Feature detection is a process by which specialized nerve cells in the brain respond to specific features of a visual stimulus, such as lines, edges, angle, or movement. The nerve cells fire selectively in response to stimuli that have specific characteristics E.G shape, angle, or movement. Feature detection was discovered by David Hubel and Torsten Wiesel of Harvard University, an accomplishment which won them the 1981 Nobel Prize.
In the area of computer vision, feature detection usually refers to the computation of local image features as intermediate results of making local decisions about the local information contents (image structure) in the image; see also the article on interest point detection.
In the area of psychology, the feature detectors are neurons in the visual cortex that receive visual information and respond to certain features such as lines, angles, movements, etc. When the visual information changes, the feature detector neurons will quiet down, to be replaced with other more responsive neurons.