A New Phenomenon of Apparent Movement and its After-Effect

1950 ◽  
Vol 2 (3) ◽  
pp. 119-123 ◽  
Author(s):  
J. A. Deutsch

It is found that a stationary spiral pattern gives an appearance of movement in a flickering light, and, furthermore, that this apparent rotation gives rise to the same kind of after-effect as a spiral actually rotating. The illusion is obtainable over a wide range of conditions. Detailed results are given in the case of six subjects, but a large number of subjects experienced the illusion. The experimenter has as yet found no one who was not subject to the illusion itself. The after-effects are not universally experienced.

1964 ◽  
Vol 41 (4) ◽  
pp. 805-824
Author(s):  
J. S. KENNEDY ◽  
C. O. BOOTH

1. Flight has a cumulative ‘priming’ effect (excitatory after-effect) on the settling responses of an aphid landing on a surface, even when the flight has been interrupted by one or more previous landings. But when the bouts of flying between landings were kept brief (1 min.) there was also an opposite, depressing or inhibitory after-effect on settling which reduced and in certain conditions regularly outweighed the priming effect. 2. Which of the two after-effects predominated depended on the kind of surface landed on each time, on the strength of the settling responses at previous landings and on the total time the aphid had been flying. 3. The depressing effect as measured on a standard host leaf was negligible when the flight had been interrupted by landings on a card, where the settling responses were weakest and soonest inhibited by flight again, greater after landings on a non-host leaf and greatest after landings on the host leaf, itself where settling responses were strongest. 4. When two successive landings were both made on the same surface, a depression of settling at the second landing was more likely after a strong previous settling response than after a weak one; it was also more likely when the two landings were made on a non-host than when they were made on a host. 5. Flight and settling are nervous antagonists and the terms ‘antagonistic induction’ and ‘antagonistic depression’ are applied, respectively, to the excitatory and the inhibitory after-effects of flight on settling. These are components in the co-ordination of flight and settling as successive activities and do not necessarily describe the sequences observed.


1986 ◽  
Vol 34 (1) ◽  
pp. 37-47
Author(s):  
J.H.J. Spiertz ◽  
L. Sibma

The N yield and the N use efficiency were studied in a 3-year experiment with various cropping systems of Lolium perenne, Medicago sativa and maize. N yields of L. perenne and maize were about 450 and 200 kg/ha, resp. N yields of M. sativa ranged from about 400 to 600 kg/ha depending on crop age and weather conditions. N fixation rates of M. sativa were assessed in 1982 and ranged from 107 to 507 kg/ha for high (450 kg N/ha) and no N fertilization, resp. The after-effects of 1-, 2- and 3-year crops of L. perenne, M. sativa and maize on the DM and N yields of a test crop of maize were measured. Depending on the age of the preceding L. perenne crop, annually supplied with 450 kg N/ha, the N after-effects ranged from 120 to 175 kg/ha. The after-effect of a previous cropping with M. sativa was independent of the N dressing and ranged from 140 to 175 kg/ha. For comparison, the after-effect of a preceding maize crop ranged from 90 to 110 kg/ha. Mineral soil N reserves were determined in spring and autumn. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1977 ◽  
Vol 29 (2) ◽  
pp. 203-218 ◽  
Author(s):  
Valerie Mackay ◽  
Donald M. Mackay

McCollough's (1965) original demonstration of an orientation-contingent chromatic after-effect (OCCA) used two orthogonal inducing gratings in complementary colours. Fidell (1970) has shown that inducing gratings whose orientations are separated by less than 90° give progressively smaller OCCAs, becoming ineffective below 20° or so. Stromeyer (1969) found that with only a single inducing grating, orthogonal test fields still appeared tinted in complementary hues, and claimed that these hues could be “neutralized” by rotating the inducing grating by 90°. These results raise the question whether (A) the neural representations of orthogonal orientations are coupled with respect to colour in “opponent” fashion, so that red-horizontal has similar effects to green-vertical; or (B) the representations of orientations separated by some minimum angle are chromatically independent, and can develop substantially independent OCCAs. We report the following results which favour hypothesis (B): (1) With a single coloured inducing grating à la Stromeyer (1969), the measured OCCA at right angles shows no signs of “opponent processing”, if the hue of the test grating is compared against that of a plain field rather than an orthogonal grating. (2) With inducing gratings at several orientations, the resultant OCCA has an angular distribution which is the algebraic sum of those for each grating separately. (3) It is possible to associate the same colour with two orientations at right angles without mutual cancellation. (4) Multiple OCCAs show independent time-courses of decay, and can be induced and retained for at least eight orientations at once.


