psych chap 3

Absolute Threshold of Stimulation

Minimal stimulation needed to register a stimulus 50% of the time.

Signal Detection Theory

A model for predicting how and when a person will detect a weak stimulus, partly based on context.

Difference Threshold

The ability to differentiate between stimuli.

Weber's Law

We perceive differences on a logarithmic scale; it's the percent of change that matters, not the amount.

Transduction

The process of converting sensory stimuli into electrical signals.

Cornea

The clear, outer layer of the eye that bends light to help focus it.

Pupil

The black circle that controls how much light enters the eye.

Iris

The colored part of the eye that adjusts the size of the pupil.

Lens

A flexible structure that focuses light onto the retina.

Retina

The inner layer at the back of the eye containing light-sensitive cells (rods and cones).

Optic Nerve

Carries visual information from the retina to the brain for processing.

Parallel Processing

The ability to process and analyze multiple aspects of a situation simultaneously.

Depth Perception

The ability to estimate distances between objects and ourselves.

Occlusion

An object blocking the view of another object must be in front of it.

Texture Gradient

As texture gets farther away, it forms smaller visual angles and is less noticeable.

Relative Height

Objects appearing higher in our visual field are perceived to be further away.

Familiar Size

Knowledge of the normal size of certain objects provides cues to depth.

Linear Perspective

Parallel lines seem to converge as they move into the distance.

Aerial Perspective

Objects that are farther away appear hazier and bluer.

Relative Brightness

Brighter images are perceived as closer and more shaded images are perceived as farther away.

Perception

Guided by organizational principles laid out by Gestalt psychologists.

Proximity

Closer figures are grouped together perceptually.

Good Continuation

A preference for organizing forms in a way where contours continue smoothly along their original course.

Pareidolia

The tendency to see images and patterns in incomplete figures.

Nativism

Belief in innate abilities and bottom-up processing.

Empiricism

Belief in acquired or learned skills and top-down processing.