The level below which there is no response to a stimulus.
Some value a stimulus must reach to produce a response.
The point at which something starts, e.g. where something can be perceived by the body or where a drug starts to have an effect.
The point at which a sensation is strong enough to be sensed by the sensory nerves.
Minimal point at which a stimulus evokes a response.
The point at which a stimulus begins to evoke a response, and therefore a measure of the sensitivity of a system under particular conditions. A thermoreceptor that responds to an increase in temperature of only two degrees is said to have a much lower threshold than one that will only respond to a change in temperature of ten degrees or more. In this example the threshold can be measured directly in terms of degrees.
The degree of stimulation, or electrical depolarization, necessary to produce an action potential in a nerve-fibre. Stimulation below this level elicits no conducted impulse, and supramaximal stimulation will elicit the same response as a threshold stimulus.
Point at which a psychological or physiological effect begins to be produced.
The minimal level of stimulus that can create an impact on consciousness or trigger a response.
The opening of a canal.