The name is absent

52

purely by chance.

However, Γ can be quite low even when most spikes from the reduced system
are coincident. Thus, to better evaluate the effect of false positives, we introduce two
metrics: percentage matched, which is the number of spikes from the nonlinear system
that are also found in the reduced system; and percentage mismatched, which is how
many spikes from the reduced system do not match any spikes from the nonlinear
system:

_rw , ,          # matched

% matched = 100—----;--------—                  (2.46)

# nonlinear spikes

,_w .      , ,   , ,ʌ,ʌ # unmatched reduced spikes            ,_n

% mismatched = lθθɪ------------------------.          (2.47)

# reduced spikes

We vary ½j₁ between 8 and 20 mV, with at least 20 simulations at each threshold
value, and we use τ_ref = 4 ms throughout. Each simulation lasts 1000 ms, during
which time alpha-function synaptic inputs arrive at random locations and at random
times.

We ran two sets of simulations to assess the effect of low- and high-activity inputs.
The low-activity set used 250 “strong” inputs per simulation, while the high-activity
one used 1250 “weak” inputs. These inputs are realistically calibrated by computing
‰ values for the reduced system (as in §2.5.2). These values are scaled to obtain
synaptic conductances at each compartment that would give approximately 3 mV
depolarizations at the soma for the strong inputs, but only 1 mV depolarizations for

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