No one has ever transmitted a thought directly from one brain to another through biological means alone. The electromagnetic fields your brain produces are billions of times too weak to trigger activity in someone else’s neurons, and no natural mechanism for brain-to-brain thought transfer has been identified. But the story doesn’t end there. Researchers have built laboratory devices that can send simple signals between brains using electrodes and magnetic pulses, and newer work on decoding inner speech from brain implants is pushing the boundary of what “reading someone’s mind” could eventually mean.
Why Your Brain Cannot Broadcast on Its Own
The brain runs on electricity, which tempts people into thinking it might work like a radio. It doesn’t. Neurons generate electrical activity that produces magnetic fields on the order of femtoteslas, roughly a billion times weaker than the Earth’s own magnetic field. Sensitive equipment can detect these fields, and one study demonstrated that brain electromagnetic signals could be picked up through a shielded channel at distances up to about 63 centimeters, but only with specialized sensors in a carefully controlled setup.1PubMed Central. Measuring the Electromagnetic Field of the Human Brain at a Distance Using a Shielded Electromagnetic Field Channel That is detection, not communication. The signal reaching another brain at any meaningful distance would be absurdly faint.
To actually influence a neuron, you need magnetic fields many orders of magnitude stronger. Research on molluscan neurons found that pulsed fields in the millitesla range could synchronize neuronal firing or alter action potentials, but milliteslas are roughly a trillion times stronger than what a human brain emits.2Heliyon. Mechanisms of direct brain-to-brain communication and telepathy There is no plausible amplification mechanism that would bridge that gap biologically. The physics, in short, is a wall, not a door.
Brain-to-Brain Interfaces Built in the Lab
If nature won’t do it, technology can approximate it, at least crudely. Several research teams have built systems that read a signal from one person’s brain and deliver a corresponding stimulus to another person’s brain. The reading side typically uses electroencephalography (EEG), which picks up electrical patterns from the scalp. The delivery side typically uses transcranial magnetic stimulation (TMS), which sends a focused magnetic pulse through the skull to activate a small patch of cortex.
In 2014, a team demonstrated the first conscious brain-to-brain transmission between people on different continents. A sender in India used a brain-computer interface to encode simple words like “hola” and “ciao” into binary sequences. Those sequences were transmitted over the internet to Strasbourg, France, where a TMS device stimulated a receiver’s visual cortex to produce flashes of light corresponding to the binary code. The receiver then decoded the message. Transmission integrity was described as excellent.3PLoS ONE. Conscious Brain-to-Brain Communication in Humans Using Non-Invasive Technologies
A later system called BrainNet expanded this to three people collaborating on a simple task. Two senders observed a Tetris-like game and used their brain signals to recommend whether a block should be rotated. A third person, the receiver, got those recommendations delivered via TMS and made a decision without ever seeing the senders’ screens.4PubMed Central. BrainNet: A Multi-Person Brain-to-Brain Interface for Direct Collaboration Between Brains It worked, but the “thoughts” being transmitted were binary choices, essentially yes-or-no signals, not rich mental content. A systematic review of brain-to-brain interface research found that the vast majority of studies used a one-to-one model between just two subjects, with only a handful attempting multi-person setups.5Frontiers in Neurorobotics. Direct Communication Between Brains: A Systematic PRISMA Review of Brain-To-Brain Interface
To be clear about what these systems are and are not: they transmit crude signals, not experiences, memories, or complex ideas. Nobody is beaming a mental image of a sunset into another person’s head. The technology proves a principle, that brain activity in one person can trigger brain activity in another via a machine intermediary, but the bandwidth is laughably narrow compared to the richness of an actual thought.
Decoding Inner Speech From the Brain
A related and arguably more impressive line of research involves reading thoughts out of a brain, even when those thoughts are never spoken aloud. In 2025, a study using multi-unit recordings from electrodes implanted in the motor cortex of four participants found that inner speech, the silent internal monologue you carry on inside your head, is robustly represented in motor cortex and that imagined sentences can be decoded in real time.6Cell. Inner speech, perceived speech, and read-out in motor cortex for speech BCIs This is significant because it means the brain treats thinking a sentence and saying a sentence using overlapping neural machinery, which gives decoders something to work with.
Non-invasive approaches are catching up, too. Researchers have developed models that reconstruct continuous language from fMRI brain scans recorded while people listen to stories. One approach uses a predictive coding framework, drawing on signals from specific brain regions to outperform earlier decoding methods on several measures.7arXiv. Language Reconstruction with Brain Predictive Coding from fMRI Data The output is rough, more like a paraphrase of what someone was hearing or thinking about than a verbatim transcript, but the trajectory over the past few years has been steep.
If you combine a system that can decode thoughts from one brain with a system that can stimulate another brain based on that decoded output, you arrive at something that starts to resemble actual thought transmission. Nobody has closed that loop with anything approaching rich semantic content yet. But individually, each half of the pipeline is advancing quickly.
