On demand: "Motherboard"

As gestured to by its punning title, the British indie doc Motherboard functions as a reverse-angle on Richard Linklater's much-admired Boyhood. Sometime TV director Victoria Mapplebeck picked up a camera of her own upon giving birth to her son Jim in 2004, when she was 38, and kept it running over the ups and downs of the two decades that followed. In the film's opening montage, we glimpse Jim as he is today, befringed and upright graduate of the Brit School; then we flash back twenty years to a pivotal life moment, and Mapplebeck begins to show how everybody got here. She fell pregnant from a man she confesses she went on a total of four dates with - a fellow who then dumped her, before moving to Spain - so the film's subject is more precisely single motherhood. Mapplebeck quit TV, aware it's not the most supportive industry to work in as a single parent, took a new gig teaching film, then set about raising a child and making a film about raising a child. As you can imagine, it wasn't always fun and games: dad insisted on a paternity test, there was a brush with breast cancer, and Jim had his moodier moments as he approached and passed through adolescence. But Mapplebeck wound up making a young man and a film in parallel: for an hour and a half - rather than Linklater's three - we're watching an extended process of fruition. Women tend to get things done with far less fuss than we men.

A lot of Motherboard could be described as routine: it's washing up, bedtime stories, bus journeys, mother telling son not to pick his nose, holidays, Christmas, small conversations on major topics (Jim's relationship with his dad, Victoria's medical issues). There are small but noticeable changes. Life gets rapidly more digital than it was in 2004: Jim describes his father's Facebook profile as "ones and zeroes", consumer video footage is succeeded by smartphone footage. The big change is that Jim gets bigger and stroppier, both more independent and more troubled, because that's how growing up works. Mapplebeck, for her part, seems very conscious of the fact this is mostly home video, and so strives to mix up her approach with montage, slow-motion, the South London equivalent of Ozu's pillow shots, freeze-frames, X-rays, despairing texts and answerphone or voicemail messages as well as snippets of retrospective narration; Motherboard is absolutely a film made by someone who's taught issues of film form, and resolved to convert theory into practice. Most obviously, she's reviewed the hundreds of hours she must have shot and worked out exactly what story she wanted to tell in these 87 minutes, which is bigger than it first appears, and possibly even bigger than Victoria and Jim themselves. Much as the filmmaker has a realisation while observing her cancer cells through a microscope, Motherboard curates its scenes of small, everyday activity in such a way that they start to speak to far bigger themes: adaptation and endurance, responsibility and care. (You may also wonder to what extent Mapplebeck kept on filming to show Jim's absent father just what he chose to miss out on; though dialled down over time, this is, on some level, film as fuck-you.) It may not look like much at first glance - a low-budget, independently rendered documentary, pieced together for the price of home editing software - but Motherboard remains alert and true to the contours of life.

Motherboard is exclusively available to rent via the BFI Player from Monday.