The Pentagon wants $30 million to build an AI-powered lie detector

五角大楼寻求 3000 万美元预算，用于开发人工智能测谎仪

EXECUTIVE SUMMARY The US government wants to spend $30.3 million over the next five years on an improved form of lie detector, according to a Department of Defense budget request. The program, called Polygraph+ or Polygraph Next, will focus on scoring algorithms that use artificial intelligence and machine learning and on a technique called “standoff sensing,” which refers to the ability to take physiological readings without attaching a device to a subject’s person. 执行摘要 根据一份国防部预算申请，美国政府计划在未来五年内投入 3030 万美元，用于开发一种改进型的测谎仪。该项目被称为“Polygraph+”或“Polygraph Next”，将重点研究利用人工智能和机器学习的评分算法，以及一种被称为“非接触式传感”（standoff sensing）的技术，即无需在受试者身上安装设备即可获取生理读数的能力。

According to details of the budget document, which were first reported by Inside Defense, the project will “modernize federal polygraph and credibility assessment technologies” to improve their accuracy and reliability. But the project may be just the latest in a long line of failed attempts to use technology to detect lies. “It’s a misguided effort to reduce the complex to something that is tangible,” says Kyri Kotsoglou, a legal scholar at Northumbria University in the UK who studies the use of polygraphs in the justice system. 根据《Inside Defense》首次披露的预算文件细节，该项目旨在“实现联邦测谎和可信度评估技术的现代化”，以提高其准确性和可靠性。然而，这可能只是长期以来利用技术检测谎言的众多失败尝试中的最新一例。英国诺森比亚大学研究司法系统中测谎仪应用的法律学者 Kyri Kotsoglou 表示：“这是一种被误导的努力，试图将复杂的问题简化为某种有形的东西。”

The move comes at a time of high tension within the department. Under Defense Secretary Pete Hegseth, the Pentagon has been increasingly turning to polygraph tests in an attempt to find the sources of alleged leaks to the press. In September, the New York Times reported that around 50 officers on the Joint Staff had been given polygraph tests after news coverage reported on the depletion of US weapons stockpiles in the war with Iran. 此举正值国防部内部高度紧张之际。在国防部长皮特·海格塞斯（Pete Hegseth）的领导下，五角大楼越来越多地求助于测谎测试，试图找出所谓向媒体泄密的源头。今年 9 月，《纽约时报》报道称，在有新闻报道披露美国在与伊朗的战争中武器库存耗尽后，联合参谋部约 50 名军官接受了测谎测试。

Polygraph+ will be run by the Defense Counterintelligence and Security Agency (DCSA), which conducts background checks for the federal government. According to the budget document, which has not yet been approved by Congress, the new technology will be used for vetting of prospective employees and “insider threat detection.” It is not yet clear which specific technologies will be used, and the DCSA did not respond to a request for more information. “Polygraph+”项目将由负责联邦政府背景调查的国防反情报与安全局（DCSA）运营。根据尚未获得国会批准的预算文件，这项新技术将用于审查潜在员工和“内部威胁检测”。目前尚不清楚具体将使用哪些技术，DCSA 也未回应进一步提供信息的请求。

But other Pentagon efforts offer potential clues. In 2023, the department’s Defense Innovation Unit (DIU) ran an open submission process to find companies with products that could be used for deception detection. It selected two companies to build prototypes: Presage Technologies, which claims to be able to measure heart rate and breathing rate using standard cameras, and Altec Research, a medical sensor company now branching out into non-contact sensing technologies. 但五角大楼的其他举措提供了一些潜在线索。2023 年，国防部国防创新小组（DIU）开展了一项公开征集活动，旨在寻找能够用于欺骗检测的产品公司。该小组选择了两家公司来构建原型：Presage Technologies（声称能够使用标准摄像头测量心率和呼吸频率）和 Altec Research（一家正在向非接触式传感技术领域拓展的医疗传感器公司）。

A screenshot of Altec’s prototype technology released by the DIU shows that it tracks head movement, facial skin temperature, and pore activity. Presage Technologies and Altec Research did not respond to requests for comment. The DIU declined to comment. DIU 发布的一张 Altec 原型技术截图显示，该技术可以追踪头部运动、面部皮肤温度和毛孔活动。Presage Technologies 和 Altec Research 未回应置评请求。DIU 拒绝置评。

Current lie detection technology has barely changed since the polygraph was invented in the 1920s. Examiners rely on blood pressure, pulse, breathing, and sweat measurements to determine if someone is lying. They make judgments about the veracity of respondents’ replies on the basis of differences in their physiological response to baseline questions like “Is the sky blue?” and target questions like “Have you ever committed a crime?” 自 20 世纪 20 年代测谎仪发明以来，目前的测谎技术几乎没有改变。审查员依靠血压、脉搏、呼吸和汗液测量来判断某人是否在撒谎。他们根据受试者对“天空是蓝色的吗？”这类基准问题，与“你是否犯过罪？”这类目标问题在生理反应上的差异，来判断受试者回答的真实性。

