the activation in V1

[kalok87]

Sorry for bothering, but this problem confuses me for a while.

Assume there is a pattern (activation) in ON sheet at time t, then it will eventually affect primary cortex via afferent connections at t + delta*t and it will give the contribution according to the equation (5) mentioned in Steven, J (2013) The Journal of Neuroscience:

C(j,p)(t + delta*t) = Sum{j} eta{i,p} w{ij,p}

and the activation in V1 is calculated by:

eta{j, V}(t) = f( Sum{p} gamma{p} C{jp}(t) )

where the p = A, E, I, and they are for afferent, excitatory, inhibitory, respectively. eta{j, A} is actually the activation in ON/OFF sheet. But the parts for E and I confuse me. Since there are still no activity in V1 sheet at t + delta*t, which means eta{i, E} and eta_{i, I} are both zero, how can we sum up their contribution?

[jbednar]

Initially, the E and I contributions are zero. Once V1 is activated, they become nonzero, leading activity to evolve at the V1 level. You can try presenting the same pattern for 0.05, 0.10, 0.15, etc. time units, to see the activity evolve over time.

[kalok87]

Dear Prof. Bednar,

So the initial activity in V1 eta{j, V} is triggered by eta{i, A} which is the activity of ON/OFF. Assume the initial activity caused by afferent connections is Eta, then the contribution for E and I in V1 can be calculated by:

C{j, E} = Sum{i}( Etaw{ij, E} ) C{j, I} = Sum_{i}( Etaw_{ij, I} )

Is that correct?

[jbednar]

Looks good.