Synchronization Binding? Freq. Locking? Bursting?

[Christof Koch]

Sorry for not replying earlier to Thomas Edwards RFC on oscillations and
sychnronization.
The issue of oscillations is primarily an experimental one. Do single
cells in the awake monkey show an oscillatory component in their
firing activity and is their firing correlated with the firing of
other cells? Well, the only strong oscillations appear to be those
found by E. Fetz and V. Murphy in Seattle in motorcortex. If the
monkey does a repetitive handmovements these oscillations have a
small amplitude. If the monkey has to get a raisin from a Kluever box,
their amplitude increases a lot. Crick and I would interpret this to
mean that if the money has to attend, oscillations increase.
However, with the exceptions of some tantalizing hints of some power
at 40 Hz in the spectrum of single cells from some labs, nothing
much has been found in the monkey visual cortex, although maybe somebody
out there can correct me.
Of course, Llinas does see 40 Hz waves between thalamus and cortex
in the awake humans using a 37 channel MEG machine.
 
That's why I find synchronized firing, in the absence of oscillations,
an attractive possibility, in particular since phase-locked firing
will lead to a much bigger response at the single cell level than
a temporally smeared out signal (due to the low-pass nature of the
neuronal membrane).
 
Christof