phase-locking

[Neil Todd <todd@xxxxxxxxxxxxxxxxx>]

Dear All

Thanks for the replies to my previous request. Now I have another, to do
with phase-locking. A standard result in auditory physiology is the
observation of phase-locked synchronisation of AN unit responses to
sinusoidal stimulation. This may be assessed by means of the synchronisation
index a_bar. Typically for a single unit a_bar might have a sigmoid shape as
a function of stimulus intensity, e.g.

a_bar = 1/[1 + exp(-alpha(INTENSITY - beta))].

My question is this. If one were to measure the group synchronisation across
the whole nerve bundle, how would this summate as a function of the number
of recruited individual units? Assuming that the underlying units have a
well-defined distribution of growth functions, the bulk response will
correspond to integration across the distribution. Intuitively I would
expect the result of the integration to be asymptotic as a function of the
number of units recruited, and to also have a sigmoid shape as a function of
intensity. Rather than spend hours reinventing the wheel, I would be most
grateful if anyone could suggest some references where I can find the maths
for this.

Regards

Neil Todd