A terminal patient’s right to preserve their brain

Every year, millions of people die who would have preferred to continue living.^a For many, the desire to share more time with loved ones, to see how things unfold, to simply be, does not fade as death approaches.

Medicine strives to extend life, relieve suffering, and honor patient values. Over the past two centuries, it has achieved remarkable progress. Yet medicine today still reaches limits it cannot overcome, and patients die who would have preferred to live.

Brain preservation offers a scientifically plausible option for helping such patients.

The premise is straightforward. When a person’s heart stops, their brain begins to decay.^b Preservation halts this process, preventing the loss of the brain cell structures that underlie a person’s long-term memories and personality. By making use of preservative chemicals, cold temperatures, or a combination of both, it is possible to stabilize the brain’s molecular and cellular architecture, halting decay before it destroys information-bearing structures. For example, in 2018, researchers demonstrated that a technique called aldehyde-stabilized cryopreservation could indefinitely preserve an entire pig brain’s connectome well enough to trace individual connections under electron microscopy across randomly sampled areas of the brain.^3,4

The scientific foundation of brain preservation rests on a principle already accepted in clinical medicine, which is that what matters for survival is the integrity of brain structure, not continuous brain activity. In deep hypothermic circulatory arrest, a technique used in cardiac surgery, patients can experience cessation of brain electrical activity for thirty minutes, yet recover with memories and personality intact.^5,6 The information that makes someone who they are resides in physical neural structures, including biomolecular structures, thus making long-term preservation theoretically plausible.

Modern neuroscience increasingly confirms this. Large-scale connectomics projects have published studies on how function can be derived from structure alone. In 2024, a computational model built from a fruit fly’s complete neural wiring diagram exhibited realistic feeding and grooming behaviors.⁷ In 2025, researchers used the largest functionally-imaged connectomics dataset to date to show that there is a high degree of correspondence between neuronal connectivity patterns and response properties.⁸ While much remains unknown about the brain, and the leap from model organisms to humans involves real uncertainty, the available evidence in neuroscience clearly shows that durable cellular and molecular structures are the substrate of long-term memories. For preservation to not be possible in principle, much of what we know about the physical basis of memory would have to be wrong.

Crucially, preservation and revival are separable problems. While a preserved individual cannot be restored to consciousness with current technology, that does not mean restoration is forever impossible. History offers precedent for this. For example, the Herculaneum scrolls, carbonized by Vesuvius in 79 CE, were unreadable for nearly two thousand years until X-ray tomography and AI extracted their contents.⁹ The San Diego Frozen Zoo began preserving genetic samples in 1972, decades before animal genome sequencing existed.¹⁰ We do not need to know how to restore something today to have good reason to preserve it.

Neuroscience can speak to whether a given preservation procedure is expected to maintain the information that encodes a person’s memories and identity. It cannot predict what future technology will achieve in terms of restoration capacity, which is a question that no one can answer with certainty. Nor can it tell anyone whether pursuing preservation aligns with their values, which is a question that each person must answer for themselves. What the public looks to the neuroscience community for is an assessment of whether the underlying science of memory preservation is sound.

In a 2024 report, the median neuroscientist estimated a 40% probability that a well-preserved brain retains its memories.¹¹ And a 2025 survey of over 300 US physicians showed that the median doctor believes a well-preserved patient has a 25% chance of eventually being revivable.¹² These numbers place preservation in the range of other medical interventions that are undertaken despite uncertain outcomes.^c

Since revival cannot yet be tested directly, any probability estimate requires extrapolation from indirect evidence, and reasonable experts may weigh that evidence differently. On current neuroscience, the probability of successful information preservation following high-quality preservation is clearly non-negligible,^d and an expectation of success of 10% or above is scientifically plausible.^e

In light of the above, three suggestions follow:

None of this is to suggest preservation should be exempt from scrutiny. Quality matters enormously, as procedures performed without rigorous standards may offer false hope and cause harm. Nor does any of this take a position on how, when, or if revival might become possible or desirable. The narrower point is that well-executed brain preservation has a strong likelihood of retaining the information that makes revival potentially possible in the future, and that this possibility deserves serious consideration.

Supporting the statement above does not mean a signatory personally wishes to be preserved. Such a choice is a deeply personal matter. While individuals should be free to access preservation if they so choose, they should also be equally free to decline without pressure.

As with any such treatment, there is risk. Preservation may ultimately prove ineffective, and resources spent on it may yield nothing. But that risk runs in both directions. If preservation works, then people are dying today who could be saved. It means that there are patients who would have had a chance at continued life, had this option been available and accepted. This possibility is substantial enough to warrant serious engagement from the scientific, medical, and policy communities.