Samir Okasha
- Published in print:
- 2006
- Published Online:
- January 2007
- ISBN:
- 9780199267972
- eISBN:
- 9780191708275
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199267972.001.0001
- Subject:
- Philosophy, Philosophy of Science
Does natural selection act primarily on individual organisms, on groups, on genes, or on whole species? This book provides a comprehensive analysis of the long-standing controversy in evolutionary ...
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Does natural selection act primarily on individual organisms, on groups, on genes, or on whole species? This book provides a comprehensive analysis of the long-standing controversy in evolutionary biology over the levels of selection, focusing on conceptual, philosophical, and foundational questions. In the first half of the book, a systematic framework is developed for thinking about natural selection acting at multiple levels of the biological hierarchy; the framework is then used to help resolve outstanding issues. Considerable attention is paid to the concept of causality as it relates to the levels of selection, particularly the idea that natural selection at one hierarchical level can have effects that ‘filter’ up or down to other levels. Full account is taken of the recent biological literature on ‘major evolutionary transitions’ and the recent resurgence of interest in multi-level selection theory among biologists. Other biological topics discussed include Price's equation, kin and group selection, the gene's eye view, evolutionary game theory, selfish genetic elements, species and clade selection, and the evolution of individuality. Philosophical topics discussed include reductionism and holism, causation and correlation, the nature of hierarchical organization, and realism and pluralism about the levels of selection.Less
Does natural selection act primarily on individual organisms, on groups, on genes, or on whole species? This book provides a comprehensive analysis of the long-standing controversy in evolutionary biology over the levels of selection, focusing on conceptual, philosophical, and foundational questions. In the first half of the book, a systematic framework is developed for thinking about natural selection acting at multiple levels of the biological hierarchy; the framework is then used to help resolve outstanding issues. Considerable attention is paid to the concept of causality as it relates to the levels of selection, particularly the idea that natural selection at one hierarchical level can have effects that ‘filter’ up or down to other levels. Full account is taken of the recent biological literature on ‘major evolutionary transitions’ and the recent resurgence of interest in multi-level selection theory among biologists. Other biological topics discussed include Price's equation, kin and group selection, the gene's eye view, evolutionary game theory, selfish genetic elements, species and clade selection, and the evolution of individuality. Philosophical topics discussed include reductionism and holism, causation and correlation, the nature of hierarchical organization, and realism and pluralism about the levels of selection.
Arnold J. Wilkins
- Published in print:
- 1995
- Published Online:
- January 2008
- ISBN:
- 9780198521747
- eISBN:
- 9780191706691
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198521747.003.0001
- Subject:
- Psychology, Cognitive Neuroscience
This introductory chapter discusses eye-strain as a physical consequence of visual stimulation, and then provides an overview of the remainder of the book. A general and unified theory of visual ...
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This introductory chapter discusses eye-strain as a physical consequence of visual stimulation, and then provides an overview of the remainder of the book. A general and unified theory of visual discomfort is provided in Chapters 2–4, and then applied to a variety of everyday problems, such as eye-strain from reading (Chapter 5), from lighting (Chapter 6), from television and visual display terminals (Chapter 7), and more generally from design (Chapter 8). The role of colour in therapy is reviewed in Chapter 9. Chapter 10 provides some theoretical speculations, and the Appendix gives a summary of techniques for preventing discomfort.Less
This introductory chapter discusses eye-strain as a physical consequence of visual stimulation, and then provides an overview of the remainder of the book. A general and unified theory of visual discomfort is provided in Chapters 2–4, and then applied to a variety of everyday problems, such as eye-strain from reading (Chapter 5), from lighting (Chapter 6), from television and visual display terminals (Chapter 7), and more generally from design (Chapter 8). The role of colour in therapy is reviewed in Chapter 9. Chapter 10 provides some theoretical speculations, and the Appendix gives a summary of techniques for preventing discomfort.
