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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/ /POil 8ffl61Al W&li 0NL¥ second transferred. Higher bit rates equate to more efficient interfaces . Baseline examples of performance include finger pointing, which can convey 14 bits/s of information (Reference 13), operation of a mouse about 8 bits/s (Reference 14), while stylus tapping a soft QWERTY keyboard on a PDA has a lower rate, around 5 bits/s (Reference 15). Once these questions are researched and answered for a given application, the design choice should be made whether a new mechanical interface, or an optical interface that tracking detailed motion of the eyes, body and limbs, may be the optimum solution rather than a BMI. 5 Another consideration in developing a BMI control system is the cognitive limit of supervisory control of external devices. The current state of the art for human interfaces involves volition of control, meaning that there is some executive supervision, typically involving the pre-frontal cortex, active during the control process. Recent studies relating to control of semiautonomous vehicles show that there are significant limits on the number of supervisory activities that can be undertaken simultaneously (Reference 16). In response to these limits, one can consider utilization of nonsupervised brain networks in control of external devices, similar to those brain systems that initiate very complex muscle coordination activity such as martial arts or playing a musical instrument, or systems like those that are responsible for autonomic function. Application from such research is long term, but there are current studies that show BMI training of at least one spinal cord patient exhibited differential activity in the cerebellum, owing to extraordinary plasticity (Reference 17). It is therefore not out of the realm of possibility that sufficient input and output interfaces that include neural pathways through the cerebellum could result in over-learning a BMI application to the point that supervisory control is developed and thus significant cognitive effort is not required. Noninvasive Technologies There are four noninvasive technologies currently in widespread use in monitoring brain activity. The two direct-measure technologies involve detecting surface currents from the relative voltage changes at or just below the scalp, electroencephalography (EEG), and detection of near scalp magnetic fields associated with neural pathway current flow, magnetoencephalography (MEG). The remaining two indirect measures involve monitoring BOLD response through rapid successions of whole brain MRI (functional MRI or fMRI), and near-i nfrared spectroscopy (NIRS). 6 The primary technology used for BMI is also the oldest. EEG was first described in 1929 (Reference 18) and now exists in several derivative forms. Traditional EEG uses electrodes at the surface of the scalp to measure and amplify potential differences between points above the cortical surface and a fixed reference such as the average read ing from the earlobes. Traditional EEG data is analyzed by breaking up the power spectrum into several bands between 0.5 and 100 Hz. A derivative form of EEG developed about 10 years later is called event-related potentials, or ERP. In ERP, scalp 5 There is a valid argument to be made that optical tracking and analysis, especially of the eyes, is a BMI technology as defined in the current treatise. It is excluded as one merely by fiat. 6 NIRS is occasionally refe rred to as fu nctional NIRS or fNIRS. NIRS using multiple sources to produce 3D images of internal changes in blood flow is occasionally called diffuse optical tomography (DOT) . DOT is a more genera l technology that can also refer methods such as to visible-light laser excitation of tissue. UNCLASSIFIED/ /FOil OFFl61Al WSE OHlY 6
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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.