The federal government conducts tens of thousands of the tests each year while screening employees, but the reliability of this technology has been repeatedly challenged—and its results are rarely admissible in court. In 1983, Congress’s Office of Technology Assessment concluded that there was very limited evidence supporting the polygraph’s use for screening employees, and in 2003, the US National Research Council (NRC) said evidence for its efficacy was “weak at best.” 联邦政府每年在筛选员工时会进行数万次此类测试，但该技术的可靠性屡遭质疑，且其结果在法庭上几乎不被采纳。1983 年，国会技术评估办公室得出结论，支持使用测谎仪进行员工筛选的证据非常有限；2003 年，美国国家研究委员会（NRC）表示，其有效性的证据“充其量是薄弱的”。

Research suggests humans can spot a lie just over half the time without any technical assistance. The American Polygraph Association claims the polygraph is between 80% and 94% accurate. But the 2003 NRC report pointed out that a screening test with this level of accuracy could still lead to a lot of mistakes. The DOD employs 2.8 million people; an imperfect system applied at that scale could end up falsely accusing tens of thousands. 研究表明，在没有任何技术辅助的情况下，人类识破谎言的概率仅略高于一半。美国测谎协会声称测谎仪的准确率在 80% 到 94% 之间。但 2003 年的 NRC 报告指出，即使具有这种准确率的筛选测试，仍可能导致大量错误。国防部雇佣了 280 万人；在一个不完善的系统下，如此大规模的应用可能会导致数万人被错误指控。

There are other issues too. Polygraph interpretations are often subjective: Different examiners get wildly different results, and people from minority groups are more likely to be judged as deceptive. What’s more, with training it’s possible for interviewees to learn a variety of countermeasures that can help beat the test; for example, they may artificially heighten their physiological response to baseline questions by stepping on a pin hidden in their shoe. 此外还存在其他问题。测谎仪的解读往往具有主观性：不同的审查员会得出截然不同的结果，且少数群体成员更容易被判定为具有欺骗性。更重要的是，通过训练，受试者可以学习各种有助于通过测试的对策；例如，他们可以通过踩在藏在鞋里的图钉上来人为提高对基准问题的生理反应。

“If you know how it works, you can beat it,” says Sophie van der Zee, an associate professor who studies deception at Erasmus University in Rotterdam. She says the machine’s biggest effect is deterrence—often, subjects confess before it even begins. “But that only works if people think a polygraph works,” she points out. “如果你知道它是如何工作的，你就能打败它，”鹿特丹伊拉斯姆斯大学研究欺骗行为的副教授 Sophie van der Zee 说。她表示，这种机器最大的作用是威慑——通常，受试者在测试开始前就会坦白。“但这只有在人们认为测谎仪有效的情况下才有用，”她指出。

Various new strategies for lie detection have been attempted over the decades, with technologies ranging from thermal cameras to pupil trackers to brain scans. None of them have yielded reliable results outside the lab. The problem is that there’s no single telltale sign of lying that’s true for everyone all the time. “There is still no Pinocchio’s nose,” says van der Zee. 几十年来，人们尝试了各种新的测谎策略，技术范围从热成像摄像机到瞳孔追踪器，再到脑部扫描。然而，没有一种技术能在实验室外产生可靠的结果。问题在于，不存在一种对所有人、在任何时候都适用的单一谎言迹象。“目前还没有‘匹诺曹的鼻子’，”van der Zee 说。

AI could theoretically improve polygraphs if it could find patterns in the data that examiners can’t. AI algorithms are also more likely to be used for “multi-modal” deception detection, which seeks to combine multiple measurements into an overall deception “score” that is harder for people to game. 如果人工智能能够发现审查员无法察觉的数据模式，理论上它可以改进测谎仪。人工智能算法也更有可能用于“多模态”欺骗检测，这种方法试图将多种测量结果结合成一个整体的欺骗“评分”，使人们更难作弊。

Three things are happening under the surface that lie detection tries to home in on, van der Zee says: physiological stress, cognitive load, and the conscious efforts people make to conceal the fact that they’re lying. Current polygraph technology tackles only one. “The more you can have combined methods that approach it from these three different angles, the more successful you will be,” van der Zee says. This isn’t a new concept. van der Zee 说，测谎试图锁定的表面之下有三件事在发生：生理压力、认知负荷，以及人们为掩盖撒谎事实而做出的有意识努力。目前的测谎技术只解决了其中一个。“你越能结合从这三个不同角度切入的方法，你就越能成功，”van der Zee 说。这并不是一个新概念。