Vision and Gestalt Principles

Fovea

center of the retina where visual acuity is the highest

Retina

light-sensitive layer in the back of the eye that lines the membrane converts incoming light into electrical systems

Parts of the Eye

Cornea- covers front of eyeball, protects eye, bends light to provide focus, transparent tissue

Pupil- adjustable opening in center of iris, light enters interior eye through pupil

Iris- provides pigment, controls size of pupil

Lens- Behind iris and pupil. Focusing process

Retina- membrane lining the rear interior of the fluid filled eyeball

Photoreceptors- light detecting cells that lie in the retina

Sclera- the white outer layer of the eyeball

Vitreous- clear gel that fills the space between the lens and the retina of the eyeball of humans.

Transduction

The process by which receptor cells translate sensory stimuli into electrical impulses, and produces an electrical change in response to physical stimulation/stimuli

Photoreceptors- rods and cones

Rods- photoreceptors in the retina that help with vision in low light or in the night

Cones- photoreceptors in the retina that allows us to see in finer detail and in color

Bipolar and Ganglian

Rods and Cones synapse with neurons called bipolar cells

Bipolar cells then synapse with neurons called ganglian cells

Dark Adaptation

gradual increase in sensitivity to light after you enter a darkened room or turn of the light. Iris dilates and pupils widen

Color Blindness

inability to distinguish certain colors, or any colors at all

Feature Detectors

neurons in brain that identify specific features of visual stimuli such as color, movement, or orientation of lines

Blindspot

spot of the retina where the optic nerve connects and there are no photoreceptors, This means that the brain gets no information from the eye in that particular spot.

Trichromatic Theory

theory that suggests that human color perception is based on three primary color cone photoreceptors in the retina (red, green, and blue). By combining these cones we are able to see all colors.

Opponent Process Theory

Color perception is facilitated by neurons that can either be excited or inhibited, depending on wavelength of light. The theory states that color is perceived in terms of opposing pairs, such as red to green, blue to yellow, and white to black. When one color is activated, it inhibits the perception of its opposite.

Afterimages

image that continues to appear in the eye even after removed exposure to that object because when you see something, the photorecptors seeing it get tired so when you lose your eyes the ones that aren’t tired are stronger

occipital lobe

part of brain that is responsible for visual processing

visual acuity

sharpness of vision, abiloty to discern letters and images.

Gestalt

studies how brain percieves objects as a whole instead of individual things.

constancy

the perception of objects as stable and unchanging despite changes in sensory input.

The ability to perceive an object as being the same size despite the fact that the size of the retinal image changes depending the distance from the observer. So if elizabeth is walking towards me I think that she is the same size even though technically she is getting bigger

closure

the tendency to perceive incomplete shapes as complete by filling in gaps in visual information.

perceptual organization that explains how humans fill in visual gaps, so if there is a whole in a square we still see it as a square because we perceive it to be connected

figure- ground

tendency of a human to simplify a scene into the main object while everything else forms the background. Something stands our and everything fades into background

This principle helps in distinguishing objects from their surroundings, allowing us to focus on specific elements in our visual field.

continuation

the perceptual tendency to perceive a series of points or lines as a continuous path. This principle allows us to see shapes and forms as smooth and flowing rather than abrupt or disjointed.

tendency to create continuous patterns and perceive connected objects as uninterrupted. We like to see patterns and we like to see whole, continuous things

top down processing

the cognitive process where perception is guided by prior knowledge, experiences, and expectations, allowing individuals to interpret sensory information based on what they already know.

bottom up processing

the cognitive process that begins with sensory input, building up to perception through the analysis of individual components, allowing individuals to form a complete understanding of the sensory information.

proximity

the Gestalt principle that suggests objects that are close together are perceived as belonging to the same group or pattern. This principle highlights how spatial relationships influence our perception of objects.

Similarity

the Gestalt principle that states objects that are similar in appearance are perceived as part of the same group. This principle emphasizes how visual characteristics influence our perception and organization of stimuli.

perceptual set

a mental predisposition to perceive one thing and not another, influenced by prior experiences, expectations, and context.

monocular cues for depth perception (examples)

visual information that can be perceived with one eye, such as relative size, interposition, and linear perspective, which help us judge distances and depth.

binocular cues for depth perception

visual information that requires both eyes, such as retinal disparity and convergence, which aid in depth perception and spatial awareness.

relative size

the perception that objects closer to us appear larger than those further away, aiding in depth judgment.