What’s up at Boston-area art galleries

It's something most of us negotiate absent-mindedly. Vlatka Horvat, in her installation "Also Called: Backbone, Anchor, Lifeline" at Boston University Art Gallery at the Stone Gallery, brings space to awareness. How does a body respond to the built environment? To the detritus of city life?

For this exhibit, the Croatian-born, London-based artist, who is also known for performance, photography, video, and collage work, scoured the neighborhood around the university for materials. She acquired discards from a local lumberyard and went dumpster diving.

The work is trashy. Rolled up bits of foam rubber, splintery wood. Yet there's something sweetly playful about the installation — much of it is just the right scale for a child. And that sets up a tension with the taboos of a gallery setting. Throughout the space, Horvat has placed planks on their edges, making low, cockeyed corrals that you have to step over to pass through. Is it not verboten to step over art?

Here it's all right, but don't climb on the series of planks near the front of the gallery that look like ramps and a teeter-totter, one delicately joined to the next by strips of foam rubber. And take care not to stub your toe on the upright concrete blocks, scattered throughout the gallery like shy strangers at a party, close enough to nod but not to make conversation. Then there are protruding tubes and ribbons of foam rubber flopping off walls and columns, which seem vaguely unseemly, like someone sticking out a tongue.

Despite its antic energy, the installation exudes anxiety. It's as if neuroses, usually suppressed by the gallery's perfect white-painted walls and stately columns, have erupted through unseen fissures, or seeped in from the more chaotic environment on the street and under the nearby BU Bridge. Horvat uses her scavenged materials to manifest a physical reality that reveals the seductions and indignities we experience every day as we move through spaces, many of which were not made for our comfort.

Horvat's work would fit in "On Sincerity," a large group show curated by Lynne Cooney  and Liz Munsell, at BU's 808 Gallery. An exhibition about sincerity is a compelling premise in an ironic age, although to set up a dichotomy between irony and sincerity is misguided — many use irony to make sincere points. With art-making, and often in this show, it becomes complicated to define sincerity because a degree of artifice is inevitable in the work.

For instance, Laurel Nakadate's series of photos "365 Days: A Catalogue of Tears" documents her yearlong performance, for which she cried every day, to combat the barrage of photos of happy people she found on Facebook. Sure, Facebook, like class notes in an alumni magazine, presents a particular face to the world. But is the face Nakadate presents through a daily ritualized performance any more authentic?

Cooney and Munsell break sincerity in art into four categories: performance art, such as Nakadate's, in which artists use their bodies to express vulnerability; art that critiques mass media (including social media); art in which the material is paramount; and art that builds community.

Douglas Weathersby is in that last category: He'll come and clean up storage spaces and make art out of what he finds. His "808 Gallery Storage Project" is a tree house of a sculpture that shows off paintings left by former BU students dating back decades. Some are good, others are mediocre, but the fantastical display elevates the work.

And materiality? Well, that's an easy one. Art that's driven by clay, paint, wood, or video footage, as opposed to that driven by concept, feels untinged by cynicism. Suara Welitoff's video "Here Comes the Sun" is a painterly, contemplative, strangely fluid work made from footage of pedestrians, and the team Davis-Cherubini's sculptures crafted from two-by-fours, ceramics, and sometimes other materials, speak directly to the body with their off-kilter suggestions of utility and sensuality.

But it's hard to critique the media, especially humorously, without sounding — well, just as sarcastic as the media itself. Charles Gute's "Random Tweets Reformatted as Telegrams" includes "We bought a rotten cantaloupe :(" Imagine feeling the need to report that news in a telegram 150 years ago. Information is a lot cheaper these days, so there's more of it that we don't need. Magda Archer, who pulls imagery from knickknacks, paints a saccharine image of a frolicking lamb with the sentiment "My life is crap." Like Nakadate, Archer jumps from insincere happiness to a despair that in this context looks reactive and snarky.

Real life is complicated and it's hard to be sincere, sometimes even with oneself. Yet, on some level, any artist who works hard on craft and concept can claim sincerity — even David Letterman, whose craft is irony. There's earthy, funny, and poignant work in this show. But remember, in the "Peanuts" comic strip and perennial TV special, how Linus waited and waited for the Great Pumpkin, who would only visit the most sincere pumpkin patch on Halloween? He never came; a standard for sincerity was elusive. That may be the truest depiction of sincerity in art that I've seen.

VLATKA HORVAT:  Also Called: Backbone, Anchor, Lifeline  

At: Boston University Art Gallery at the Stone Gallery, 855 Commonwealth Ave., through Dec. 20.

617-353-3329, www.bu.edu/art/

ON SINCERITY

At: 808 Gallery, Boston University, 808 Commonwealth Ave., through Dec. 16.

617-353-3349, www.bu.edu/cfa

Cate McQuaid can be reached at catemcquaid@gmail.com.