Nita Farahany's 2023 book—frequently misattributed in memory to Eagleman, whose own work on the brain's hidden life shares adjacent concerns—arrived at a peculiar inflection point. Consumer EEG headbands were novelty items. Meta's acquisition of CTRL-labs was still being processed as a curiosity rather than a strategy. The phrase "cognitive liberty" had not yet entered legislative language anywhere on Earth. Farahany wrote *The Battle for Your Brain* as a warning about a world that was, in 2023, roughly eighteen months away from becoming undeniable. By 2026, nearly every major theme in this book has migrated from speculative concern to active regulatory battlefield. That speed is the book's vindication and its limitation.

What Farahany got right is substantial and specific. The workplace neurosurveillance chapters—SmartCap headbands on truckers, EEG monitoring in Chinese factories—read now less as exposé than as prologue. The EU's AI Act, finalized in 2024, explicitly carved out provisions for emotion recognition systems in workplaces, a category Farahany was among the first to treat as a civil liberties matter rather than an occupational safety curiosity. Her framing of neural data as the next frontier of surveillance capitalism proved accurate almost to the letter: by 2025, at least three major wearable companies had faced regulatory scrutiny over the secondary use of biometric brain data. The chapter on neuromarketing, which might have seemed paranoid at publication, now describes standard practice at several advertising firms that have since been named in FTC complaints. She saw the shape of the problem clearly.

What she did not see—what almost no one writing in 2022-2023 could have seen—was the degree to which large language models and generative AI would subsume and complicate the neurotechnology conversation. The book treats the brain as the primary site of cognitive manipulation, but by 2025 the more urgent vector was not a headband reading your EEG but an AI system modeling your cognition from behavioral data alone, no electrodes required. The elaborate neural interface future Farahany describes is arriving, yes, but it is arriving into a world where the cruder, cheaper, and more pervasive threat to cognitive autonomy comes from algorithmic persuasion systems that never touch the skull. The CTRL-labs wristband she spends considerable time on remains a niche research device in 2026; meanwhile, AI-generated personalized influence operates at scale. The book's framework of "cognitive liberty" remains essential, but its threat model is incomplete—it over-indexed on hardware and under-indexed on software.