Visual Perception
Visual Cortex
Area of the OCCIPITAL LOBE concerned with the processing of visual information relayed via VISUAL PATHWAYS.
Perception
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
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
Vision, Ocular
Space Perception
The awareness of the spatial properties of objects; includes physical space.
Attention
Psychophysics
Perceptual Disorders
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.
Psychomotor Performance
Cues
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.
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.
Fixation, Ocular
The positioning and accommodation of eyes that allows the image to be brought into place on the FOVEA CENTRALIS of each eye.
Occipital Lobe
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.
Brain Mapping
Auditory Perception
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).
Consciousness
Sense of awareness of self and of the environment.
Human Body
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
Magnetic Resonance Imaging
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.
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.
Speech Perception
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
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.
Perceptual Masking
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.
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.
Discrimination Learning
Perceptual Distortion
Field Dependence-Independence
Analysis of Variance
Color
The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.
Visual Field Tests
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.
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.
Unconscious (Psychology)
Those forces and content of the mind which are not ordinarily available to conscious awareness or to immediate recall.
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.
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.
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.
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.
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
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.
Recognition (Psychology)
The knowledge or perception that someone or something present has been previously encountered.
Electroencephalography
Alpha Rhythm
Motion
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.
Face
Learning
Relatively permanent change in behavior that is the result of past experience or practice. The concept includes the acquisition of knowledge.
Memory
Neurons
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)
Image Processing, Computer-Assisted
Task Performance and Analysis
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.
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.
Macaca
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.
Questionnaires
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.
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.
Olfactory Perception
Adaptation, Physiological
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.
Cerebral Cortex
Health Knowledge, Attitudes, Practice
Attitude of Health Personnel
Computer Simulation
Action Potentials
Algorithms
Oxygen
Sensory Deprivation
Lighting
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.).
Schizophrenia
A severe emotional disorder of psychotic depth characteristically marked by a retreat from reality with delusion formation, HALLUCINATIONS, emotional disharmony, and regressive behavior.
Touch
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.
Cross-Sectional Studies
Attitude
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.
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.
Sensation
Visually Impaired Persons
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.
Ocular Physiological Phenomena
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)
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.
Work Schedule Tolerance
Emotions
Qualitative Research
Superior Colliculi
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).
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)
Patient Satisfaction
Reading
Adaptation, Ocular
Facial Expression
Observable changes of expression in the face in response to emotional stimuli.
Interviews as Topic
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)
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Eyeglasses
Feedback, Sensory
A mechanism of communicating one's own sensory system information about a task, movement or skill.
Mutation
Work Capacity Evaluation
Pain
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.
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.
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.
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.
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.
Color Perception Tests
Type of vision test used to determine COLOR VISION DEFECTS.
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.
Return to Work
Resumption of normal work routine following a hiatus or period of absence due to injury, disability, or other reasons.
Kinesthesis
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.
Hand
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.
Prospective Studies
Refractive Errors
Odors
The volatile portions of substances perceptible by the sense of smell. (Grant & Hackh's Chemical Dictionary, 5th ed)
Flicker Fusion
The point or frequency at which all flicker of an intermittent light stimulus disappears.
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.
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)
Quality of Life
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.
Darkness
The absence of light.
Head Movements
Voluntary or involuntary motion of head that may be relative to or independent of body; includes animals and humans.
Aging
Neuronal Plasticity
Psychoacoustics
Follow-Up Studies
Feedback
United States
The term "United States" in a medical context often refers to the country where a patient or study participant resides, and is not a medical term per se, but relevant for epidemiological studies, healthcare policies, and understanding differences in disease prevalence, treatment patterns, and health outcomes across various geographic locations.
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.
Treatment Outcome
Age Factors
Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.
Art
"Art therapy is a form of expressive therapy that uses the creative process of making art to improve a person's physical, mental, and emotional well-being."
Pursuit, Smooth
Culture
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.