2011 ◽  
Vol 366 (1581) ◽  
pp. 3106-3114 ◽  
Author(s):  
Astrid M. L. Kappers

In this paper, I focus on the role of active touch in three aspects of shape perception and discrimination studies. First an overview is given of curvature discrimination experiments. The most prominent result is that first-order stimulus information (that is, the difference in attitude or slope over the stimulus) is the dominant factor determining the curvature threshold. Secondly, I compare touch under bimanual and two-finger performance with unimanual and one-finger performance. Consistently, bimanual or two-finger performance turned out to be worse. The most likely explanation for the former finding is that a loss of accuracy during intermanual comparisons is owing to interhemispheric relay. Thirdly, I address the presence of strong after-effects after just briefly touching a shape. These after-effects have been measured and studied in various conditions (such as, static, dynamic, transfer to other hand or finger). Combination of the results of these studies leads to the insight that there are possibly different classes of after-effect: a strong after-effect, caused by immediate contact with the stimulus, that does only partially transfer to the other hand, and one much less strong after-effect, caused by moving over the stimulus for a certain period, which shows a full transfer to other fingers.


2013 ◽  
Vol 28 (3) ◽  
pp. 230-240 ◽  
Author(s):  
Laura A. Malone ◽  
Amy J. Bastian

Background. Step asymmetries during gait in persons after stroke can occur in temporal or spatial domains. Prior studies have shown that split-belt locomotor adaptation can temporarily mitigate these asymmetries. Objective. We investigated whether baseline gait asymmetries affected how patients adapt and store new walking patterns. Methods. Subjects with stroke and age-matched controls were studied walking at a 2:1 speed ratio on the split-belt during adaptation and assessed for retention of the learned pattern (the after-effect) with both belts at the same speed. Results. Those with stroke adapted more slowly ( P < .0001), though just as much as healthy older adults. During split-belt walking, the participants with stroke adapted toward their baseline asymmetry (eg, F = 14.02, P < .01 for step symmetry), regardless of whether the subsequent after-effects improved or worsened their baseline step asymmetries. No correlation was found between baseline spatial and temporal measures of asymmetry ( P = .38). Last, the initial spatial and temporal asymmetries predicted after-effects independently of one another. The after-effects in the spatial domain (ie, center of oscillation difference) are only predicted by center of oscillation difference baseline ( F = 15.3, P = .001), while all other parameters were nonsignificant (all Ps > .17). Temporal coordination (ie, phasing) after-effects showed a significant effect only from phasing baseline ( F = 26.92, P < .001, all others P > .33). Conclusion. This work demonstrates that stroke patients adapt toward their baseline temporal and spatial asymmetries of walking independently of one another. We define how a given split-belt training session would affect asymmetries in these domains, which must be considered when developing rehabilitation interventions for stroke patients.


Author(s):  
I Gede Herri Yudiana Sucitra . ◽  
I Gede Mahendra Darmawiguna, S.Kom, M.Sc . ◽  
Gede Aditra Pradnyana, S.Kom., M.Kom .

Tradisi Dewa Mesraman merupakan salah satu tradisi yang tergolong upacara Dewa Yadnya yang terdapat di Kecamatan Dawan, Desa Paksabali, Banjar Timrah tepatnya berada di Pura Panti Timrah. Film Dokumenter Dewa Mesraman ini bertujuan untuk : (1) mengimplementasikan Pengembangan Film Dokumenter Tradisi Dewa Mesraman Di Pura Panti Timrah Klungkung (2) meluruskan persepsi masyarakat terhadap makna dari tradisi Dewa Mesraman. Metode penelitian yang digunakan adalah cyclic strategy atau strategi berputar, cyclic strategy merupakan sebuah metode yang ada kalanya suatu tahap perlu diulang kembali sebelum tahap berikutnya dilanjutkan. Pengulangan tahap ini sering disebut dengan loop. Adapun tahap – tahap dari cyclic stragey diantaranya adalah Brief, Tahap 1, Tahap 2, evaluasi 1, Tahap 3, Evaluasi 2, Tahap 4, Outcome. Pengembangan film ini diimplementasikan menggunakan Adobe Premiere Pro Cs6 sebagai software editing video beserta bantuan Adobe After Effect sebagai penambah efek pada video. Dengan dibuatnya film dokumenter “Tradisi Dewa Mesraman”, masyarakat diharapkan bisa lebih mengetahui dan mengenal segala kearifan lokal yang ada di Desa Paksebali Klungkung, sehingga film dokumenter ini dapat dijadikan sebagai media informasi serta menjadi inspirasi bagi masyarakat Kabupaten Klungkung dan masyarakat luas pada umumnya.Kata Kunci : Dewa Mesraman, Pura Panti Timrah, Film Dokumenter, Tradisi. Dewa Mesraman tradition is one of the traditions that belong to Deity ceremony Yadnya contained in Dawan sub district, village Paksabali, Banjar Timrah precisely located in Panti Pura Timrah. Documentary Mesraman Dewa aims to: (1) implement the Development of Documentary Tradition Dewa Mesraman In Pura Panti Timrah Klungkung (2) align public perception of the significance of tradition Mesraman god. The method used is the cyclic strategy or strategies revolve, cyclic strategy is a method that is sometimes a necessary step before the next step was repeated followed. The repetition of this phase is often called the loop. As for the stage - the stage of cyclic stragey include Brief, Phase 1, Phase 2, the evaluation 1, Phase 3, Evaluation 2, Phase 4, Outcome. Development of the film is implemented using Adobe Premiere Pro CS6 as video editing software along with the help of Adobe After Effects as an addition to the effect on the video. With the making of the documentary film "Gods Mesraman Tradition", the public is expected to be more aware of and familiar with all the local knowledge that exists in the village Paksebali Klungkung, so this documentary can be used as a medium of information as well as an inspiration for the people of Klungkung and the public at large. keyword : Dewa Mesraman, Pura Panti Timrah, Documentary, Tradition.


