Anesthesia was routinely withheld from babies undergoing surgery in the 1980s because clinicians believed they were not conscious.

Understanding what consciousness is, and why and how it evolved, is perhaps the greatest mystery known to science. Watch interviews with the world's leading experts on what it is and whether we'll ever know.

The nature of consciousness—what it is, where it comes from, and how it manifests as moment-to-moment experience—remains under debate by scientists. Recent studies show psychedelics were found to boost low-frequency brain signals known as delta waves, a behavior also seen during dream states.

In the final moments of life there are distinctive bursts of coordinated neural activity. Researchers are interested in parsing that data to better understand the dying process and also exploring how this data relates to our understanding of consciousness.

Despite the powerful memories associated with NDEs, scientists question the idea that the experiences prove consciousness endures after death, opting instead to find physiological explanations for common reports of out-of-body experiences, euphoric and lucid thinking, and more.

Technology has advanced to where the seemingly separate fields of psychology and neuroscience are asking the same questions about dreams, such as whether they're more closely related to perception or visualization. Some field-intersecting findings include research that shows people with impaired face perception don't dream of faces, those with brain legion-related cognition difficulties deal with similar issues in dreams, and children's dreams change in parallel to their cognitive development.

Seeking to resolve long-standing variations between hospitals and state procedures, in 2023 several expert groups published comprehensive step-by-step guidance for clinicians to follow when determining brain death in kids and adults. Among other guidelines, it stated that doctors don't need to get family consent to do the tests needed to make this determination.

Consciousness is a complex emergent phenomenon of the brain, which is primarily composed of neurons and glial cells. Since all matter is composed of atoms that follow the laws of physics, there may be quantum processes beyond classical electrochemical interactions that can explain where consciousness comes from.

There's only one thing in our solar system sophisticated enough to study itself: the human brain. But this self-investigation is challenging because a living brain is shielded by skull, swaddled in tissue, and made up of billions of tiny cells. How do we study living brains without harming their owners? Two experts explain how the various techniques like EEGs, fMRIs, and PETs work in this TedEd talk.

Since quantum systems exist as a superposition of states before producing a definitive outcome, some quantum pioneers wondered if the act of conscious observation was what collapsed the wave function of possibilities into one state.

This video and accompanying article in the peer-reviewed New England Journal of Medicine show the then-standard steps of a full brain death examination—demonstrating the process on a medical dummy to search for pain, blinking, eye movement, cough, gagging, or other forms of responsiveness. (May need to sign up for a free account to view.)

The definition set a legal and medical precedent for how we define death, important for issues including organ donation. This 2020 video podcast discusses the history of brain death controversies and the variability in how death has been determined, including discussions in the late 1960s about when patients are considered dead in the context of organ donations.

A new study found that 3-year-olds were less averse to the smell of vegetables they had been repeatedly exposed to in utero, suggesting that what mothers eat in late pregnancy can leave a lasting imprint on their children's tastes.

A key ethical dilemma—the contemplation conundrum—explores whether implants might misinterpret mere imagination as intent to act. Neuroscientists have found no brain signal that clearly marks when someone decides to act, making intent hard to detect in neurotechnological systems.

Brain organoid research is enabling researchers to study distinct electrical firing patterns associated with schizophrenia. These "mini-brains" that are constructed in the lab from patients' cells could lead to better diagnosis approaches and drug development.

David Chalmers is one of the leading philosophers of consciousness. In this video, he outlines some of the major questions in this field, including the "hard problem of consciousness," which seeks to find neural correlate for every conscious experience.

Several companies developing brain-computer interfaces have begun testing on humans with promising results. These implants have helped reanimate paralyzed limbs and enable communication, though ethical concerns remain about data privacy.

Fear is a survival mechanism that originates in the brain's amygdala, triggering the body's fight-or-flight response. However, in modern society, without the same natural dangers, fear can lead to anxiety and mental health issues when unnecessarily triggered. Understanding individuals without fear may help identify new methods to treat anxiety disorders.

Neurons in the brain are singular nerve cells that flicker on and off or connect to each other based on incoming stimuli. The more neurons communicate by firing electrical impulses through tendrils known as synapses, the stronger their connection becomes. The electrical energy zipping along these interneural connections in an attempt to classify and respond to incoming stimuli may be what gives rise to thoughts.

Researchers have discovered that a combination of experiences and genetic factors shape the anatomy of the human brain. They found even quick experiences affect the brain’s genetic makeup, which—over time—means every person develops a completely unique brain anatomy. While brain imaging could be used to identify individuals, it remains much more expensive than fingerprinting for now. Read to found out more about this study from the University of Zurich.

Though little indentations form on the side of the fetus's neck at roughly nine weeks—with some formations taking place even before then—developmentally, these indentations don't become ears that allow a little one to hear until around 18 weeks.

Near-death experiences usually happen during death or on the border of life and death when a person isn't understood to be conscious. This article details the science of what's going on with the brain during NDEs.

Limited safeguards prevent governments from accessing and companies from sharing brain data. Foreign governments may also be developing technology to spy on and potentially disrupt human thoughts.

Babies are drawn to their mother's smell—and the particular odor of their mother's breast milk—within days, even as their vision remains blurry for months after birth. In the womb, the olfactory center also forms in the early stages of development.

The arc toward anesthetics was painfully slow, with early pain mitigation offerings ranging from analgesics—drugs that dim pain but don't block it—and numbing surgical sites with cold water to gassing patients with carbon dioxide or bashing or bleeding them unconscious. Such treatments and the torturous surgery they preceded led many to avoid even life-saving procedures, and those who survived often kept silent about the trauma.

Researchers at a hospital in the US have successfully used artificial wombs to care for preterm lambs and are now looking at the possibility of human trials. This nine-minute video includes interviews with the researchers and explains the reasoning...

Though babies don't initially produce tears when they cry, this podcast discusses how humans are hardwired to cry throughout life. Most crying research relies on self-reporting of crying and emotions. This podcast notes that there aren't neuroimaging studies of crying—they're quite expensive to complete. As a result, the brain precursors and processes during a bout of crying remain understudied.

Artificial wombs may be able to help preterm babies survive their early entry into the world and possibly curb the long-term adverse health effects associated with such premature birth. This article dives into the current ethics and science behind artificial wombs and ectogenesis, which is when a fetus develops in artificial conditions.

Conclusions from this 2024 analysis from a team of Danish researchers included that touch interventions were particularly useful for newborns in regulating cortisol levels, helping newborns gain weight, and reducing pain.

Dutch cardiologist Dr. Pim van Lommel conducted one of the largest studies of near-death experiences following cardiac arrest, publishing the results in the prestigous journel The Lancet. He later went on to argue (to significant criticism from peers) that his findings suggest consciousness can exist outside the body.

This thought-provoking piece highlights newer research suggesting sleep twitches may not be random dream leftovers, but instead a crucial way our brains map and understand our bodies. From sleeping rat pups to dreaming octopi, this biological mapping system appears universal across animal species.