Unit 2 / Chpt. 3 - Perception & Sensation Flashcards
Sensation
The stimulation of sensory receptors and the transmission of sensory information to the central nervous system. Biological process.
Perception
The process by which sensations are organized into an inner representation of the world. Your interpretation of the world.
Absolute Threshold
The minimal amount of energy that can produce a sensation.
-For example, the absolute threshold for light would be the minimum brightness (physical energy) required to activate the visual sensory system.
What are the absolute thresholds for vision, hearing, taste, smell, and touch?
- Vision: a candle flame viewed from about 30 miles on a clear, dark night.
- Hearing: a watch ticking from about 20 feet away in a quiet room.
- Taste: 1 teaspoon of sugar dissolved in 2 gallons of water.
- Smell: about one drop of perfume diffused throughout a small house (1 part in 500 million).
- Touch: the pressure of the wing of a fly falling on a cheek from a distance of about 0.4 inch.
What are Feature Detectors?
Neurons in the sensory cortex that fire in response to specific features of sensory information such as lines or edges of objects.
What is the Optic Nerve?
The nerve that transmits sensory information from the eye to the brain.
What is Perceptual Organization?
The tendency to integrate perceptual elements into meaningful patterns.
What are the Gestalt Principles of Perceptual Organization?
- Proximity
- Similarity
- Continuity
- Connectedness
- Closure
- Figure-Ground
What is Proximity?
Nearness. The perceptual tendency to group together objects that are near one another.
What is Similarity?
The perceptual tendency to group together objects that are similar in appearance.
What is Continuity?
The tendency to perceive a series of points or lines as having unity.
What is Closure?
Related to principle of good continuation, there is
a tendency to close simple figures, independent of continuity or similarity. This results in a effect of filling in missing information or organising information which is present to make a whole.
What is Connectedness?
Elements that are connected by uniform visual properties are perceived as being more related than elements that are not connected.
What is Figure-Ground?
Describes the tendency of the visual system to simplify a scene into the main object that we are looking at (the figure) and everything else that forms the background (or ground).
Figure-Ground is always in?
Every perception.
What is Top-Down Processing?
The use of contextual information or knowledge of a pattern to organize parts of the pattern.
-ex: having the box when putting a puzzle together. You have the complete picture. You use the larger pattern to guide subordinate perceptual motor tasks such as hunting for particular pieces.
What is Bottom-Up Processing?
The organization of the parts of a pattern to recognize, or form an image of, the pattern they compose.
-ex: not having the box when putting a puzzle together. You begin with bits and pieces of information and become aware of the pattern formed only after you have worked at it for a while.
What is Depth Perception?
- Important part of any process.
- Biological. Involves Monocular and Binocular cues.
- Allows us to judge distance.
- Not born with it. Develop around 6 mo.
- Not the same every place around the world.
What are Monocular Cues?
Stimuli suggestive of depth that can be perceived with only one eye.
List the Monocular Cues.
- Texture Gradient
- Linear Perspective
- Interposition (Superposition)
- Relative Clarity (Aerial Perspective)
- Relative Height
- Shadowing
- Motion Parallax
What is Interposition?
A monocular cue for depth based on the fact that a nearby object obscures a more distant object behind it.
What is Shadowing?
A monocular cue for depth based on the fact that opaque objects block light and produce shadows.
What is Texture Gradient?
A monocular cue for depth based on the perception that closer objects appear to have rougher (more detailed) surfaces.
What is Motion Parallax?
A monocular cue for depth based on the perception that nearby objects appear to move more rapidly in relation to our own motion.
