Considering the double-slit-experiment version whereby only one electron is fired at once, and a measuring device is placed by one of the slits, which can determine through which slit te electron travels. My question would be: Which case is sufficient to qualify as an observation that will collapse the wavefunction of the observed electrons, thereby destroying the interference-pattern? 1) The presence of a measuring device that is switched on and measuring by one of the slits, or 2) The observation of the results of the measurement from this device by a human being, 3) Otherwise? This experiment could be relatively easy to do. Just place a measuring device by one of the slits, turn it on, totally discard the measuring results, and watch the surface behind the slits for an interference pattern to emerge or not. In my opinion, it will reveal wether consciousness is required to make an observation in the QM sense.