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After-Imagery in Defective Fields of Vision* by Morris B

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After-Imagery in Defective Fields of Vision* by Morris B J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.12.3.196 on 1 August 1949. Downloaded from J. Neurol. Neurosurg. Psychiat., 1949, 12, 196. AFTER-IMAGERY IN DEFECTIVE FIELDS OF VISION* BY MORRIS B. BENDER and ROBERT L. KAHN From the Department of Neurology, New York University College ofMedicine, and Neurologic Services of the Mount Sinai Hospital and Bellevue Psychiatric Hospital In a study of visual after-images of patients with "bizarre" visual disturbances. There was a long- homonymous hemianopia one would anticipate standing history of hypertension and arteriosclerotic an after-image only in that part of the field which cardiovascular disease. His average blood pressure during the illness was 200/120 mm. Hg. A bilateral is perceived by the patient during fixation. Fuchs sympathectomy for relief of hypertension had been (1920, 1921), however, found that such patients saw perPormed in 1945. During the course of his long illness more in the after-image than in the stimulus field or he had symptoms and signs of embolization to the lungs, the perceived field of vision. Thus Fuchs noted kidneys, popliteal artery, and brain. that a figure only partly seen on fixation (the The cerebral infarcts which first occurred in 1942 were remainder of the figure was not seen because it was clinically localized to the occipital lobes. The visualguest. Protected by copyright. situated in the blind part of the field) was perceived symptoms consisted of-episodes of blurring of vision to by the same patient in its entirety in the after- the left of his fixation point, spells of momentary blind- image. This is known as the phenomenon of ness, teleopsia, micropsia, monocular diplopia, and dysmorphopsia. The perimetric and tangent screen completion.t Using simple figures, such as circles examinations of the visual fields showed homonymous and squares, Fuchs postulated that completion scotomas in the left upper quadrants and macular regions. depended on the " inner structural requirements of There was also a relative scotoma in a small region of the the stimulus figures." On the other hand, Bender right field of vision as indicated in Fig. 1. In 1946, and and Teuber (1946), who also studied completion on admission to the Bellevue Psychiatric Hospital in effects in impaired fields of vision, and used complex 1948, a marked dissociated nystagmus was noted when- figures such as an American flag in complementary ever he trietto view an object in his left field of vision. colours, believed that these effects need not neces- In the spring of 1948, the patient became worse, and he sarily be explained only by qualities of the stimulus died in cardiac failure. Autopsy examination was limited to the brain. This revealed areas of infarction figure. They observed that the after-image may oh the under surface of both occipital lobes. The represent only partial tendencies toward completion. ischaemic softening was greatest on the right side and Thus additional areas seen in the after-image or the extended forward but not into the temporal lobe. It " completed areas " did not always produce a included Brodmann's area 18, the inferior calcarine smoothing of contours or the completion of a total region of area 17, and the tip of the occipital pole. The figure. Sometimes there occurred in the after- lesion on the left was limited to a small region in Brod- image irregular additions to that which was perceived mann's area 18. http://jnnp.bmj.com/ in the stimulus field. Method of Testing Visual After-Imagery The present investigation was undertaken to study The figures (stimulus fields) used to elicit visual after- the nature of after-image alterations in a patient images consisted of various sized red and green coloured with irregular but homonymous defects in the-fields squares presented to the patient on a white background. of vision following lesions in both occipital lobes. Six different patterns were presented (series 1 to 6, as The test patterns used were simple geometric figures. illustrated in Figs. 2 to 7). Binocular fixation was main- tained on a small cross in the centre of the stimulus field. Case Report After sixty seconds' fixation the stimulus field was on September 30, 2021 by J. G., a forty-year-old salesman, was admitted to the manually removed and the patient continued to fixate on Mount Sinai Hospital in the latter part of 1946 because a small cross on the white background which now served -of occipital headaches, generalized weakness, and as the post-exposure or " after-field." Immediately, or a few seconds thereafter, the patient reported that he saw * This work was aided by a grant from the Dazian Foundation of Medical Research, New York. an after-image which was always a negative after-image. t The term " completion " as used in this paper will signify any Conditions of illumination were varied. Usually the extension of area of the perceived field in the after-image field. patient was seated at a desk and the stimulus and back- 196 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.12.3.196 on 1 August 1949. Downloaded from AFTER-IMAGERY IN DEFECTIVE VISION 197 A in 120 lO1 9 75 60 4SI 13Sa a.1 120 los-- 90 7sI - 60 45 30 ISo 30 ISO, R14 L/IN LN \ /I \1.., 160 N, IS 165 -*"K 15i ..