Unit 3: Reading and Notes Flashcards
Sensation vs. Perception
Sensation - the process of conducting mental representations of the external world by converting it to neural signals
Perception - how we select, organize, and interpret our sensations
Bottom-up processing
Analysis of stimulus that begins with the sense receptors and works up to the level of the brain
Top-down processing
Information processing guided by high level mental process as we construct perceptions drawing on our experience and expectations
Selective attention
The focusing of conscious awareness on a particular stimulus
Transduction
Conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brain can interpret
Psychophysics
The study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them
Inattentional blindness
Failing to see visible objects when our attention is somewhere else
Three steps basic to all our sensory systems
- Receive sensory stimulation (often using specialized receptor cells)
- Transform that stimulation into natural impulses
- Deliver the neural information
Change blindness
Failing to notice changes in the environment
Absolute threshold
The minimum stimulation needed to detect a particular stimulus 50 percent of the time
Signal detection theory
A theory predicting how and when we detect the presence of a faint stimulus amid background stimulation. Assumes that there is no single absolute threshold and that detection depends partly on a person’s experience, expectations, motivation, and alertness
Weber’s Law
The principle that to be perceived as different, two stimuli must differ by a constant percentage, rather than a constant amount
Sensory adaptation
Diminished sensitivity as a consequence of constant stimulation
Perceptual set
A mental predisposition to perceive one thing and not another because of our mental tendencies and previous experiences
How does the human eye see?
Not using light particles itself, but by using wavelength to determine the hue and amplitude to determine intensity
How do the brain and eye work together?
The retina’s receptor cells convert particles of light energy to neural impulses and send them to the brain. The brain reassembles them into an image
Trichromatic Theory
The retina contains three receptor cones, sensitive to red, green, and blue
Opponent Process Theory
Says that we process colors opposed in pairs, red-green, blue-yellow, white-black
Wavelength
The distance from the peak of one wave to the peak of the next
Accommodation
The process by which the eye’s lens changes shape to focus near or far objects on the retina
Feature detectors
Nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement
Parallel processing
The processing of many aspects of a problem simultaneously; the brain’s natural mode of information processing for many functions, including vision.
Gestalt
German word meaning organized whole. When given a cluster of sensations, people tend to organize them into a meaningful whole (example: Necker’s cube)
Depth perception
How you perceive how far or close something is
