Lie detection One recent instrument using cognitive chronometry for this purpose is the timed antagonistic response alethiometer, or TARA. Brain-reading uses fMRI and the multiple voxels activated in the brain evoked by a stimulus to determine what the brain has detected, and so whether it is familiar. People often evaluate lies based on non-verbal behavior, but are quick to place too much merit in misleading indicators, such as: avoidance of eye contact, increased pauses between statements, and excessive movements originating from the hands or feet. Non-invasive lie detection using non-verbal behavior is performed by the Silent Talker Lie Detector. Silent Talker monitors
Detector (radio) local oscillator, hence the name. By heterodyning, the received signal is mixed (in some type of nonlinear device) with a signal from the local oscillator, to give sum and difference frequencies to the signals being mixed, just as a "first mixer" stage in a superhet would produce an intermediate frequency; the beat frequency in this case, the low frequency modulating signal is recovered and the unwanted high frequencies filtered out from the output of the product detector. Product detector circuits are and so essentially ring modulators or synchronous detectors and closely related to some phase-sensitive detector circuits. They can be