Visual Cognition
Perception allows humans to process visual input and assess their immediate surroundings with the exchange of signals between the eye and the brain.
The eyes are receptacles to the physical light of the world, it is in the eyes that light is processed into features on the retina with the help of rods and cones.
Eye as light receptacle.
When these light sensitive cells catch a light wave that they are tuned to, the eye sends signals through neural pathways from the retina to the brain’s visual cortex. These signals are then processed into channels filtered into their according selective pathways, where they are processed separately and potentially stored as patterns (form, color, depth, position, motion are processed in different parts of the brain).
Rods, the most numerous types, are specialized for very low light levels.
Cone receptors are the basis for normal daytime vision, and they come in three sub-types, each sensitive to a different color allowing a wide range of perceivable colors.
Three types of cone receptors on the retina.
The sequence of processing from V1 through the inferotemporal cortex can be thought of as a series of ever more complex pattern processors known as the Bottom-Up processes.
In contrast, Top-Down processes are goal driven, these Pathways and higher brain functions tune to certain features ( in V1), guide the attention of the viewer (in V4), identify objects (through the what pathways) and guide eye-movement and other visually guided actions through the where pathways.
Pattern processing with brain and eye coordination.
Eye movements are a big part of perception as they can quickly scan the environment and reflect the viewer’s attention. It is mostly to remedy that most of the features processed in the eye are blurry.
The Fovea is the only place in the layers of the retina where light hits directly the cones, providing the sharpest image.
Visual thinking is a series of acts of attention, driving eye movements and tuning our pattern-finding circuits to look for what we are trying to see.
Fovea location.
We are only aware of a small bandwidth on a gigantic spectrum. What we see comes from processes that filter the physical information to categorize and project biased idiosyncratic concepts essentially making almost everyone see something completely different. Everyone has a unique experience and inner model of reality.
Sources :
- Eye movements in natural behavior - Mary Hayhoe and Dana Ballard.
- Visual Thinking for Design - Chapter 4 - Colin Ware - 2010.
Tools: Adobe After Effects, Adobe Illustrator.