The philosophy of perception is concerned with the nature of perceptual experience and the status of perceptual data, in particular how they relate to beliefs about, or knowledge of, the world. Any explicit account of perception requires a commitment to one of a variety of ontological or metaphysical views. Philosophers distinguish internalist accounts, which assume that perceptions of objects, and knowledge or beliefs about them, are aspects of an individual's mind, and externalist accounts, which state that they constitute real aspects of the world external to the individual. The position of naïve realism—the 'everyday' impression of physical objects constituting what is perceived—is to some extent contradicted by the occurrence of perceptual illusions and hallucinations and the relativity of perceptual experience as well as certain insights in science. Realist conceptions include phenomenalism and direct and indirect realism. Anti-realist conceptions include idealism and skepticism. Recent philosophical work have expanded on the philosophical features of perception by going beyond the single paradigm of vision.
Perception is the organization, identification, and interpretation of sensory information in order to represent and understand the presented information or environment. All perception involves signals that go through the nervous system, which in turn result from physical or chemical stimulation of the sensory system. Vision involves light striking the retina of the eye; smell is mediated by odor molecules; and hearing involves pressure waves.
Binocular rivalry is a phenomenon of visual perception in which perception alternates between different images presented to each eye.
Multistability is a scientific phenomenon unique to multicellular living systems, which allows multiple steady-state equilibrium points to exist. These stable states are alternated between, through periods of instability, as a single, final perception is derived from physical stimuli1.
Multistable perception is a perceptual phenomenon in which an observer experiences an unpredictable sequence of spontaneous subjective changes. While usually associated with visual perception, multistable perception can also be experienced with auditory and olfactory percepts.
Monocular rivalry is a phenomenon of human visual perception that occurs when two different images are optically superimposed. During prolonged viewing, one image becomes clearer than the other for a few moments, then the other image becomes clearer than the first for a few moments. These alternations in clarity continue at random for as long as one looks. Occasionally one image will become exclusively visible and the other image invisible.
The Hering illusion is one of the geometrical-optical illusions and was discovered by the German physiologist Ewald Hering in 1861. When two straight and parallel lines are presented in front of radial background, the lines appear as if they were bowed outwards. The Orbison illusion is one of its variants, while the Wundt illusion produces a similar, but inverted effect.
David J. Heeger is an American neuroscientist, psychologist, computer scientist, data scientist, and entrepreneur. He is a professor at New York University, Chief Scientific Officer of Statespace Labs, and Chief Scientific Officer and co-founder of Epistemic AI.
Cue recruitment is a form of associative learning in human perception. A cue in perception is a signal that can be measured by an observer's perceptual system, that is informative about the state of some property of the world. A trusted cue is one that the system utilizes to construct appearance, i.e. to build a percept that depends on the world state. In a cue recruitment experiment, an arbitrarily chosen signal is put into correlation with trusted cues, which makes the signal into an artificial cue. If the artificial cue acquires the ability to affect appearance in a manner similar to the trusted cues, it is said to have been recruited.
The flash lag illusion or flash-lag effect is a visual illusion wherein a flash and a moving object that appear in the same location are perceived to be displaced from one another. Several explanations for this simple illusion have been explored in the neuroscience literature.
In vision, filling-in phenomena are those responsible for the completion of missing information across the physiological blind spot, and across natural and artificial scotomata. There is also evidence for similar mechanisms of completion in normal visual analysis. Classical demonstrations of perceptual filling-in involve filling in at the blind spot in monocular vision, and images stabilized on the retina either by means of special lenses, or under certain conditions of steady fixation. For example, naturally in monocular vision at the physiological blind spot, the percept is not a hole in the visual field, but the content is “filled-in” based on information from the surrounding visual field. When a textured stimulus is presented centered on but extending beyond the region of the blind spot, a continuous texture is perceived. This partially inferred percept is paradoxically considered more reliable than a percept based on external input..
The Chubb illusion is an optical illusion or error in visual perception in which the apparent contrast of an object varies substantially to most viewers depending on its relative contrast to the field on which it is displayed. These visual illusions are of particular interest to researchers because they may provide valuable insights in regard to the workings of human visual systems.
Motion Induced Blindness (MIB) is a phenomenon of visual disappearance or perceptual illusions observed in the lab, in which stationary visual stimuli disappear as if erased in front of an observer's eyes when masked with a moving background. Most recent research has shown that microsaccades counteract disappearance but are neither necessary nor sufficient to account for MIB.
The neural correlates of consciousness (NCC) constitute the minimal set of neuronal events and mechanisms sufficient for a specific conscious percept. Neuroscientists use empirical approaches to discover neural correlates of subjective phenomena; that is, neural changes which necessarily and regularly correlate with a specific experience. The set should be minimal because, the brain is necessary to give rise to any given conscious experience, the question is which of its components is necessary to produce it.
Dichoptic is viewing a separate and independent field by each eye. In dichoptic presentation, stimulus A is presented to the left eye and a different stimulus B is presented to the right eye.
Visual space is the experience of space by an aware observer. It is the subjective counterpart of the space of physical objects. There is a long history in philosophy, and later psychology of writings describing visual space, and its relationship to the space of physical objects. A partial list would include René Descartes, Immanuel Kant, Hermann von Helmholtz, William James, to name just a few.
Continuous flash suppression (CFS) is an adapted version of the original flash suppression method, first reported in 2004. In CFS, the first eye is presented with a static stimulus, such as a schematic face, while the second eye is presented with a series of rapidly changing stimuli. The result is the static stimulus becomes consciously repressed by the stimuli presented in the second eye. A variant of CFS to suppress a dynamic stimulus is also reported
Multistable auditory perception is a cognitive phenomenon in which certain auditory stimuli can be perceived in multiple ways. While multistable perception has been most commonly studied in the visual domain, it also has been observed in the auditory and olfactory modalities. In the olfactory domain, different scents are piped to the two nostrils, while in the auditory domain, researchers often examine the effects of binaural sequences of pure tones. Generally speaking, multistable perception has three main characteristics: exclusivity, implying that the multiple perceptions cannot simultaneously occur; randomness, indicating that the duration of perceptual phases follows a random law, and inevitability, meaning that subjects are unable to completely block out one percept indefinitely.
Binocular rivalry is a visual phenomenon wherein one experiences alternating perceptions due to the occurrence of different stimuli presented to the corresponding retinal regions of the two eyes and their competition for perceptual dominance.
Binocular switch suppression (BSS) is a technique to suppress usually salient images from an individual's awareness, a type of experimental manipulation used in visual perception and cognitive neuroscience. In BSS, two images of differing signal strengths are repetitively switched between the left and right eye at a constant rate of 1 Hertz. During this process of switching, the image of lower contrast and signal strength is perceptually suppressed for a period of time.
