competitive learning (equation)?

[Richard M Young]

I feel a bit embarassed about asking what is presumably a rather 
basic question, especially with the Summer School going on and the 
workshop about to happen, but ... there's frequent mention in emails 
and workshop talks about something called "competitive learning" and 
its associated equation.  The 1998 book doesn't have an index entry 
for it, and Table 12.2 of the basic equations doesn't have one thus 
called.

Could someone explain briefly, or give me a pointer, to what 
"competitive learning" is?

Thanks,
-- Richard