L. Weiskrantz
- Published in print:
- 1990
- Published Online:
- January 2008
- ISBN:
- 9780198521921
- eISBN:
- 9780191706226
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198521921.003.0011
- Subject:
- Psychology, Cognitive Neuroscience
On a number of occasions when the two eyes were compared, it was found that the left eye seemed better than the right. This was confirmed in this study for detection of a 10° disc. It was possible ...
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On a number of occasions when the two eyes were compared, it was found that the left eye seemed better than the right. This was confirmed in this study for detection of a 10° disc. It was possible that the inequality stemmed from the fact that D. B. had undergone right cervical sympathectomy prior to his brain surgery, resulting in a constricted pupil in his right eye. The two eyes were compared when the vision of each was restricted by an artificial pupil of 4 mm aperture. With the artificial pupil, the difference between the eyes was no longer significant.Less
On a number of occasions when the two eyes were compared, it was found that the left eye seemed better than the right. This was confirmed in this study for detection of a 10° disc. It was possible that the inequality stemmed from the fact that D. B. had undergone right cervical sympathectomy prior to his brain surgery, resulting in a constricted pupil in his right eye. The two eyes were compared when the vision of each was restricted by an artificial pupil of 4 mm aperture. With the artificial pupil, the difference between the eyes was no longer significant.
Susan Jones
- Published in print:
- 1999
- Published Online:
- October 2011
- ISBN:
- 9780198184485
- eISBN:
- 9780191674273
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198184485.003.0001
- Subject:
- Literature, European Literature, 20th-century Literature and Modernism
Joseph Conrad is widely recognised as a writer of sea stories with predominantly masculine themes. This book argues that despite this established reputation, Conrad did not neglect women's themes in ...
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Joseph Conrad is widely recognised as a writer of sea stories with predominantly masculine themes. This book argues that despite this established reputation, Conrad did not neglect women's themes in all his works. The evidence of his biography, correspondence, and fiction indicates a complex and intriguing relationship between Conrad, the women in his life, his female characters, and readers of his work. He began in the Malay fiction by producing prominent female figures whose position offered an important critique of imperialism, a role that women continued to fulfill in the political works of the middle years, such as Nostromo, The Secret Agent, and Under Western Eyes. He increasingly turned to the issue of gender, female identity, and in relation to romance, how women are invited to conform to its conventionalised gestures and plots.Less
Joseph Conrad is widely recognised as a writer of sea stories with predominantly masculine themes. This book argues that despite this established reputation, Conrad did not neglect women's themes in all his works. The evidence of his biography, correspondence, and fiction indicates a complex and intriguing relationship between Conrad, the women in his life, his female characters, and readers of his work. He began in the Malay fiction by producing prominent female figures whose position offered an important critique of imperialism, a role that women continued to fulfill in the political works of the middle years, such as Nostromo, The Secret Agent, and Under Western Eyes. He increasingly turned to the issue of gender, female identity, and in relation to romance, how women are invited to conform to its conventionalised gestures and plots.
Samir Okasha
- Published in print:
- 2006
- Published Online:
- January 2007
- ISBN:
- 9780199267972
- eISBN:
- 9780191708275
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199267972.003.0005
- Subject:
- Philosophy, Philosophy of Science
This chapter examines the ‘genic’ view of evolution associated with Williams, Dawkins, Maynard Smith, and others. A distinction is drawn between the process of genic selection and a gene's eye ...
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This chapter examines the ‘genic’ view of evolution associated with Williams, Dawkins, Maynard Smith, and others. A distinction is drawn between the process of genic selection and a gene's eye perspective on selection processes that occur at other levels. Outlaw genes or selfish genetic elements, which spread at the expense of other genes in the same organism, are briefly examined and the use of multi-level selection theory to explore the evolutionary dynamics of outlaws is discussed. A number of objections to gene's eye thinking are examined, including the charge of ‘confusing bookkeeping with causality’ and the charge of ignoring the context-dependence of genes' effects on phenotype.Less
This chapter examines the ‘genic’ view of evolution associated with Williams, Dawkins, Maynard Smith, and others. A distinction is drawn between the process of genic selection and a gene's eye perspective on selection processes that occur at other levels. Outlaw genes or selfish genetic elements, which spread at the expense of other genes in the same organism, are briefly examined and the use of multi-level selection theory to explore the evolutionary dynamics of outlaws is discussed. A number of objections to gene's eye thinking are examined, including the charge of ‘confusing bookkeeping with causality’ and the charge of ignoring the context-dependence of genes' effects on phenotype.
