China
Africa
Explore chapters and articles related to this topic
Measuring children’s cognitive development
Published in David Cohen, How the child's mind develops, 2017
A set of lines are presented in an instrument called a tachistoscope, and subjects have to press a button if they see them. The time it takes to make a motor response (pressing the button) can be subtracted from the time it takes to make the decision as to whether or not the lines are there. People with high IQ will report the line being there correctly when it’s shown for much shorter periods than those with low IQ.
Biopsychosocial Assessment of Cancer Patients: Methods and Suggestions
Published in David M. Dush, Barrie R. Cassileth, Dennis C. Turk, Psychosocial Assessment in Terminal Care, 2014
Patricia L. Dobkin, Gary R. Morrow
Folstein et al. (1984) administered a brief bedside battery of tests to assess cognitive functioning in cancer patients. One test in the battery, the linear analogue scale of consciousness, is simple to use with acceptable interrater reliability (r's = .81 to .97). The scale rates consciousness on a 0 to 10 cm scale (from very drowsy (0) to normally alert (10)). A second test, a hand held Tachistoscope, is employed in order to determine the patient's ability to perceive stimuli. Delirious patients are unable to perform this task within normal time limits (l/60th second). Perception time will thus identify most clinically delirious cancer patients. The third test in the battery is the Mini-Mental State Examination (MMSE: Folstein, Folstein, & McHugh, 1975) which assesses (a) orientation, (b) registration, (c) attention and calculation, (d) recall, and (e) language. The MMSE is derived from the National Institute of Mental Health Diagnostic Interview. The original diagnostic interview has been administered to a normative sample of approximately 15,000 individuals in five geographic locations.
Neuropsychological Assessment in Elderly People
Published in José León-Carrión, Margaret J. Giannini, Behavioral Neurology in the Elderly, 2001
José León-Carrión, Juan Manuel Barroso y Martín
For assessment of problems of inattention and hemianopsia, a letter cancellation test is administered with a tachistoscopic methodology adapted to the computer. In this task, patients must keep their eyes fixed on a white point that appears at the center of the monitor, while different letters appear in the center of each of the four quadrants into which the computer screen is divided. Patients should look at the white spot in the center without shifting their eyes, and should press the space bar only when the letter O appears in one of the quadrants. Three subtests make up this module: Subtest of tachistoscopic attention for both eyesSubtest of tachistoscopic attention of the right eyeSubtest of tachistoscopic attention of the left eye
Alfred Wilhelm Volkmann on stereoscopic vision
Published in Strabismus, 2022
Wheatstone2 (p. 392) had already considered and rejected this hypothesis: “Another and a beautiful proof that the appearance of relief in binocular vision is an effect independent of the motion of the eyes, may be obtained by impressing on the retinæ ocular spectra [afterimages] of the component figures.” Volkmann reached the same conclusion using a novel method. In the same year as his article on stereoscopic vision, he invented the tachistoscope20 to examine precisely this question; the instrument enabled brief presentation of paired stimuli, one to each eye, to determine whether depth was still seen – it was. Dove21 had reached the same conclusion using paired afterimages produced by illumination with an electrical spark. Thus, the evidence against Brücke’s eye movement hypothesis was strong.
The vision of Helmholtz
Published in Journal of the History of the Neurosciences, 2021
Eye movements were implicated in stereoscopic vision by Brücke (1841), a close associate of Helmholtz, in order to reconcile the binocular phenomena with Müller’s theory of identical retinal points. If the eyes changed convergence rapidly while viewing solid objects, this could be the basis for perceived depth rather than the combination of slightly disparate retinal points in the two eyes. Although Helmholtz adopted eye movement interpretations of many visual effects, this did not apply to stereoscopic vision. Dove (1841) illuminated stereoscopic pairs with brief electrical sparks, which generated afterimages, and depth was visible with them. Volkmann (1859) presented paired stimuli briefly with a tachistoscope, and this also resulted in stereoscopic depth. Helmholtz confirmed these observations and wrote: “Both these experiments and those with electric sparks show that ocular movements are not necessary for perception of depth; because afterimages move with every movement of the eye, and it is simply impossible to make disparate images correspond to each other by any such movement” (1925, 456).
The stereoscopic phenomena in relation to the doctrine of identical retinal points
Published in Strabismus, 2020
I also find, when I stereoscopically look at Wheatstone’s images communicated in Poggendorf’s Annalen, that only the fixated points of the image appear single, the non-fixated, on the other hand, appear double, but I cannot admit that this gives the Brücke’s theory an inherent advantage. It is possible that the figures just mentioned do not completely correspond to the originals, and it is also possible that the tendency to fuse perceptions from different points is greater with Wheatstone than with Brücke and me. Brücke’s assumption that the non-perception of the double images is based on fluctuations of the visual range under all circumstances is in any case inadmissible according to the tachistoscopic experiments. It is true that one could question the evidential value of these experiments themselves and find it questionable whether observations of only momentary duration would not overlook the double images that really exist. But this concern is also unfounded. If, with the aid of the tachistoscope, one looks at figures with a difference too large to permit fusion to form a collective image, one recognizes the double images very clearly, and if one offers one visual field a vertical line and the other a tilted line, one thus sees a cross if the inclination of the tilted line is too large, on the other hand one sees a single line and not just a point, if the inclination of the tilted one is in proportion.