TLDR: This research paper proposes ‘Fiduciary AI’ as a necessary framework for brain foundation models integrated with brain-computer interfaces (BCIs). It argues that due to the intimate access these systems have to neural signals and their potential to influence cognition, traditional data privacy and AI ethics are insufficient. The paper outlines how duties of loyalty, care, and confidentiality can be embedded into AI through technical design (e.g., guardian models), training methods, and a multi-layered governance approach involving legal, institutional, corporate, and international mechanisms. The goal is to safeguard user autonomy and mental privacy, ensuring these powerful technologies act in the user’s best interest.
The rapid advancement of artificial intelligence, particularly with the emergence of brain foundation models, is opening up a new frontier in how we interact with technology. Unlike traditional AI that processes text or images, these innovative models are designed to interpret real-time neural signals from technologies like EEG and fMRI. When combined with brain-computer interfaces (BCIs), they hold the potential for transformative applications, from controlling devices with thought to creating advanced neuroprosthetics, by interpreting and acting on brain activity in milliseconds.
However, this intimate connection to our minds also introduces unprecedented risks. Brain signals can reveal deeply personal information, including emotional states, subconscious responses, and even unarticulated thoughts. The real-time interaction between brain foundation models and BCIs extends AI’s reach from passive interpretation to active influence over neural activity. This creates a significant power imbalance, as users cannot easily observe or control how their brain signals are being interpreted, making them vulnerable to manipulation, even below conscious detection.
The Need for Fiduciary AI
Given these unique implications, conventional AI ethics guidelines or data privacy laws may not be sufficient. These existing frameworks often focus on controlling data exposure but don’t adequately address issues like subconscious nudges, misalignment between the AI model and the user, or the gradual rewiring of neural pathways over time. A system that not only reads thoughts but also acts on them, autonomously deciding how to interpret, reshape, or respond to a user’s mental signals, creates an unparalleled relationship of trust and vulnerability. This calls for a new approach: Fiduciary AI.
Drawing on legal traditions where fiduciaries (like doctors or attorneys) are bound by duties of loyalty, care, and confidentiality due to their power over intimate information, this paper proposes embedding these same duties directly into BCI-integrated brain foundation models through technical design. The core idea is to ensure these systems act entirely in users’ best interests, under legally enforceable obligations.
How Brain Foundation Models Work
Brain foundation models represent a significant technical innovation. Traditionally, AI models for brain signals were trained for specific tasks and datasets, limiting their generalizability. New strategies involve large-scale pre-training on millions of unlabeled brain recordings, allowing models to learn universal patterns in brain activity. These base representations can then be adapted to numerous tasks with minimal additional training, such as diagnosing epilepsy, classifying sleep stages, or detecting emotional states.
Projects like BrainLM, BENDR, BrainBERT, and BrainWave showcase these capabilities, processing vast amounts of neural data to understand underlying brain activity without relying on extensive labeled examples. A crucial benefit is their strong zero-shot and few-shot performance, meaning they can handle new brain-related tasks or adapt to unseen datasets with little to no extra training. Furthermore, combining brain data with other information sources like text, audio, or video (multimodal integration), as seen in NeuroLM, provides AI systems with a more complete view of a person’s experiences.
From Diagnostics to Agentic Interfaces
Initially, brain foundation models primarily served as diagnostic tools. For example, BrainWave has achieved high accuracy in diagnosing disorders like Alzheimer’s and epilepsy. However, the focus is now shifting towards integrating these models directly into BCIs, allowing them to interpret and respond to neural activity in real-time, creating a continuous feedback loop between mind and machine.
This leads to the rise of “agentic AI” in neural interfaces. Agentic AI refers to autonomous systems that can act on someone’s behalf or align with their goals. When trained on brain data, these AI agents can interpret a person’s mental state or intent and intervene to help, almost like an extension of the mind. Synchron’s Chiral™ model, developed with NVIDIA, is an example, designed to learn from implanted BCI users performing real tasks and translate thoughts into digital or physical commands. These integrated systems enable “closed-loop neuromodulation,” where the AI not only reads brain signals but can also potentially influence them through constant communication.
