Premature vision can interfere with how the brain sets up sight, Brandeis study finds

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Premature vision can interfere with how the brain sets up sight, Brandeis study finds

January 29, 2026

Research in Stephen Van Hooser's laboratory suggests the brain may follow a different set of rules during the third trimester of pregnancy and after a full-term birth, when newborns are normally exposed to visual scenes for the first time.

The findings, published recently in the academic journal eLife, suggest that premature birth may lead to a "too early" visual experience that can interfere with the construction of important connections and pathways in the visual cortex, the part of the brain that receives visual sensory information. Van Hooser, an associate professor of biology at Brandeis, said the study could eventually inform the way we care for premature infants, particularly when it comes to protecting vision.

Van Hooser's lab studied ferrets, mammals born at the equivalent of the second trimester of a human pregnancy, and that don't typically open their eyes for about a month after birth.

"We wanted to ask, even if there is no brain damage, what is the impact of visual experience that is too early?" Van Hooser said.

Drawing a parallel to modern handheld technology like computers and smartphones, Van Hooser said the study found the brain essentially runs background tests as it builds the connections that finalize the ferrets' ability to see and detect motion. In the study, the team found that when the ferret kits' eyes were opened early, the process of cementing those connections was altered.

Van Hooser's team was deep into research on "motion selectivity," or how visual experience helped ferrets develop the ability to distinguish moving bars and edges, when they noticed a surprising and abrupt change. When shown specific flickering patterns, animals that hadn't yet opened their eyes developed a selectivity to the specific patterns shown, while slightly older animals with open eyes developed normal motion sensitivity. It indicated to the researchers that "experience-independent" processes in sensory development is very important. Akin to playing a piano before the keyboard is fully completed, opening the eyes before those processes are complete may alter the way the brain processes vision, Van Hooser explained.

Connections between premature birth and medical issues in humans have long been known and studied, particularly in vision. But Van Hooser's lab's study for the first time parsed some of what's happening in the mammalian brain when eyes first open. The team found evidence the visual experience had biological implications, noting a reduction in cells sensitive to motion in the ferrets' brains, and higher "background response rates" in neurons across both hemispheres in the brain, even if only one eye was opened early, Van Hooser said.

He said the team plans to seek additional funding to continue the research with high-resolution imaging and other techniques to more definitively focus on why these processes unfold as they do.