The Effect of Feature Uncertainty on Spatial Discriminations

Perception ◽  
1988 ◽  
Vol 17 (5) ◽  
pp. 565-577 ◽  
Author(s):  
Rufin Vogels ◽  
Hilde Eeckhout ◽  
Guy A Orban

Just noticeable differences (JNDs) in orientation and spatial frequency were measured under two conditions. In one condition the subject was cued before stimulus presentation as to the feature to be discriminated on that trial, while in the other condition the subject was cued only after stimulus offset. JNDs were larger in the latter, feature uncertainty, condition. This feature uncertainty effect increased with decreasing stimulus processing time. The results suggest that this feature uncertainty effect is of sensorial origin. They also demonstrate that it is possible for humans to address selectively those mechanisms that are most relevant for a given discrimination task.

1995 ◽  
Vol 73 (4) ◽  
pp. 1341-1354 ◽  
Author(s):  
G. Sary ◽  
R. Vogels ◽  
G. Kovacs ◽  
G. A. Orban

1. We recorded from neurons responsive to gratings in the inferior temporal (IT) cortices of macaque monkeys. One of the monkeys performed an orientation discrimination task; the other maintained fixation during stimulus presentation. Stimuli consisted of gratings based on discontinuities in luminance, relative motion, and texture. 2. IT cells responded well to gratings defined solely by relative motion, implying either direct or indirect motion input into IT, an area that is part of the ventral visual cortical pathway. 3. Response strength in general did not depend on the cue used to define the gratings. Latency values observed for the two static grating types (luminance- and texture-defined gratings) were similar, but significantly shorter than those measured for the kinetic gratings. 4. Stimulus orientation had a significant effect in 27%, 27%, and 9% of the cells tested with luminance-, kinetic-, and texture-defined gratings, respectively. 5. Only a small proportion of cells were orientation sensitive for more than one defining cue. The average preferred orientation for luminance and kinetic gratings matched; the tuning width was similar for the two cues. 6. Our results indicate that IT cells may contribute to cue-invariant coding of boundaries and edges. We discuss the relevance of these results to visual perception.


1994 ◽  
Vol 78 (2) ◽  
pp. 479-487 ◽  
Author(s):  
Eiichi Naito

This study examined the relation between control of motor imagery and generation and transformation of visual imagery by testing 54 subjects. We used two measures of the Controllability of Motor Imagery test to evaluate the ability to control motor imagery. One was a recognition test on which the subject imagines as if one sees another's movement, and the other was a regeneration test on which one imagines as if one moves one's own body. The former test score was related to processing time of a mental rotation task and the latter one was not but would reflect sport experience. It was concluded that two meanings of the test could reflect different aspects such as observational motor imagery and body-centered motor imagery.


1970 ◽  
Vol 13 (2) ◽  
pp. 369-381 ◽  
Author(s):  
Deedra L. Engmann ◽  
Robert H. Brookshire

In order to determine whether aphasic and nonaphasic subjects would perform differentially in simultaneous and successive discrimination tasks, 10 aphasic and 10 nonaphasic hospital patients performed in a successive and a simultaneous discrimination task in which 2 stimuli were presented on each trial, and in a successive discrimination with a single stimulus presented on each trial. Aphasic and nonaphasic subjects learned the successive discrimination task with a single stimulus faster than the other two discriminations. When the discrimination involved two stimuli, simultaneous presentation of stimuli resulted in faster learning by aphasic subjects than did successive presentation. Learning of visual discriminations by aphasic and nonaphasic subjects appeared to occur all at once, rather than as gradual improvement over trials. The hypothesis that aphasic subjects would have difficulty with inhibition of responses to negative discriminative stimuli was not supported.


Author(s):  
S.R. Allegra

The respective roles of the ribo somes, endoplasmic reticulum, Golgi apparatus and perhaps nucleus in the synthesis and maturation of melanosomes is still the subject of some controversy. While the early melanosomes (premelanosomes) have been frequently demonstrated to originate as Golgi vesicles, it is undeniable that these structures can be formed in cells in which Golgi system is not found. This report was prompted by the findings in an essentially amelanotic human cellular blue nevus (melanocytoma) of two distinct lines of melanocytes one of which was devoid of any trace of Golgi apparatus while the other had normal complement of this organelle.


2010 ◽  
Vol 4 (2) ◽  
pp. 135-156 ◽  
Author(s):  
Dorothea E. Schulz

Starting with the controversial esoteric employment of audio recordings by followers of the charismatic Muslim preacher Sharif Haidara in Mali, the article explores the dynamics emerging at the interface of different technologies and techniques employed by those engaging the realm of the Divine. I focus attention on the “border zone” between, on the one hand, techniques for appropriating scriptures based on long-standing religious conventions, and, on the other, audio recording technologies, whose adoption not yet established authoritative and standardized forms of practice, thereby generating insecurities and becoming the subject of heated debate. I argue that “recyclage” aptly describes the dynamics of this “border zone” because it captures the ways conventional techniques of accessing the Divine are reassessed and reemployed, by integrating new materials and rituals. Historically, appropriations of the Qur’an for esoteric purposes have been widespread in Muslim West Africa. These esoteric appropriations are at the basis of the considerable continuities, overlaps and crossovers, between scripture-related esoteric practices on one side, and the treatment by Sharif Haidara’s followers of audio taped sermons as vessels of his spiritual power, on the other.


