PSYC 303 Lecture Notes - Lecture 10: Edward B. Titchener, Railways Act 1921, Receptive Field
Middle or midlevel vision: a loosely defined stage of visual processing that comes after basic features have been extracted from the image (low level or early, vision) and before object recognition and scene understanding (high level vision) Act of recognition involve anything what we perceive now to a memory of something we perceived in the past. Goal of middle vision is to organize elements of visual scene into groups that we can then recognize as objects. We can"t just group all the edges that touch each other into an object. Plus, quality of the raw edge effects shows that tracing the edges of objects might result in tracing points of the shape that has no edge at all. Occasional lack of an edge doesn"t seem to bother our visual system at all. In early stages of processing, our visual system is figuring out which edges mark the boundaries of objects and which represent surface features.