A novel about James Joyce’s troubled daughter, Lucia, and a reimagining of the chemical castration of Alan Turing have been named the joint winners of the Republic of Consciousness prize, which celebrates the best work by small publishers.

Murmur by Will Eaves (CB Editions), inspired by Turing’s punishment for gross indecency, tied with Lucia by Alex Pheby (Galley Beggar Press) for the Republic of Consciousness award on Thursday night. Both titles win £3,500, split between the press, which is awarded £2,500, and the author, who receives £1,000.

Judge Catherine Taylor said of Murmur: “Will Eaves’ playful, fiercely intelligent interpretation of aspects of the life of a character who closely resembles the brilliant, multifaceted Alan Turing is a dreamlike wonder of memory and consciousness. Its ways are mysterious, its effect deepens with every reading,” she said. Murmur is also shortlisted for the £30,000 Wellcome prize for science-related writing.

Fellow judge David Collard described Pheby’s book Lucia as mesmerising, rich and strange. “She spent much of her life locked away in grim institutions. Pheby is a magician and – quite literally and breathtakingly – ushers Lucia’s restless spirit into a serene afterlife through the careful application of Egyptian funerary rituals.”

The wins come in a year when small presses continue to outperform their larger competitors; all but two of the 13 titles longlisted for the Man Booker International prize come from independent publishers.

Set up by author Neil Griffiths, the Republic of Consciousness prize specifies that works entered must have been published by presses with fewer than five full-time staff members, and which have a commitment to “hardcore literary fiction and gorgeous prose”. In previous years, it has been won by Fitzcarraldo Editions for Counternarratives by John Keene and Influx Press for Attrib and Other Stories by Eley Williams. This year, organisers decided that finding a sole winner was no longer a prerequisite for judges, because “while the competitive dynamic of prizes points readers towards ‘the best books’, they also create a false hierarchy where ‘the best’ becomes a valid category”.

Instead, judges will be told “to select the winning book(s) on the criteria that book X or Y cannot not win”, said Griffiths. “Yes, it’s a double negative, but a minus plus a minus is a positive.”

The award is funded by the University of East Anglia, the Times Literary Supplement, crowdfunding, private donors and an Arts Council England grant; if more money is raised next year, said Griffiths, more books will be able to win the award.

“It may be that a single book wins, it may be that four do. We want to get to a place where we don’t have to choose between books that we can’t choose between. What I really want is that we don’t have winners at all, but a celebration of the best work of small presses,” he said. “Giving three writers an award might split the pecuniary upside by three, but it triples the good feeling.”