When Brains Synchronize During Conversation
Even without any technological intermediary, something interesting happens when two people interact: their brain activity starts to align. This phenomenon, known as inter-brain synchrony, has been measured using various neuroimaging tools during face-to-face conversation, cooperative tasks, and shared emotional experiences. A review of the field describes synchrony across brains as playing a role in enabling social interaction and communication, shaping coordination and learning, and even notes that reduced synchrony may be a feature of certain mental health conditions.8PubMed Central. Synchrony Across Brains
What does this look like in practice? In one study, pairs of people working together on creative design and model-building tasks showed dynamic states of inter-brain synchrony that shifted as the collaboration progressed.9PubMed. Dynamic inter-brain synchrony in real-life inter-personal cooperation: A functional near-infrared spectroscopy hyperscanning study Another study using EEG found that romantic couples showed significantly correlated brain activity in the gamma frequency band during naturalistic social interactions, while pairs of strangers did not.10Scientific Reports. Brain-to-Brain Synchrony during Naturalistic Social Interactions
This is emphatically not telepathy. Brains align because two people are processing the same sensory inputs, responding to the same conversational cues, and sharing emotional states through perfectly ordinary channels like facial expressions, tone of voice, and gesture. The synchrony is a byproduct of shared experience, not evidence of direct neural communication. Still, it helps explain why people sometimes feel eerily “in sync” with someone else. The feeling has a real neural correlate, even if the mechanism is conventional.
Thought Broadcasting as a Psychiatric Symptom
For some people, the experience of thought transmission is not a futuristic concept but a distressing daily reality. In schizophrenia and related psychotic disorders, patients sometimes report that their thoughts are being inserted into their mind by an outside force, withdrawn from it, or broadcast outward for others to hear. These experiences are classified as first-rank symptoms and are among the most distinctive features of the illness.
A 20-year prospective study found that thought broadcasting tends to cluster with other symptoms including auditory verbal hallucinations, somatic hallucinations, delusions of self-depreciation, fantastic delusions, sexual delusions, and depersonalization. Auditory hallucinations and self-depreciation delusions were significantly associated with both thought insertion and thought broadcasting.11PubMed. ‘Are these my thoughts?’: A 20-year prospective study of thought insertion, thought withdrawal, thought broadcasting, and their relationship to auditory verbal hallucinations The experience feels completely real to the person having it, which is part of what makes these symptoms so disabling.
Research into why these experiences occur points to disruptions in the sense of agency, the feeling that you are the author of your own actions and thoughts. A study examining schizophrenia patients found impairments in both motor control and the ability to detect one’s own control over objects using sensory feedback, though the broader evaluation of agency remained relatively less affected.12Schizophrenia. Hierarchical analysis of the sense of agency in schizophrenia: motor control, control detection, and self-attribution When the brain’s system for tagging thoughts as “mine” malfunctions, internal experiences can feel alien, planted, or leaked.
A separate study using transcranial magnetic stimulation found that patients with ego-boundary disturbances, the group reporting experiences like thought broadcast, thought withdrawal, and feeling that their actions are externally controlled, showed significantly lower mirror neuron activity compared to schizophrenia patients without those symptoms.13PubMed Central. Mirror neuron dysfunction and ego-boundary disturbances in schizophrenia: a transcranial magnetic stimulation study Research on psilocybin-induced ego dissolution has identified a possibly related mechanism: decreased connectivity between the medial temporal lobe and higher cortical regions, along with reduced integrity of the salience network, a system that helps the brain decide what is internally versus externally generated.14PubMed Central. Finding the self by losing the self: Neural correlates of ego-dissolution under psilocybin The boundary between “my thought” and “the world” appears to depend on specific neural circuits, and when those circuits break down, the experience of thought transmission can emerge spontaneously.
What Parapsychology Research Actually Shows
The idea that humans possess latent telepathic abilities has been tested in formal experiments for more than a century. The most well-known modern protocol is the Ganzfeld experiment, in which a “receiver” in sensory deprivation tries to identify a target image that a “sender” in another room is concentrating on. Results above the chance hit rate of 25 percent have been reported in some meta-analyses, but the field remains deeply contested.
A recent meta-analysis of Ganzfeld telepathy studies examined factors in the sender-receiver dynamic that had not been investigated before. It found that when the sender could hear the receiver’s verbal stream of consciousness during the session, hit rates went up, while adding a review period after the session actually decreased success rates.15Journal of Anomalous Experience and Cognition. Understanding the Factors at Play in the Sender-Receiver Dynamic During the Telepathy Ganzfeld: A Meta-Analysis Critics point out that the sender hearing the receiver introduces a potential sensory channel, the receiver might unconsciously describe the target, and the sender’s reactions could feed back through subtle cues.
