The EmeraldDream

The bridge between mind and machine is real, and people are crossing it in trials, though only a handful so far. A systematic review published in July 2025 counted 80 people worldwide with an implant for paralysis or lost speech, and Neuralink reported 21 trial participants in January 2026. Listening is the stronger half of the craft. Speech decoders have reached 97.5% word accuracy and can give a voice back with about a fortieth of a second of delay, and people steer cursors, tablets and games by intention alone. Speaking back into the brain is far cruder. Retinal and cortical implants return low-resolution sight in trials, and stimulating the touch cortex can let a paralysed hand feel again, but nothing yet approaches the senses we were born with. No implanted BCI has passed the FDA's full premarket approval; Synchron's planned pivotal trial is aimed at the first such filing.

1. Jan 2024Neuralink's first human implant

   Neuralink implanted its first device in a man paralysed by a spinal cord injury, who went on to use it to play video games and chess.

   1 participantEuronews
2. Aug 2024Speech BCI reaches 97.5% accuracy

   UC Davis researchers decoded the attempted speech of a man with ALS from a 125,000-word vocabulary and read it aloud in a voice built from his pre-ALS recordings.

   97.5% word accuracyUC Davis Health
3. Sep 2024Synchron's six-patient safety trial succeeds

   In the first US trial of a chronically implanted BCI, all six patients met the 12-month safety goal with no serious adverse events involving the brain or blood vessels.

   6 of 6 patientsThe Robotics Media
4. Jun 2025Real-time voice from brain signals

   A UC Davis system turned a man's attempted speech into synthesised voice with about a fortieth of a second of delay, letting him change intonation and sing simple melodies.

   ~60% of words understoodUC Davis Health
5. Aug 2025Inner speech decoded, with a mental password

   A Stanford-led team decoded imagined speech in four people with paralysis and showed that a password phrase can keep private inner speech locked.

   4 participantsStanford Medicine
6. Oct 2025Retinal implant restores reading vision

   In a 38-patient trial reported in NEJM, 80% of people blinded by geographic atrophy gained meaningful visual acuity from a tiny light-powered implant, and most could read letters and words.

   80% meaningful improvementScience Corporation
7. Jan 2026Neuralink reaches 21 trial participants

   Two years after its first human implant, Neuralink said 21 people were enrolled in its trials worldwide, up from 12 using implants in September 2025.

   21 participantsReuters (via Yahoo News)
8. Jun 2026Paradromics begins its speech trial

   Surgeons at University of Michigan Health implanted the first participant in Paradromics' FDA-approved Connect-One study of a wireless implant meant to restore communication.

   421 electrodesMichigan Medicine

Next on the road

Synchron plans the first US pivotal trial of a permanently implanted BCI in 2026, and Neuralink says it is ready for its first human Blindsight vision implant once regulators allow it.

The far shore

A safe, fully implanted, wireless link that lasts for decades and carries the world both ways, at the full bandwidth of our senses and muscles.

Whole wiring maps now exist for insects. The newest, a male fruit fly's brain and nerve cord, charts 166,700 neurons. Mammals, though, are still mapped one cubic millimetre at a time. The finest mammalian maps, a cubic millimetre of mouse visual cortex (523 million synapses) and a similar sliver of human cortex (about 150 million synapses), cover roughly a thousandth of a mouse brain and about 0.00007% of a human one. The cost has fallen like a stone, from an estimated $16,500 per reconstructed neuron for the first worm map to roughly $100 in recent zebrafish work. Yet imaging a whole human brain at synaptic resolution would still yield an estimated 2 to 2.8 zettabytes of data, and checking the AI's tracing by hand remains the narrowest pass on this road.

1. 1986First connectome: the C. elegans worm

   Researchers traced every connection among the 302 neurons of a millimetre-long worm by hand, a job that took 16 years.

   302 neuronsGoogle Research
2. Mar 2023First whole insect brain: the fruit fly larva

   The complete synapse-level wiring of a larval fruit fly brain was published in Science, the most complex whole brain mapped at the time.

   3,016 neurons, 548,000 synapsesMRC Laboratory of Molecular Biology
3. May 2024A cubic millimetre of human cortex (H01)

   Harvard and Google reconstructed a tiny piece of human temporal cortex, removed during epilepsy surgery, at nanoscale resolution.

   ~57,000 cells, ~150 million synapses, 1.4 PBScience (via PubMed)
4. Oct 2024Whole adult fly brain (FlyWire)

   The FlyWire consortium published the first complete wiring diagram of an adult fruit fly brain, an animal that can walk and see.

