The Afterlife Experiments
Gary Schwartz PhD is a professor of psychiatry, medicine, neurology, surgery and psychology at the University of Arizona. "The Afterlife Experiments" is a book that was published in 2003, and is a description of a series of experiments that he undertook investigating communication through mediums, to examine whether consciousness exists after death.
The experiments used well known mediums in the US, and were conducted under increasingly rigorous conditions to investigate messages that the mediums received from people who had died. The experiments used "sitters" - people who were related to the people who had died - to verify the accuracy of the information.
A follow up study was published in 2007, using more stringent methods to discount possible experimental flaws, by Beischel et al (2007) in the journal Explore, and can be downloaded here.
I understand that these experiments have been ongoing, and more up to date information can be found in Dr Schartz's later books.
To be honest my favourite parts of "The Afterlife Experiments" were not so much about the mediumship, perhaps because I'd already read the more recent scientific papers, but more the information towards the end of the book where Dr Schwartz speculates about how we and the world might change if it did become scientifically accepted that life continues after death.
He also goes on to offer some scientific hypotheses for how life after death might occur, from a physics perspective, how we might impact the universe through electromagnetic waves emanating from our heart, and how love might be the driving force of the universe.
You can read a scientific critique of this book, and the responses to this critique, on this website: https://archive.is/S6ii7