Spatial Localization under Conflict Conditions: Is There a Single Explanation?

Perception ◽  
1979 ◽  
Vol 8 (3) ◽  
pp. 323-337 ◽  
Author(s):  
David H Warren

Visual–auditory (VA) and visual–proprioceptive (VP) localization conflict paradigms were varied to explore the comparability of the conflict situations. In experiment 1 various attempts were made to decrease the dominance of visual information over proprioceptive and auditory target information. Pairing auditory with proprioceptive information against conflicting visual information did not lessen the visual dominance, nor did dimming the visual field. A ‘cognitive’ manipulation, in which the subject was led to doubt the reliability of the visual information, reduced visual dominance over audition but not visual dominance over proprioception. This difference between the two conflict situations was further explored and corroborated in experiment 2. In experiment 3 no attempt was made to lead the subject to believe that paired discrepant targets were related, and the visual dominance of audition was strong while the visual dominance of proprioception did not occur. The apparent differences between the VA and the VP conflict situations are discussed with regard to the feasibility of generating a unitary explanation of localization conflict results. Several further factors are discussed that must be explored before undertaking such a unitary formulation.

Perception ◽  
1988 ◽  
Vol 17 (5) ◽  
pp. 623-632 ◽  
Author(s):  
Viola Cavallo ◽  
Michel Laurent

Previous studies on the visual origin of time-to-collision ( Tc) information have demonstrated that Tc estimates can be based solely on the processing of target expansion rate (optic variable τ). But in the simulated situations used (film clips), there was little reliable information on speed (owing to reduced peripheral vision) and distance (owing to the absence of binocular distance cues) available. In order to determine whether these kinds of information are also taken into account, it is necessary to take an approach where the subject receives a more complete visual input. Thus, an experiment conducted on a circuit under actual driving conditions is reported. Experienced drivers and beginners, who were passengers in a car, had to indicate the moment they expected a collision with a stationary obstacle to take place. Subjects were blindfolded after a viewing time of 3 s. The conditions for speed evaluation (normal versus restricted visual field) and distance evaluation (binocular versus monocular vision) by subjects were varied. The approach speed (30 and 90 km h−1) and actual Tc (3 and 6 s) were also varied. The results show that accuracy of Tc estimation increased with (i) normal visual field, (ii) binocular vision, (iii) higher speeds, and (iv) driving experience. These findings have been interpreted as indicating that both speed and distance information are taken into account in Tc estimation. They suggest furthermore that these two kinds of information may be used differently depending on the skill level of the subject. The results are discussed in terms of the complementarity of the various potentially usable visual means of obtaining Tc information.


1970 ◽  
Vol 6 (1) ◽  
pp. 202-214
Author(s):  
Олена Савченко

У статті розглядається рефлексивна компетентність як інтегративне особистісне утворення, що формується в ході набуття суб’єктом рефлексивного досвіду при застосуванні різних форм рефлексивної активності, спрямованих на розв’язання визначених рефлексивних задач. У структурі рефлексивної компетентності оцінно-мотиваційний компонент виконує наступні функції: оцінку форм рефлексивної активності та її результатів, прогнозування можливих змін у процесі розв’язування проблемно-конфліктних ситуацій, визначення пріоритетних завдань подальшого розвитку себе як суб’єкта рефлексивної активності. На когнітивному рівні функціонує система критеріїв оцінювання власних форм рефлексивної активності, яка характеризується ступенем когнітивної складності, що відображає рівень диференціації та інтеграції системи. Функціонування оцінно-мотиваційного компонента на метакогнітивному рівні забезпечує система здібностей до прогнозування власної активності. Особистісний рівень представлений системою життєвих задач на саморозвиток, які стимулюють суб’єкта докладати зусилля щодо розвитку в себе певних якостей, формування певних вмінь та знань. Розрізненість елементів компонента є індикатором незавершеності процесу формування його внутрішньої структури, низький рівень інтеграції окремих складових не дозволяє системі ефективно компенсувати недорозвинені елементи. Найбільшу вагу у внутрішній структурі оцінно-мотиваційного компонента має показник сформованості системи здібностей до прогнозування власної активності, що підтверджує системотвірну функцію структур метакогнітивного рівня. In the article the reflective competence is seen as an integrative personal formation which develops in the process of acquiring of the reflective experience, when the subject is using various forms of the reflective activity for the solving of specific reflective tasks. In the structure of the reflective competence the value-motivational component performs such functions: an evaluation of forms of the reflective activity and its results, a prediction of the possible changes in the process of solving of the problem-conflict situations, a determining of the priorities for further development of himself as a subject of the reflective activity. The system of the criteria of an evaluating of the reflective activity`s forms functions on the cognitive level of the reflective competence. The level of the cognitive complexity is the basic feature of this system. The predictive abilities` system, that allows to form the expectations of the activity`s results, presents the value-motivational component on the metacognitive level. The system of the life tasks for the self-development, which stimulates the subject to make efforts to develop his own qualities, to form specific skills and knowledge, functions on the personal level. The fragmentation of the elements is an indicator of the incompleteness of the formation of the internal structure of the value-motivational component. The low level of integration of the separate elements does not allow effectively to compensate the functioning of the unformed elements of the system. The index of the formation of the abilities to predict his own activity has the greatest meaning in the internal structure of the value-motivational component. These data confirm the hypothesis about the system-forming function of the metacognitive structures that unite other structures. Thus the development of the predictive abilities will promote the increase of the abilities to the prediction of the others` behavior. An adequate assessment of other people significantly reduces the inconsistency of his own expectations and estimations of others. The development of the predictive abilities creates favorable conditions for the formation of the life tasks for the self-development to increase their value in the system of other tasks