Thomas W. Cronin, Sönke Johnsen, N. Justin Marshall, and Eric J. Warrant
- Published in print:
- 2014
- Published Online:
- October 2017
- ISBN:
- 9780691151847
- eISBN:
- 9781400853021
- Item type:
- book
- Publisher:
- Princeton University Press
- DOI:
- 10.23943/princeton/9780691151847.001.0001
- Subject:
- Biology, Evolutionary Biology / Genetics
Visual ecology is the study of how animals use visual systems to meet their ecological needs, how these systems have evolved, and how they are specialized for particular visual tasks. This book ...
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Visual ecology is the study of how animals use visual systems to meet their ecological needs, how these systems have evolved, and how they are specialized for particular visual tasks. This book provides the first up-to-date synthesis of the field to appear in more than three decades. Featuring some 225 illustrations, including more than 140 in color, spread throughout the text, the book begins by discussing the basic properties of light and the optical environment. It then looks at how photoreceptors intercept light and convert it to usable biological signals, how the pigments and cells of vision vary among animals, and how the properties of these components affect a given receptor's sensitivity to light. The book goes on to examine how eyes and photoreceptors become specialized for an array of visual tasks, such as navigation, evading prey, mate choice, and communication. A timely and much-needed resource for students and researchers alike, the book also includes a glossary and a wealth of examples drawn from the full diversity of visual systems.Less
Visual ecology is the study of how animals use visual systems to meet their ecological needs, how these systems have evolved, and how they are specialized for particular visual tasks. This book provides the first up-to-date synthesis of the field to appear in more than three decades. Featuring some 225 illustrations, including more than 140 in color, spread throughout the text, the book begins by discussing the basic properties of light and the optical environment. It then looks at how photoreceptors intercept light and convert it to usable biological signals, how the pigments and cells of vision vary among animals, and how the properties of these components affect a given receptor's sensitivity to light. The book goes on to examine how eyes and photoreceptors become specialized for an array of visual tasks, such as navigation, evading prey, mate choice, and communication. A timely and much-needed resource for students and researchers alike, the book also includes a glossary and a wealth of examples drawn from the full diversity of visual systems.
Paul F. Lurquin and Linda Stone
- Published in print:
- 2007
- Published Online:
- September 2007
- ISBN:
- 9780195315387
- eISBN:
- 9780199785674
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195315387.003.0003
- Subject:
- Religion, Religion and Society
This chapter rebuts irreducible complexity and creationism by explaining the reliability of dating techniques as well as sophisticated laboratory techniques that allow researchers to synthesize ...
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This chapter rebuts irreducible complexity and creationism by explaining the reliability of dating techniques as well as sophisticated laboratory techniques that allow researchers to synthesize extinct genes (genetic archaeology, gene resurrection) and study their homology to other genes. These techniques clearly demonstrate that the irreducible complexity of the eye, the immune system, and the bacterial flagellum are subjective impressions. On the contrary, phylogenetic trees based on gene homology show a deep evolutionary link between simple life-forms and complex ones. Finally, the chapter gives several examples of “poor design” that cast doubt on the principle of Intelligent Design.Less
This chapter rebuts irreducible complexity and creationism by explaining the reliability of dating techniques as well as sophisticated laboratory techniques that allow researchers to synthesize extinct genes (genetic archaeology, gene resurrection) and study their homology to other genes. These techniques clearly demonstrate that the irreducible complexity of the eye, the immune system, and the bacterial flagellum are subjective impressions. On the contrary, phylogenetic trees based on gene homology show a deep evolutionary link between simple life-forms and complex ones. Finally, the chapter gives several examples of “poor design” that cast doubt on the principle of Intelligent Design.
