Visual Perception: The selecting and organizing of visual stimuli based on the individual's past experience.Visual Cortex: Area of the OCCIPITAL LOBE concerned with the processing of visual information relayed via VISUAL PATHWAYS.Perception: The process by which the nature and meaning of sensory stimuli are recognized and interpreted.Photic Stimulation: Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.Evoked Potentials, Visual: The electric response evoked in the cerebral cortex by visual stimulation or stimulation of the visual pathways.Visual Pathways: Set of cell bodies and nerve fibers conducting impulses from the eyes to the cerebral cortex. It includes the RETINA; OPTIC NERVE; optic tract; and geniculocalcarine tract.Visual Fields: The total area or space visible in a person's peripheral vision with the eye looking straightforward.Motion Perception: The real or apparent movement of objects through the visual field.Visual Acuity: Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.Pattern Recognition, Visual: Mental process to visually perceive a critical number of facts (the pattern), such as characters, shapes, displays, or designs.Depth Perception: Perception of three-dimensionality.Vision, Ocular: The process in which light signals are transformed by the PHOTORECEPTOR CELLS into electrical signals which can then be transmitted to the brain.Form Perception: The sensory discrimination of a pattern shape or outline.Discrimination (Psychology): Differential response to different stimuli.Space Perception: The awareness of the spatial properties of objects; includes physical space.Attention: Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating.Psychophysics: The science dealing with the correlation of the physical characteristics of a stimulus, e.g., frequency or intensity, with the response to the stimulus, in order to assess the psychologic factors involved in the relationship.Perceptual Disorders: Cognitive disorders characterized by an impaired ability to perceive the nature of objects or concepts through use of the sense organs. These include spatial neglect syndromes, where an individual does not attend to visual, auditory, or sensory stimuli presented from one side of the body.Contrast Sensitivity: The ability to detect sharp boundaries (stimuli) and to detect slight changes in luminance at regions without distinct contours. Psychophysical measurements of this visual function are used to evaluate visual acuity and to detect eye disease.Size Perception: The sensory interpretation of the dimensions of objects.Sensory Thresholds: The minimum amount of stimulus energy necessary to elicit a sensory response.Illusions: The misinterpretation of a real external, sensory experience.Reaction Time: The time from the onset of a stimulus until a response is observed.Optical Illusions: An illusion of vision usually affecting spatial relations.Psychomotor Performance: The coordination of a sensory or ideational (cognitive) process and a motor activity.Phosphenes: A subjective visual sensation with the eyes closed and in the absence of light. Phosphenes can be spontaneous, or induced by chemical, electrical, or mechanical (pressure) stimuli which cause the visual field to light up without optical inputs.Cues: Signals for an action; that specific portion of a perceptual field or pattern of stimuli to which a subject has learned to respond.Fixation, Ocular: The positioning and accommodation of eyes that allows the image to be brought into place on the FOVEA CENTRALIS of each eye.Agnosia: Loss of the ability to comprehend the meaning or recognize the importance of various forms of stimulation that cannot be attributed to impairment of a primary sensory modality. Tactile agnosia is characterized by an inability to perceive the shape and nature of an object by touch alone, despite unimpaired sensation to light touch, position, and other primary sensory modalities.Occipital Lobe: Posterior portion of the CEREBRAL HEMISPHERES responsible for processing visual sensory information. It is located posterior to the parieto-occipital sulcus and extends to the preoccipital notch.Color Perception: Mental processing of chromatic signals (COLOR VISION) from the eye by the VISUAL CORTEX where they are converted into symbolic representations. Color perception involves numerous neurons, and is influenced not only by the distribution of wavelengths from the viewed object, but also by its background color and brightness contrast at its boundary.Vision, Binocular: The blending of separate images seen by each eye into one composite image.Brain Mapping: Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.Auditory Perception: The process whereby auditory stimuli are selected, organized, and interpreted by the organism.Eye Movements: Voluntary or reflex-controlled movements of the eye.Vision Disorders: Visual impairments limiting one or more of the basic functions of the eye: visual acuity, dark adaptation, color vision, or peripheral vision. These may result from EYE DISEASES; OPTIC NERVE DISEASES; VISUAL PATHWAY diseases; OCCIPITAL LOBE diseases; OCULAR MOTILITY DISORDERS; and other conditions (From Newell, Ophthalmology: Principles and Concepts, 7th ed, p132).Human Body: The human being as a non-anatomical and non-zoological entity. The emphasis is on the philosophical or artistic treatment of the human being, and includes lay and social attitudes toward the body in history. (From J. Cassedy, NLM History of Medicine Division)Consciousness: Sense of awareness of self and of the environment.Orientation: Awareness of oneself in relation to time, place and person.Time Perception: The ability to estimate periods of time lapsed or duration of time.Saccades: An abrupt voluntary shift in ocular fixation from one point to another, as occurs in reading.Visual Prosthesis: Artificial device such as an externally-worn camera attached to a stimulator on the RETINA, OPTIC NERVE, or VISUAL CORTEX, intended to restore or amplify vision.Signal Detection, Psychological: Psychophysical technique that permits the estimation of the bias of the observer as well as detectability of the signal (i.e., stimulus) in any sensory modality. (From APA, Thesaurus of Psychological Index Terms, 8th ed.)Magnetic Resonance Imaging: Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.Gestalt Theory: A system which emphasizes that experience and behavior contain basic patterns and relationships which cannot be reduced to simpler components; that is, the whole is greater than the sum of its parts.Functional Laterality: Behavioral manifestations of cerebral dominance in which there is preferential use and superior functioning of either the left or the right side, as in the preferred use of the right hand or right foot.Speech Perception: The process whereby an utterance is decoded into a representation in terms of linguistic units (sequences of phonetic segments which combine to form lexical and grammatical morphemes).Awareness: The act of "taking account" of an object or state of affairs. It does not imply assessment of, nor attention to the qualities or nature of the object.Social Perception: The perceiving of attributes, characteristics, and behaviors of one's associates or social groups.Perceptual Masking: The interference of one perceptual stimulus with another causing a decrease or lessening in perceptual effectiveness.Temporal Lobe: Lower lateral part of the cerebral hemisphere responsible for auditory, olfactory, and semantic processing. It is located inferior to the lateral fissure and anterior to the OCCIPITAL LOBE.Models, Neurological: Theoretical representations that simulate the behavior or activity of the neurological system, processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Parietal Lobe: Upper central part of the cerebral hemisphere. It is located posterior to central sulcus, anterior to the OCCIPITAL LOBE, and superior to the TEMPORAL LOBES.Feeding Methods: Methods of giving food to humans or animals.Vision Disparity: The difference between two images on the retina when looking at a visual stimulus. This occurs since the two retinas do not have the same view of the stimulus because of the location of our eyes. Thus the left eye does not get exactly the same view as the right eye.Field Dependence-Independence: The ability to respond to segments of the perceptual experience rather than to the whole.Perceptual Distortion: Lack of correspondence between the way a stimulus is commonly perceived and the way an individual perceives it under given conditions.Discrimination Learning: Learning that is manifested in the ability to respond differentially to various stimuli.Color: The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.Visual Field Tests: Method of measuring and mapping the scope of vision, from central to peripheral of each eye.Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Unconscious (Psychology): Those forces and content of the mind which are not ordinarily available to conscious awareness or to immediate recall.Magnetoencephalography: The measurement of magnetic fields over the head generated by electric currents in the brain. As in any electrical conductor, electric fields in the brain are accompanied by orthogonal magnetic fields. The measurement of these fields provides information about the localization of brain activity which is complementary to that provided by ELECTROENCEPHALOGRAPHY. Magnetoencephalography may be used alone or together with electroencephalography, for measurement of spontaneous or evoked activity, and for research or clinical purposes.Retina: The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.Dominance, Ocular: The functional superiority and preferential use of one eye over the other. The term is usually applied to superiority in sighting (VISUAL PERCEPTION) or motor task but not difference in VISUAL ACUITY or dysfunction of one of the eyes. Ocular dominance can be modified by visual input and NEUROTROPHIC FACTORS.Macaca mulatta: A species of the genus MACACA inhabiting India, China, and other parts of Asia. The species is used extensively in biomedical research and adapts very well to living with humans.Neuropsychological Tests: Tests designed to assess neurological function associated with certain behaviors. They are used in diagnosing brain dysfunction or damage and central nervous system disorders or injury.Transcranial Magnetic Stimulation: A technique that involves the use of electrical coils on the head to generate a brief magnetic field which reaches the CEREBRAL CORTEX. It is coupled with ELECTROMYOGRAPHY response detection to assess cortical excitability by the threshold required to induce MOTOR EVOKED POTENTIALS. This method is also used for BRAIN MAPPING, to study NEUROPHYSIOLOGY, and as a substitute for ELECTROCONVULSIVE THERAPY for treating DEPRESSION. Induction of SEIZURES limits its clinical usage.Acoustic Stimulation: Use of sound to elicit a response in the nervous system.Judgment: The process of discovering or asserting an objective or intrinsic relation between two objects or concepts; a faculty or power that enables a person to make judgments; the process of bringing to light and asserting the implicit meaning of a concept; a critical evaluation of a person or situation.Models, Psychological: Theoretical representations that simulate psychological processes and/or social processes. These include the use of mathematical equations, computers, and other electronic equipment.