1998 ◽  
Vol 4 (2) ◽  
pp. 79-84 ◽  
Author(s):  
N Accornero ◽  
S Rinalduzzi ◽  
M Capozza ◽  
E Millefiorini ◽  
G C Filligoi ◽  
...  

Color visual field analysis has proven highly sensitive for early visual impairments diagnosis in MS, yet it has never attained widespread popularity usually because the procedure is difficult to standardize, the devices are costly, and the test is fatiguing. We propose a computerized procedure running on standard PC, cost effective, clonable, and easy handled. Two hundred and sixty-four colored patches subtending 18 angle of vision, with selected hues and low saturation levels are sequentially and randomly displayed on gray equiluminous background of the PC screen subtending 2486408 angle of vision. The subject is requested to press a switch at the perception of the stimulus. The output provides colored maps with quantitative information. Comparison between normals and a selected population of MS patients with no actual luminance visual field defects, showed high statistical difference.


2021 ◽  
Vol 58 (1) ◽  
pp. 2759-2769
Author(s):  
Gafurova Gulrukh Baxtiyarovna

The sphere of communication in general over the past two decades has attracted the attention of researchers. The nature of communication, its age and individual characteristics, mechanisms of course and change have become the subject of study by philosophers and sociologists, psycholinguists, specialists in the field of social child and age psychology. Most scientific research and psychological and pedagogical recommendations on the formation of communication skills are dedicated to childhood. Studies of the communicative skills of preschoolers were devoted to such scientists as A.V. Hawks, E.R. Saitbaev. The approaches to teaching communication, forming a communicative function are felt much more slowly than in other areas of pedagogy and psychology. This is because a child can be taught, for example, to draw (take his hand), but to physically help him speak is much more difficult. For graduates of schools it is necessary to be sociable, contact in various social groups, to be able to work together in different areas, preventing conflict situations or skillfully getting out of them. These skills should provide the young man with mobility, the ability to quickly respond in a changing world with a state of mental comfort, which provides emotional balance. In modern conditions, dialogue takes on a new meaning and quality, acting as the basic principle of the communicative content of education. A multicultural society, saturated with diverse communicative ties, involves not only the establishment of relations of cooperation, mutual understanding, but also the emergence of contradictions, polemic disputes. Therefore, the ability of school graduates to conduct a fruitful, effective dialogue in various fields of the sociocultural sphere, to learn the world not from monological (with a claim to absolute truth), but dialogically, pluralistically becomes the most important and communicative property. Meanwhile, observations of the experience of discussions, political meetings and rallies, business meetings, scientific conferences give reason to conclude that in many speeches there is no deliberation, depth and credibility of arguments, consistency and consistency of reasoning, compliance with ethical standards, flexibility of thinking and speed reactions. They still “see” the monopoly on truth, a special style of communication and belief with its monologue moral teachings and harsh, peremptory judgments. In this regard, communicatively-oriented education departs from the monologic way of teaching and reorientes to the dialogical one, which promotes the development of communicative properties among schoolchildren, namely: the ability to discuss, agree, argue, prove, agree (or disagree) [8]. In order for a modern graduate to possess these skills, it is necessary that he be taught this. This requires appropriate organization of the educational process of modern schools, lyceums and gymnasiums. In connection with the relevance of this problem, a research topic arises - Dialogue, as a means of developing students' communicative literacy.


