threshold

…idea of the establishment of thresholds. Thus threshold sensitivity might be set quite low for certain priority classes of stimuli, which, even when basically unattended and hence attenuated, may nevertheless be capable of activating the perceptual systems. Examples would be the sensitivity displayed to hearing one’s own name spoken or…

…as the just-perceptible intensity (threshold, or limen) of the appropriate stimulus. The smallest detectable stimulus is called the absolute threshold, while the smallest detectable change in the intensity of a stimulus is called the difference threshold. Such thresholds can serve as points of reference, or anchors, against which subsequent…

…a precise measurement of intensity thresholds. (A threshold is the lowest point at which a particular stimulus will cause a response in an organism.)

An important means of measuring a sensation is to determine the threshold stimulus—i.e., the minimum energy required to evoke the sensation. In the case of vision, this would be the minimum number of quanta of light entering the eye in unit time. If it…

…potential, on reaching sufficient (threshold) strength, acts to generate a nerve impulse within the corpuscle. Among insects, movements of tactile hairs have been shown (sometimes specifically) to affect the receptor potential and the impulse frequency in the connected nerve fibre.