Your Brain: Under the Hood
By Abby Roberts
June 1, 2026—The human brain is one of the most complicated systems in the known universe. In New Orleans on June 1, neuroscientist and science communicator David Eagleman, PhD, launched his opening keynote at AIHA Connect 2026 with a set of facts demonstrating our brains’ complexity. Its 86 billion neurons are linked via 200 trillion connections, Eagleman said. Yet most of its processes occur without our conscious knowledge, or “under the hood,” as he put it.
Eagleman, who is also an author, a consultant for the HBO show “Westworld,” and the host of the podcast “Inner Cosmos,” described the conscious mind as “the broom closet in the mansion of the brain” because it plays a small part in decision-making. Or it can be compared to a CEO who receives only a summary of the company’s operations. According to Eagleman, we think of ourselves as individuals, but we’re really collections of neurological systems with competing priorities. In the realm of occupational safety, this means that guardrails and checklists are necessary to constrain our competing neurological systems. As Eagleman pointed out, “people are not rational.”
Eagleman explained that people have a larger, more wrinkled cortex than non-human animals, enabling more connections for the brain’s “circuitry” and a greater ability to set goals. Our neurons also have the ability to reconfigure throughout our lives. In neuroscience, this is commonly known as “neuroplasticity,” but Eagleman prefers to call it “liveware,” in analogy with computer hardware and software.
But the human brain’s senses are also limited compared to the rest of the animal kingdom. Eagleman drew comparisons with bats, which locate prey via echolocation; ticks, which sense heat and body odor; and ghost knifefish, distant relatives of the electric eel that use weak electrical signals to communicate. The “world” inhabited by each species is constrained by their ability to sense and perceive it, a concept known to biologists as an “umwelt.”
“Our experience of reality is constrained by our biology,” Eagleman said.
Humans, however, can use technology to expand their umwelt. Eagleman explained that sensory perception consists of signals that your brain interprets to construct meaning, but the brain itself is a “general purpose compute device” that doesn’t care where the signals come from. For years, his work has focused on "sensory substitution," or feeding information into the brain through unconventional channels. Eagleman is the founder of the company Neosensory Inc., which has developed a vest that can be programmed to vibrate in response to input, as well as a wristband that operates similarly. Among a host of other applications, these devices allow Deaf wearers to perceive sound waves or blind users to navigate unfamiliar environments.
According to Eagleman, there’s no end to the possibilities of human sensory perception. “How do you want to experience your universe?” he asked the audience. “How do we move beyond automatized behavior?”
Novel experiences and continuous challenges are vital to long-term brain health. Eagleman cited a 30-year study of 678 Catholic nuns who underwent annual neuropsychological assessments and donated their brains for research after death. While some of the donated brains showed signs of Alzheimer’s disease, none of the nuns had exhibited symptoms of cognitive decline in life. The study’s authors concluded that the nuns’ lifelong learning and cognitive stimulation were among the factors contributing to their neurological health.
“Nothing is meant to be glued down,” Eagleman said. He ended his keynote by challenging his audience to think about their work in new ways. “It’s the best thing you can do with your brain.”
Abby Roberts is assistant editor of The Synergist.