2018 ◽  
Vol 119 (5) ◽  
pp. 1981-1992 ◽  
Author(s):  
Laura Mikula ◽  
Valérie Gaveau ◽  
Laure Pisella ◽  
Aarlenne Z. Khan ◽  
Gunnar Blohm

When reaching to an object, information about the target location as well as the initial hand position is required to program the motor plan for the arm. The initial hand position can be determined by proprioceptive information as well as visual information, if available. Bayes-optimal integration posits that we utilize all information available, with greater weighting on the sense that is more reliable, thus generally weighting visual information more than the usually less reliable proprioceptive information. The criterion by which information is weighted has not been explicitly investigated; it has been assumed that the weights are based on task- and effector-dependent sensory reliability requiring an explicit neuronal representation of variability. However, the weights could also be determined implicitly through learned modality-specific integration weights and not on effector-dependent reliability. While the former hypothesis predicts different proprioceptive weights for left and right hands, e.g., due to different reliabilities of dominant vs. nondominant hand proprioception, we would expect the same integration weights if the latter hypothesis was true. We found that the proprioceptive weights for the left and right hands were extremely consistent regardless of differences in sensory variability for the two hands as measured in two separate complementary tasks. Thus we propose that proprioceptive weights during reaching are learned across both hands, with high interindividual range but independent of each hand’s specific proprioceptive variability. NEW & NOTEWORTHY How visual and proprioceptive information about the hand are integrated to plan a reaching movement is still debated. The goal of this study was to clarify how the weights assigned to vision and proprioception during multisensory integration are determined. We found evidence that the integration weights are modality specific rather than based on the sensory reliabilities of the effectors.


Perception ◽  
10.1068/p3393 ◽  
2003 ◽  
Vol 32 (4) ◽  
pp. 395-414 ◽  
Author(s):  
Marina V Danilova ◽  
John D Mollon

The visual system is known to contain hard-wired mechanisms that compare the values of a given stimulus attribute at adjacent positions in the visual field; but how are comparisons performed when the stimuli are not adjacent? We ask empirically how well a human observer can compare two stimuli that are separated in the visual field. For the stimulus attributes of spatial frequency, contrast, and orientation, we have measured discrimination thresholds as a function of the spatial separation of the discriminanda. The three attributes were studied in separate experiments, but in all cases the target stimuli were briefly presented Gabor patches. The Gabor patches lay on an imaginary circle, which was centred on the fixation point and had a radius of 5 deg of visual angle. Our psychophysical procedures were designed to ensure that the subject actively compared the two stimuli on each presentation, rather than referring just one stimulus to a stored template or criterion. For the cases of spatial frequency and contrast, there was no systematic effect of spatial separation up to 10 deg. We conclude that the subject's judgment does not depend on discontinuity detectors in the early visual system but on more central codes that represent the two stimuli individually. In the case of orientation discrimination, two naïve subjects performed as in the cases of spatial frequency and contrast; but two highly trained subjects showed a systematic increase of threshold with spatial separation, suggesting that they were exploiting a distal mechanism designed to detect the parallelism or non-parallelism of contours.


Author(s):  
Allan H. Frey ◽  
Edwin S. Eichert

This study was concerned with an evaluation of holography in training and for job aids. Experimentation comparing holograms, line drawings, and photographs as methods of presenting visual information is reported. It appears that with the tasks used, holograms generally are as good as or better visual aids than either photographs or line drawings. The use of holograms tends to reduce errors rather than speed assembly time in assembly tasks. They also seem to enhance the discovery of errors when the subject is attempting to locate assembly errors in a construction. The results of this experimentation suggest that serious consideration should be given to the use of holography in the development of job aids and in training. Applications in technical documentation and storage relevant to the use of holograms as job aids are also considered.


Development ◽  
1981 ◽  
Vol 65 (1) ◽  
pp. 199-217
Author(s):  
C. Kennard

The extent, and the development, of the ipsilateral retinothalamic projection in the frog Xenopus laevis have been studied using terminal degeneration and autoradiographic techniques. This ipsilateral projection derives only from those retinal areas receiving visual information from the binocular portion of the visual field. In Xenopus, the ipsilateral retinothalamic projection arises from a larger area of the retina than was found to be the case in earlier studies on Rana. This correlates with the fact that Xenopus has a larger binocular visual field than does Rana. The ipsilateral retinothalamic projection is just detectable at about stage 56 of larval life, considerably later than its contralateral counterpart. Experimental manipulation of the developing eye vesicle at early larval stages followed by histological studies of the ipsilateral retinothalamic projections showed, however, that the retinal areas which give rise to this projection are determined by stage 32 of larval life. Further studies, in which monocular enucleation was performed at different larval stages with subsequent examination of the retinothalamic projections from the remaining eye, indicated that the selective pattern of decussation and non-decussation of retinothalamic fibres at the optic chiasma does not require interactions, at the chiasma, between optic fibres from the two eyes.


