I know very little about QM, so forgive me if this question is a bit difficult to comprehend. I understand that there is some debate about whether a conscious observer is necessary to collapse the wave function. But I was wondering if there was any experimental evidence showing to what degree a conscious observer is actually able to collapse the wave function. What I mean by this is, as an example, as I understand it, in the double slit experiment it doesn't matter if a device is set up to monitor which slit the particle went through, as long as the information about what the device "saw" is not available to an observer, then the device's observation alone is not sufficient to collapse the wave function. Basically if we turn on the device but do not record the information, then the wave function won't collapse. Turn on a recording device, and the wave function collapses. So is a conscious observer, i.e. a person, a sufficient recording device? If we set up the double slit experiment so that a person gets a visual indication of which slit the particle went through, and then sees where on the detector the particle was found, is the observer's memory a sufficient recording device. In an experimental setting wouldn't we have to send many thousands of particles through the experiment in order to establish a clear interference, or non-interference pattern? Obviously a person would be unable to remember all the slit and detection information, and lacking that information, what type of pattern should we expect to see? If a mechanical recording device was unable to accurately record the information, wouldn't we expect the interference pattern to remain. Likewise a person might be able to collapse the wave function of one individual particle, but after a large number of particles, shouldn't we expect to see an interference pattern? So even with a person watching, might we not expect an interference pattern in the double slit experiment? If the conscious observer is the key in collapsing the wave function, then we would expect to see a non-interference pattern, but if the observer is simply a recording device, (and an insufficient one) then wouldn't we still see an interference pattern in the double slit experiment? To me it seems that the conscious observer is merely a recording device, which is why I ask if there is any experimental evidence indicating that a conscious observer can actually collapse the wave function. Is a conscious observer only able to collapse the wave function of that which they are currently observing, but on a long term scale wouldn't the system revert to a probability wave, as the observer's memory is an unreliable recording device? As you can tell, I'm confused. Any information that might help me clear this up would be appreciated.