ABSTRACT.
Weight modifications in traditional neural nets are computed
by hard-wired algorithms. Without exception, all previous
weight change algorithms have many specific limitations.
Is it (in principle) possible to overcome
limitations of hard-wired algorithms
by allowing neural nets to run
and improve their own weight change algorithms?
This paper constructively demonstrates
that the answer (in principle) is `yes'.
I derive an initial gradient-based
sequence learning algorithm for a `self-referential'
recurrent network that can `speak' about its own
weight matrix in terms of
activations. It uses some of its input and output units
for observing its own errors and for explicitly analyzing and modifying
its own weight matrix, including those parts of the weight matrix
responsible for analyzing and modifying the weight matrix. The
result is the first `introspective' neural net
with explicit potential control over all of its own adaptive parameters.
A disadvantage of
the algorithm is its high computational complexity per time step
which is independent of the sequence length and equals
, where
is the number of connections.
Another disadvantage is the high number of local minima of
the unusually complex error surface.
The purpose of this paper, however, is not to come up with
the most efficient `introspective' or `self-referential' weight
change algorithm, but to show that such algorithms are possible at all.