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Maybe I could help tidy things up a bit here as someone whose main
research lies in vision.
The argument that coupled oscillations in the visual system are caused
by high frequency eye movements does not seem very viable. The eye shows
a tremor at between 30-70Hz, but of very low amplitude (typically around
1/4 of the half-height width of the optical point spread function).
These will not normally lead to changes in the retinal stimulation of a
sufficiently high contrast to cause measurable temporal effects on the
visual system. More interestingly, perhaps for this discussion, in the
visual system the various different attributes, such as colour,
contrast, motion, depth and so on are all subject to very different
speeds of neuronal conduction and different processing rates. Hence at
the point where it is appropriate to ask how the information is combined
into a single coherent representation, that information is not
synchronous in arrival time. If it turns out to be synchronous
nevertheless, then the implication must be that it has been pushed into
synchrony at that stage.
In vision, there is exquisite spatial precision as well as resolution
but much less precision in the time domain, despite reasonable temporal
resolution. Presumably this reflects the constraint that on the one hand
photon noise is a problem at lower light levels, and on the other hand
that most visual events to be treated as a single object are spatially
I wonder whether anyone has any views on the situation in the auditory
does it invest in high temporal precision (as well as high frequency
do events need to be temporally contiguous and correlated to become a
do events need to be spatially contiguous and correlated to become a
The drift of the discussion so far suggests that the auditory system
maps temporal frequency onto spatial layout. How about temporal
information (ie envelope information)?
Professor of Psychology
University of Stirling