Psychology Wood Wood & Boyd Ch. 3

Term/Question Definition/Answer
Sensation The process through which the senses pick up visual, auditory, and other sensory stimuli and transmit them to the brain
Perception The process by which the brain actively organizes and interprets sensory information
Absolute Threshold The minimum amount of sensory stimulation that can be detected 50% of the time
Difference Threshold A measure of the smallest increase or decrease in a physical stimulus that is required to produce a difference in sensation that is noticeable 50% of the time
Weber's Law The law stating that the just noticeable difference (JND) for all the senses depends on a proportion or percentage of change in stimulus rather than on a fixed amount of change
Transduction the process through which sensory receptors convert the sensory stimulation into neural impulses
Cornea The tough, transparent, protective layer that covers the front of the eye and bends light rays inward through the pupil
Lens The transparent disk-shaped structure behind the iris and the pupil that changes shape as it focuses on objects at varying distances
Retina The layer of the tissue that is located on the inner surface of the eyeball and contains the sensory receptors for vision
Rods The light sensitive receptor cells in the retina that look like slender cylinders and allow the eye to respond to as few as five photons
Cones The light sensitive cells in the retina that enable humans to see color and fine detail in adequate light but do not function in very dim light
Trichromatic Theory The theory of color vision suggesting that three types of cones in the retina each make a maximal chemical response to one of three colors – blue, green, or red
Opponent-process Theory The theory of color vision suggesting that three kinds of cells respond by increasing or decreasing their rate of firing when different colors are present
Color Blindness The inability to distinguish certain colors from one another
Kinesthetic Sense The sense providing information about in relation to each other and the movement of the entire body or its parts
Gestalt A german word that roughly refers to the whole form, pattern, or configuration that a person perceives
Synesthesia The capacity for responding to stimuli simultaneously with normal and unusual perceptions
Subliminal perception The capacity to percieve and respond to stimuli that are presented below the threshold of awareness
Extrasensory Perception (ESP) Gaining information about objects, events, or another person's thoughts through some means other than the known sensory channels
Myopia nearsighted
Presbyopia Farsighted
Sensory Receptors highly specialized cells in the sense organs that detect and respond to one type of sensory stimuli and transduce (convert) the stimuli into neural impulses
Sensory Adaptation The process in which sensory receptors grow accustomed to constant, unchanging levels of stimuli over time
Just Noticeable Difference (JND) The smallest change in sensation that a person is able to detect 50% of the time
Vestibular Sense The sense that detects movement and provides information about the body's orientation in space
Gate-control Theory that an area in the spinal cord can act like a gate and either block pain messages or transmit them to the brain
Who came up with the Gate-control Theory? Melzack and Wall
Figure-ground the figure often seems to stand out from the ground
Similarity Objects that have similar characteristics are perceived as a unit
Proximity Objects that are close together in space or time are usually perceived as belonging together
Continuity We tend to perceive figures or objects as belonging together if they appear to form a continuous pattern
Closure We perceive figures with gaps in them to be complete
Cross-modal perception a process whereby the brain integrates information from more than one sense
Depth perception The ability to perceive the visual world in three dimensions and to judge distances accurately
Size constancy as objects move farther away you continue to perceive them as being about the same size
Shape constancy the tendency to perceive objects as having a stable or unchanging shape, regardless of changes in the retinal image resulting from differences in viewing angle
Telepathy gaining awareness of the thoughts, feelings, or activities of another person without the use of senses
Clairvoyance gaining information about objects or events without the use of the senses
Precognition refers to an awareness of an event before it occurs
Ganzfield procedure a study design in which two individuals, a sender and a receiver are placed in separate rooms and try to send messages without using senses