Consciousness is irrelevant to quantum measurement. Decoherence is something that happens in the measuring device as a rapidly increasing number of particles become entangled with each other. This holds regardless of what quantum interpretation you employ, settling both the Schodinger’s cat and Wigner’s friend dilemmas once and for all.
Science cannot and never will be able to establish the existence of something spiritual, immaterial, non-physical, or whatever you want to call it. THAT is the difference between something which is physical/material and something which is spiritual/immaterial. Physical things are a part of the mathematical space-time structure of the universe and spiritual things are not, and it is ONLY those space-time relationships which make scientific measurements possible.
The death of materialism was the discovery by science that everything is not matter, but rather that everything is energy. Thus there are no materialists anymore. What we have instead are naturalists, who believe that the scientific worldview is the limits of reality itself – that the only real knowledge is scientific knowledge.
I found only 2 Scientific American articles about the soul.
We have a Soul, and so do crows by John Horgan December 21, 2017
Physics and the Immortality of the Soul by Sean Carroll May 23, 2011
The first article is about the continuity of human (and animal) personality even when we have both lost our memories and our ability to make new memories is gone. It establishes that who we are is not reducible to memory alone. Even identical bacteria (easy to obtain since they divide into genetically identical copies) do not behave identically To be sure this does not even come close to establishing that anything immaterial is involved or that there is anything which is going to survive the death of the cell or body.
The second article by famous atheist scientist Sean Carroll addresses the claims of Adam Frank, who made this argument about the moon and green cheese which frankly shows a profound misunderstanding of science. By explaining this I can do a lot better than Sean Carroll’s treatment which is simply to call this “obviously absolutely crazy.” Way to go Sean, the only thing you establish with that remark is your prejudice. The way science works is that we make the hypothesis that the moon is made of green cheese and then we test it. Sending men to the moon accomplishes this and the test gives a negative result. We now have a procedure that anyone can perform to get the same result. And the test keeps coming back negative. The point is not that there is no possibility that such a test will ever be positive, but only that it is most reasonable to conform our belief to what the evidence shows which is always that the moon is not made of green cheese.
To be sure there are no spirit particles (as Sean entertained) interacting with the particles of matter to connect the physical measurable reality to something eternal. But any particles discovered will only alter the mathematical laws to include them and thus extend our awareness of the physical universe to include these also. Belief in an immaterial soul thus simply rejects the overall premise of Sean Carroll that what science discovers and even can discover is the limit of reality itself. But what can we say to Sean Carroll? Well we can ask him if there is evidence that the laws of physics are not a causally closed system? And that is where Carroll will fall flat on his face because the answer to the great chagrin and confusion of a great many physicists, is yes. In fact it is an an open and shut case that there are are no hidden variables allowed within the scientific worldview to determine some events or to determine the results of some measurements which can be made.
The result is that Sean Carroll can only hold his premise of naturalism by an act of faith alone that nothing (outside the limits of the scientific worldview) ever determines any of these events or measurements. The explanation that works on the moon made of green cheese argument completely fails here because there never will or could be any tests of an hypothesis like that. The most that Sean Carroll can say is that there will never be any objective evidence for such a cause from outside the limits of the scientific worldview and thus never any objective means to settle disagreements about such causes.