(n.) A luminous impression produced through excitation of the retina by some cause other than the impingement upon it of rays of light, as by pressure upon the eyeball when the lids are closed. Cf. After-image.
Example Sentences:
(1) Excitatory (positive) phenomena are subjective photic sensations (phosphenes) which can be elicited by transcranial magnetic stimulation over occipital parts of the skull.
(2) Stimulation substantially above threshold may produce a second conjugate phosphene, inverted about the horizontal meridian.8.
(3) Phosphenes appear immediately when stimulation is begun, and disappear immediately upon cessation of stimulation.18.
(4) The position of phosphenes in the visual field corresponds only roughly with expectations based on classical maps showing the projection of the visual field onto the cortex.14.
(5) The configuration of the phosphene fields hints at an excitation of the primary visual cortex (Brodmann's area 17).
(6) A visual prosthesis based on electrical stimulation of the visual cortex with an array of penetrating electrodes is expected to produce pixelized visual images consisting of punctate spots of light (phosphenes).
(7) The findings of these examinations correlated best of all with the clinical picture when visual evoked potentials (latency increase, decrease of the amplitude with atrophy augmentation, interhemispheric asymmetry in chiasmal and retro-chiasmal involvement) or the critical frequency of phosphene disappearance (reliably reduced if a disease was developing) were recorded.
(8) The phenomenon of deformation phosphenes was instrumental in prompting some pre-Socratic philosophers and Plato to conceive the idea that efferent light is emitted from the eye for the purpose of vision and a 'cone of vision' is formed by interaction with the external light.
(9) Because of the variation in repeated observations of the same phosphene pair, some method is needed to provide the 'best' fitting map to the observations.
(10) The increment threshold for a small spot of light on the phosphene in the dark is some 0.5 log td higher than for the same spot on a patch of light matched in appearance to the phosphene under the same conditions.5.
(11) Our findings indicate that the psychological component of the perception of electric and magnetic phosphenes must not be underestimated.
(12) For cortical phosphenes there is no sharp flicker fusion frequency, and probably no flicker fusion frequency at all.7.
(13) From experimental work on humans in 1905 with unencapsulated radium, it is known that approximately 80% of the intensity of the radium phosphene is from the beta-ray component and approximately 20% from the gamma-ray.
(14) Experiments are described in which the phosphene produced by passing alternating current of frequency 100 Hz through the eye is matched with a patch of light having the same apparent size.2.
(15) The prosthesis would create a pixelized visual sense consisting of punctate spots of light (phosphenes).
(16) The phosphenes appear on the left or right side of the visual field depending upon the direction of the coil currents, which determines whether the visual cortex of the right or the left hemisphere is activated.
(17) Electrical stimulation of the occipital cortex resulted in discrete photic sensations or "phosphenes" in two volunteers who had been totally blind for 7 and 28 years, respectively.
(18) Patterns of up to four phosphenes produced by four electrodes have been recognized.
(19) The influence of coil position on the size of electromyographic responses and on the intensity and position of phosphenes in the binocular visual field was studied.
(20) In the medial area (10-15 mm from the midline) of the occipital lobe, stimuli above the calcarine fissure resulted in phosphenes in the lower quadrant of the visual field.
Sensation
Definition:
(n.) An impression, or the consciousness of an impression, made upon the central nervous organ, through the medium of a sensory or afferent nerve or one of the organs of sense; a feeling, or state of consciousness, whether agreeable or disagreeable, produced either by an external object (stimulus), or by some change in the internal state of the body.
(n.) A purely spiritual or psychical affection; agreeable or disagreeable feelings occasioned by objects that are not corporeal or material.
(n.) A state of excited interest or feeling, or that which causes it.
Example Sentences:
(1) Since it was established, it has stoked controversy about contemporary art, though in recent years it has been more notable for its lack of sensationalism.
(2) Panic disorder subjects showed a negative relationship between pulmonary function and hyperventilation symptoms, suggesting a heightened sensitivity to, and discomfort with, sensations associated with normal pulmonary function.
(3) Frequency of symptoms like dizziness, headache, lachrymation, burning sensation in eyes, nausea and anorexia, etc, were much more in the exposed workers.
(4) Independent t test results indicated nurses assigned more importance to psychosocial support and skills training than did patients; patients assigned more importance to sensation--discomfort than did nurses.
(5) Substantial percentages of both physicians and medical students reported access to drugs, family histories of substance abuse, stress at work and home, emotional problems, and sensation seeking.
(6) The results showed the kind of needling sensation while acupuncture had close relation with the appearance of PSM and the acupuncture effect.
(7) Although 95% of the patients are satisfied, 60% have some impairment of sensation in the lower lip.
(8) No significant changes in maximal work load, exercise time, systolic blood pressure at maximal work load, or subjective sensation of well-being could be demonstrated during combined drug treatment.
(9) Subjective measures of anxiety, frightening cognitions and body sensations were obtained across the phases.
(10) The analysis of the neurophysiological correlations of the image formation process is followed by a study of the functional role of the image in psychic dynamics, its genetic relationship with sensation and speech, its role in the communication functions, in the structuring of the relationship between the internal and the external world.
(11) These additional cues involved different sensations in effort of the perfomed movement sliding heavy object vs. sliding light object (sS test), as well as different sensations in pattern of movement and joints - sliding vs. lifting of an object (SL test).
(12) Work over the past 17 years has consistently failed to reveal any objective sign accompanying the transient sensations that some individuals experience after the experimental ingestion of monosodium glutamate and it is questionable whether the term 'Chinese Restaurant Syndrome' has any validity.
(13) Forty-four patients of meralgia paraesthetica presented with combination of symptoms mainly of numbness with loss of superficial sensation on the anterolateral aspect of a thigh were selected for the study.
(14) The incidence of phantom pain and nonpainful phantom sensations was 13.3% and 15.0%, respectively, 3 weeks after mastectomy, 12.7% and 11.8%, respectively, after a year, and 17.4% and 11.8%, respectively, after 6 years.
(15) History is littered with examples of byelection sensations that soon turned to dust.
(16) The return of sensation is of particular benefit to elderly patients who make up the greatest number of patients in the series.
(17) The subjects described the thirst sensations as mainly due to a dry unpleasant tasting mouth, which was promptly relieved by drinking.
(18) Similarly, subjects that were trained to focus their attention on the magnitude of the immediate (first) pain sensation evoked by brief electrical or mechanical stimulation did not report reduction by morphine of pain attributed to conduction in myelinated peripheral nociceptors.
(19) This scale thus provides a reproducible and sensitive estimation of the sensation of dyspnoea during effort and thus appears valuable in evaluating the subjective response in therapeutic trials in patients who are dyspnoeic on effort.
(20) Examination revealed that five patients in the nerve divided group had a small area of altered sensation but this was not significant either for the patient or statistically between the groups.