Author(s):  
Iryna Rusnak

The author of the article analyses the problem of the female emancipation in the little-known feuilleton “Amazonia: A Very Inept Story” (1924) by Mykola Chirsky. The author determines the genre affiliation of the work and examines its compositional structure. Three parts are distinguished in the architectonics of associative feuilleton: associative conception; deployment of a “small” topic; conclusion. The author of the article clarifies the role of intertextual elements and the method of constantly switching the tone from serious to comic to reveal the thematic direction of the work. Mykola Chirsky’s interest in the problem of female emancipation is corresponded to the general mood of the era. The subject of ridicule in provocative feuilleton is the woman’s radical metamorphoses, since repulsive manifestations of emancipation becomes commonplace. At the same time, the writer shows respect for the woman, appreciates her femininity, internal and external beauty, personality. He associates the positive in women with the functions of a faithful wife, a caring mother, and a skilled housewife. In feuilleton, the writer does not bypass the problem of the modern man role in a family, but analyses the value and moral and ethical guidelines of his character. The husband’s bad habits receive a caricatured interpretation in the strange behaviour of relatives. On the one hand, the writer does not perceive the extremes brought by female emancipation, and on the other, he mercilessly criticises the male “virtues” of contemporaries far from the standard. The artistic heritage of Mykola Chirsky remains little studied. The urgent task of modern literary studies is the introduction of Mykola Chirsky’s unknown works into the scientific circulation and their thorough scientific understanding.


Author(s):  
Maxim B. Demchenko ◽  

The sphere of the unknown, supernatural and miraculous is one of the most popular subjects for everyday discussions in Ayodhya – the last of the provinces of the Mughal Empire, which entered the British Raj in 1859, and in the distant past – the space of many legendary and mythological events. Mostly they concern encounters with inhabitants of the “other world” – spirits, ghosts, jinns as well as miraculous healings following magic rituals or meetings with the so-called saints of different religions (Hindu sadhus, Sufi dervishes),with incomprehensible and frightening natural phenomena. According to the author’s observations ideas of the unknown in Avadh are codified and structured in Avadh better than in other parts of India. Local people can clearly define if they witness a bhut or a jinn and whether the disease is caused by some witchcraft or other reasons. Perhaps that is due to the presence in the holy town of a persistent tradition of katha, the public presentation of plots from the Ramayana epic in both the narrative and poetic as well as performative forms. But are the events and phenomena in question a miracle for the Avadhvasis, residents of Ayodhya and its environs, or are they so commonplace that they do not surprise or fascinate? That exactly is the subject of the essay, written on the basis of materials collected by the author in Ayodhya during the period of 2010 – 2019. The author would like to express his appreciation to Mr. Alok Sharma (Faizabad) for his advice and cooperation.


2019 ◽  
Vol 95 (2) ◽  
pp. 231-245
Author(s):  
Erik Ode

Abstract De-Finition. Poststructuralist Objections to the Limitation of the Other The metaphysic tradition always tried to structure the world by definitions and scientific terms. Since poststructuralist authors like Derrida, Foucault and Deleuze have claimed the ›death of the subject‹ educational research cannot ignore the critical objections to its own methods. Definitions and identifications may be a violation of the other’s right to stay different and undefined. This article tries to discuss the scientific limitations of the other in a pedagogical, ethical and political perspective.


2020 ◽  
Author(s):  
Abimael Francisco do Nascimento

The general objective of this study is to analyze the postulate of the ethics of otherness as the first philosophy, presented by Emmanuel Levinas. It is a proposal that runs through Levinas' thinking from his theoretical foundations, to his philosophical criticism. Levinas' thought presents itself as a new thought, as a critique of ontology and transcendental philosophy. For him, the concern with knowledge and with being made the other to be forgotten, placing the other in totality. Levinas proposes the ethics of otherness as sensitivity to the other. The subject says here I am, making myself responsible for the other in an infinite way, in a transcendence without return to myself, becoming hostage to the other, as an irrefutable responsibility. The idea of the infinite, present in the face of the other, points to a responsibility whoever more assumes himself, the more one is responsible, until the substitution by other.


2014 ◽  
pp. 104-121
Author(s):  
Aleksandra Kułaga

The article is devoted to the subject of the goals of the climate and energy policy of the European Union, which can have both a positive, and a negative impact on the environmental and energy policies. Positive aspects are the reduction of greenhouse gas emissions, diversification of energy supplies, which should improve Europe independence from energy imports, and increasing the share of renewable energy sources (RES) in the national energy system structures. On the other hand, overly ambitious targets and actions can lead to large losses for the economies of EU Member States. The article also highlights the realities prevailing in the international arena and noncompliance of international actors with global agreements on climate protection.


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