Neurosecurity: When the Brain Becomes a Battlespace

Moreno did not demonstrate science-fiction mind control. His argument was more consequential: advances in neuropharmacology, brain imaging, neural interfaces, cognitive enhancement, and behavioral science would inevitably attract military and intelligence interest, raising ethical questions before many technologies became operationally mature. [1]

That concern quickly became institutional. In 2008, the U.S. National Research Council published Emerging Cognitive Neuroscience and Related Technologies to identify developments in cognitive neuroscience with potential implications for U.S. national security. [2]

James Giordano and colleagues pushed the discussion toward an explicit national-security framework. In 2010 they argued that neuroscience and neurotechnology would have defense and security applications and called for preparedness and an ethics of responsible action. [4]

A decade later, DeFranco, DiEuliis, and Giordano discussed “neuroweapons,” dual-use neuroscience, neural data, human-machine interfaces, and security vulnerabilities in National Defense University’s PRISM. Recent NDU material also discusses the brain as a potential “battlespace.” [5,6]

Throughout this article, we trace the spread of scientific, strategic, and defense interest in these ideas. We do not claim that such interests were formalized or deployed as real, operational weapons unless there is separate public evidence for that claim.

The term neurosecurity originally had a narrower technical meaning. Denning, Matsuoka, and Kohno used it in 2009 for the security and privacy problems created by neural devices and neural information. [3]

Cognitive warfare is broader and less settled. The International Committee of the Red Cross notes that there is no universally agreed definition; the term can include attempts to affect perception, emotion, belief, judgment, decision-making, and behavior through information operations, behavioral science, cyber capabilities, AI, immersive environments, and potentially neurotechnology. [7]

A useful distinction is simple: cognitive warfare treats cognition as an objective; neurotechnology treats the nervous system as an interface; neurosecurity becomes especially important where those two domains overlap.

Modern implanted brain-computer interfaces can extract useful information from neural activity. In 2023, a Nature study reported a high-performance speech neuroprosthesis that translated attempted speech from intracortical recordings into text. [8]

The conditions matter: implanted electrodes, a consenting participant, extensive calibration, a defined task, and individualized machine-learning models.

Non-invasive decoding methods are advancing as well. In 2025, d’Ascoli and colleagues reported a deep-learning approach for decoding individual words from EEG and MEG using data from 723 participants; part of the author team was affiliated with Meta AI. MEG signals were generally decoded more accurately than EEG, and under the best conditions the model reached up to 37% top-10 accuracy within a 250-word retrieval set. [14]

That is a meaningful advance, but the experimental setup also defines its limits: recordings were obtained under controlled conditions during known tasks, and the authors themselves describe natural-language decoding from non-invasive recordings as an open challenge. [14]

Non-invasive neuromodulation is real. Transcranial magnetic and electrical stimulation can alter neural excitability, and low-intensity focused ultrasound is being studied as a way to influence targeted brain regions with greater spatial precision and access to deeper structures. A 2024 Nature Reviews Methods Primers review summarizes a growing human literature on focused-ultrasound neuromodulation. [9]

Published scientific literature shows that TMS, tES/tDCS, and focused ultrasound can, under certain conditions, modify neural activity and measurable functional responses. The same literature does not demonstrate targeted remote transmission of complex thoughts, beliefs, or behavioral commands.

As implants, wearables, and closed-loop systems acquire, transmit, analyze, or modify neural information, confidentiality is only one concern. Integrity matters too: who can alter the data, algorithm, stimulation parameters, or device behavior?

UNESCO’s 2025 Recommendation on the Ethics of Neurotechnology explicitly addresses autonomy, freedom of thought, mental privacy, mental and physical integrity, cybersecurity, mental-state inference, AI-neurotechnology convergence, dual use, misuse, and malicious use. [12]

In ordinary cybersecurity, compromised data may expose a password. In neurosecurity, the long-term concern is that compromised technology may expose, infer, or eventually alter something much closer to the person.

This topic is included for a specific reason, not as a random detour. Directed energy regularly appears in neurosecurity and cognitive-warfare discussions, and Anomalous Health Incidents, commonly associated with “Havana Syndrome,” are among the best-known cases in which a radiofrequency mechanism received formal scientific consideration. In 2020, a National Academies committee judged directed, pulsed radiofrequency energy a plausible mechanism for the distinctive acute symptoms in some cases. [10]

That finding did not establish that a weapon had been used, identify a device, identify an attacker, or demonstrate a capability to control cognition. In 2024, an NIH-led study found no significant differences between affected participants and controls on most clinical, cognitive, auditory, vestibular, visual, and biomarker measures, while documenting genuine symptom burdens in affected individuals. [11]

The episode is best treated as an example of epistemic difficulty: biological plausibility, incomplete evidence, classified information, real illness, and dramatic technological claims can coexist without yielding a definitive conclusion.

Cognitive influence does not require electrodes. Information systems can shape what people repeatedly see; recommendation systems can privilege emotionally engaging material; generative AI can create persuasive content at scale; profiling can segment audiences; and cyber operations can alter the information environment in which decisions are made.

None of this provides deterministic control over an individual. But it may still be strategically important. The ICRC’s analysis emphasizes the convergence of information operations, cyber capabilities, AI, behavioral influence, and prospective neurotechnology. [7]

This suggests a layered view: information environments on the outside, behavioral targeting beneath them, physiological and biometric sensing deeper in, and EEG, neural implants, BCIs, and neuromodulation closest to the nervous system.

The OECD adopted its Recommendation on Responsible Innovation in Neurotechnology in 2019. [13] UNESCO followed with a broader global ethics recommendation in 2025. [12] The ICRC has argued that cognitive warfare and emerging neurotechnologies remain subject to international humanitarian and human-rights law. [7]

The practical agenda is therefore less dramatic than “defending against mind control,” but more urgent: security-by-design for neural devices, strong protections for neural and inferred mental-state data, transparent risk assessment, legal and ethical review of military applications, and clear evidence labels that separate demonstrated capability from plausible mechanism, strategic scenario, and speculation.

Neurosecurity matters not because the human brain has become fully understood or controllable, but because some neural signals can already be measured, decoded, and modified through technological intervention.

It is that increasingly capable systems can measure fragments of neural activity, infer limited states, connect to the nervous system, modify selected processes, and surround people with information environments optimized to influence attention and behavior.

The brain does not need to become completely controllable to become strategically valuable. It only needs to become accessible enough. At that point, neurosecurity stops being science fiction and becomes security.