   139,255 neurons, 54.5 million synapsesScience News
5. Apr 2025A cubic millimetre of mouse cortex (MICrONS)

   A consortium mapped a piece of mouse visual cortex and matched it to recordings of about 75,000 of its neurons responding to images.

   200,000 cells, 523 million synapsesMICrONS Explorer
6. Oct 2025Protein barcodes for cheaper mapping (PRISM)

   E11 Bio showed that tagging neurons with unique protein 'barcodes' makes AI tracing nearly ten times more accurate, and says the approach could cut tracing costs 100-fold or more.

   ~10x tracing accuracyMedical Xpress
7. Sep 2026A whole fly nervous system, eyes to legs

   The first complete connectome of a male fruit fly's brain and nerve cord, joined at the neck, was published in Cell after the equivalent of 44 years of human labour.

   166,700 neuronsMRC Laboratory of Molecular Biology

Next on the road

A first whole mammal. NIH BRAIN CONNECTS projects are imaging about 10 cubic millimetres of mouse brain (2–3% of it) to learn whether a whole mouse, some 70 million neurons, lies within reach.

The far shore

A whole human brain: about 86 billion neurons and an estimated 100–1,000 trillion synapses. A whole mouse brain, about 70 million neurons, is the next great step.

No creature has yet been emulated in a way the field agrees is faithful, not even the 302-neuron worm. What exists are models that echo pieces of behaviour: a whole-fly-brain model built from its wiring predicts which neurons drive feeding and grooming, and a startup has joined such a model to a simulated fly body. Sheer scale is no longer the tallest wall. A supercomputer has run a biophysically detailed model of a whole mouse cortex, and GPU clusters have run simplified networks nearing human-brain scale, but those are woven from averaged atlas data, not copied from any one living brain. The State of Brain Emulation Report 2025 names the true obstacles: the models are starved of data, key biology such as neuromodulation is still largely left out, and no one yet knows which details a faithful copy needs.

1. 2011OpenWorm sets out to simulate a whole worm

   An open-science project launched to build the first detailed biophysical simulation of the nematode C. elegans, a goal it is still working toward.

   302 neuronsPhilosophical Transactions of the Royal Society B (via PMC)
2. Sep 2024Wiring alone predicts fly vision

   A model built from the fly visual system's connectome plus the task of detecting motion predicted the activity of 64 neuron types and reproduced more than two dozen past experiments.

   64 cell typesHHMI Janelia Research Campus
3. Oct 2024A whole fly brain, simulated from its wiring

   A simplified model of the adult fly brain, built from its connectome and predicted neurotransmitters, predicted the neurons that drive feeding and grooming, and the team tested those predictions in real flies.

   125,000+ neurons, 50 million synapsesNature (via PMC)
4. Dec 2024Blue Brain Project closes

   EPFL's Blue Brain Project, which pioneered biologically detailed brain simulation, ended after running from 2005 to the end of 2024; a nonprofit foundation carried its tools on from 2025.

   ~20 yearsEPFL Blue Brain Project
5. Nov 2025A whole mouse cortex on a supercomputer

   The Allen Institute and Japan's University of Electro-Communications ran a biophysically detailed model of an entire mouse cortex on the Fugaku supercomputer.

   ~10 million neurons, 26 billion synapsesAllen Institute
6. Mar 2026A fly brain model gets a virtual body

   Startup Eon Systems connected a whole-fly-brain model to a physics-simulated fly that walks, grooms and feeds; the company notes many brain-body links were chosen by hand and the internal dynamics are not yet validated.

   ~140,000-neuron modelEon Systems

Next on the road

Faithful copies of small creatures come first. The State of Brain Emulation Report 2025 calls for 'detail-first' work in worms, larval zebrafish and flies, and the Allen Institute says it is moving toward simulating an entire mouse brain.

The far shore

A simulation of one particular brain that behaves as the original did: a worm, then a fly, then a mouse, and one day a human brain of about 86 billion neurons.

Form can be kept; function, so far, cannot be brought back at any scale. Aldehyde-stabilized cryopreservation (ASC) has held every synapse visible across whole rabbit and pig brains. But it begins by fixing the brain with chemicals, which the Brain Preservation Foundation itself describes as death by today's standards and which makes biological revival exceedingly impractical; scanning and emulation are the only imagined way back. Nectome has posted a version meant to follow physician-assisted death. On the side of true sleep, a 2026 PNAS study woke working synapses, long-term potentiation among them, in vitrified mouse brain tissue, though in slices rather than living animals. Whether a preserved structure still holds a person is unproven: in a 2025 survey, neuroscientists' median estimate that an ASC-preserved brain keeps enough to decode some long-term memories was 41%.

