Documents / Official release
This Defense Intelligence Reference Document was produced by the Defense Intelligence Agency's Defense Warning Office under the Advanced Aerospace Weapon System Applications program and dated 23 March 2010. It surveys noninvasive and invasive brain-machine interface technologies, including EEG, MEG, fMRI, NIRS and implanted electrode arrays, that could control external devices without limb-operated interfaces. It concludes that noninvasive electrical monitoring is the most promising near-term approach. For the long term it favors invasive single-neuron cortical connections.
From the source: Release of 2026-09-18 Incident: 3/23/10, Las Vegas, Nevada. Released with redactions. This document is a Defense Intelligence Reference Document (DIRD), a technical reference format used by the Defense Intelligence Agency (DIA) to capture baseline knowledge on a specific topic for later analytic use. DIRDs are best understood as reference and synthesis products rather than as original research. It is one of 38 DIRDs produced under the Advanced Aerospace Weapon System Applications Program (AAWSAP) between 2009 and 2011. Because AAWSAP’s scope permitted a broad range of supporting topics, not every DIRD in the series directly concerns aerospace systems or future threat assessment. The following summary reflects the DIRD’s scope and framing at the time of writing and should not be read as implying current validation of the concepts discussed. This DIRD surveys brain-machine interface technologies intended to allow users to control external devices without conventional manual controls, and it evaluates both noninvasive and invasive approaches for turning neural or related physiological signals into usable commands. The report reviews the underlying neural signals, distinguishes between open- and closed-loop control systems, and examines technologies including scalp-based electrical recording, magnetic and imaging-based methods, and implanted cortical interfaces, with particular attention to bandwidth, response time, signal quality, and practical usability. It concludes that, in the near term, the most practical systems are likely to be noninvasive electrical approaches that draw heavily on muscle and neural signals, while longer-term high-bandwidth control would likely require more advanced invasive interfaces capable of robust two-way communication with individual neurons. The document presents thought-based control of external devices as a research field with plausible assistive and specialized applications, while emphasizing that naturalistic, high-performance control remained constrained by major technical and physiological limits.
UNCLASSIFIED/ /P91t 9Ffl@IAL YSIE 8HLY cerebral-spinal fluid (CSF), and internal tissue structures of various other organs. Unlike x-ray based technologies, MRI scans can be optimized to contrast any of the many parts of the physics signal: total density of protons, water content, lipid content, and even particle motion in advanced techniques involving diffusion or spin label ing. Using such scans sequences that take several minutes, one can construct very high resolution images of gray and white matter structure for comparison with, and also mapping onto a "standard brain" template. In addition to electron screening, macroscopic susceptibility will also change the local response to RF stimulation. The presence of even a small amount of metal, say as small as a hairpin, will greatly distort the reconstructed images. Indeed, the usual effect is a shift of frequency completely outside the sensitivity of the machine RF receiver in what is known as "drop-out." Smaller changes in local susceptibility, like produced in the BOLD effect, are measureable. A series of fast scan sequences, typically collecting an entire brain volume at a resolution of 3 mm 3 in 2 seconds, that are calibrated to optimize detection of the BOLD signal will show the dynamics of brain function under the specific internal or applied conditions; this is known as a functional MRI, or simply fMRI. 11 The major advantages of fMRI are unmatched 3D spatial resolution, compared to other noninvasive imaging methods, and complete skull penetration, making it the only imaging modality to unambiguously detect limbic activations important for determining emotionally-laden neuropsychological states. The main disadvantage for BMI is t hat the BOLD signal is detected several seconds after the neuronal firing takes place, making fMRI inappropriate for many naturalistic applications. A long term prospect, likely in the 20- to 40-year timeframe, is that combined low-field MRI and MEG technology could detect neuronal firing deep in the brain and with high temporal accuracy. Initial experiments indicate some level of feasibi lity, but there is substantial development work required in room temperature low field magnetic field detection devices, such as atomic magnetometers, and signal processing algorithms to sift through the substantial electromagnetic background (References 32, 33). NIRS Near-infrared spectroscopy is an additional technology to monitor the BOLD effect noninvasively. Studies have shown it correlates well with the fMRI signal in animal models, although with reduced coverage and lower resolution (Reference 34 ). This lowered resolution greatly affects the accuracy of the technique, with recent work involving single trials and a decision attaining only 80 percent accuracy (Reference 35). Invasive Technologies The most prolific invasive BMI for use in humans is the cochlear implant (Reference 36), a sensory neuroprosthesis designed to aid in hearing for deaf individuals. This device, under continued development and refinement for more than 30 years, consists of a microphone, sound processor, and a receiver t hat is attached to an array of 11 Specifically this is T2 * Echo-Planar Imaging, also cal led BOLD EPI, Gradient Echo EPI, or BOLD fMRI. This approach is used in well over 95 percent of published functional studies, though there are more advanced techniques that concentrate on smaller portions of the hemodynamic signal. For example, Spin-Echo EPI will provide a higher localization within the gray matter, but the cost is a loss of 90 percent of the signal amplitude. UNCLASSIFIED/ /FOR OFFI&Il.tk WSE 8Hk¥ 10
Not linked to a story yet.
Official release, from the pursue collection. The PDF is mirrored here; the original link is above. 36 pages are in the text index: search them above, or from the library's search.