The CIA’s Stargate program, which investigated “remote viewing” (attempting to perceive distant locations or events using only the mind), ran from the 1970s through 1995. A follow-up study using recommended improvements to the original protocols reported hit rates significantly above chance in several groups, with one group achieving what the authors described as a comparatively high effect size.16PubMed Central. Follow-up on the U.S. Central Intelligence Agency’s (CIA) remote viewing experiments The CIA ultimately shut the program down, and the broader scientific community has not accepted remote viewing as a real phenomenon. The core objection remains: no known physical mechanism could explain it, and replication has been inconsistent across independent labs.
The honest assessment is that parapsychology has produced a body of work with some statistically unusual results but no consensus explanation. Mainstream neuroscience does not incorporate telepathy into its models, and the gap between “statistically above chance in certain experimental setups” and “people can transmit thoughts” is enormous.
Privacy Concerns as the Technology Matures
Even if natural telepathy isn’t real, the technology to decode what someone is thinking is advancing fast enough to raise serious practical questions about mental privacy. Scholars working on “neurorights” have argued that existing privacy frameworks are inadequate for a world where neural data can be extracted, noting that the protective scope needs to extend beyond brain-targeted devices to encompass the full spectrum of technologies that can infer mental content.17Neuroethics. Neurorights, Mental Privacy, and Mind Reading
One concrete worry is “brainjacking,” the unauthorized control of someone’s electronic brain implant. Deep brain stimulation devices, already used by hundreds of thousands of people for conditions like Parkinson’s disease, have been shown to be vulnerable to interference with their software settings. The possibility of hacking a brain-computer interface has been demonstrated in both experimental and real-world contexts.18PubMed Central. Brainjacking in deep brain stimulation and autonomy If your brain implant can be hacked, someone could alter your mood, your motor function, or your decision-making without your knowledge. That goes beyond thought reading into something closer to thought manipulation.
Consumer-grade brain-computer interfaces are also entering the market. Companies sell EEG headbands for meditation, gaming, and productivity tracking. These devices generate neural data that, in principle, could be decoded to infer mental states, emotional responses, or cognitive patterns. The resolution of consumer devices is far below research-grade equipment, but the data they collect still has value, and the question of who owns your neural data and what they can do with it is largely unanswered in current law.
Emotional Contagion Without Language
Thought transmission in the science-fiction sense may not exist, but emotional states do “jump” between individuals through well-understood channels. This is often called emotional contagion, and it works across species. A study on dogs found that after hearing negatively valenced emotional sounds, whether from humans or other dogs, the animals showed behavioral indicators of increased arousal and negatively valenced emotional states. The response pattern was the same regardless of whether the sound came from a human or a conspecific, suggesting emotional state-matching that crosses species boundaries.19PubMed Central. Investigating emotional contagion in dogs (Canis familiaris) to emotional sounds of humans and conspecifics
In humans, emotional contagion happens constantly and usually without conscious awareness. You walk into a room where everyone is tense, and within minutes you feel tense too, even before anyone has explained why. Mirror neurons, facial mimicry, vocal prosody, and postural alignment all contribute to this process. It isn’t thought transmission in any literal sense, but it accomplishes something similar in practice: your internal state shifts to match someone else’s, and you may not realize the shift was externally triggered rather than internally generated.
Evolutionary theorists have argued that the ability to model other minds, known as theory of mind, may represent a specialized form of cognitive intelligence that emerged through changes in the prefrontal cortex. The capacity to infer what someone else is thinking, feeling, or intending is so central to human social life that it often feels like reading minds, even though the mechanism is inference from behavioral cues rather than direct neural access. People who are highly skilled at this, who read body language and context with unusual fluency, are sometimes described as having an almost telepathic ability. The description is metaphorical, but the skill itself is real and varies substantially across individuals.
How Culture Shapes the Idea
Beliefs about thought transmission are not confined to any one era or society. Across cultures and historical periods, people have reported experiences that don’t fit neatly within materialist explanations: perceived communication with the dead, shared dreams, knowing who is calling before picking up the phone, or sensing a loved one’s distress at a distance. These experiences recur so reliably across unrelated traditions that they constitute a recognizable catalog of human phenomenology, even if their interpretation varies wildly from culture to culture.
Western scientific culture tends to classify all such experiences as either coincidence, cognitive bias, or psychopathology. Other traditions treat them as evidence of a spiritual reality or a faculty that can be cultivated through practice. Neither framing is particularly interested in the other’s evidence. The gap between “people reliably report these experiences” and “these experiences reflect an actual transmission of information” remains the central unresolved tension in the field. What neuroscience can contribute is an increasingly detailed account of what the brain is doing when people have these experiences, without necessarily resolving whether anything beyond the brain is involved.
Media representation compounds the confusion. Science fiction has spent decades depicting telepathy as a clean, reliable channel, think of characters who can project fully formed sentences or images directly into another person’s awareness. When real brain-to-brain interfaces are announced, journalists often frame them through that lens, and the gap between a binary signal sent via TMS and a rich telepathic conversation tends to get lost. The result is a public that consistently overestimates how close the technology is to science-fiction-grade mind reading, which in turn distorts policy conversations about regulation and consent.