For four decades, Susan Hiller has investigated the spaces between dream and reality. Her main theme is how we absorb cultural and personal memories. Juxtaposing knowledge derived from her studies as an anthropologist with psychoanalysis and other scientific disciplines, she melds psychological, intellectual and visual concerns. And by investigating what is repressed, forgotten or pushed to the margins of society, her art confers legitimacy on that which lies beyond the bounds of conventional experience.

Hiller was born in Florida in 1940 but, since the early 1970s, she has lived and worked in Britain as an artist. Her extensive body of work, now the subject of a major survey at Tate Britain, has taken many forms, from installations of humdrum objects, placed like talismans in archaeological archive boxes at the Freud Museum, to multi-screen videos such as Psi Girls (1999), in which adolescent girls perform telekinetic feats that offer subversive ideas about the potency of female desire and pubescent sexuality.

Ritual and the power of the human imagi­nation are subjects that Hiller has returned to frequently in works such as her 1970s "group investigation" Dream Mapping, in which participants met to discuss their dreams, and Sisters of Menon (1972-79), created while she was engaged in another group experiment that explored telepathy. Here, mindless scribbles turn into a stream of words in a handwriting that is not the artist's own; it is an investigation into individual identity within the collective.

The Tate exhibition, which focuses on her major works, is a powerful argument for Hiller's status as one of the leading artists in Britain. At the heart of the exhibition is Belshazzar's Feast, the Writing on Your Wall (1983-84). In a mock-up living room, a fire glows on a tele­vision screen like a homely hearth, accompanied by a strange soundtrack. Issues of belief and faith are also explored in Witness (2000), a forest of dangling speakers, which, when put

to the ear, play out individual witness accounts of UFO sightings from around the world in a range of languages. In Hiller's work, something elusive and uncanny lurks beneath the surface of what may, at first, seem familiar or easy to understand.

Her background in feminist politics has informed her work but, first and foremost, she is a visual artist whose practice was influenced by the tenets of minimalism and conceptualism, at a time when such thinking provided an alternative discourse to the grand, gestural statements of (mainly) male painters. Her debt to art history is acknowledged in her Homages, a series of tributes to the 20th-century artists Marcel Broodthaers, Marcel Duchamp, Joseph Beuys and Yves Klein.

Among her most potent works is The J Street Project (2005), which charts every street sign in Germany bearing the prefix Juden (Jew). It speaks eloquently about the absence of a people who have been erased from the places that carry their name.

Another is her installation Monument (1980-81), based on George Frederic Watt's Memorial to Heroic Self-Sacrifice in Postman's Park, London - a tribute to ordinary people who died saving the lives of others. Hiller's version, made from a collage of photographs, supplies a park bench on which the viewer can sit and listen to a recording of the artist as she delivers a series of thoughts on death, heroism and the power of memory. The Last Silent Movie (2007) gives voice to the last speakers of extinct or endangered languages, using recordings from sound archives. Accompanied only by a black screen and white subtitles in which the languages are transcribed, this moving work brings together Hiller's explorations of language, memory and identity.

Runs until 15 May. Details: tate.org.uk/britain [2]