The "consciousness causes collapse" idea is utter nonsense. Suppose I perform an experiment, the result of which is recorded on a photographs plate, which I do not see. I photocopy the plate, without looking at it, and post 100 copies to 100 separate physicists who all look at their copy at the same time. Which of the 100 consciousnesses has caused the collapse?
Let us consider a more elaborate scenario. The property being measured is the spin state of an electron. The electron will trigger a left hand detector if it is spin-up or a right hand detector if it is spin down. The detectors are connected to a computer which notes which detector is triggered and prints the result in the form of a six-digit code. The encoded result is put into an envelope by a robot and posted to a physicist currently on holiday at Malibu.
While the result is en route to Malibu, individual digits of the code are sent by expert radio operators to teams of crack masons at various stone quarries around the world. The masons hastily carve their allotted digit in giant blocks of granite in front of a live crowd, the carving of the granite being beamed to a world-wide TV audience.
Some days later, the physicist in Malibu gets round to opening her mail and sees the six-digit code. She looks in her code-book and deciphers the message to reveal the result of the measurement, hers being the first conscious mind to see it. The wave function now collapses.
Up until that point, the six-digit code was simultaneously in a state off being the code for spin-up and the code for spin down. The giant blocks of carved granite were simultaneously in states of having being carved into one set of digits and having been carved into another. The massive TV audience was simultaneously in a state of having seen the granite blocks spelling out the code for spin-up and having seen the granite blocks spelling out the code for spin down. Ok, I get it- it all makes sense now.