The experiment that changed the question
Planarian flatworms regenerate: cut one in half and each half grows back what is missing. That has been known since the nineteenth century.
Levin's lab changed the membrane voltage pattern in regenerating fragments using drugs that act on ion channels. The fragments grew a second head where the tail should have been. The surprising part came next. When the two-headed worms were cut again, without any further treatment, the pieces regenerated two heads again, over several rounds, with genomes identical to normal worms (Durant et al., Biophysical Journal, 2017).
If the DNA is unchanged and every tissue has been rebuilt, the instruction "build two heads" has to be stored somewhere else. The candidate is the bioelectric pattern itself: a stable distribution of voltages across a network of connected cells.
Eyes on tails, faces in voltage
In frog embryos (Xenopus), Pai and colleagues imposed a specific voltage state on cells far from the head and induced eyes to form there, including on the tail and gut (Development 139, 313, 2012). Earlier, the lab imaged a voltage "pre-pattern" of the face appearing across the embryo before the face's anatomy develops.
The voltage map seems to act like a set of instructions or a target that tissue works towards.
Xenobots and anthrobots
In 2020 Kriegman, Blackiston, Levin and Bongard described xenobots (PNAS 117, 1853): clusters of frog skin and heart cells, arranged by a design algorithm, that move, push particles together and heal. Their genome was never edited. Later work from the lab built anthrobots from adult human airway cells, which crawl and can encourage neurons to grow across a scratch in a dish.
The point for theory: cells whose developmental program ends in skin can coordinate into new, working body forms that no genome encoded.
Levin's framework: cognition as a continuum
Levin interprets these results in terms of goals and memory at many scales. In his TAME framework (Technological Approach to Mind Everywhere, 2022), a cell collective counts as an agent to the degree that it pursues a target state despite perturbations. Its "cognitive light cone" is the size of the goals it can pursue.
This is a working vocabulary with experimental payoffs, which is why it spread quickly. It stays agnostic about subjective experience.
Why this matters for Neural Cosmology
The research programme on this site proposes that memory and form can live in a shared, addressable structure that local units read from, a scheme it calls Pointer Architecture. Levin's results are the clearest biological case of that scheme: cells behave like clients reading a stored target, and the target survives the replacement of the cells.
That view makes a prediction Levin's methods could test: a bioelectric pattern should be transferable between organisms without transferring genetic material. Impose the voltage landscape of a two-headed planarian on a normal one and it should start building two heads at its next regeneration. If that fails under good conditions, this leg of the programme fails too. The full reasoning is in the essay Levin's hologram.
What remains unknown
- How a voltage pattern encodes a specific anatomy, and at what resolution.
- Whether the stored pattern is local to the tissue or depends on long-range coordination.
- Where information processing in cell collectives ends and anything like experience would begin. Nobody has a measurement for that yet.
Bottom line
Levin showed that bioelectric networks store and execute part of the body plan, independently of changes to DNA. That makes biology one of the best places to test ideas about distributed memory, including the ideas behind this programme.