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Alpha Rhythm: Brain waves characterized by a relatively high voltage or amplitude and a frequency of 8-13 Hz. They constitute the majority of waves recorded by EEG registering the activity of the parietal and occipital lobes when the individual is awake, but relaxed with the eyes closed.Motion: Physical motion, i.e., a change in position of a body or subject as a result of an external force. It is distinguished from MOVEMENT, a process resulting from biological activity.Cognition: Intellectual or mental process whereby an organism obtains knowledge.Geniculate Bodies: Part of the DIENCEPHALON inferior to the caudal end of the dorsal THALAMUS. Includes the lateral geniculate body which relays visual impulses from the OPTIC TRACT to the calcarine cortex, and the medial geniculate body which relays auditory impulses from the lateral lemniscus to the AUDITORY CORTEX.Electroencephalography: Recording of electric currents developed in the brain by means of electrodes applied to the scalp, to the surface of the brain, or placed within the substance of the brain.Recognition (Psychology): The knowledge or perception that someone or something present has been previously encountered.Face: The anterior portion of the head that includes the skin, muscles, and structures of the forehead, eyes, nose, mouth, cheeks, and jaw.Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Behavior: The observable response of a man or animal to a situation.Pain Perception: The process by which PAIN is recognized and interpreted by the brain.Learning: Relatively permanent change in behavior that is the result of past experience or practice. The concept includes the acquisition of knowledge.Memory: Complex mental function having four distinct phases: (1) memorizing or learning, (2) retention, (3) recall, and (4) recognition. Clinically, it is usually subdivided into immediate, recent, and remote memory.Rotation: Motion of an object in which either one or more points on a line are fixed. It is also the motion of a particle about a fixed point. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Neurons: The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.Image Processing, Computer-Assisted: A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.Nerve Net: A meshlike structure composed of interconnecting nerve cells that are separated at the synaptic junction or joined to one another by cytoplasmic processes. In invertebrates, for example, the nerve net allows nerve impulses to spread over a wide area of the net because synapses can pass information in any direction.Task Performance and Analysis: The detailed examination of observable activity or behavior associated with the execution or completion of a required function or unit of work.Movement: The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.Macaca: A genus of the subfamily CERCOPITHECINAE, family CERCOPITHECIDAE, consisting of 16 species inhabiting forests of Africa, Asia, and the islands of Borneo, Philippines, and Celebes.Memory, Short-Term: Remembrance of information for a few seconds to hours.Touch Perception: The process by which the nature and meaning of tactile stimuli are recognized and interpreted by the brain, such as realizing the characteristics or name of an object being touched.Neural Pathways: Neural tracts connecting one part of the nervous system with another.Mental Processes: Conceptual functions or thinking in all its forms.Pitch Perception: A dimension of auditory sensation varying with cycles per second of the sound stimulus.Taste Perception: The process by which the nature and meaning of gustatory stimuli are recognized and interpreted by the brain. The four basic classes of taste perception are salty, sweet, bitter, and sour.Olfactory Perception: The process by which the nature and meaning of olfactory stimuli, such as odors, are recognized and interpreted by the brain.Questionnaires: Predetermined sets of questions used to collect data - clinical data, social status, occupational group, etc. The term is often applied to a self-completed survey instrument.Blindness: The inability to see or the loss or absence of perception of visual stimuli. This condition may be the result of EYE DISEASES; OPTIC NERVE DISEASES; OPTIC CHIASM diseases; or BRAIN DISEASES affecting the VISUAL PATHWAYS or OCCIPITAL LOBE.Vision Tests: A series of tests used to assess various functions of the eyes.Adaptation, Physiological: The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.Vision, Monocular: Images seen by one eye.Cerebral Cortex: The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulchi. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.Weight Perception: Recognition and discrimination of the heaviness of a lifted object.Health Knowledge, Attitudes, Practice: Knowledge, attitudes, and associated behaviors which pertain to health-related topics such as PATHOLOGIC PROCESSES or diseases, their prevention, and treatment. This term refers to non-health workers and health workers (HEALTH PERSONNEL).Attitude to Health: Public attitudes toward health, disease, and the medical care system.Action Potentials: Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.Attitude of Health Personnel: Attitudes of personnel toward their patients, other professionals, toward the medical care system, etc.Sensory Deprivation: The absence or restriction of the usual external sensory stimuli to which the individual responds.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.Lighting: The illumination of an environment and the arrangement of lights to achieve an effect or optimal visibility. Its application is in domestic or in public settings and in medical and non-medical environments.Vision, Low: Vision considered to be inferior to normal vision as represented by accepted standards of acuity, field of vision, or motility. Low vision generally refers to visual disorders that are caused by diseases that cannot be corrected by refraction (e.g., MACULAR DEGENERATION; RETINITIS PIGMENTOSA; DIABETIC RETINOPATHY, etc.).Music: Sound that expresses emotion through rhythm, melody, and harmony.Touch: Sensation of making physical contact with objects, animate or inanimate. Tactile stimuli are detected by MECHANORECEPTORS in the skin and mucous membranes.Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Hemianopsia: Partial or complete loss of vision in one half of the visual field(s) of one or both eyes. Subtypes include altitudinal hemianopsia, characterized by a visual defect above or below the horizontal meridian of the visual field. Homonymous hemianopsia refers to a visual defect that affects both eyes equally, and occurs either to the left or right of the midline of the visual field. Binasal hemianopsia consists of loss of vision in the nasal hemifields of both eyes. Bitemporal hemianopsia is the bilateral loss of vision in the temporal fields. Quadrantanopsia refers to loss of vision in one quarter of the visual field in one or both eyes.Schizophrenia: A severe emotional disorder of psychotic depth characteristically marked by a retreat from reality with delusion formation, HALLUCINATIONS, emotional disharmony, and regressive behavior.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Attitude: An enduring, learned predisposition to behave in a consistent way toward a given class of objects, or a persistent mental and/or neural state of readiness to react to a certain class of objects, not as they are but as they are conceived to be.Amblyopia: A nonspecific term referring to impaired vision. Major subcategories include stimulus deprivation-induced amblyopia and toxic amblyopia. Stimulus deprivation-induced amblyopia is a developmental disorder of the visual cortex. A discrepancy between visual information received by the visual cortex from each eye results in abnormal cortical development. STRABISMUS and REFRACTIVE ERRORS may cause this condition. Toxic amblyopia is a disorder of the OPTIC NERVE which is associated with ALCOHOLISM, tobacco SMOKING, and other toxins and as an adverse effect of the use of some medications.Visually Impaired Persons: Persons with loss of vision such that there is an impact on activities of daily living.Sensation: The process in which specialized SENSORY RECEPTOR CELLS transduce peripheral stimuli (physical or chemical) into NERVE IMPULSES which are then transmitted to the various sensory centers in the CENTRAL NERVOUS SYSTEM.Focus Groups: A method of data collection and a QUALITATIVE RESEARCH tool in which a small group of individuals are brought together and allowed to interact in a discussion of their opinions about topics, issues, or questions.Ocular Physiological Phenomena: Processes and properties of the EYE as a whole or of any of its parts.Scotoma: A localized defect in the visual field bordered by an area of normal vision. This occurs with a variety of EYE DISEASES (e.g., RETINAL DISEASES and GLAUCOMA); OPTIC NERVE DISEASES, and other conditions.Superior Colliculi: The anterior pair of the quadrigeminal bodies which coordinate the general behavioral orienting responses to visual stimuli, such as whole-body turning, and reaching.Color Vision: Function of the human eye that is used in bright illumination or in daylight (at photopic intensities). Photopic vision is performed by the three types of RETINAL CONE PHOTORECEPTORS with varied peak absorption wavelengths in the color spectrum (from violet to red, 400 - 700 nm).Cats: The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)Pain Measurement: Scales, questionnaires, tests, and other methods used to assess pain severity and duration in patients or experimental animals to aid in diagnosis, therapy, and physiological studies.Cross-Sectional Studies: Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.Phonetics: The science or study of speech sounds and their production, transmission, and reception, and their analysis, classification, and transcription. (Random House Unabridged Dictionary, 2d ed)ReadingFacial Expression: Observable changes of expression in the face in response to emotional