Ch. 3 Perception and Imagery

Monocular Depth Cues

Visual cues that the mind uses to construct a 3D understanding when the eyes have the same view

Linear perspective

Parallel lines appear close together and converge on a single point (a vanishing point) as they recede into the distance,

Texture Gradient

Textual elements that are presumably of similar size appear to get smaller and more densely packed together as they recede into the distance

Associative Agnosia

The inability to recognize or name objects despite early functions.

• Later stage of recognition and cognition

Apperceptive Agonsia

The inability to perform simple visual tasks, implying impaired object recognition stems from deficits in early vision.

Boundary Extension

A phenomenon in which people tend to remember pictures as having extended beyond their edges.

The View-based Approach

In the study of object recognition, the idea that we match real-world images to mental representations that are like-two dimensional pictures or templates.

Structural Descriptions

Models that represent objects as sets of 3D parts organized in spatial relationships to each other

Recognition by Components

A model proposed by Biederman to explain object recognition according to basic shapes or component parts, called geons.

Geons

Basic shapes or component parts, in two or three dimensions, that the brain may use to recognize objects

Multiple-trace Memory Model

The idea that we store multiple mental representations corresponding to multiple views (or templates) of the same object, allowing us to quickly match an incoming object to the corresponding representation.

Color Constancy

In color perception, the ability to factor in difference in illumination

Lightness Constancy

In brightness perception, the ability to factor in illumination conditions

Binocular Depth Cues

The visual cues that support depth perception but which requires the use of both eyes

Object Constancy

The ability to recognize objects despite different orientations, lighting, other variation.

Size Constancy

The ability to perceive the sizes of objects as stable despite radical difference in their image size, which may vary with distance

Top-down Information

The knowledge and expectations that influence and enhance the interpretation of sensory input

Unconscious Inference

The perceptual process of making educated guesses based on visual clues, without being aware of the process

Occlusion

The blockage of one’s view of an object by other objects

Object Segmentation

The visual assignment of the elements of a scene to separate objects and background

Figure-Ground Organization

The perceptual segmentation of a visual scene into object (“figure”) and background “hround

Bottom-up Information

• Feedback forward

• Sensation

• Transduction

Top-down information processing

• Feedback process

• Context

• Experience

• Predictions

• always at work

Claims that perception is cognitively penetrable could include claims that

Beliefs affect perceptions

Binocular Disparity

A phenomenon in which the closer something is to you, the greater the difference between what your two eyes see.

Object Recognition

Matching perceptual images with stored representations

Mental Scanning

The process of moving from one point in a mental image to another

Depictive Explanation of Mental Imagery

In mental imagery, referring to the view that the brain creates representations of mental images the same way it creates real images perceived through the eyes

• Kosslyn

• Color-highlighted route on a map

Propositional Explanation of Mental Imagery

Referring to the view that mental images are held in a post-perceptual, abstract way, more like a linguistic description than a picture.

• Pylyshyn

• Verbal directions to a location

Epiphenomenon

A phenomenon that occurs together with a process of interest but it not central for its function

Topographic

Referring to a feature of the occipital cortex, whereby items adjacent in visual space are represented by neurons that are close to each other in the cortex.

Spatial Neglect

Following a brain injury, the failure to process stimuli on one side of the visual field.

Mental Imagery

The ability of the mind to construct images w/o immediate input from the environment

Aphantasia

An inability to engage in mental imagery

Mental Rotation

The ability of the mind to compare and match rotated images

Inverse Projection

The challenge our visual system faces in enabling us to perceive a 3D world despite the input to our eyes being a 2D projection

Structural Descriptions

Models that represent objects as sets of 3d parts organized in spatial relationships to each other

Holistic Perception

The processing of a whole object at once, including the relations of the individual parts to each other

High-Level Vision

Low-Level Vision

“What” Pathway

“Where” Pathway