what does "setNew interpreter error: LOW_MEMORY,MEMORY" mean?

Title says all.
I keep getting errors that say "setNew interpreter error: LOW_MEMORY,MEMORY."
I'm assuming it means my Espruino Pico is out of RAM but then again, my code is only 13 lines.

function pause(){}

while (1) {
  digitalWrite(A4, 0);
  setTimeout('pause()', 20);
  digitalWrite(B4, 1);
  digitalWrite(B3, 0);
  setTimeout('pause()', 20);
  digitalWrite(A4, 1);
  digitalWrite(B4, 0);
  setTimeout('pause()', 20);
  digitalWrite(B3, 1);
}

Please help!