Arnold J. Wilkins
- Published in print:
- 1995
- Published Online:
- January 2008
- ISBN:
- 9780198521747
- eISBN:
- 9780191706691
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198521747.003.0006
- Subject:
- Psychology, Cognitive Neuroscience
Most electric lighting pulsates in brightness twice with each cycle of the alternating electricity supply. Fluorescent lighting fluctuates to such an extent as to affect the firing of visual neurons. ...
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Most electric lighting pulsates in brightness twice with each cycle of the alternating electricity supply. Fluorescent lighting fluctuates to such an extent as to affect the firing of visual neurons. The fluctuation is responsible for more than half the headaches and eye-strain suffered by office workers. Glasses that absorb light at the short wavelength end of the visible spectrum, where the fluctuations are maximal, may reduce headaches in children with migraine.Less
Most electric lighting pulsates in brightness twice with each cycle of the alternating electricity supply. Fluorescent lighting fluctuates to such an extent as to affect the firing of visual neurons. The fluctuation is responsible for more than half the headaches and eye-strain suffered by office workers. Glasses that absorb light at the short wavelength end of the visible spectrum, where the fluctuations are maximal, may reduce headaches in children with migraine.
Michael F. Land and Dan-Eric Nilsson
- Published in print:
- 2012
- Published Online:
- December 2013
- ISBN:
- 9780199581139
- eISBN:
- 9780191774652
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199581139.001.0001
- Subject:
- Biology, Animal Biology
This book provides a comparative account of all the types of eye in the animal kingdom. It gives an outline of the structure and function of each kind of eye, with an emphasis on the nature of the ...
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This book provides a comparative account of all the types of eye in the animal kingdom. It gives an outline of the structure and function of each kind of eye, with an emphasis on the nature of the optical systems and the physical principles involved in image formation. The book also covers the evolution and taxonomic distribution of each type of eye, and their roles in the behaviour and ecology of the animals that possess them. In comparing the capabilities of eyes, it considers the factors that lead to good resolution of detail, and to the ability to function under a wide range of light conditions. The book also deals with movements of the eyes: how they sample the world in time as well as space.Less
This book provides a comparative account of all the types of eye in the animal kingdom. It gives an outline of the structure and function of each kind of eye, with an emphasis on the nature of the optical systems and the physical principles involved in image formation. The book also covers the evolution and taxonomic distribution of each type of eye, and their roles in the behaviour and ecology of the animals that possess them. In comparing the capabilities of eyes, it considers the factors that lead to good resolution of detail, and to the ability to function under a wide range of light conditions. The book also deals with movements of the eyes: how they sample the world in time as well as space.
David P. Wright
- Published in print:
- 2009
- Published Online:
- September 2009
- ISBN:
- 9780195304756
- eISBN:
- 9780199866830
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195304756.003.0006
- Subject:
- Religion, Biblical Studies
This explores the compositional logic involved in creating the laws on homicide (Exodus 21:12–14), injury/assault (vv. 18–19), slave homicide (vv. 20–21), aggravated miscarriage (abortion; vv. ...
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This explores the compositional logic involved in creating the laws on homicide (Exodus 21:12–14), injury/assault (vv. 18–19), slave homicide (vv. 20–21), aggravated miscarriage (abortion; vv. 22–23), talion ("an eye for and eye," etc.; vv. 23b-25), and slave injury (vv. 26–27). It demonstrates that all of these laws are a unity based on sources in the Laws of Hammurabi. It also shows that the talion law is integrally connected to the legislation on homicide and injury, giving the requirement that one must indemnify a victim or their kin, even if the injury or homicide was accidental. The Covenant Code thus identifies and solve problems in the homicide and injury laws of its source.Less
This explores the compositional logic involved in creating the laws on homicide (Exodus 21:12–14), injury/assault (vv. 18–19), slave homicide (vv. 20–21), aggravated miscarriage (abortion; vv. 22–23), talion ("an eye for and eye," etc.; vv. 23b-25), and slave injury (vv. 26–27). It demonstrates that all of these laws are a unity based on sources in the Laws of Hammurabi. It also shows that the talion law is integrally connected to the legislation on homicide and injury, giving the requirement that one must indemnify a victim or their kin, even if the injury or homicide was accidental. The Covenant Code thus identifies and solve problems in the homicide and injury laws of its source.
