The recording of autonomous activities can be very useful to the researcher, because it enables to measure associations between neurometric findings (brain activity) and physiological responses observed during the presentation of stimulus, reinforcing or weakening the tested hypotheses.
A lot of the autonomic responses may offer physiologic measures to the researcher, such as: galvanic skin response, pupil dilation, heart rate variability, blood pressure (beat to beat), quantitative measurements of sweat, Valsalva maneuver, etc.