The internal competition between categories in the adaptive resonance theor
y (ART) neural model can be biased by replacing the original choice functio
n by one that contains an attentional tuning parameter under external contr
ol. For the same input but different values of the attentional tuning param
eter, the network can learn and recall different categories with different
degrees of generality, thus permitting the coexistence of both general and
specific categorizations of the same set of data. Any number of these categ
orizations can be learned within one and the same network by virtue of gene
ralization and discrimination properties. A simple model in which the atten
tional tuning parameter and the vigilance parameter of ART are linked toget
her is described. The self-stabilization property is shown to be preserved
for an arbitrary sequence of analog inputs, and for arbitrary orderings of
arbitrarily chosen vigilance levels.