From the people who brought us the Internet, here is one of DARPA's latest proposals.

DARPA SB032-038 TITLE: Integrated System for Emotional State Recognition for the Enhancement of Human Performance and Detection of Criminal Intent. 

OBJECTIVE:  Develop a non invasive emotion recognition system for the detection and categorization of the emotional/stress state of the subject.  The system should be suitable for deployment in military/operational environments or in environments in which discrete observation of potential enemy threats is desired.

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DESCRIPTION:  Humans communicate both intentionally and unintentionally through a variety of emotional expressions.  These expressions are most easily observed in the speech patterns, facial expressions, and body language of the individual.   From these expressions we naturally draw inferences about an individual's hostile or friendly intent, or their level of stress, fatigue, or confusion.  In many circumstances, however, it is difficult or impossible for human observers to make the necessary observations of another's emotional expressions and make reliable assessments of the individual's future actions or capabilities.  The observer's own emotional or psychological states can affect such judgments, or the individual of interest may be in an operational environment that is not conducive to direct observation by others.  In addition, there is information available on the emotional or stress state of the individual that has not yet been explored or exploited; examples of this include thermal imaging of the human face and body and detection of chemosignals (e.g. pheromones, volatile steroids).

Automated emotion detection systems could perform such assessments around the clock and free from personal bias.  Such systems could be used to assess fitness for duty, integrated into closed loop systems regulating user vigilance and workload, or used to detect the sinister intent of individuals and prompt pre-emptive interdictions.  These systems could unobtrusively monitor individuals within military operational environments or crowded civilian settings by relying on passive detection of the emotional aspects of speech, face, and gesture patterns and other novel measurements. 

The current effort would build upon existing technologies and incorporate novel remote sensing technologies to develop systems capable of detecting, categorizing, and responding to the emotional information encoded in humanspeech, facial expressions, gestures and other emitted signals.  Key emotional/cognitive states detected should include, but need not be limited to, anger, drowsiness, anxiety, fear, confusion, disorientation, and frustration.  The necessary systems must be capable of functioning in crowded civilian and/or military/operational environments characterized by high background noise and multiple speech sources and should be sufficiently rugged, light weight, and unobtrusive to function in military/operational environments.  (More)