Chapter 5: Sensation And Perception Flashcards
Sensation
Stimulus detection process by which our sense organs respond to and translate environmental stimuli into nerve impulses that are sent to the brain
Perception
Making “sense” of what our senses tell us; it is the active process of organizing the stimulus and giving it meaning
What is the difference between sensation and perception?
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Sensory transduction
The process where the characteristics of a stimulus are converted into nerve impulses
Psychophysics
Studies the relationship between the physical characteristics of stimuli and sensory capabilities (f.eks how low a sound can the human ear perceive)
Absolute threshold
The lowest intensity at which a stimulus can be perceived by a human 50 percent of the time
Decision criterion
A standard of how certain someone must be that a stimulus is present before they will say they can detect it
Signal detection theory
Concerned with the factors that influence sensory judgements
Difference threshold
Defined as the smallest difference between two stimuli that people can perceive 50 percent of the time
Weber’s law
States that the difference threshold (or JND) is directly proportional to the magnitude of the stimulus with which the comparison is being made
Sensory adaption
The diminishing sensitivity to an unchanging stimulus
Lens (eye)
Elastic structure that becomes thinner to focus on distant objects, and thicker to focus on nearby objects
Retina
Multilayered light-sensitive tissue at the rear of the fluid-filled eyeball
Myopia
Nearsightedness
Hyperopia
Farsightedness
Rods (eye)
- primarily black and white brightness receptors
- function best in dim light
Cones (eye)
- color receptors
- function best in bright illumination
Fovea
Small area in the center of the retina that contains no rods, but mainly densely packed cones
Optic nerve
Ganglion cells, whose axons are collected into a bundle to form the optic nerve
Visual acuity
Ability to see fine detail
Photo-pigments
Rods and cones translate light waves into nerve impulses through the action of protein molecules called photo-pigments
Dark adaptation
The progressive improvement in brightness sensitivity that occurs over time under conditions of low illumination