the process by which you detect physical energy from your environment and encode it as neural signals
the study of the relationship between physical energy and psychological experiences
a change in the environment that can be detected by sensory receptors
the weakest level of a stimulus that can be correctly detected at least half the time
signal detection theory
maintains that minimum threshold varies with fatigue, attention, expectations, motivation, emotional distress, and from one person to another
minimum difference between any two stimuli that a person can detect 50% of the time
just noticeable difference (jnd)
experience of the difference threshold
difference thresholds increase in proportion to the size of the stimulus
receiving message below one's absolute threshold for conscious awareness
transformation of stimulus energy to the electrochemical energy of neural impulses
the process of selecting, organizing, and interpreting sensations, enabling you to recognize meaningful objects and events
transparent, curved layer in the front of the eye that bends incoming light rays
colored muscle surrounding the pupil that regulates the size of the pupil opening
small adjustable opening in the iris that is smaller in bright light and larger in darkness
structure behind the pupil that changes shape, becoming more spherical or flatter to focus incoming rays into an image on the light-sensitive retina
process of changing the curvature of the lens to focus light rays on the retina
light sensitive surface in the back of the eye containing rods and cones that transduce light energy. Also has layers of bipolar cells and ganglion cells that transmit visual information to the brain
small area of the retina in the most direct line of sight where cones are most concentrated for highest visual acuity in bright light
modified neurons (rods and cones) that convert light energy to electrochemical neural impulses
photoreceptors that detect black, white, and gray and that detect movement. rods are necessary for peripheral and dim-light vision when cones do not respond. distributed through the retina but not in fovea.
photoreceptors that detect color and fine detail in daylight or in bright-light conditions. most concentrated at the fovea of the retina, none are in the periphery.
nerve formed by ganglion cell axons; carries the neural impulses from the eye to the thalamus of the brain.
ability to detect fine details, sharpness of vision. can be affected by small distortions in the shape of the eye.
rays of light form a clear image on the retina of the eye
too much curvature of the cornea and/or lens focuses image in front of the retina so nearby objects are seen more clearly than distant objects
too little curvature of the cornea and/or lens focuses the image behind the retina, so distant objects are seen more clearly than nearby objects
increased visual sensitivity that gradually develops when it gets dark
second layer of neurons in the retina that transmit impulses from rods and cones to ganglion cells
third layer of neurons in the retina, whose axons converge to form the optic nerve
region of the retina where the optic nerve leaves the eye so there are no receptor cells; creates an area with no vision
individual neurons in the primary visual cortex/occipital lobes that respond to specific features of a visual stimulus
simulataneously analyzing different elements of sensory information, such as color, brightness, shape, etc.
proposed mechanism for color vision with cones that are differentially sensitive to different wave lengths of light; each color you see results from a specific ratio of activation among the three types of receptors
proposed mechanism for color vision with opposing retinal processes for red-green, yellow-blue, white-black. some retinal cells are stimulated by one of a pair and inhibited by the other
temporary decrease in sensitivity to a stimulus that occurs when stimulation is unchanging
the set of processes from which you choose among the various stimuli bombarding your senses at any instant, allowing some to be further processed by your senses and brain.
the sense of hearing. the loudness of sound is determined by the amplitude or height of the sound wave