In philosophical circles, "strong AI" has a specific meaning.
It means that executing a certain type of computer program *produces*
consciousness. This happens irrespective of the nature of the computer
which executes the program. Any kind of computer which executes an AI
program (of which no examples are yet known to exist) becomes conscious
(or perhaps we might more carefully say that it causes consciousness
to exist).
Weaker forms of AI might propose that computer programs have some
properties like consciousness, or that we can learn more about human
consciousness by studying programs which model it, etc. Strong AI says
that all you need to be conscious is to execute the right kind of program,
an AI program.
Many thought experiments have been proposed on each side. Searle's
chinese room is designed to show that strong AI can not be true, while
the gradual-neuron-replacement scenarios are intended to show that it
must be true. It is probably one of the most contentious issues in the
philosophy of consciousness.
Hal