Cell membrane has voltage {threshold, neuron} at which it starts depolarization spike. Low threshold allows too much noise. High threshold cuts off boundary effects, shading, and small differences.
absolute
Senses have smallest detectable stimulus {absolute threshold}, which people can sense 50% of time. For vision, humans can detect light if seven photons flash in absolute darkness. For hearing, humans can detect whisper at five meters in absolute silence. For touch, humans can detect small insect wing or foot in still air. For smell, if small perfume drop is in ballroom, air is still, and no other odors are present, humans can detect perfume. For taste, humans can detect four grams of sugar in one liter of water.
Biological Sciences>Zoology>Organ>Nerve>Neuron>Physiology
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Date Modified: 2022.0224