stimuli.Adaptation, Ocular: The adjustment of the eye to variations in the intensity of light. Light adaptation is the adjustment of the eye when the light threshold is increased; DARK ADAPTATION when the light is greatly reduced. (From Cline et al., Dictionary of Visual Science, 4th ed)Emotions: Those affective states which can be experienced and have arousing and motivational properties.Patient Satisfaction: The degree to which the individual regards the health care service or product or the manner in which it is delivered by the provider as useful, effective, or beneficial.Fovea Centralis: An area approximately 1.5 millimeters in diameter within the macula lutea where the retina thins out greatly because of the oblique shifting of all layers except the pigment epithelium layer. It includes the sloping walls of the fovea (clivus) and contains a few rods in its periphery. In its center (foveola) are the cones most adapted to yield high visual acuity, each cone being connected to only one ganglion cell. (Cline et al., Dictionary of Visual Science, 4th ed)Self Concept: A person's view of himself.Feedback, Sensory: A mechanism of communicating one's own sensory system information about a task, movement or skill.Eyeglasses: A pair of ophthalmic lenses in a frame or mounting which is supported by the nose and ears. The purpose is to aid or improve vision. It does not include goggles or nonprescription sun glasses for which EYE PROTECTIVE DEVICES is available.Qualitative Research: Any type of research that employs nonnumeric information to explore individual or group characteristics, producing findings not arrived at by statistical procedures or other quantitative means. (Qualitative Inquiry: A Dictionary of Terms Thousand Oaks, CA: Sage Publications, 1997)Cochlear Implants: Electronic hearing devices typically used for patients with normal outer and middle ear function, but defective inner ear function. In the COCHLEA, the hair cells (HAIR CELLS, VESTIBULAR) may be absent or damaged but there are residual nerve fibers. The device electrically stimulates the COCHLEAR NERVE to create sound sensation.Proprioception: Sensory functions that transduce stimuli received by proprioceptive receptors in joints, tendons, muscles, and the INNER EAR into neural impulses to be transmitted to the CENTRAL NERVOUS SYSTEM. Proprioception provides sense of stationary positions and movements of one's body parts, and is important in maintaining KINESTHESIA and POSTURAL BALANCE.Figural Aftereffect: A perceptual phenomenon used by Gestalt psychologists to demonstrate that events in one part of the perceptual field may affect perception in another part.Color Perception Tests: Type of vision test used to determine COLOR VISION DEFECTS.Interviews as Topic: Conversations with an individual or individuals held in order to obtain information about their background and other personal biographical data, their attitudes and opinions, etc. It includes school admission or job interviews.Public Opinion: The attitude of a significant portion of a population toward any given proposition, based upon a measurable amount of factual evidence, and involving some degree of reflection, analysis, and reasoning.Kinesthesis: Sense of movement of a part of the body, such as movement of fingers, elbows, knees, limbs, or weights.Electroretinography: Recording of electric potentials in the retina after stimulation by light.Speech: Communication through a system of conventional vocal symbols.Retinal Pigments: Photosensitive protein complexes of varied light absorption properties which are expressed in the PHOTORECEPTOR CELLS. They are OPSINS conjugated with VITAMIN A-based chromophores. Chromophores capture photons of light, leading to the activation of opsins and a biochemical cascade that ultimately excites the photoreceptor cells.Noise: Any sound which is unwanted or interferes with HEARING other sounds.Refractive Errors: Deviations from the average or standard indices of refraction of the eye through its dioptric or refractive apparatus.Pain: An unpleasant sensation induced by noxious stimuli which are detected by NERVE ENDINGS of NOCICEPTIVE NEURONS.Flicker Fusion: The point or frequency at which all flicker of an intermittent light stimulus disappears.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Strabismus: Misalignment of the visual axes of the eyes. In comitant strabismus the degree of ocular misalignment does not vary with the direction of gaze. In noncomitant strabismus the degree of misalignment varies depending on direction of gaze or which eye is fixating on the target. (Miller, Walsh & Hoyt's Clinical Neuro-Ophthalmology, 4th ed, p641)Vestibule, Labyrinth: An oval, bony chamber of the inner ear, part of the bony labyrinth. It is continuous with bony COCHLEA anteriorly, and SEMICIRCULAR CANALS posteriorly. The vestibule contains two communicating sacs (utricle and saccule) of the balancing apparatus. The oval window on its lateral wall is occupied by the base of the STAPES of the MIDDLE EAR.Evoked Potentials: Electrical responses recorded from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported.Decision Making: The process of making a selective intellectual judgment when presented with several complex alternatives consisting of several variables, and usually defining a course of action or an idea.Head Movements: Voluntary or involuntary motion of head that may be relative to or independent of body; includes animals and humans.Hand: The distal part of the arm beyond the wrist in humans and primates, that includes the palm, fingers, and thumb.Language: A verbal or nonverbal means of communicating ideas or feelings.Psychometrics: Assessment of psychological variables by the application of mathematical procedures.Odors: The volatile portions of substances perceptible by the sense of smell. (Grant & Hackh's Chemical Dictionary, 5th ed)Psychoacoustics: The science pertaining to the interrelationship of psychologic phenomena and the individual's response to the physical properties of sound.Smell: The ability to detect scents or odors, such as the function of OLFACTORY RECEPTOR NEURONS.Glaucoma: An ocular disease, occurring in many forms, having as its primary characteristics an unstable or a sustained increase in the intraocular pressure which the eye cannot withstand without damage to its structure or impairment of its function. The consequences of the increased pressure may be manifested in a variety of symptoms, depending upon type and severity, such as excavation of the optic disk, hardness of the eyeball, corneal anesthesia, reduced visual acuity, seeing of colored halos around lights, disturbed dark adaptation, visual field defects, and headaches. (Dictionary of Visual Science, 4th ed)Auditory Cortex: The region of the cerebral cortex that receives the auditory radiation from the MEDIAL GENICULATE BODY.Pursuit, Smooth: Eye movements that are slow, continuous, and conjugate and occur when a fixed object is moved slowly.Darkness: The absence of light.Body Image: Individuals' concept of their own bodies.Cataract Extraction: The removal of a cataractous CRYSTALLINE LENS from the eye.Neuronal Plasticity: The capacity of the NERVOUS SYSTEM to change its reactivity as the result of successive activations.Retinal Cone Photoreceptor Cells: Photosensitive afferent neurons located primarily within the FOVEA CENTRALIS of the MACULA LUTEA. There are three major types of cone cells (red, blue, and green) whose photopigments have different spectral sensitivity curves. Retinal cone cells operate in daylight vision (at photopic intensities) providing color recognition and central visual acuity.Loudness Perception: The perceived attribute of a sound which corresponds to the physical attribute of intensity.Cataract: Partial or complete opacity on or in the lens or capsule of one or both eyes, impairing vision or causing blindness. The many kinds of cataract are classified by their morphology (size, shape, location) or etiology (cause and time of occurrence). (Dorland, 27th ed)Afterimage: Continuation of visual impression after cessation of stimuli causing the original image.Hallucinations: Subjectively experienced sensations in the absence of an appropriate stimulus, but which are regarded by the individual as real. They may be of organic origin or associated with MENTAL DISORDERS.ArtDark Adaptation: Adjustment of the eyes under conditions of low light. The sensitivity of the eye to light is increased during dark adaptation.Culture: A collective expression for all behavior patterns acquired and socially transmitted through symbols. Culture includes customs, traditions, and language.Feedback: A mechanism of communication within a system in that the input signal generates an output response which returns to influence the continued activity or productivity of that system.Behavior, Animal: The observable response an animal makes to any situation.Quality of Life: A generic concept reflecting concern with the modification and enhancement of life attributes, e.g., physical, political, moral and social environment; the overall condition of a human life.Retinal Ganglion Cells: Neurons of the innermost layer of the retina, the internal plexiform layer. They are of variable sizes and shapes, and their axons project via the OPTIC NERVE to the brain. A small subset of these cells act as photoreceptors with projections to the SUPRACHIASMATIC NUCLEUS, the center for regulating CIRCADIAN RHYTHM.Physician-Patient Relations: The interactions between physician and patient.Pattern Recognition, Physiological: The analysis of a critical number of sensory stimuli or facts (the pattern) by physiological processes such as vision (PATTERN RECOGNITION, VISUAL), touch, or hearing.Nystagmus, Optokinetic: Normal nystagmus produced by looking at objects moving across the field of vision.Eye Diseases: Diseases affecting the eye.Data Collection: Systematic gathering of data for a particular purpose from various sources, including questionnaires, interviews, observation, existing records, and electronic devices. The process is usually preliminary to statistical analysis of the data.Vision Screening: Application of tests and examinations to identify visual defects or vision disorders occurring in specific populations, as in school children, the elderly, etc. It is differentiated from VISION TESTS, which are given to evaluate/measure individual visual performance not related to a specific population.Deafness: A general term for the complete loss of the ability to hear from both ears.Gravity Sensing: Process whereby a cell, bodily structure, or organism (animal or plant) receives or detects a gravity stimulus. Gravity sensing plays an important role in the directional growth and development of an organism (GRAVITROPISM).

