With Invention, director Courtney Stephens and writer-actor Callie Hernandez tell a very “American” story. In spite of its disarming, self-deprecating tone, the film depicts a culture of artifice held together with little more than dodgy credit and naïveté, where we’re happy to celebrate scammers if they can bamboozle enough of us into investing in their “therapeutic objects.” Invention, in this land of boosterism, has as much to do with reinventing the self as it does with patenting ideas for novel stress-reduction gadgets.

Invention blends fiction and autobiography to fascinating implications. The plot follows Carrie (Callie Hernandez), a cynical woman whose rather idiosyncratic father has recently died. Hernandez plays a lightly fictionalized version of herself here, with her real father, likewise deceased, making ghostly appearances throughout the film via various ’90s infomercials, in which he leverages his MD to hawk miracle cures beyond the pale of Western medicine.

Dr. J...