Why do we need the flag variable?
p=1
ISI
q=1
i=
flag=
1
0
The simulation iterates looking for the first place to start a spike.
Suppose p=1 is the iteration of the last peak and that the (ISI)
refractory period is 5 milliseconds (ms) and timestep is 1 ms.
Suppose we set flag=0 to mean we are in the refractory
period and flag=1 to mean we are in the rising spike.
Why do we need the flag variable?
The test used: timestep*(i­p) < ISI succeed
p=1
ISI
q=1
i=
flag=
1 2
0 0
The simulation iterates looking for the first place to start a spike.
Suppose p=1 is the iteration of the last peak and that the (ISI)
refractory period is 5 milliseconds (ms) and timestep is 1 ms.
Suppose we set flag=0 to mean we are in the refractory
period and flag=1 to mean we are in the rising spike.
Why do we need the flag variable?
The test used: timestep*(i­p) < ISI succeed
p=1
ISI
q=1
i=
flag=
1 2 3
0 0 0
The simulation iterates looking for the first place to start a spike.
Suppose p=1 is the iteration of the last peak and that the (ISI)
refractory period is 5 milliseconds (ms) and timestep is 1 ms.
Suppose we set flag=0 to mean we are in the refractory
period and flag=1 to mean we are in the rising spike.
Why do we need the flag variable?
The test used: timestep*(i­p) < ISI succeed
p=1
ISI
q=1
i=
flag=
1 2 3 4
0 0 0 0
The simulation iterates looking for the first place to start a spike.
Suppose p=1 is the iteration of the last peak and that the (ISI)
refractory period is 5 milliseconds (ms) and timestep is 1 ms.
Suppose we set flag=0 to mean we are in the refractory
period and flag=1 to mean we are in the rising spike.
Why do we need the flag variable?
The test used: timestep*(i­p) < ISI succeed
p=1
ISI
q=1
i=
flag=
1 2 3 4 5
0 0 0 0 0
The simulation iterates looking for the first place to start a spike.
Suppose p=1 is the iteration of the last peak and that the (ISI)
refractory period is 5 milliseconds (ms) and timestep is 1 ms.
Suppose we set flag=0 to mean we are in the refractory
period and flag=1 to mean we are in the rising spike.
Why do we need the flag variable?
The test used: timestep*(i­p) < ISI fail
p=1
ISI
q=1
i=
flag=
1 2 3 4 5 6
0 0 0 0 0 0
The simulation iterates looking for the first place to start a spike.
Suppose p=1 is the iteration of the last peak and that the (ISI)
refractory period is 5 milliseconds (ms) and timestep is 1 ms.
Suppose we set flag=0 to mean we are in the refractory
period and flag=1 to mean we are in the rising spike.
Why do we need the flag variable?
The test used: timestep*(i­p) < ISI fail
flag == 0 success
p=1
ISI
q=1
i=
flag=
1 2 3 4 5 6
0 0 0 0 0 0
The simulation iterates looking for the first place to start a spike.
Suppose p=1 is the iteration of the last peak and that the (ISI)
refractory period is 5 milliseconds (ms) and timestep is 1 ms.
Suppose we set flag=0 to mean we are in the refractory
period and flag=1 to mean we are in the rising spike.
Why do we need the flag variable?
The test used: timestep*(i­p) < ISI fail
flag == 0 success
p=1
ISI
q=1
i=
flag=
We located the start of a spike:
we are outside the refractory
period but flag = 0
1 2 3 4 5 6
0 0 0 0 0 0
The simulation iterates looking for the first place to start a spike.
Suppose p=1 is the iteration of the last peak and that the (ISI)
refractory period is 5 milliseconds (ms) and timestep is 1 ms.
Suppose we set flag=0 to mean we are in the refractory
period and flag=1 to mean we are in the rising spike.
Why do we need the flag variable?
The test used: timestep*(i­p) < ISI fail
flag == 0 success
p=1
ISI
q=1
i=
flag=
Set q=i
Vneuron(i)=0;
flag=1;
1 2 3 4 5 6
0 0 0 0 0 0
The simulation iterates looking for the first place to start a spike.
Suppose p=1 is the iteration of the last peak and that the (ISI)
refractory period is 5 milliseconds (ms) and timestep is 1 ms.
Suppose we set flag=0 to mean we are in the refractory
period and flag=1 to mean we are in the rising spike.
Why do we need the flag variable?
The test used: timestep*(i­p) < ISI fail
flag == 0 success
p=1
q=6
i=
flag=
Set q=i
Vneuron(i)=0;
flag=1;
1 2 3 4 5 6
0 0 0 0 0 0
The simulation iterates looking for the first place to start a spike.
