Biomaterial Database

Visual evoked spectrum array and interhemispheric variations. 1978

G G Celesia, and V K Soni, and W S Rhode

An EEG spectrum analysis during visual stimulation was computed in 19 normal subjects. Visual stimulation consisted of trains of flashes at frequencies ranging between 2.5 and 20 flashes per second. Recordings were carried out simultaneously from the right and left occipital regions with bipolar and referential montages. Compressed spectral arrays were computed for eight-second epochs at each recording site using a fast Fourier transform. The ratio of the spectral energy from homologus regions of right and left hemispheres at each stimulation frequency was determined. The ratios were graphically displayed in a visual evoked spectrum array (VESA) ratio plot (VESA-GRAM); the mean of the ratio plot was designated the VESA coefficient. The range of variation for these measurements was determined for normal subjects. An application of the technique to patients with hemianopia showed abnormal VESA (characterized by smaller spectral amplitudes over the appropriate hemisphere), abnormal VESA ratio plots, and high VESA coefficients. These preliminary findings suggest that VESA may be a promising method to detect retrochiasmatic visual defects.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009778	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.	Annectant Gyrus,Calcarine Fissure,Calcarine Sulcus,Cuneate Lobule,Cuneus,Cuneus Cortex,Cuneus Gyrus,Gyrus Lingualis,Lingual Gyrus,Lunate Sulcus,Medial Occipitotemporal Gyrus,Occipital Cortex,Occipital Gyrus,Occipital Region,Occipital Sulcus,Sulcus Calcarinus,Calcarine Fissures,Calcarinus, Sulcus,Cortex, Cuneus,Cortex, Occipital,Cortices, Cuneus,Cortices, Occipital,Cuneate Lobules,Cuneus Cortices,Fissure, Calcarine,Fissures, Calcarine,Gyrus Linguali,Gyrus, Annectant,Gyrus, Cuneus,Gyrus, Lingual,Gyrus, Medial Occipitotemporal,Gyrus, Occipital,Linguali, Gyrus,Lingualis, Gyrus,Lobe, Occipital,Lobes, Occipital,Lobule, Cuneate,Lobules, Cuneate,Occipital Cortices,Occipital Lobes,Occipital Regions,Occipitotemporal Gyrus, Medial,Region, Occipital,Regions, Occipital,Sulcus, Calcarine,Sulcus, Lunate,Sulcus, Occipital
D010775	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.	Stimulation, Photic,Visual Stimulation,Photic Stimulations,Stimulation, Visual,Stimulations, Photic,Stimulations, Visual,Visual Stimulations
D004569	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.	EEG,Electroencephalogram,Electroencephalograms
D005071	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.	Event Related Potential,Event-Related Potentials,Evoked Potential,N100 Evoked Potential,P50 Evoked Potential,N1 Wave,N100 Evoked Potentials,N2 Wave,N200 Evoked Potentials,N3 Wave,N300 Evoked Potentials,N4 Wave,N400 Evoked Potentials,P2 Wave,P200 Evoked Potentials,P50 Evoked Potentials,P50 Wave,P600 Evoked Potentials,Potentials, Event-Related,Event Related Potentials,Event-Related Potential,Evoked Potential, N100,Evoked Potential, N200,Evoked Potential, N300,Evoked Potential, N400,Evoked Potential, P200,Evoked Potential, P50,Evoked Potential, P600,Evoked Potentials, N100,Evoked Potentials, N200,Evoked Potentials, N300,Evoked Potentials, N400,Evoked Potentials, P200,Evoked Potentials, P50,Evoked Potentials, P600,N1 Waves,N2 Waves,N200 Evoked Potential,N3 Waves,N300 Evoked Potential,N4 Waves,N400 Evoked Potential,P2 Waves,P200 Evoked Potential,P50 Waves,P600 Evoked Potential,Potential, Event Related,Potential, Event-Related,Potential, Evoked,Potentials, Event Related,Potentials, Evoked,Potentials, N400 Evoked,Related Potential, Event,Related Potentials, Event,Wave, N1,Wave, N2,Wave, N3,Wave, N4,Wave, P2,Wave, P50,Waves, N1,Waves, N2,Waves, N3,Waves, N4,Waves, P2,Waves, P50
D005260	Female		Females
D006423	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.	Hemianopsia, Binasal,Hemianopsia, Bitemporal,Hemianopsia, Homonymous,Quadrantanopsia,Altidudinal Hemianopia,Altitudinal Hemianopsia,Binasal Hemianopia,Bitemporal Hemianopia,Hemianopia,Homonymous Hemianopia,Quadrantanopia,Altidudinal Hemianopias,Altitudinal Hemianopsias,Binasal Hemianopias,Binasal Hemianopsia,Binasal Hemianopsias,Bitemporal Hemianopias,Bitemporal Hemianopsia,Bitemporal Hemianopsias,Hemianopia, Altidudinal,Hemianopia, Binasal,Hemianopia, Bitemporal,Hemianopia, Homonymous,Hemianopias,Hemianopias, Altidudinal,Hemianopias, Binasal,Hemianopias, Bitemporal,Hemianopias, Homonymous,Hemianopsia, Altitudinal,Hemianopsias,Hemianopsias, Altitudinal,Hemianopsias, Binasal,Hemianopsias, Bitemporal,Hemianopsias, Homonymous,Homonymous Hemianopias,Homonymous Hemianopsia,Homonymous Hemianopsias,Quadrantanopias,Quadrantanopsias
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D014786	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).	Hemeralopia,Macropsia,Micropsia,Day Blindness,Metamorphopsia,Vision Disability,Visual Disorders,Visual Impairment,Blindness, Day,Disabilities, Vision,Disability, Vision,Disorder, Visual,Disorders, Visual,Hemeralopias,Impairment, Visual,Impairments, Visual,Macropsias,Metamorphopsias,Micropsias,Vision Disabilities,Vision Disorder,Visual Disorder,Visual Impairments