2020 ◽  
Author(s):  
Nicholas K. Reimold ◽  
Holly A. Knapp ◽  
Alyssa N. Chesnutt ◽  
Alexa Agne ◽  
Jesse C. Dean

AbstractBackgroundPeople with chronic stroke (PwCS) often exhibit a weakened relationship between pelvis motion and paretic step width, a behavior important for gait stabilization. We have developed a force-field able to manipulate this relationship on a step-by-step basis.ObjectiveThe objective of this study was to investigate the effects of a single exposure to our novel force-field on the step-by-step modulation of paretic step width among PwCS, quantified by the partial correlation between mediolateral pelvis displacement at the start of a step and paretic step width (step start paretic ρdisp).MethodsFollowing a 3-minute period of normal walking, participants were exposed to 5-minutes of either force-field assistance (n=10; pushing the swing leg toward a mechanically-appropriate step width) or perturbations (n=10; pushing the swing leg away from a mechanically-appropriate step width). This period of assistance or perturbations was followed by a 1-minute catch period to identify any after-effects, a sign of sensorimotor adaptation.ResultsWe found that assistance did not have a significant direct effect or after-effect on step start paretic ρdisp. In contrast, perturbations directly reduced step start paretic ρdisp (p=0.004), but were followed by an after-effect in which this metric was increased above the baseline level (p=0.02).ConclusionsThese initial results suggest that PwCS have the ability to strengthen the link between pelvis motion and paretic foot placement if exposed to a novel mechanical environment, which may benefit gait stability. Future work is needed to determine whether this effect can be extended with repeated exposure to force-field perturbations.


1941 ◽  
Vol 87 (368) ◽  
pp. 370-382 ◽  
Author(s):  
H. A. Palmer

The psychiatrist is brought into contact with the patient who has received a blow on the head some time after the event in the majority of cases. His task is in many instances to be shared with the neurological surgeon. The Army psychiatrist is called upon to see such a large number of such cases that the following somewhat exoteric account is offered as covering some of the major considerations involved.A blow to the head may result simply in stunning, in which case the patient thereafter remembers, if vaguely, the essentials of his behaviour and experience, or the alteration of consciousness may be more severe and for some recognizable interval he may subsequently possess a true amnesia, in which case we speak of concussion.The degree of concussion clearly comprehends a wide range of disturbance of function which may almost immediately be fatal.Thirdly, the patient may be killed outright.Functionally considered, therefore, there are three degrees of effect from head injury : stunning, concussion, and death. Structurally we have no real parallelism of observed pathology, since it is only cases of severe concussion which characteristically come to autopsy. Consequently nothing is known for certain concerning the pathology of concussion. Cerebral contusion is therefore clearly inadmissible as a synonym, although its existence may be presumed in severe cases.As regards the after-effects of head injury it is clear that the disturbance of function may be psychogenic or physiogenic, or a mixture of the two, and in discussing the physiogenic results there are two main clinical methods of approach. In the first our interest is focused on syndrome production, and in the second we are more concerned with individual function. Clinical orientation, however, as in all psychiatry, can only be achieved by the former.


1951 ◽  
Vol 3 (1) ◽  
pp. 43-46 ◽  
Author(s):  
J. A. Deutsch

It is found that protracted monotic stimulation at a certain frequency lowers the DL of that frequency for the contralateral ear by some 47 per cent. There were eight subjects and six controls; the frequency was 1,000 c.p.s. at 40 d.b.s. It is suggested that this after-effect is analogous to figural after-effects in vision. (Some further related findings, as yet preliminary, are also reported).


1971 ◽  
Vol 33 (3_suppl) ◽  
pp. 1029-1030
Author(s):  
John K. Collins

Tracking the apparent movement of a stationary target following prior stimulation by rotation was used to estimate the subjective velocity of the visual motion aftereffect. 10 Ss were given 4 trials each with the apparent velocity averaged over a 10-sec. period following 60 sec. stimulation. The intertrial interval was 5 min. The mean apparent rotation was 1.5° per sec. with SD of 1.6°.


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