*  PPT - Perceptual Systems PowerPoint Presentation - ID:2161940

Sources: Wolfe, J, Kluender , K, Levi, D. et al Sensation & Perception 2012 3 rd ed Sinauer - 15% discount and free shipping if ... Perception and Perceptual Distortions -Outline. we are going to focus on visual perceptionapproaches:david marr - bottom-up ... Perceptual Constancies -Unit 1 psychology - visual perception. what are perceptual constancies?. in vision, perceptual ... perception, memory and reason\' are reliable but not infallible.there are errors of reasoning and sensory illusions to which ...
slideserve.com/marinel/perceptual-systems

*  Brain and Visual Perception - David H. Hubel; Torsten N. Wiesel - Oxford University Press

This relates to the machinery that underlies visual perception. ... Brain and Visual Perception. The Story of a 25-Year ... Brain and Visual Perception. The Story of a 25-Year Collaboration. David H. Hubel, M.D. and Torsten N. Wiesel, M.D.. ... Brain and Visual Perception. The Story of a 25-Year Collaboration. David H. Hubel, M.D. and Torsten N. Wiesel, M.D.. ... Brain and Visual Perception. The Story of a 25-Year Collaboration. David H. Hubel, M.D. and Torsten N. Wiesel, M.D.. ...
https://global.oup.com/academic/product/brain-and-visual-perception-9780195176186?cc=us&lang=en&facet_narrowbybinding_facet=Ebook&facet_narrowbybinding_facet=Ebook&tab=toc

*  Visual Neuroscience | Topic Collections | ARVO Journals

Perception and Action (30) * Crowding (18) * Oncology (14) * External Eye Disease (10) ... TAGS: ethics, neurons, psychophysics, visual pathways, visual system, confidence limits, inspection, heterogeneity of variance, ... Visual Neuroscience You will receive an email whenever topic 'Visual Neuroscience' is updated. You can manage this and all ... TAGS: astronauts, dilatation, pathologic, intracranial pressure, syndrome, visual impairment, optic nerve sheath Invest. ...
abstracts.iovs.org/solr/topicresults.aspx?f_Categories=Visual Neuroscience&resourceid=38487

*  BBB Business Profile | Visual Perceptions, LLC

Visual Perceptions, LLC. 20 years in business. 2139 Silas Deane Hwy. Rocky Hill, CT 06067-2336 ... Visual Perceptions, LLC offers comprehensive eye examination services, including: dilation of the pupil, cataract & glaucoma ... Glaucoma diagnosis and treatment using the diagnostic tools like scanning laser ophthalmoscopy and visual field analysis. They ...
https://bbb.org/connecticut/Business-Reviews/optometrists/visual-perceptions-llc-in-rocky-hill-ct-87012226/directions

*  Principles of Visual Perception - Carolyn M. Bloomer - Google Books

... and how they are related to the perception of art in particular. ... Surveys the principles of visual perception based on ... surface theory things tion tive tune vanishing-point perspective viewer vision visual field visual language visual perception ... Visual_Perception.html?id=JuBOAAAAMAAJ&utm_source=gb-gplus-sharePrinciples of Visual Perception. ... Surveys the principles of visual perception based on psychological research and everyday experience, and how they are related ...
https://books.google.com/books?id=JuBOAAAAMAAJ&dq=related:ISBN3540404570&lr=&source=gbs_similarbooks_r&hl=en

*  Designing Websites for Visual Perception

It is important for UX designers to have an understanding of visual design principles. ... You do not need to be a visual designer to succeed at this, but you must understand key visual theory like the aforementioned. ... In order to better define the relationship between visual design and user experience we will explore the following visual ... However, whether visual design is done by UX designers or by other specialized designers, it is important for you to have an ...
https://generalassemb.ly/blog/designing-websites-for-visual-perception/