Author(s):  
Elizabeth Schechter

The largest fibre tract in the human brain connects the two cerebral hemispheres. A ‘split-brain’ surgery severs this structure, sometimes together with other white matter tracts connecting the right hemisphere and the left. Split-brain surgeries have long been performed on non-human animals for experimental purposes, but a number of these surgeries were also performed on adult human beings in the second half of the twentieth century, as a medical treatment for severe cases of epilepsy. A number of these people afterwards agreed to participate in ongoing research into the psychobehavioural consequences of the procedure. These experiments have helped to show that the corpus callosum is a significant source of interhemispheric interaction and information exchange in the ‘neurotypical’ brain. After split-brain surgery, the two hemispheres operate unusually independently of each other in the realm of perception, cognition, and the control of action. For instance, each hemisphere receives visual information directly from the opposite (‘contralateral’) side of space, the right hemisphere from the left visual field and the left hemisphere from the right visual field. This is true of the normal (‘neurotypical’) brain too, but in the neurotypical case interhemispheric tracts allow either hemisphere to gain access to the information that the other has received. In a split-brain subject however the information more or less stays put in whatever hemisphere initially received it. And it isn’t just visual information that is confined to one hemisphere or the other after the surgery. Rather, after split-brain surgery, each hemisphere is the source of proprietary perceptual information of various kinds, and is also the source of proprietary memories, intentions, and aptitudes. Various notions of psychological unity or integration have always been central to notions of mind, personhood, and the self. Although split-brain surgery does not prevent interhemispheric interaction or exchange, it naturally alters and impedes it. So does the split-brain subject as a whole nonetheless remain a unitary psychological being? Or could there now be two such psychological beings within one human animal – sharing one body, one face, one voice? Prominent neuropsychologists working with the subjects have often appeared to argue or assume that a split-brain subject has a divided or disunified consciousness and even two minds. Although a number of philosophers agree, the majority seem to have resisted these conscious and mental ‘duality claims’, defending alternative interpretations of the split-brain experimental results. The sources of resistance are diverse, including everything from a commitment to the necessary unity of consciousness, to recognition of those psychological processes that remain interhemispherically integrated, to concerns about what the moral and legal consequences would be of recognizing multiple psychological beings in one body. On the other hand underlying most of these arguments against the various ‘duality’ claims is the simple fact that the split-brain subject does not appear to be two persons, but one – and there are powerful conceptual, social, and moral connections between being a unitary person on the one hand and having a unified consciousness and mind on the other.


2004 ◽  
Vol 92 (4) ◽  
pp. 2380-2393 ◽  
Author(s):  
M. A. Admiraal ◽  
N.L.W. Keijsers ◽  
C.C.A.M. Gielen

We have investigated pointing movements toward remembered targets after an intervening self-generated body movement. We tested to what extent visual information about the environment or finger position is used in updating target position relative to the body after a step and whether gaze plays a role in the accuracy of the pointing movement. Subjects were tested in three visual conditions: complete darkness (DARK), complete darkness with visual feedback of the finger (FINGER), and with vision of a well-defined environment and with feedback of the finger (FRAME). Pointing accuracy was rather poor in the FINGER and DARK conditions, which did not provide vision of the environment. Constant pointing errors were mainly in the direction of the step and ranged from about 10 to 20 cm. Differences between binocular fixation and target position were often related to the step size and direction. At the beginning of the trial, when the target was visible, fixation was on target. After target extinction, fixation moved away from the target relative to the subject. The variability in the pointing positions appeared to be related to the variable errors in fixation, and the co-variance increases during the delay period after the step, reaching a highly significant value at the time of pointing. The significant co-variance between fixation position and pointing is not the result of a mutual dependence on the step, since we corrected for any direct contributions of the step in both signals. We conclude that the co-variance between fixation and pointing position reflects 1) a common command signal for gaze and arm movements and 2) an effect of fixation on pointing accuracy at the time of pointing.


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