Suppose p=1 is the iteration of the last peak and that the (ISI)
refractory period is 5 milliseconds (ms) and timestep is 1 ms.
Suppose we set flag=0 to mean we are in the refractory
period and flag=1 to mean we are in the rising spike.
Why do we need the flag variable?
The test used: timestep*(i­p) < ISI fail
flag == 0 success
p=1
q=6
i=
flag=
1 2 3 4 5 6
0 0 0 0 0 0
The simulation iterates looking for the first place to start a spike.
Suppose p=1 is the iteration of the last peak and that the (ISI)
refractory period is 5 milliseconds (ms) and timestep is 1 ms.
Suppose we set flag=0 to mean we are in the refractory
period and flag=1 to mean we are in the rising spike.
Why do we need the flag variable?
The test used: timestep*(i­p) < ISI fail
flag == 0 fail
Vneuron(i) >= Vthr fail
p=1
Vthr
q=6
i=
flag=
1 2 3 4 5 6 7
0 0 0 0 0 0 1
q stays at 6 because
flag is 1 – then we can
compute Vneuron(i)from
(1­exp(­Dt/RC))*Vcc
The simulation iterates looking for the first place to start a spike.
Suppose p=1 is the iteration of the last peak and that the (ISI)
refractory period is 5 milliseconds (ms) and timestep is 1 ms.
Suppose we set flag=0 to mean we are in the refractory
period and flag=1 to mean we are in the rising spike.
Why do we need the flag variable?
The test used: timestep*(i­p) < ISI fail
flag == 0 fail
Vneuron(i) >= Vthr fail
p=1
Vthr
q=6
i=
flag=
1 2 3 4 5 6 7 8
0 0 0 0 0 0 1 1
q stays at 6 because
flag is 1 – then we can
compute Vneuron(i)from
(1­exp(­Dt/RC))*Vcc
The simulation iterates looking for the first place to start a spike.
Suppose p=1 is the iteration of the last peak and that the (ISI)
refractory period is 5 milliseconds (ms) and timestep is 1 ms.
Suppose we set flag=0 to mean we are in the refractory
period and flag=1 to mean we are in the rising spike.
Why do we need the flag variable?
The test used: timestep*(i­p) < ISI fail
flag == 0 fail
Vneuron(i) >= Vthr success
p=9
Vthr
Set p =i;
flag=0;
q=6
Vneuron(i)=0;
i=
flag=
1 2 3 4 5 6 7 8 9
0 0 0 0 0 0 1 1 0
The simulation iterates looking for the first place to start a spike.
Suppose p=1 is the iteration of the last peak and that the (ISI)
refractory period is 5 milliseconds (ms) and timestep is 1 ms.
Suppose we set flag=0 to mean we are in the refractory
period and flag=1 to mean we are in the rising spike.
Why do we need the flag variable?
The test used: timestep*(i­p) < ISI success
Vthr
p=9
ISI
q=6
i=
flag=
1 2 3 4 5 6 7 8 9 10
0 0 0 0 0 0 1 1 0 0
The simulation iterates looking for the first place to start a spike.
Suppose p=1 is the iteration of the last peak and that the (ISI)
refractory period is 5 milliseconds (ms) and timestep is 1 ms.
Suppose we set flag=0 to mean we are in the refractory
period and flag=1 to mean we are in the rising spike.
Why do we need the flag variable?
The test used: timestep*(i­p) < ISI success
Vthr
p=9
ISI
q=6
i=
flag=
1 2 3 4 5 6 7 8 9 10 11
0 0 0 0 0 0 1 1 0 0 0
The simulation iterates looking for the first place to start a spike.
Suppose p=1 is the iteration of the last peak and that the (ISI)
refractory period is 5 milliseconds (ms) and timestep is 1 ms.
Suppose we set flag=0 to mean we are in the refractory
period and flag=1 to mean we are in the rising spike.
Why do we need the flag variable?
The test used: timestep*(i­p) < ISI success
Vthr
p=9
ISI
q=6
...
i=
flag=
1 2 3 4 5 6 7 8 9 10 11
0 0 0 0 0 0 1 1 0 0 0
The simulation iterates looking for the first place to start a spike.
Suppose p=1 is the iteration of the last peak and that the (ISI)
refractory period is 5 milliseconds (ms) and timestep is 1 ms.
Suppose we set flag=0 to mean we are in the refractory
period and flag=1 to mean we are in the rising spike.