*  Light: The Physics of Art and Visual Perception

... (2011, April 7). Retrieved September 23, 2017, from University of Toledo: http ... T Light: The Physics of Art and Visual Perception. %I University of Toledo. %V 2017. %N 23 September 2017. %8 April 7, 2011. %9 ... Light: The Physics of Art and Visual Perception. Toledo: University of Toledo, April 7, 2011.,/a, ... misc{ Title = {Light: The Physics of Art and Visual Perception}, Publisher = {University of Toledo}, Volume = {2017}, Number ...
https://compadre.org/informal/items/detail.cfm?ID=11139

*  Jigsaw Puzzles (Visual Perception) by Evan-Moor | TpT

... that require students to use visual perception skills and create jigsaw puzzles ... that require students to use visual perception skills and create jigsaw puzzles ... Teacher directions and eight patterns (with two to six pieces) that require students to use visual perception skills and create ...
https://teacherspayteachers.com/Product/Jigsaw-Puzzles-Visual-Perception-2662492

*  Visual Perception | VanCleave's Science Fun

This is called visual perception.. Again, objects have color because they reflect visual light energy. The spectrum of visual ... Filed Under: Chemistry Tagged With: Leuco Dyes, liquid crystals, specrum of visual light, thermochromic, visual perception, ... As a unit, the spectrum of visual light energy is called white light. Sunlight is an example of white light.. ... Objects appear black if they do not reflect any of the spectrum of visual light energy. When white light strikes an object and ...
scienceprojectideasforkids.com/tag/visual-perception/

*  The Great and the Small | Visual Perception | Jesus

... a true sense-perception of the external world, the mind forming accurate judgments from the images presented to it by the eye. ... suddenly by surgical operation restored to sight have made clearer the gradual acquisition of this faculty of sense perception ...
https://scribd.com/document/156206356/The-Great-and-the-Small

*  Visual Perceptions | Euro Mediterranean Arts

2017 EM Arts - Napoli - P.I. & C.F. 07615690638. ...
https://em-arts.org/programma-films/venerdi-18-novembre-visual-perceptions-ore-2000

*  British Library EThOS: A study of the relationship between visual perception and typographic organisation.

Psychology Psychology
ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376104

*  Effects of psychodysleptic drug psilocybin on visual perception. Changes in brightness preference - University of Minnesota...

Effects of psychodysleptic drug psilocybin on visual perception. Changes in brightness preference. Experientia, 25:166 --169. ... Effects of psychodysleptic drug psilocybin on visual perception. Changes in brightness... ...
upress.umn.edu/test-division/bibliography/1960-1969/1968/fischer_effects_1968

*  Pohl Dr., Wilfried | Visual Perception WORKSHOP - LED professional Symposium +Expo (LpS)

All session by Pohl Dr., Wilfried , Visual Perception WORKSHOP. Workshops (4 parallel WS) - DAY 1 , SEPT 26. 08:00 - 09:30 ... including visual perception and light and health. Leader of various international planning and R&D-projects in these fields, ...
https://led-professional-symposium.com/speaker/wilfried-pohl

*  Dr. Alice Cronin-Golomb presents, "Visual Perception, Attention, & Cognition in Parkinson's Disease": Research Lecture Series

The non-motor symptoms include, among others, changes in visual perception, attention, and cognition, all of which may be ... Alice Cronin-Golomb presents, "Visual Perception, Attention, & Cognition in Parkinson's Disease". * Sep. 5, 2017 ... Alice Cronin-Golomb, Boston University, for a presentation entitled "Visual Perception, Attention and Cognition in Parkinson's ... including visual-cue training for navigation, and an action intervention to address biological-motion perception deficits and ...
neco.edu/events/detail/dr-alice-cronin-golomb

*  Prosthetic visual perception: retinal electrical stimulation in blind human patients :: University of Southern California...

Prosthetic visual perception: retinal electrical stimulation in blind human patients. Page 1. Save page Remove page Previous. 1 ... PROSTHETIC VISUAL PERCEPTION: RETINAL ELECTRICAL STIMULATION IN BLIND HUMAN PATIENTS by Alan Matthew Horsager A Dissertation ... PROSTHETIC VISUAL PERCEPTION: RETINAL ELECTRICAL STIMULATION IN BLIND HUMAN PATIENTS by Alan Matthew Horsager A Dissertation ... However, the visual experience of these subjects is nothing like a digital scoreboard-like movie, with each electrode acting as ...
digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/227587/rec/13

*  Frontiers | Enhancing Visual Perception and Motor Accuracy among School Children through a Mindfulness and Compassion Program |...

Visual Perception, Motor Accuracy, and Child Development. Visual perception refers to comprehending and organizing visual input ... Visual-motor integration has been described as being multifaceted and encompassing: visual receptive functions; visual ... visual perception, motor accuracy, anxiety. Citation: Tarrasch R, Margalit-Shalom L and Berger R (2017) Enhancing Visual ... Visual Perception. A significant main effect of gender was obtained [F(1,198) = 3.96, p , 0.05, η. p. 2. = 0.020]. Girls had a ...
journal.frontiersin.org/article/10.3389/fpsyg.2017.00281/full

*  Login Medical Bookstores: Visual Perception: A Clinical Orientation : 1259585018 : Schwartz, Steven H. OD, PhD : Medical Books ...

Visual Perception: A Clinical Orientation : 1259585018 : Schwartz, Steven H. OD, PhD : Medical Books : Optometry and Eyecare- ... The information presented in Visual Perception, Fifth Edition cannot be found in any other single volume. The book.s unique ... Wide in scope, the book covers every clinically important aspect of visual science, including color vision and its defects, ... If you require a comprehensive text on visual science that imparts fundamental concepts in an engaging and interesting style, ...
webmedbooks.com/loginbookstore/content/productdetail.aspx/upc=9a9df8ab-890d-4e1b-911a-b556a8008b72

*  Nonverbal Communication: Notes on the Visual Perception of Human Relations. de RUESCH, Jurgen and KEES, Weldon.: University of...

Notes on the Visual Perception of Human Relations * mit O r i g i n a l - S c h u t z u m s c h l a g Jürgen Ruesch and Weldon ... Nonverbal Communication: Notes on the Visual Perception of Human Relations.. RUESCH, Jurgen and KEES, Weldon.. Editorial: ... A continuaci n, le mostramos una lista de copias similares de Nonverbal Communication: Notes on the Visual Perception of Human ... 1. Nonverbal Communication Notes on the Visual Perception of Human Relations Ruesch, Jurgen and Weldon Kees. ...
https://iberlibro.com/Nonverbal-Communication-Notes-Visual-Perception-Human/11010226514/bd

*  Visual Perception Test - PLAY4FUN

Test your visual perception in 10 levels. Find how fast can one element different from others on the board. ... Visual Perception Test. Test your visual perception in 10 levels. Find how fast can one element different from others on the ... play4fun.se/games/Visual-Perception-Test.swf', ,embed src='http://play4fun.se/games/Visual-Perception-Test.swf' width='640' ...
play4fun.se/board-game/visual-perception-test

*  visual perception

Tag Archives: visual perception. Post navigation. Feb 21 2015 Secrets In Plain Sight - Macrocosmic Harmony The best temples ... The beauty of repeating 5's harmonizing our visual perception, 5 symbolizing life, is not lost on me. ... which forms the center point of our visual perception? At other frequencies, more radiant intensity is required to achieve the ... How far from your awareness are your sensations, perceptions or thoughts? Examine your experience and you will see that there ...
https://edithboyertelmer.wordpress.com/tag/visual-perception/

*  Visual Effects and Perception - CBC Player

Film aficionado Jesse Wente, and philosopher of perception Mohan Matthen, on how perception of visual effects changes with time ... Film aficionado Jesse Wente, and philosopher of perception Mohan Matthen, on how perception of visual effects changes with time ...
cbc.ca/player/play/2390115514

