Module 3: Sensation and Perception

• Absolute Threshold: minimum stimulation needed to register a particular stimulus 50% of the time

Example: hearing the tick of a clock 20 feet away in a quiet room

• Signal Detection Theory: a model for predicting how and when a person will detect a weak stimulus, particularly based on context

• Difference Threshold:

• Weber’s Law: we perceive differences on a logarithmic rather than liner scale, not amount of change but rather the percent of change that matters

• Transduction:

• Hue: color or shade we see

• Purity: richness or saturation of color

• Red, most curvature long frequency

• Blue, least curvature short frequency

• Chromostereopsis: pure colors at the same distance from the eye appear at different distances

• Amplitude: the amount of energy in a given lightwave

• Edge Detection:

• Feature Detecters:

• Parallel Processing: ability to process and analyze many aspects of the situation at once

• Depth Perception: allows us to estimate distances between objects and ourselves

• Occlusion: an object that blocks the view of another object must be in front of it

• Relative Size: smaller objects are farther away

• Texture Gradient: as texture gets farther away it forms smaller visual angles or pictures on the retina and is less noticeable

• Relative Height: objects that appear higher in our visual field are farther away than objects that appear lower

• Familiar Size: knowledge of the normal size of certain objects can provide cues to depth

• Linear Perspective: parallel lines seem to converge as they move into the distance

• Aerial Perspective: objects that are farther away also appear to be hazier and bluer

• Relative Brightness: brighter images are closer, and more shaded images are further away

• Proximity: the closer figures are to each other, the more we tend to group them together perceptually

• Good Continuation: a preference for organizing form in a way where contours continue smoothly along their original course (subjective contours)

• Closures: filling in information to complete perceptions

• Perception is a hypothesis, not knowledge

• Similarity is an example of a Gestalt Principle

Module 3: Color Theory

• Hue is another word for color

• Saturation refers to the intensity of the color, how vivid or subtle the color is

• Value is how dark or light the color is, ranging from black to white

• Analogous: uses colors that are next to each other on the color wheel

• Complementary: uses colors across from each other on the color wheel

• Split Complementary: uses colors surrounding the complementary colors on the color wheel

• Monochromatic: uses only one color or hue on the color wheel

• Triadic: uses three colors that are evenly spaced, forming a triangle

• Tetradic: uses a color scheme that forms a rectangle on the wheel, using not one but two complementary