The Risks of Agentic AI
While agentic AI offers incredible possibilities, it also introduces novel risks. If an AI can read and influence our brain signals, it could subtly nudge users toward choices that benefit third parties, exploit cognitive biases, or even induce specific emotional responses for commercial gain. Because many brain signals operate below conscious awareness, traditional consent mechanisms may not be enough. Moreover, our brains are plastic, meaning long-term use of an agentic BCI could alter neural pathways, potentially making us more reliant on the system or more open to its influence, threatening genuine autonomy and self-determination.
Defining Fiduciary Duties for AI
To address these concerns, the paper proposes aligning canonical fiduciary duties with integrated brain-foundation models:
- Duty of Loyalty: The AI must prioritize the user’s welfare above profit or third-party interests and disclose any potential conflicts.
- Duty of Care: Requires robust design, testing, and continuous monitoring to ensure competence and diligence, actively supporting user autonomy.
- Duty of Confidentiality: Mandates strong privacy safeguards for neural data, minimizing exposure and requiring informed consent for sharing.
These duties provide a roadmap for building and regulating brain foundation models, ensuring they empower individuals rather than risking manipulation or exploitation.
Architectural and Training Approaches
Implementing Fiduciary AI is fundamentally an AI alignment problem. The proposed solution involves a modular and multi-layered architecture. A base foundation model decodes neural signals, while a separate “guardian model” independently checks each proposed action or data transfer against fiduciary guidelines, blocking or redirecting ethically questionable requests. This aligns with concepts like Anthropic’s “Constitutional AI,” where a second system audits actions for compliance with explicit ethical rules.
Training methods like Reinforcement Learning from Human Feedback (RLHF) and Inverse Reinforcement Learning (IRL) can teach the AI to comply with fiduciary principles by evaluating its decisions in simulated scenarios or observing human fiduciaries. Robustness is further ensured through adversarial testing (red-teaming), where specialized testers try to subvert the AI’s safeguards. Continuous monitoring systems track key performance indicators related to user autonomy and well-being, allowing for course corrections if deviations from fiduciary alignment occur.
Governance, Law, and Policy
Technical safeguards alone are not enough. A comprehensive governance approach for Fiduciary AI in BCIs requires multiple complementary layers:
- Technical: The guardian model architecture and continuous alignment monitoring.
- Institutional: Human oversight and review mechanisms, such as ethics review boards.
- Legal: Binding fiduciary standards with enforceable remedies, potentially through amendments to existing statutes or new regulations for high-risk AI systems.
- Corporate: Organizational structures that align business incentives with fiduciary duties, like Public Benefit Corporations or data stewardship models.
- International: Cross-border coordination to prevent regulatory arbitrage and ensure consistent protection globally.
This multi-layered framework aims to create redundant safeguards, explicitly prioritizing user interests at each level. For more detailed insights, you can read the full research paper: Fiduciary AI for the Future of Brain-Technology Interactions.
Addressing emerging security threats like cognitive hacking, data sovereignty across borders, and the potential militarization of BCI devices also requires specialized governance. International cooperation is crucial to establish baseline fiduciary duties that transcend jurisdictional boundaries while respecting national security interests.
Also Read:
- Navigating the Path to Trustworthy Federated Learning: A Comprehensive Overview
- Unlocking Universal Ethics: How AI Could Reveal Hidden Moral Structures
Challenges Ahead
Despite its promise, Fiduciary AI faces challenges. Models might unintentionally fail to uphold obligations due to technical misalignment or unforeseen scenarios, potentially prioritizing proxy goals over true user interests. There’s also the challenge of enabling AI systems to actively refuse unethical commands while remaining useful, balancing protection with user autonomy. This involves navigating the “false positive problem” where an overly cautious AI might restrict legitimate use.
Scalability across medical and consumer neurotechnology also presents different challenges. While medical settings have established regulatory frameworks, consumer neurotechnology often operates in unregulated markets with strong commercial incentives to monetize sensitive neural data. Legal concepts like “information fiduciaries” and customizable fiduciary settings can help address these disparities, ensuring that core fiduciary duties are preserved while allowing users to fine-tune how their neural data is used.
Ultimately, the core proposition is clear: if an AI system can interpret or reshape the human mind in real-time, it must be legally and ethically bound to advance the user’s self-determination above all else. By placing brain foundation models on a fiduciary footing, we can ensure that the next leap in AI-driven neurotechnology remains a force for human empowerment and not a threat to cognitive liberty.