*  Common auditory-visual space perception in early infancy :: Memorial University - Electronic Theses and Dissertations 1

Space perception; Auditory perception; Visual perception; Notes Bibliography : leaves 42-43. Source Paper copy kept in the ...
collections.mun.ca/cdm/compoundobject/collection/theses/id/291573

*  Prefrontal cortex modulates posterior alpha oscillations during top-down guided visual perception

Here, we probed visual perception on a fine-grained temporal scale to study the oscillatory dynam- ics supporting prefrontal- ... Prefrontal cortex modulates posterior alpha oscillations during top-down guided visual perception Authors:. *Randolph F. ... Conscious visual perception is proposed to arise from the selective synchronization of functionally specialized but widely ... We tested whether a predictive context that was embedded in a rapid visual stream modulated the perception of a subsequent near ...
knightlab.berkeley.edu/publications/detail/575/

*  Simulating Film Effects with Curves

In the end, our appreciations and perceptions have been formed by the pictures we have seen. Certain types of visual cues have ...
prime-junta.net/pont/How_to/100_Curves_and_Films/_Curves_and_films.html

Immaculate perception: The expression immaculate perception has been used in various senses by various philosophers.Meridian (perimetry, visual field): Meridian (plural: "meridians") is used in perimetry and in specifying visual fields. According to IPS Perimetry Standards 1978 (2002): "Perimetry is the measurement of [an observer's] visual functions ...Biological motion: Biological motion is a term used by social and cognitive neuroscientists to refer to the unique visual phenomenon of a moving, animate object. Often, the stimuli used in biological motion experiments are just a few moving dots that reflect the motion of some key joints of the moving organism.LogMAR chart: A LogMAR chart comprises rows of letters and is used by ophthalmologists and vision scientists to estimate visual acuity. This chart was developed at the National Vision Research Institute of Australia in 1976, and is designed to enable a more accurate estimate of acuity as compared to other charts (e.Stereopsis: Stereopsis (from the Greek στερεο- [meaning "solid", and ὄψις] opsis, "appearance, [[visual perception|sight") is a term that is most often used to refer to the perception of depth and 3-dimensional structure obtained on the basis of visual information deriving from two eyes by individuals with normally developed binocular vision.Gary H. Posner: Gary H. Posner (born c.Korte's law: In psychophysics, Korte's law, also known more completely as Korte's third law of apparent motion, is an observation relating the phenomenon of apparent motion to the distance and duration between two successively presented stimuli. It was originally proposed in 1915 by Adolf Korte.Hemispatial neglectSubatomic scale: The subatomic scale is the domain of physical size that encompasses objects smaller than an atom. It is the scale at which the atomic constituents, such as the nucleus containing protons and neutrons, and the electrons, which orbit in spherical or elliptical paths around the nucleus, become apparent.Percolation threshold: Percolation threshold is a mathematical concept related to percolation theory, which is the formation of long-range connectivity in random systems. Below the threshold a giant connected component does not exist; while above it, there exists a giant component of the order of system size.Auditory illusion: An auditory illusion is an illusion of hearing, the aural equivalent of an optical illusion: the listener hears either sounds which are not present in the stimulus, or "impossible" sounds.List of optical illusions: This is a list of optical illusions.PhospheneCue stick: A cue stick (or simply cue, more specifically pool cue, snooker cue, or billiards cue), is an item of sporting equipment essential to the games of pool, snooker and carom billiards. It is used to strike a ball, usually the .Apperceptive agnosia: Apperceptive agnosia is failure in recognition that is due to a failure of perception. In contrast, associative agnosia is a type of agnosia where perception occurs but recognition still does not occur.Binocular vision: Binocular vision is vision in which creatures having two eyes use them together. The word binocular comes from two Latin roots, bini for double, and oculus for eye.Auditory scene analysis: In psychophysics, auditory scene analysis (ASA) is a proposed model for the basis of auditory perception. This is understood as the process by which the human auditory system organizes sound into perceptually meaningful elements.Operation Eyesight Universal: Operation Eyesight Universal is a Canada-based international development organisation, founded in 1963. It works to prevent avoidable blindness and to cure blindness that is treatable.John Vanderpoel: John Henry Vanderpoel (November 15, 1857 – May 2, 1911), born Johannes (Jan) van der Poel, was a Dutch-American artist and teacher, best known as an instructor of figure drawing. His book The Human Figure, a standard art school resource featuring numerous of his drawings based on his teaching at the Art Institute of Chicago, was published in 1907.Qualia: In philosophy, qualia ( or ; singular form: quale) are individual instances of subjective, conscious experience. The term "qualia" derives from the Latin neuter plural form (qualia) of the Latin adjective quālis () meaning "of what sort" or "of what kind").Canon EOS 5Precise Time and Time Interval: Precise Time and Time Interval (PTTI) is a Department of Defense Military Standard which details a mechanism and waveform for distributing highly accurate timing information.Saccade: A saccade ( , French for jerk) is quick, simultaneous movement of both eyes between two phases of fixation in the same direction.Cassin, B.Photovoltaic retinal prosthesis: Photovoltaic retinal prosthesis is a technology for restoring sight to blind patients suffering from degenerative retinal diseases. In retinal degenerative diseases such as Retinitis Pigmentosa and Age-Related Macular Degeneration, patients loss ‘image capturing’ photo-receptors, but, neurons in the ‘image-processing’ inner retinal layers are relatively well preserved.Vigilance (psychology): In modern psychology, vigilance, also termed sustained concentration, is defined as the ability to maintain concentrated attention over prolonged periods of time.Warm, J.HyperintensityCerebral hemisphere: The vertebrate cerebrum (brain) is formed by two cerebral hemispheres that are separated by a groove, the medial longitudinal fissure. The brain can thus be described as being divided into left and right cerebral hemispheres.Continuous flash suppression: Continuous flash suppression (CFS) is an adapted version of the original flash suppression method. 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.Fritz Heider: Fritz Heider (February 19, 1896 – January 2, 1988)American Psychologist., "Fritz Heider (1896 - 1988)".Brodmann area 38: Brodmann area 38, also BA38 or temporopolar area 38 (H), is part of the temporal cortex in the human brain. BA 38 is at the anterior end of the temporal lobe, known as the temporal pole.Amorphosynthesis: Amorphosynthesis is a medical condition where the patient is unaware of somatic sensations from one side of the body; the left side is most commonly affected. This condition is usually a sign of a lesion in the right parietal lobe.Makyo: The term is a Zen term that means “ghost cave” or “devil’s cave.” It is a figurative reference to the kind of self-delusion that results from clinging to an experience and making a conceptual “nest” out of it for oneself.Blue colour works: A blue colour works () is a paintworks where blue paint for use in glassmaking is produced. Usually the pigment, cobalt blue, needed for this purpose, was manufactured from cobalt-containing ore as in the case of the factories listed below.Plaque-forming unit: In virology, a plaque-forming unit (PFU) is a measure of the number of particles capable of forming plaques per unit volume, such as virus particles. It is a functional measurement rather than a measurement of the absolute quantity of particles: viral particles that are defective or which fail to infect their target cell will not produce a plaque and thus will not be counted.Unconscious cognition: Unconscious cognition is the processing of perception, memory, learning, thought, and language without being aware of it.Magnetoencephalography: Magnetoencephalography (MEG) is a functional neuroimaging technique for mapping brain activity by recording magnetic fields produced by electrical currents occurring naturally in the brain, using very sensitive magnetometers. Arrays of SQUIDs (superconducting quantum interference devices) are currently the most common magnetometer, while the SERF (spin exchange relaxation-free) magnetometer is being investigated for future machines.Retinal regeneration: Retinal regeneration deals with restoring retinal function to vertebrates so impaired.Ocular dominance: Ocular dominance, sometimes called eye preference or eyedness, is the tendency to prefer visual input from one eye to the other. It is somewhat analogous to the laterality of right- or left-handedness; however, the side of the dominant eye and the dominant hand do not always match.Repeatable Battery for the Assessment of Neuropsychological Status: The Repeatable Battery for the Assessment of Neuropsychological Status is a neuropsychological assessment initially introduced in 1998. It consists of ten subtests which give five scores, one for each of the five domains tested (immediate memory, visuospatial/constructional, language, attention, delayed memory).Neurotechnology: Neurotechnology is any technology that has a fundamental influence on how people understand the brain and various aspects of consciousness, thought, and higher order activities in the brain. It also includes technologies that are designed to improve and repair brain function and allow researchers and clinicians to visualize the brain.Adaptive comparative judgement: Adaptive Comparative Judgement is a technique borrowed from psychophysics which is able to generate reliable results for educational assessment - as such it is an alternative to traditional exam script marking. In the approach judges are presented with pairs of student work and are then asked to choose which is better, one or the other.Temporal analysis of products: Temporal Analysis of Products (TAP), (TAP-2), (TAP-3) is an experimental technique for studyingAlpha wavePrinciples of motion economy: The principles of motion economy form a set of rules and suggestions to improve the manual work in manufacturing and reduce fatigue and unnecessary movements by the worker, which can lead to the reduction in the work related trauma.Cognitive skill: Cognitive functioning is a term referring to a human’s ability to process to (thoughts) that should not deplete on a large scale in healthy individuals. Cognition mainly refers to things like memory, the ability to learn new information, speech, understanding of written material.Quantitative electroencephalography: Quantitative electroencephalography (QEEG) is a field concerned with the numerical analysis of electroencephalography data and associated behavioral correlates.Face.com: Face.com was a Tel Aviv-based technology company that developed a platform for efficient and accurate facial recognition in photos uploaded via web and mobile applications.Grow lightThermal grill illusion: The thermal grill illusion is a sensory illusion originally demonstrated in 1896 by the Swedish physician Torsten Thunberg. The illusion is created by an interlaced grill of warm (e.Explicit memory: Explicit memory is the conscious, intentional recollection of previous experiences and information. People use explicit memory throughout the day, such as remembering the time of an appointment or recollecting an event from years ago.Doxanthrine: Doxanthrine is a synthetic compound which is a potent and selective full agonist for the dopamine D1 receptor. Doxanthrine has been shown to be orally active in producing contralateral rotation in the 6-hydroxy-dopamine rat model of Parkinson's disease.HSD2 neurons: HSD2 neurons are a small group of neurons in the brainstem which are uniquely sensitive to the mineralocorticosteroid hormone aldosterone, through expression of HSD11B2. They are located within the caudal medulla oblongata, in the nucleus of the solitary tract (NTS).Image fusion: In computer vision, Multisensor Image fusion is the process of combining relevant information from two or more images into a single image.Haghighat, M.Voluntary Parenthood League: The Voluntary Parenthood League (VPL) was an organization that advocated for contraception during the birth control movement in the United States. The VPL was founded in 1919 by Mary Dennett.Pitch spaceClosed-ended question: A closed-ended question is a question format that limits respondents with a list of answer choices from which they must choose to answer the question.Dillman D.

