Chapter 4: Interpreting Sensory Information / Sensation and Perception

Absolute Sensory Threshold

Intensity at which a given individual detects a stimulus 50% of the time

Signal Detection Theory

The study of people's tendencies to make hits, correct rejections, misses, and false alarms

Subliminal Perception

The processing of information by sensory systems without conscious awareness

Feature Detectors

Specialised neurons in the visual cortex that respond to the presence of simple features; e.g. lines and angles

Gestalt Psychology

A psychological approach that emphasises that we often perceive the whole rather than the sum of the parts

Bottom-Up Process

Tiny elements combine to produce larger items

Top-Down Process

You apply your experience and expectations to interpret each item in context

Figure and Ground

You distinguish the object from the background

Reversible Figures

Visual illusions in which the figure and ground can be reversed

Proximity

To perceive objects that are close together as belonging to a group

Similarity

To perceive objects that are similar as belonging to a group

Continuation

"Filling in the Gaps"

Closure of the figure

We imagine the rest of the figure to see something that is simple, symmetrical, or consistent with our past experience

Common Fate

The tendency to perceive objects that are moving together as belonging together

Good Figure

A simple, familiar, symmetrical figure

Visual Constancy

The tendency to perceive objects as keeping their shape, size, and colour, despite distortions in the actual pattern reaching the retina

Induced Movement

Incorrectly perceive the object as moving

Stroboscopic Movement

A type of apparent movement based on the rapid succession of still images, as in motion pictures

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

Retinal Disparity

The differences between the images stimulating each eye

Binocular Cues

Depth cues, such as retinal disparity and convergence, that depend on the use of two eyes

Monocular Cues

Depth cues, such as interposition and linear perspective, available to either eye alone

Motion Parallax

A depth cue in which the relative movement of elements in a scene gives depth information when the observer moves relative to the scene

Optical Illusion

An optical phenomenon that results in a false or deceptive visual impression

Moon Illusion

A visual illusion involving the misperception that the moon is larger when it is on the horizon than when it is directly overhead.