During which decade did neural networks first lead to practically useful systems?

Context: The development of metal–oxide–semiconductor very-large-scale integration, in the form of complementary MOS technology, enabled increasing MOS transistor counts in digital electronics. This provided more processing power for the development of practical artificial neural networks in the 1980s. From 1988 onward, the use of neural networks transformed the field of protein structure prediction, in particular when the first cascading networks were trained on profiles produced by multiple sequence alignments.

Answer: The development of metal–oxide–semiconductor (MOS) very-large-scale integration (VLSI), in the form of complementary MOS (CMOS) technology, enabled the development of practical artificial neural networks in the 1980s