Unit 2: Cognition 2.1

2.1 Principles of Perception

Perception

The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

Sensation

Picked up passively through the senses. Nose, eyes or other sensory organs bring in information.

Processing Stimuli

Includes bottom-up and top-down processing.

Bottom-up Processing

COMING FROM OUTSIDE WORLD- Starting with the sensory input, the brain attempts to understand/make sense.

Top-down Processing

COMING FROM YOUR BRAIN- Guided by experience and higher-level processes, we see what we expect to see.

Schema

A collection of basic knowledge about a concept or entity that serves as a guide to perception, interpretation, imagination, or problem solving.

Perceptual Set

A bias or readiness to perceive certain aspects of available sensory data and to ignore others.

Context Effect

describes how people are influenced by environmental factors through one's perception of a stimulus. (Considered top-down processing).

Selective Attention

Our tendency to focus on just a particular stimulus among the many that are being received.

Cocktail party effect

the ability to focus one's attention a particular stimulus while filtering out a range of other stimuli.

Inattentional blindness

failing to see visible objects when our attention or focus is directed elsewhere.

Change Blindness

failing to notice changes in the visual environment.

A group of German psychologists noticed that people who are given a cluster of sensations tend to organize them into a…

Gestalt

Figure-ground

the organization of the visual field into objects (the figures) that stand out from their surroundings (the ground)

Closure

A Gestalt law of grouping that states we fill in gaps to create a complete, whole object.

Continuity

A Gestalt law of grouping that states we perceive smooth, continuous patterns rather than discontinuous ones.

Proximity

A Gestalt law of grouping that states we group nearby figures together.

Depth Perception

the ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance.

Monocular Depth cue

The relative clarity of objects under varying atmospheric conditions. Nearer objects are usually clearer in detail.

Relative Size

If we assume two objects are similar in size, most people perceive the one that casts the smaller retinal image as farther away.

Linear Perspective

Parallel lines appear to meet in the distance. The sharper the angle of convergence, the greater the perceived distance.

Interposition

A monocular depth cue occurring when two objects are in the same line of vision and the closer object, which is fully in view, partly conceals the farther object- making the farther object appear smaller.

Binocular Cues

Depth cues, such as retinal disparity and convergence, that depend on the use of two eyes. Help us judge distance.

Convergence

The rotation of the two eyes inward toward a light source so that the image falls on corresponding points on the foveas.

Retinal Disparity

By comparing retinal images from the two eyes, the brain computes distance.

Size, Shape, Brightness, Color is part of…

Perceptual Constancies

Shape Constancy

We perceive an object as having an unchanging shape, even while our distance from it varies.

Size Constancy

We perceive an object as having an unchanging size even while our distance from it varies.

Relative Motion

Objects in front of the point will appear to move backward. The farther an object is from the fixation point, the faster it will seem to move.

Apparent Movement

an optical illusion where a STATIONED object appears to have MOVED.

stroboscopic movement

Our brain perceives a rapid series of slightly varying images as continuous movement.