Hank, I think the hangup for you is how you generate the pattern.

If you use some counters to "decide" when and what led to light up, instead of hanging your program for .4 seconds, you will see the flag check much faster.

Maybe have your interrupt be a time base, like .1mS or something. Then while in the ISR, check for button press and inc your "led counters"

I know this is vague, but all I have time for right now.