Visual Perception and Depth Cues Lecture

Flashcards covering visual perception, Gestalt principles, depth cues, and visual illusions as discussed in the lecture.

Inattentional blindness

A phenomenon where individuals fail to notice unexpected stimuli

e.g. a gorilla passing through a scene, because they are focused on a specific task like counting basketballs.

Feature detectors

Specialized neurons in the visual cortex designed to fire when they see particular kinds of forms or specific elements in the visual field.

Bottom-up processing

A peacemeal approach where different elements of the visual field are reconstructed based on sensory information coming into the visual cortex.

Top-down processing

The application of innate templates or cognitive schemas based on experience to anticipate and make sense of ambiguous stimuli.

Gestalt principles

Innate top-down processes where we perceive the whole of an image rather than just its component parts.

Phi phenomenon

The illusion of movement created by presenting visual stimuli in rapid succession, such as flashes of light appearing to move in a clockwise rotation.

Figure and ground effect

Dividing the visual field into a figure up front against a background, such as the face-vase illusion.

Proximity

The Gestalt principle that things close together tend to belong together, such as seeing a set of circles as a square.

Closure

The tendency to see disconnected objects as a whole or complete image by 'closing' gaps or dashes, such as perceiving a series of lines as a circle.

Similarity

Grouping objects together based on shared characteristics like colors.

Simplicity

Grouping items to produce a good, simple form, such as seeing two intersecting circles rather than multiple complex distinct elements.

Continuity

The tendency to follow objects in a direction we perceive them to flow in, seeing crossing lines as continuous squiggles.

Distal stimuli

Actual objects outside of the human body that exist in the visual field.

Perceptual hypothesis

An inference about a distal stimulus where we assume its properties remain constant despite changes in the retinal image.

Size and shape constancy

The perceptual assumption that an object remains the same size or shape even as its image on the retina changes as it moves.

Binocular depth cues

Depth cues that rely on the use of both eyes.

Retinal disparity

A binocular cue involving the slight difference in the images projected onto the right and left retinas, which helps determine depth.

Monocular depth cues

Depth cues that are effective when using only one eye.

Motion parallax

A monocular cue where closer objects appear to move more quickly than distant objects when the observer is in motion.

Linear perspective

A pictorial depth cue where parallel lines appear to converge in the distance.

Texture gradient

A pictorial depth cue where objects in the foreground are detailed and less dense, while the background appears blurred and more concentrated.

Interposition

A pictorial depth cue where closer objects occlude or come between the viewer and distant objects.

Relative size

A pictorial depth cue where closer objects typically appear larger than distal objects.

Height in plane

A pictorial depth cue where distant objects appear higher in the visual field while closer objects appear lower.

Light and shadow

A pictorial depth cue where closer objects cast shadows over the background to help determine depth.

Müller-Lyer illusion

A visual illusion where two lines of equal length appear different because of the direction of the arrowheads attached to them.

Ponzo illusion

A visual illusion where two lines of the same length appear different in length due to background cues like converging lines.

Moon illusion

The phenomenon where the moon appears larger when it is closer to the ground than when it is high in space.

Ames room

A specially constructed room that creates an illusion by manipulating geometry to make people of the same size look different in size.