Olshausen BA, Anderson CH, Van Essen DC (1993). A neurobiological model
of visual attention and invariant pattern recognition based on dynamic
routing of information. The Journal of Neuroscience, 13(11), 4700-4719.
We present a biologically plausible model of an attentional mechanism for
forming position- and size-invariant representations of objects in the
visual world. The model relies on a set of control neurons to dynamically
modify the synaptic strengths of intracortical connections so that information
from a windowed region of primary visual cortex (V1) is selectively routed
to higher cortical areas. Local spatial relationships (i.e., topography)
within the attentional window are preserved as information is routed through
the cortex. This enables attended objects to be represented in higher cortical
areas within an object-centered reference frame that is position and scale
invariant. We hypothesize that the pulvinar may provide the control signals
for routing information through the cortex. The dynamics of the control
neurons are governed by simple differential equations that could be realized
by neurobiologically plausible circuits. In preattentive mode, the control
neurons receive their input from a low-level "saliency map" representing
potentially interesting regions of a scene. During the pattern recognition
phase, control neurons are driven by the interaction between top-down (memory)
and bottom-up (retinal input) sources. The model respects key neurophysiological,
neuroanatomical, and psychophysical data relating to attention, and it
makes a variety of experimentally testable predictions.