Chapter 3 - sensation and perception Flashcards
sensation
the process by which sensory organs in the eyes, ears, nose, mouth, skin and other tissues receive and detect stimuli
perception
the organization and interpretation of sensory stimuli by the brain
bottom up processing
taking basic information about incoming sensory stimuli and processing it for further interpretation
top down processing
drawing on past experiences and knowledge to understand and interpret sensory information
transduction
the process of transforming stimuli into neural signals
absolute thresholds
the weakest stimuli that can be detected 50% of the time
sensory adaptation
the process through which sensory receptors become less sensitive to constant stimuli
difference threshold
the minimum difference between two stimuli that can be noticed 50% of the time
weber’s law
the law stating that each of the five senses has its own constant ratio determining difference thresholds
signal detection theory
a theory explaining how internal and external factors influence our ability to detect weak signals in the environment
wavelength
the distance between wave peaks or troughs
hue
the color of an object determined by the wavelength of the light it reflects
amplitude
the height of a wave; distance from midpoint to peak or trough
saturation
color purity
cornea
the clear, outer layer of the eye that shields it from damage and focuses incoming light waves
iris
the muscle responsible for changing the size of the pupil
accommodation
the process by which the lens changes shape in order to focus on objects near and far
retina
the layer of the eye containing photoreceptor cells, which transduce light energy into neural activity
photoreceptors
specialized cells in the retina that absorb light energy and turn it into electrical and chemical signals for the brain to process
rods
photoreceptors that enable us to see in dim lighting; not sensitive to color, but useful for night vision
cones
photoreceptors that enable us to sense color and minute details
optic nerve
the bundle of axons from ganglion cells leading to the visual cortex