(1/7911) Visual perception: mind and brain see eye to eye.

Recent functional imaging studies have identified neural activity that is closely associated with the perception of illusory motion. The mapping of the mind onto the bin appears to be one-to-one: activity in visual 'motion area' MT is highly correlated with perceptual experience.  (+info)

(2/7911) Vision: modular analysis--or not?

It has commonly been assumed that the many separate areas of the visual system perform modular analyses, each restricted to a single attribute of the image. A recent paper advocates a radically different approach, where all areas in the hierarchy analyse all attributes of the image to extract perceptually relevant decisions.  (+info)

(3/7911) On the neural correlates of visual perception.

Neurological findings suggest that the human striate cortex (V1) is an indispensable component of a neural substratum subserving static achromatic form perception in its own right and not simply as a central distributor of retinally derived information to extrastriate visual areas. This view is further supported by physiological evidence in primates that the finest-grained conjoined representation of spatial detail and retinotopic localization that underlies phenomenal visual experience for local brightness discriminations is selectively represented at cortical levels by the activity of certain neurons in V1. However, at first glance, support for these ideas would appear to be undermined by incontrovertible neurological evidence (visual hemineglect and the simultanagnosias) and recent psychophysical results on 'crowding' that confirm that activation of neurons in V1 may, at times, be insufficient to generate a percept. Moreover, a recent proposal suggests that neural correlates of visual awareness must project directly to those in executive space, thus automatically excluding V1 from a related perceptual space because V1 lacks such direct projections. Both sets of concerns are, however, resolved within the context of adaptive resonance theories. Recursive loops, linking the dorsal lateral geniculate nucleus (LGN) through successive cortical visual areas to the temporal lobe by means of a series of ascending and descending pathways, provide a neuronal substratum at each level within a modular framework for mutually consistent descriptions of sensory data. At steady state, such networks obviate the necessity that neural correlates of visual experience project directly to those in executive space because a neural phenomenal perceptual space subserving form vision is continuously updated by information from an object recognition space equivalent to that destined to reach executive space. Within this framework, activity in V1 may engender percepts that accompany figure-ground segregations only when dynamic incongruities are resolved both within and between ascending and descending streams. Synchronous neuronal activity on a short timescale within and across cortical areas, proposed and sometimes observed as perceptual correlates, may also serve as a marker that a steady state has been achieved, which, in turn, may be a requirement for the longer time constants that accompany the emergence and stability of perceptual states compared to the faster dynamics of adapting networks and the still faster dynamics of individual action potentials. Finally, the same consensus of neuronal activity across ascending and descending pathways linking multiple cortical areas that in anatomic sequence subserve phenomenal visual experiences and object recognition may underlie the normal unity of conscious experience.  (+info)

(4/7911) Competitive mechanisms subserve attention in macaque areas V2 and V4.

It is well established that attention modulates visual processing in extrastriate cortex. However, the underlying neural mechanisms are unknown. A consistent observation is that attention has its greatest impact on neuronal responses when multiple stimuli appear together within a cell's receptive field. One way to explain this is to assume that multiple stimuli activate competing populations of neurons and that attention biases this competition in favor of the attended stimulus. In the absence of competing stimuli, there is no competition to be resolved. Accordingly, attention has a more limited effect on the neuronal response to a single stimulus. To test this interpretation, we measured the responses of neurons in macaque areas V2 and V4 using a behavioral paradigm that allowed us to isolate automatic sensory processing mechanisms from attentional effects. First, we measured each cell's response to a single stimulus presented alone inside the receptive field or paired with a second receptive field stimulus, while the monkey attended to a location outside the receptive field. Adding the second stimulus typically caused the neuron's response to move toward the response that was elicited by the second stimulus alone. Then, we directed the monkey's attention to one element of the pair. This drove the neuron's response toward the response elicited when the attended stimulus appeared alone. These findings are consistent with the idea that attention biases competitive interactions among neurons, causing them to respond primarily to the attended stimulus. A quantitative neural model of attention is proposed to account for these results.  (+info)

(5/7911) MST neuronal responses to heading direction during pursuit eye movements.

