
20
10
0
0
50
100
150
200
250
300
350
400
Sensitivity
(c)
0.8
0.6
0.4
0.2
0
0
50
100
150
200
250
300
350
400
Time (100ms)
FIgURE 4.5:
RMLP time-varying sensitivity. (a)
X
,
Y
, and
Z
desired trajectories for three similar
movements. (b) Neuronal firing counts summed (at each time bin) over 104 neurons. (c) Sensitivity
(averaged over 104 neurons) for three coordinate directions.
both the FIR and RMLP models (Figure
4.6
) shows an initially sharp decrease from maximum
indicating that only a few neurons are required for outlining the movement reconstruction. Of the
104 neurons from the animal used in this study, the 10 highest sensitivity neurons for a given move-
ment are presented in the image plot in Figure
4.6
, and are grayscale coded by cortical area (PP,
posterior parietal; M1, primary motor; PMd, premotor dorsal; M1/PMd, ipsilateral). The highest
sensitivity neurons are primarily distributed over the PP and M1. Of the 104 neurons, 7 of the 10
highest-ranking neurons are common for the WF and RMLP. By experimentally verifying the
