Filtering Reveals Form in Temporally Structured Displays
E.H. Adelson and H. Farid
Science, 286:2231, 1999
In a recent report
[Science, 284:1165-1168, 1999], Lee and Blake asked whether the
visual system could use temporal microstructure to bind image regions
into unified objects, as has been proposed in some neural models.
This work has already generated much
They presented two regions of dynamic texture. The elements of the
target region changed in synchrony according to a random sequence,
while the elements of the background region changed at independent
times. Subjects were readily able to distinguish the shape of the
target region. Lee and Blake posited the existence of new visual
mechanisms ``exquisitely sensitive to the rich temporal structure
contained in these high-order stochastic events.''
We believe the effects can be explained with well-known mechanisms.
The filtering properties of early vision can convert the task into a
simple static or dynamic texture discrimination problem. A sustained
cell (temporal lowpass) will emphasize static texture through the
mechanisms of visual persistence; a transient cell (temporal bandpass)
will emphasize texture that is flickering or moving. These cues
probably suffice to explain the perception of form in the experiments.
response from Lee and Blake.