1. Feb 2016Whole rabbit brain preserved, synapses intact

   The Brain Preservation Foundation awarded its Small Mammal Prize for aldehyde-stabilized cryopreservation, which kept connectivity intact across an entire rabbit brain.

   1 whole rabbit brainBrain Preservation Foundation
2. Mar 2018Whole pig brain preserved

   The same method, scaled up, won an $80,000 prize for preserving a pig's brain so well that every synapse could be seen with an electron microscope.

   $80,000 prizeMIT Technology Review
3. Jun 2025Neuroscientists weigh in on preserved memory

   In a survey of 312 neuroscientists, the median estimate that an ASC-preserved brain retains enough information to decode some long-term memories was 41%.

   41% median estimatePLOS One
4. Mar 2026Vitrified mouse brain tissue comes back

   German researchers vitrified mouse hippocampal slices and whole brains, stored them for up to about a week, and after rewarming recorded working synapses - in tissue, not living mice.

   stored up to 8 daysScientific American
5. Mar 2026Nectome adapts ASC to physician-assisted death

   Nectome posted a preprint, not yet peer reviewed and written by company employees, adapting ASC for use after physician-assisted death, demonstrated in pigs.

   whole pig brainsbioRxiv

Next on the road

Carrying reversible vitrification from mouse tissue to human tissue and whole organs. The Erlangen team reports early signs of viability in human cortical tissue, but says better solutions and rewarming methods must come first.

The far shore

A whole human brain kept with every synapse intact, ideally in a sleep it can wake from, and proof that what makes a person survives the keeping.

It does not exist, and no one has published a credible timeline for it. Full-dive would mean writing every sense into the nervous system at natural resolution, while catching every intention to move and keeping the body still. Today, eyes and ears are still reached from outside, and most haptics only buzz; Northwestern's 2025 actuator, which can push, stretch and twist the skin, is a step past that. Writing directly into the brain happens only in medical trials. A cortical vision implant with 544 electrodes aims to help blind volunteers navigate and manage basic visual tasks, while the eyes normally send the brain millions of nerve signals. Stimulating the touch cortex lets a paralysed hand feel, and has now proved safe across a combined 27 implant-years. Taste has been delivered chemically, with about 70% accuracy for simple distinctions. Our honest reckoning: decades, at the very least.

1. Oct 2016A paralysed man feels touch through his brain

   Pitt researchers stimulated Nathan Copeland's sensory cortex so he could feel touch through a robotic arm he controlled with his brain, as natural sensation rather than tingling.

   first in humansScienceDaily (University of Pittsburgh)
2. May 2021Artificial touch halves robot-arm task time

   Adding brain-stimulated touch feedback let a man with tetraplegia grasp and move objects with a robotic arm in half the time.

   20.9 s to 10.2 sUniversity of Pittsburgh
3. Feb 2022First wireless cortical vision implant

   Surgeons implanted 25 miniature wireless stimulators into the visual cortex of a blind volunteer in Illinois Tech's Intracortical Visual Prosthesis trial.

   400 electrodesIllinois Institute of Technology
4. Feb 2025Taste sent over a network (e-Taste)

   Ohio State's e-Taste released taste chemicals on digital command, even triggered from California to Ohio; testers told sour intensities apart about 70% of the time.

   ~70% accuracyOhio State News
5. Mar 2025Haptics beyond the buzz

   Northwestern engineers unveiled a wireless skin actuator that can push, stretch, slide and twist the skin in any direction instead of just vibrating.

   force in any directionTechXplore (Northwestern University)
6. May 2026Cortical vision implant scales to 544 electrodes

   The Intracortical Visual Prosthesis trial's third blind participant received 34 wireless stimulators, aimed at helping with navigation and basic visually guided tasks.

   544 electrodesIllinois Institute of Technology
7. Jul 2026A decade of touch stimulation shown safe

   Pitt and UChicago reported 168 million stimulation pulses across five volunteers with no serious adverse events, and sensations that stayed mapped to the hand.

   27 implant-yearsUniversity of Pittsburgh School of Medicine

Next on the road

Neuralink's Blindsight vision implant awaits approval for its first human, and the Pitt–UChicago touch team says its safety record means industry can begin building take-home sensory devices.

The far shore

Sight, sound, touch, balance, taste and smell delivered directly at natural resolution, every intended movement caught and the body kept safely still, for hours at a time.