Steven J. Luck and Andrew Hollingworth (eds)
- Published in print:
- 2008
- Published Online:
- September 2008
- ISBN:
- 9780195305487
- eISBN:
- 9780199894260
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195305487.001.0001
- Subject:
- Psychology, Cognitive Psychology
Vision and memory are two of the most intensively studied topics in psychology and neuroscience, and the intersection between them — visual memory — is emerging as a fertile ground for research. ...
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Vision and memory are two of the most intensively studied topics in psychology and neuroscience, and the intersection between them — visual memory — is emerging as a fertile ground for research. Certain memory systems appear to specialize in maintaining visually encoded information. Vision provides the primary input to more general memory systems. These more general systems link and integrate visual memory with other perceptual and cognitive processes. As a result, visual perception cannot be understood independently of visual memories, which support the mapping of perceptual input onto existing knowledge structures that guide and constrain perceptual selection. This book provides an account of visual memory systems. The chapters provide both a broad overview of each topic and a summary of the latest research. They also present new perspectives that advance our theoretical understanding of visual memory and suggest directions for future research. After an introductory overview by the editors, chapters address visual sensory memory (iconic memory), visual short-term memory, and the relationship between visual memory and eye movements. Visual long-term memory is then reviewed from several different perspectives, including memory for natural scenes, the relationship between visual memory and object recognition, and associative learning. The final chapters discuss the neural mechanisms of visual memory and neuropsychological deficits in visual memory.Less
Vision and memory are two of the most intensively studied topics in psychology and neuroscience, and the intersection between them — visual memory — is emerging as a fertile ground for research. Certain memory systems appear to specialize in maintaining visually encoded information. Vision provides the primary input to more general memory systems. These more general systems link and integrate visual memory with other perceptual and cognitive processes. As a result, visual perception cannot be understood independently of visual memories, which support the mapping of perceptual input onto existing knowledge structures that guide and constrain perceptual selection. This book provides an account of visual memory systems. The chapters provide both a broad overview of each topic and a summary of the latest research. They also present new perspectives that advance our theoretical understanding of visual memory and suggest directions for future research. After an introductory overview by the editors, chapters address visual sensory memory (iconic memory), visual short-term memory, and the relationship between visual memory and eye movements. Visual long-term memory is then reviewed from several different perspectives, including memory for natural scenes, the relationship between visual memory and object recognition, and associative learning. The final chapters discuss the neural mechanisms of visual memory and neuropsychological deficits in visual memory.
Michael J. Spivey, Daniel C. Richardson, and Carlos A. Zednik
- Published in print:
- 2009
- Published Online:
- May 2010
- ISBN:
- 9780199553242
- eISBN:
- 9780191720444
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199553242.003.0002
- Subject:
- Linguistics, Semantics and Pragmatics, Psycholinguistics / Neurolinguistics / Cognitive Linguistics
Cognitive science has made as much progress as possible with theories of discrete amodal symbolic computation that too coarsely approximate the neural processes underlying cognition. We describe a ...
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Cognitive science has made as much progress as possible with theories of discrete amodal symbolic computation that too coarsely approximate the neural processes underlying cognition. We describe a collection of studies indicating that internal cognitive processes are often constructed of analog spatial formats of representation, not unlike the topographic maps that populate so much of mammalian cortex. These findings point to a view of language in which, far from being a specialized module performing computations on discrete logical symbols, linguistic ability is an emergent property that opportunistically draws from the existing topographic representational formats of perceptual and motor processes.Less
Cognitive science has made as much progress as possible with theories of discrete amodal symbolic computation that too coarsely approximate the neural processes underlying cognition. We describe a collection of studies indicating that internal cognitive processes are often constructed of analog spatial formats of representation, not unlike the topographic maps that populate so much of mammalian cortex. These findings point to a view of language in which, far from being a specialized module performing computations on discrete logical symbols, linguistic ability is an emergent property that opportunistically draws from the existing topographic representational formats of perceptual and motor processes.
