The Gestalt (shape/form) school of thought of of perception is that the whole is more than the sum of its parts. It's a reaction to the idea that perceptions are built up from tiny building blocks of sensations.
It's used to figure out how we group information from the visual cortex together.
- Proximity - group nearby segments of images together
- Similarity - group similar things
- Good continuation - perceive continuous patterns
- Closure - fill in the gaps
We group nearby segments of things together; for instance we'd describe the following as, respectively, a grid, 4 columns and 4 rows.
Similarly here we group this as 4 columns and 4 rows, due to the colours.
We perceive continuous patterns, so we're more likely to continue shapes than see them as distinct.
Closure allows us to fill in the dots/lines - we can generalise an image, or see an image through a railing as we drive past.
The problem of grouping is determining what to include/exclude from our image/idea of an object/concept.
This is known as the figure-ground perception - what do we count as the background, and what as the foreground/subject, of an image.
Despite continuous changes in image/optic array, perception of properties of objects in the environment remains stable. Perceptual constancies are important for object recognition and successful interaction with the environment.
- Size constancy: perceived size of an object constant over distance despite changes in size of retinal projection
- E.g. we can know that people close up and far away are the same people-size.
- Shape constancy: perceived shape remains constant despite changes in object orientation and the shape of its retinal projection
- E.g. we can open a door and still think of it as the same door-shape.
- Colour constancy: perceived colour remains constant despite changes in illumination
- E.g. we compensate for shadows or odd lighting and still view things the same colour.