Terms Flashcards
Sensation “Detection & Encoding”
The senses collect some kind of information from the environment and convert it to a signal that can travel to the brain
-Sensing our environment through touch, taste, sight, sound, and smell (nervous system)
-Our senses depend on each other
Transduction
The transformation of stimulus energy to electrochemical energy of neural impulses (except smell)
Perception “Interpretation”
Process by which we select, organize, and interpret sensory information in order to recognize meaningful objects and events
-Information is organized, interpreted, and consciously experienced
-Enables recognition of meaningful events
Bottom-Up Processing “Sensory Analysis”
Involves starting with an incoming stimulus and working upwards until a representation of the object is formed in our minds
-Begins at entry level with our senses can detect
-Requires no previous knowledge or learning
Top-Down Processing
Form our perceptions starting with a larger object, concept, or idea before working our way toward more detailed information
-Big Picture, Tiny Details
-Influenced by prior experience and current expectations
Absolute Threshold
Smallest level of stimulus that can be detected, usually defined as at least half the time (Point something becomes noticeable)
-How dim can a light be or how soft can a sound be and still be detected half of the time
Signal Detection Theory
Theory predicting how and when we detect the presence of a faint (weak) stimulus (signal) amid background stimulation (noise)
-Assumes there is no single absolute threshold, detection depends partly on a person’s experience, expectations, motivation, and level of fatigue
Subliminal Sensation
When stimuli are below one’s absolute threshold for conscious awareness
-Much of our information processing occurs automatically, out of sight, off the radar screen of our conscious mind
Difference Threshold “Just Noticeable Difference (JND)”
The amount something must be changed in order for a difference to be noticeable, or detectable at least half the time
Weber’s Law
The principle that to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than constant amount)
-Bigger stimuli require larger differences to be noticed
-Light, 8%
-Weight, 2%
-Tone, 3%
Sensory Adaptation
Reduction in sensitivity to a stimulus after constant exposure to it
-Reduces our awareness of a constant stimulus, it helps free up our attention and resources to attend to other stimuli in the environment around us
Selective Attention
We center our attention on certain important elements of our environment while other things blend into the background or pass us by completely unnoticed
-We sense a lot of information. Scientists estimate we observe 11,000,000 its of info per second. But we weed out all but 40 bits
Divided Attention “Multitasking”
Occurs when mental focus is on multiple tasks or ideas at once
-Divided attention does decrease the amount of attention being placed on any one task or idea is there are multiple focuses going on at once
Pupil
Adjustable opening in the center of the eye through which light enters, controls the amount of light that enter the eye
Iris
A ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening (colored part of eye)
Crystalline Lens “Lens”
The transparent structure behind the pupil that changes shape to help focus images on the retina, focus eye on near or far objects.
Retina
Light-sensitive layer that lines the back of the eye
-Retina contains photoreceptors that absorb light and then transmits those signals through the optic nerve to the brain