-, -tn I I .. 11,11 I 0 ISO 0 - --. -1A M \I\N 11111 n- I 195, J --VI 345 195 345 \ A \ l\ / 'k, -,-] .1.1 I S& 4:z N / ',..,V cI 330 'N / lu I \ A r -,,.,IA 210 -,.- . L.-' 210I I ) -1 / \J A i 330 x III f 11 11 11 225 240 255 270 285 300 31S 225 240 255 270 285 300 34S O.S. O.D. LE. R.E. guest. Protected by copyright. FIG. 1.-Visual fields (a) perimetric and (b) tangent screen. Illumination daylight, size of target 5 mm., distance 33 cm. Solid black indicates region in which perception of movement is absent. Vertical lines indicate area in which movement is perceived but there is marked blurring and fluctuation in the appearance of the target. Stippling represents area in which target is less blurred. The small circles within the right field indicate region in which vision was blurred or grey. The dashes represent the borders of the field of vision for colour red. http://jnnp.bmj.com/ ground were exposed to ordinary desk lamp illumination. the vertical meridian was irregular. It was some- When the patient was confined to bed, only daylight what S-shaped, as noted on the perimetric and illumination was employed. There was no appreciable tangent screen recordings. The lower left quadrant difference between the results obtained under either type of the stimulus pattern was perceived only when of illumination. The patient's eyes were approximately large patterns were exposed, but colour was not 30 cm. from the fixation point, and no more than seven seen or eight tests were made at any one session. well in this quadrant. To the right of the fixation point there was also an area of defective on September 30, 2021 by Results vision. This area varied in size and shape, and was Stimulus Field.-On fixing at the centre of the reported by the patient as appearing " grey with stimulus field the contour of the pattern actually white spots." (Figs. 1 to 7.) In the right superior seen by the patient corresponded to his field as quadrant the patient complained of blurring and plotted on the tangent screen (Fig. lb). Under such " transparency " (Figs. 2 to 7). In this part of the conditions the area to the left of the fixation point field the true colour was perceived, although it was generally not reported. The line of division in varied in intensity. J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.12.3.196 on 1 August 1949. Downloaded from 198 MORRIS B. BENDER AND ROBERT L. KAHN STIMUUWS FIELD PERCEIVED FIELD ON FIXATION FIG. 2.-The basic pattern in series 1. Stimulusfield: a 50 mm. square, with X indicating fixation point in centre of figure. Perceived field: indicated by unshaded part of square. Cross 2 3 4 5cm hatching part of the field not perceived on fixation. White dots on grey AFTER- IMAGE DURING SUCCESSIVE PHASES background is zone which appeared blurred or grey. After-image figures in legends as above. 1 0 - s~~~ guest. Protected by copyright. STIMUUWS FIELD PERCEIVED FIELD ON FIXATION II FIG. 3.-The basic pattern in series 2. http://jnnp.bmj.com/ Stimulusfield: a 50 mm. green coloured square superimposed as illustrated on scale a 100 mm. red coloured square. 2 3 4 5cm Thus the green square was surrounded AFTER- IMAGE DURING SUCCESSIVE PHASES by a red border 25 mm. wide. Legends same as in Fig. 2. xw on September 30, 2021 by J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.12.3.196 on 1 August 1949. Downloaded from AFJTER-IMAGER Y IN DEFECTIVE VISION 199 After-Image.-On almost every test the figure seen strength and stability of the central square, the in the after-image appeared to be greater in area than visible borders of the larger square tended to be that noted during fixation of the stimulus field slightly diminished in the after-image. At times (phenomenon of completion). However, the areas the patient reported that he saw only one large in which " completion " occurred showed varying square. There were no defects in the central regions degrees of instability. In the completed regions of the after-image or in that which corresponded to there was fluctuation in intensity with waxing and the smaller square in the stimulus field.
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