Chapter 4 Flashcards
Sensation
A physical process involving the stimulation of our sense organs by features of our world. Eyes to light, ears to sound, skin to touch
Transduction
The conversion of physical to neural information. Ex: when food chemicals stimulate the taste buds in the tongue
Absolute threshold
The intensity level that a participant can see 50% of the time is that persons absolute threshold
Signal detection theory
The viewpoint that both stimulus and decision-making processes are involved in the detection of stimulus. Hits, misses, false alarms, and correct rejections
Different thresholds - Webers Law
The smallest amount of change between two stimuli that a person can detect half of the time.
Webers law states that the size of a just noticeable difference is a constant fraction of the intensity of the stimulus. Ex: if you are given two different weights to hold in each hand you don’t notice a difference
Sensory Adaptation
The process by which our sensitivity diminishes when an object constantly stimulates our senses. Ex: you get use to bad smells
Perpetual Set
The ability of the brain to preserve objects in spite of changes in retinal image when an object changes position or distance. Ex: your friend looking smaller as a they walk away
Accommodation
The process by which the muscles control the shape of the lens to adjust to viewing objects and different distances. Near v. Far vision. They eyes ability to focus at different distances
Apparent Motion
Fooled into thinking that something is moving when it’s not. Our brain interprets images that move across our retinas as movement
Figure-ground
A Gestalt notion where the figure is the thing that stands in front of a somewhat uniform background, think of illusions
Gestalt principles
We often perceive holes as more than merely the sum of their parts. Gestalt meaning “form, pattern or shape.
Similarity: to group like objects together
Continuity: points or lines that follow a continuous path
Proximity: group objects together that are near each other
Closure: perceive a whole object in the absence of complete information
Binocular disparity
The difference in retinol images due to the fact that our two eyes are separated by a few inches, depth perception. BOTH = BINOCULAR
Monocular Cues
Do not require both eyes to be effective.
Linear perspective: parallel, lines, that converge, or come together, the farther away they are from the viewer.
Texture gradient: causes the texture of a service to appear more tightly packed together as a service moves to the background, helps us judge depth
Perceptual constancies
Size constancy: we see things the same regardless of the changing of the image in our retina because we know what the object is.
Shape constancy: people shapes of common things, just as they know their sizes, example, an open door looks different in shape than I closed the door.
Color constancy: the ability of the human eye to perceive colors. Ex: red is still the same color whether it’s a cloudy day or not.
Opponent process theory
The theory that color vision results from the cone link together in three pairs of opposing colors so that the activation of one member of the pair inhibits activity and the other. Helps explain why some people have color blindness. Blue/yellow, red/green, black/white.
