Sensory cue
In perceptual psychology, a sensory cue is a statistic or signal that can be extracted from the sensory input by a perceiver, that indicates the state of some property of the world that the perceiver is interested in perceiving.
A cue is some organization of the data present in the signal which allows for meaningful extrapolation. For example, sensory cues include visual cues, auditory cues, haptic cues, olfactory cues and environmental cues. Sensory cues are a fundamental part of theories of perception, especially theories of appearance.
Concept
There are two primary theory sets used to describe the roles of sensory cues in perception. One set of theories are based on the constructivist theory of perception, while the others are based on the ecological theory.Basing his views on the constructivist theory of perception, Helmholtz held that the visual system constructs visual percepts through a process of unconscious inference, in which cues are used to make probabilistic inferences about the state of the world. These inferences are based on prior experience, assuming that the most commonly correct interpretation of a cue will continue to hold true. A visual percept is the final manifestation of this process. Brunswik later went on to formalize these concepts with the lens model, which breaks the system's use of a cue into two parts: the ecological validity of the cue, which is its likelihood of correlating with a property of the world, and the system's utilization of the cue. In these theories, accurate perception requires both the existence of cues with sufficiently high ecological validity to make inference possible, and that the system actually utilizes these cues in an appropriate fashion during the construction of percepts.
A second set of theories was posited by Gibson, based on the ecological theory of perception. These theories held that no inferences are necessary to accomplish accurate perception. Rather, the visual system is able to take in sufficient cues related to objects and their surroundings. This means that a one:one mapping between the incoming cues and the environment they represent can be made. These mappings will be shaped by certain computational constraints; traits known to be common in an organism's environment. The ultimate result is the same: a visual precept is manifested by the process.
Cue combination is an active area of research in perception, that seeks to understand how information from multiple sources is combined by the brain to create a single perceptual experience or response. Recent cue recruitment experiments have shown that the adult human visual system can learn to utilize new cues through classical conditioning.
Visual cues
Visual cues are sensory cues received by the eye in the form of light and processed by the visual system during visual perception. Since the visual system is dominant in many species, especially humans, visual cues are a large source of information in how the world is perceived.Types of cues
Depth
The ability to perceive the world in three dimensions and estimate the size and distance to an object depends heavily on depth cues. The two major depth cues, stereopsis and motion parallax, both rely on parallax which is the difference between the perceived position of an object given two different viewpoints. In stereopsis the distance between the eyes is the source of the two different viewpoints, resulting in a Binocular disparity. Motion parallax relies head and body movement to produce the necessary viewpoints.Motion
The visual system can detect motion both using a simple mechanism based on information from multiple clusters of neurons as well as by aggregate through by integrating multiple cues including contrast, form, and texture. One major source of visual information when determining self-motion is optic flow. Optic flow not only indicates whether an agent is moving but in which direction and at what relative speed.Biological motion
Humans in particular have evolved a particularly keen ability to detect if motion is being generated by biological sources, even with point light displays where dots represent the joints of an animal. Recent research suggests that this mechanism can also reveal the gender, emotional state, and action of a given human light point model.Color
The ability to distinguish between colors allows an organism to quickly and easily recognize danger since many brightly colored plants and animals pose some kind of threat, usually harboring some kind of toxin. Color also serves as an inferential cue that can prime both the motor action and interpretation of a persuasive message.Contrast
Contrast, or the difference in luminance and/or color that helps make an object distinguishable, is important in edge detection and serves as a cue.Auditory cues
An auditory cue is a sound signal that represents an incoming sign received through the ears, causing the brain to hear. The results of receiving and processing these cues are collectively known as the sense of hearing and are the subject of research within the fields of psychology, cognitive science, and neurobiology.Auditory system
The auditory system of humans and animals allows individuals to assimilate information from the surroundings, represented as sound waves. Sound waves first pass through the pinnae and the auditory canal, the parts of the ear that comprise the outer ear. Sound then reaches the tympanic membrane in the middle ear. The tympanic membrane sets the malleus, incus, and stapes into vibration. The stapes transmits these vibrations to the inner ear by pushing on the membrane covering the oval window, which separates the middle and inner ear. The inner ear contains the cochlea, the liquid-filled structure containing the hair cells. These cells serve to transform the incoming vibration to electrical signals, which can then be transmitted to the brain.The auditory nerve carries the signal generated by the hair cells away from the inner ear and towards the auditory receiving area in the cortex. The signal then travels through fibers to several subcortical structures and on to the primary auditory receiving area in the temporal lobe.