Biomedical Engineering Reference
In-Depth Information
rates
100
r(t)
r
measured
(
E
=30ms)
50
0
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
time [s]
spike trains
4
3
2
1
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
time [s]
auto−correlation
1
r(t)
r
measured
(
E
=30ms)
0.5
0
−0.5
−0.4
−0.3
−0.2
−0.1
0
0.1
0.2
0.3
0.4
0.5
lag [s]
Figure 18.9
Input distribution used to determine the
memory curves
for firing rates. Input spike trains
(second row) are generated as Poisson spike trains with a randomly drawn rate
r
(
t
)
.Therate
r
(
t
)
is chosen every 30 ms from the uniform distribution over the interval from 0 to 80 Hz (first
row, sold line). Due to random fluctuation the actual sum of firing rates
r
measured
(
t
)
(first row,
dashed line) represented by these 4 input spike trains varies around the intended firing rate
r
(
t
)
.
r
measured
(
t
)
is calculated as the average firing frequency in the interval
[
t
−
30 ms
,
t
]
.The
third row shows that the autocorrelation of both
r
(
t
)
and
r
measured
(
t
)
vanishes after 30 ms.
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