3D Space Perception

Flashcards reviewing key vocabulary and concepts from a lecture on 3D space perception, covering physicalist and phenomenological approaches, depth cues, and strabismus.

Physicalist Approach

Examining a physical image to determine the 'features' associated with 3D perception, using a cue-based approach to explain perceptual phenomena based on the presence or absence of physical cues.

Cue-based Approach

Explaining perceptual phenomena based on the presence or absence of physical cues.

Binocular Disparity

A cue that can produce 'realness' in stereoscopic pictures.

Perceptual Duality

The phenomenon where a picture is viewed with both eyes, and the brain does not ascribe a visual scale to the scene and objects.

Phenomenological Approach

Focuses on the phenomenology of egocentric distance, relative (unscaled) depth structure, and exocentric (scaled) distances to understand 3D object and space perception.

Egocentric Distance

Impression of distance to objects.

Relative (Unscaled) Depth

Impression of 3D shape and layout.

Exocentric (Scaled) Distances

Impression of object size and separation between objects.

Visual Scale

The actual size and distances among objects—exocentric distances, which the brain needs to derive for visuo-motor planning and execution.

Pictorial Duality

Under binocular viewing, the picture surface is encoded by the exocentric distance (scaled) encoding and appears 'real,' while the pictorial object is encoded by the unscaled/relative depth encoding and does not appear 'real.'

Binocular Stereopsis

The addition of binocular disparities allows the brain to derive a specific distance and scale to the object, causing it to have stereopsis (appear 'real').

Monocular-Aperture Viewing

Causes the brain to ascribe a specific fixed visual distance to the object (near the picture surface) and enables the scaling of pictorial depth cues.

Depth-of-Focus Blur

An optical cue to egocentric distance; applying it to images forces the pictured objects to appear closer.

Tilt-Shift Miniaturization Effect

An interesting phenomenology where there is an interaction of the distance perception effect of depth-of-focus blur and familiar-size information.

Strabismus

Caused by impairment in functioning of eye muscles. Results in only binocular disparity being compromised.

Relative Depth Cues

Provide information about 3D shape and layout.

Distance Cues

Accommodation, Convergence, and Depth of Focus Blur (near space); Declination from eye level, Ground-plane information (far space)

Dorsal Stream

Posterior parietal cortex, linked to scaled depth encodings required for motor interaction. Instantiates the phenomenology of stereopsis.

Ventral Stream

Temporal cortex, perception of objects and space