Not sure what you mean about by 1), but certainly, recurrent neural nets are more powerful. 2) is no longer true; see for example the GeneRec algorithm. It does something much like backpropagation, but with no derivatives explicitly calculated, there’s no concern with recurrent loops.
On the whole, neural net research has slowed dramatically based on the common view you’ve expressed; but progress continues apace, and they are not far behind cutting edge vision and speech processing algorithms, while working much more like the brain does.
Thanks. GeneRec sounds very interesting. Will take a look. Regarding 1, I was thinking of something like the theorems in chapter 9 in Perceptrons which shows that there are strong limits on what topological features of input a non-recursive neural net can recognize.
Not sure what you mean about by 1), but certainly, recurrent neural nets are more powerful. 2) is no longer true; see for example the GeneRec algorithm. It does something much like backpropagation, but with no derivatives explicitly calculated, there’s no concern with recurrent loops.
On the whole, neural net research has slowed dramatically based on the common view you’ve expressed; but progress continues apace, and they are not far behind cutting edge vision and speech processing algorithms, while working much more like the brain does.
Thanks. GeneRec sounds very interesting. Will take a look. Regarding 1, I was thinking of something like the theorems in chapter 9 in Perceptrons which shows that there are strong limits on what topological features of input a non-recursive neural net can recognize.