Eliezer J. Sternberg, M.D., is a neurologist at Yale-New Haven Hospital and the author of “NeuroLogic: The Brain’s Hidden Rationale Behind Our Irrational Behavior.”

‘Guys please help me — is this dress white and gold, or blue and black? Me and my friends can’t agree.” On Feb. 25, 2015, a photo posted on Tumblr of a party dress led to a social-media firestorm as thousands debated what color it was. Many saw it as blue and black, yet others swore it was white and gold, while still others saw the color scheme switch before their eyes. The phenomenon of “the Dress,” like other optical illusions, suggests that the human visual system can be tricked into misinterpreting reality. However, in his new book, “Deviate,” neuroscientist Beau Lotto suggests a more drastic interpretation: We never see reality.

Since all perception arises from neuronal processing in the brain, Lotto argues, we don’t experience reality directly, but rather the brain’s construal of reality. We experience an interpretation. It’s a thrilling and deeply philosophical point, and Lotto expresses it well. Many who write about the notion of reality and optical illusions would take this opportunity to sensationalize their work by claiming that, since we don’t truly perceive reality, reality does not exist. One certainly doesn’t imply the other, and to his credit, Lotto resists this temptation and instead makes a more measured case: “There is an objective ‘truth’ or reality, but our brains don’t give us access to it.” This may seem like a subtle distinction at first, but in the era of “alternative facts,” the premise that there is an objective reality, a concrete truth from which perceptions and perspectives arise, is foundational to science and makes for a powerful driving force in Lotto’s work.

"Deviate: The Science of Seeing Differently," by Beau Lotto (Hachette)

Peppered with quirky (albeit occasionally distracting) illustrations that parallel the quirks of perception, “Deviate” is an entertaining read that raises fascinating questions about how we perceive the world. Aside from being an accomplished scientist, Lotto is a talented writer who uses illustrative examples and visual experiments to dazzle and to teach.

But “Deviate” is not really about the science of perception. Rather, Lotto’s goal is to show how understanding the biases in our own perception, and intentionally trying to deviate from them, can help us “see differently.” Lotto argues that being aware of your assumptions and biases (basically, being self-aware) will “start changing not just your brain and your perceptions, but your whole way of being as a human.”

Instead of using neuroscience to follow through on this premise, however, Lotto veers into well-worn self-help tips. He relies too often on platitudes such as “we ARE our assumptions” and such empty concepts as “the physics of No.” Lotto devotes 10 pages to the advice “JUST STOP,” by which he means we should actively suppress our unpleasant thoughts or urges. He goes as far as to make the medically unsound suggestion that people who suffer from panic attacks can and should simply “ignore them.”

Short on concrete explanations and experimental results, most of the science in the book comes in the form of references to the brain’s obvious complexity (“the cells that make up your brain form 100 trillion connections”) or broad declarations of how the brain might work: “Your brain does not make big jumps.”

For someone who is arguing that there is an objective truth we can strive to perceive despite our biases and assumptions, Lotto misses a chance to showcase our main instrument in the pursuit of that reality: science. Science is the ultimate, systematic search for truth through hypothesis and prediction, experimentation and observation, drawing conclusions and establishing fact. So why does Lotto, a renowned perceptual neuroscientist, bury the science under prepackaged, superficial aphorisms?

Perhaps the reason has to do with one of Lotto’s own assumptions: that people find science boring. Lotto writes that when you hear the word “science,” “you’re likely to be thinking that science is about the sterility of lab coats and unimaginative facts.”

It is precisely that kind of thinking that is so emblematic of the post-factual age we live in. Facts aren’t “imaginative.” They are dry and boring and factual. But as Lotto expresses so eloquently, since we cannot directly perceive reality, it’s on us to navigate the spaces between bias and assumption to come as close as possible to determining what is objective and true. If we neglect this challenge, the challenge posed by scientific inquiry, we are left to indulge only in that which confirms our preconceptions.

While thousands of people debated online about the color of a dress, some wondered why anybody cared about something so seemingly banal. Lotto contends that the illusion inspired such interest because it defied viewers’ sense of reality, exposing the interpretive nature of perception. Did people really want to know the truth, or were they merely seeking confirmation of their own perspectives? Let’s hope it was the former, because if we acknowledge that we have a fragile grasp of the fabric of reality — that from the outset we merely hold on to the fringes — then it follows that if we cease in our pursuit of objective truth with the rigors of science, all that remains is illusion.

Deviate
The Science of Seeing Differently

By Beau Lotto

Hachette Books. 332 pp. $28