There’s something arresting about Rob Setrakian’s “The Continuum,” a sublime retrospective of his psychologically charged canvases at the Bolinas Gallery that opened on Saturday. Spanning five decades of oil paintings, prints and pastels, the work blends fast and loose gestures with intimate scribbles and delicate lines, all churning together in bold waves of color.

Running through Thanksgiving, the exhibition marks Mr. Setrakian’s reentry into the art world following a six-year hiatus taken after his wife Beth’s dementia diagnosis. The afternoon before the opening, Mr. Setrakian—a slender figure with a salt-and-pepper mustache—stood in the gallery, unspooling a strand of antique beads that once belonged to his uncle, a San Francisco jeweler. Though he knew he wanted them to be part of the exhibit, their precise placement was undecided.

“I don’t even know if it’s done,” he mused about the centerpiece of the show: a 14-foot canvas on Belgian linen—his first painting in years and a raw, unfiltered reflection of his recent life. “But life is a work in progress.”

The piece began under a full moon just months ago, mounted on a fence on Mr. Setrakian’s Bolinas property. As moonlight and sunlight shifted across the medium in the ensuing weeks, he traced in pastel the fleeting shadows cast from surrounding branches and the geometric lattice of the fence. In the resulting composition, tart oranges, blues, reds, greens, and dirty grays interrupt each other mid-sentence, creating a dynamic tension against a stark white background—a landscape that captures the flotsam and jetsam of the unconscious mind.

Mr. Setrakian’s work is filled with images that seem to swim, float and shapeshift. As the viewer’s gaze traverses from one end of the canvas to the other, the world tilts, perspectives flatten, and details melt away. Yet the improvised surfaces convey a startling openness and vulnerability, a kind of glyphic form of art in which each spontaneous mark serves double duty as sign, symbol, letter and notation.

A series of three oil paintings on paper from 1979—“Interior with glow,” “Kachina Doll” and “Looking Through”—offer abstract dreamscapes that summon memories and archetypes. In the first, a spectral, spindly figure stands in the doorway of a wood-paneled room—a ghost rendered in deep blacks, nocturnal blues and velvety purples. Primally familiar, it summons both memories of things seen and things imagined.

The touch of his mentor, Nathan Oliveira, whom Mr. Setrakian met as an undergraduate at Stanford, is subtly visible. Oliveira was known for his solitary figures suspended in a pigmented atmosphere.

These are contemplative paintings that encourage viewers to lose themselves, even briefly, something hard to do in galleries without a place to sit. So Mr. Setrakian turned the old barn into a living room, with chairs from his home, a desk and touches of the personal. “It’s a place for Beth,” he said.