As you move through the environment, you see a radial pattern of visual motion with a focus of expansion (FOE) that indicates your heading direction. When self-movement is combined with smooth pursuit eye movements, the turning of the eye distorts the retinal image of the FOE but somehow you still can perceive heading. We studied neurons in the medial superior temporal area (MST) of monkey visual cortex, recording responses to FOE stimuli presented during fixation and smooth pursuit eye movements. Almost all neurons showed significant changes in their FOE selective responses during pursuit eye movements. However, the vector average of all the neuronal responses indicated the direction of the FOE during both fixation and pursuit. Furthermore, the amplitude of the net vector increased with increasing FOE eccentricity. We conclude that neuronal population encoding in MST might contribute to pursuit-tolerant heading perception.  (+info)

(6/7911) Short-latency vergence eye movements induced by radial optic flow in humans: dependence on ambient vergence level.

Radial patterns of optic flow, such as those experienced by moving observers who look in the direction of heading, evoke vergence eye movements at short latency. We have investigated the dependence of these responses on the ambient vergence level. Human subjects faced a large tangent screen onto which two identical random-dot patterns were back-projected. A system of crossed polarizers ensured that each eye saw only one of the patterns, with mirror galvanometers to control the horizontal positions of the images and hence the vergence angle between the two eyes. After converging the subject's eyes at one of several distances ranging from 16.7 cm to infinity, both patterns were replaced with new ones (using a system of shutters and two additional projectors) so as to simulate the radial flow associated with a sudden 4% change in viewing distance with the focus of expansion/contraction imaged in or very near both foveas. Radial-flow steps induced transient vergence at latencies of 80-100 ms, expansions causing increases in convergence and contractions the converse. Based on the change in vergence 90-140 ms after the onset of the steps, responses were proportional to the preexisting vergence angle (and hence would be expected to be inversely proportional to viewing distance under normal conditions). We suggest that this property assists the observer who wants to fixate ahead while passing through a visually cluttered area (e.g., a forest) and so wants to avoid making vergence responses to the optic flow created by the nearby objects in the periphery.  (+info)

(7/7911) Why and how is soft copy reading possible in clinical practice?

The properties of the human visual system (HVS) relevant to the diagnostic process are described after a brief introduction on the general problems and advantages of using soft copy for primary radiology interpretations. At various spatial and temporal frequencies the contrast sensitivity defines the spatial resolution of the eye-brain system and the sensitivity to flicker. The adaptation to the displayed radiological scene and the ambient illumination determine the dynamic range for the operation of the HVS. Although image display devices are determined mainly by state-of-the-art technology, analysis of the HVS may suggest technical characteristics for electronic displays that will help to optimize the display to the operation of the HVS. These include display size, spatial resolution, contrast resolution, luminance range, and noise, from which further consequences for the technical components of a monitor follow. It is emphasized that routine monitor quality control must be available in clinical practice. These image quality measures must be simple enough to be applied as part of the daily routine. These test instructions might also serve as elements of technical acceptance and constancy tests.  (+info)

(8/7911) Visual motion analysis for pursuit eye movements in area MT of macaque monkeys.

We asked whether the dynamics of target motion are represented in visual area MT and how information about image velocity and acceleration might be extracted from the population responses in area MT for use in motor control. The time course of MT neuron responses was recorded in anesthetized macaque monkeys during target motions that covered the range of dynamics normally seen during smooth pursuit eye movements. When the target motion provided steps of target speed, MT neurons showed a continuum from purely tonic responses to those with large transient pulses of firing at the onset of motion. Cells with large transient responses for steps of target speed also had larger responses for smooth accelerations than for decelerations through the same range of target speeds. Condition-test experiments with pairs of 64 msec pulses of target speed revealed response attenuation at short interpulse intervals in cells with large transient responses. For sinusoidal modulation of target speed, MT neuron responses were strongly modulated for frequencies up to, but not higher than, 8 Hz. The phase of the responses was consistent with a 90 msec time delay between target velocity and firing rate. We created a model that reproduced the dynamic responses of MT cells using divisive gain control, used the model to visualize the population response in MT to individual stimuli, and devised weighted-averaging computations to reconstruct target speed and acceleration from the population response. Target speed could be reconstructed if each neuron's output was weighted according to its preferred speed. Target acceleration could be reconstructed if each neuron's output was weighted according to the product of preferred speed and a measure of the size of its transient response.  (+info)



depth perception


  • Depth perception is an important component of many augmented reality applications. (spiedigitallibrary.org)
  • Depth perception is a specific research field within space perception. (spiedigitallibrary.org)
  • This study focuses on depth perception within an individual's action space using a video see-through head-mounted display (HMD). (spiedigitallibrary.org)
  • 13 In the case of video see-through AR, studies on depth perception beyond personal space have been accomplished using nonstereoscopic hand-held devices 14 , 15 but not with stereoscopic HMDs. (spiedigitallibrary.org)
  • The objective was to determine the extent to which the depth perception of augmented objects can be improved with binocular disparity and relative size. (spiedigitallibrary.org)

cues


  • This indicates that for accurate depth judgments, additional depth cues should be used to facilitate stereoscopic perception within an individual's action space. (spiedigitallibrary.org)
  • Space perception provides cues, such as depth and distance, that are important for movement and orientation to the environment . (britannica.com)
  • The visual perception of three-dimensional space through monocular cues and binocular cues that are present in the two-dimensional images projected on to the retinas of the eyes. (oup.com)

space perception


  • Space perception refers to the process by which the sensation of the physical space is transformed into the perceived space. (spiedigitallibrary.org)
  • Space perception , process through which humans and other organisms become aware of the relative positions of their own bodies and objects around them. (britannica.com)
  • Many psychologists who deal with perceptual function hold that the study of space perception is rapidly becoming a distinct branch of psychology in its own right. (britannica.com)
  • Space perception research also offers insight into ways that perceptual behaviour helps orient the individual to the environment. (britannica.com)

binocular


  • Humans do not ordinarily perceive a binocular space (a separate visual world from each eye) but instead see a so-called Cyclopean space , as if the images from each eye fuse to produce a single visual field akin to that of Cyclops, a one-eyed giant in Greek mythology . (britannica.com)

stimulus


  • 1, 2 Multiple domains/loci of the visual field are simultaneously stimulated using a cortically scaled pseudorandomly reversing pattern stimulus. (bmj.com)

field


  • It can be performed by children as young as 5 years of age and holds promise as a diagnostic test capable of documenting children's visual fields objectively, even before they are able to perform subjective field tests. (bmj.com)
  • Multifocal visual evoked potential (VEP), a recent advancement in electrophysiology, has made it possible to document the visual field of an individual as a collection of evoked cortical responses. (bmj.com)
  • Visual evoked potentials corresponding to each of the loci of the visual field tested can be recorded within a short period of time to generate a perimetry of VEP. (bmj.com)

augmented reality


  • Both techniques, optical and video see-throughs, are commonly used in visual augmented reality (AR), in which computer graphics and real-world imagery are overlaid in real time. (spiedigitallibrary.org)

study


  • To study the maturation of multifocal visual evoked potentials (multifocal VEP) in normal children between the ages of 5 and 16 years and to apply the results clinically in selected cases to the diagnosis of optic pathway diseases. (bmj.com)

However


  • 4 However, the perception of the real world with video see-through display is adversely affected by some characteristics of cameras and displays such as resolution limitations and optical distortions. (spiedigitallibrary.org)
  • People could not orient themselves to their environments , however, unless the environmental information reaching them through the various sense organs offered a perception of space that corresponds to their physical "reality. (britannica.com)

research


  • Although modern research fails to verify Berkeley's emphasis on reason as central to perception, contemporary theories still include both nativistic (inborn) and empirical (learned through experience) considerations. (britannica.com)

objects


  • Human beings have been interested in the perception of objects in space at least since antiquity. (britannica.com)

time


  • Its objective nature, need for minimum cooperation from the subject and short recording time make it an ideal technique for investigating visual fields in children. (bmj.com)