Thomas W. Cronin, Sönke Johnsen, N. Justin Marshall, and Eric J. Warrant
- Published in print:
- 2014
- Published Online:
- October 2017
- ISBN:
- 9780691151847
- eISBN:
- 9781400853021
- Item type:
- chapter
- Publisher:
- Princeton University Press
- DOI:
- 10.23943/princeton/9780691151847.003.0001
- Subject:
- Biology, Evolutionary Biology / Genetics
This introductory chapter talks about how every creature is guided by its eyes as it carries out its accustomed behaviors. Each animal's eyes allows it to execute the behavior necessary for its ...
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This introductory chapter talks about how every creature is guided by its eyes as it carries out its accustomed behaviors. Each animal's eyes allows it to execute the behavior necessary for its survival. This study of how visual systems function to meet the ecological needs of animals is called visual ecology. Researchers who work at various levels of inquiry, from genes to behavior, call themselves visual ecologists, but all are primarily concerned with how animals use vision for natural tasks and behaviors. Although the outcomes of visual ecological research may well have implications for health or may be applicable for use in engineering or technology, the research itself centers on the animal of interest and on how it employs its visual system to meet its own ecological needs.Less
This introductory chapter talks about how every creature is guided by its eyes as it carries out its accustomed behaviors. Each animal's eyes allows it to execute the behavior necessary for its survival. This study of how visual systems function to meet the ecological needs of animals is called visual ecology. Researchers who work at various levels of inquiry, from genes to behavior, call themselves visual ecologists, but all are primarily concerned with how animals use vision for natural tasks and behaviors. Although the outcomes of visual ecological research may well have implications for health or may be applicable for use in engineering or technology, the research itself centers on the animal of interest and on how it employs its visual system to meet its own ecological needs.
Webb Keane
- Published in print:
- 2015
- Published Online:
- October 2017
- ISBN:
- 9780691167732
- eISBN:
- 9781400873593
- Item type:
- chapter
- Publisher:
- Princeton University Press
- DOI:
- 10.23943/princeton/9780691167732.003.0007
- Subject:
- Anthropology, Social and Cultural Anthropology
This chapter provides an understanding of the demand for moral consistency that motivates a pair of thriving contemporary piety movements, one Christian (the Urapmin Charismatics), the other Muslim ...
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This chapter provides an understanding of the demand for moral consistency that motivates a pair of thriving contemporary piety movements, one Christian (the Urapmin Charismatics), the other Muslim (the Cairene Muslims). Although they differ in their theological and moral doctrines, these movements have much in common. In particular, the participants in these movements actively and self-consciously strive to live ethically consistent lives. In both piety movements, that demand for consistency is partly explained by the inculcation of a God's-eye view, a version of the third-person perspective from which the faithful is expected to see the totality of his or her life and impose order on it.Less
This chapter provides an understanding of the demand for moral consistency that motivates a pair of thriving contemporary piety movements, one Christian (the Urapmin Charismatics), the other Muslim (the Cairene Muslims). Although they differ in their theological and moral doctrines, these movements have much in common. In particular, the participants in these movements actively and self-consciously strive to live ethically consistent lives. In both piety movements, that demand for consistency is partly explained by the inculcation of a God's-eye view, a version of the third-person perspective from which the faithful is expected to see the totality of his or her life and impose order on it.
Robert Rafal
- Published in print:
- 2002
- Published Online:
- May 2009
- ISBN:
- 9780195134971
- eISBN:
- 9780199864157
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195134971.003.0009
- Subject:
- Neuroscience, Behavioral Neuroscience, Molecular and Cellular Systems
This chapter uses eye movements as a model system to investigate how midbrain reflex circuits and frontal and parietal systems for eye movement control combine to produce goal-directed behavior. ...
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This chapter uses eye movements as a model system to investigate how midbrain reflex circuits and frontal and parietal systems for eye movement control combine to produce goal-directed behavior. Converging evidence from patients with midbrain lesions and from hemianopic patients reveals that midbrain pathways are responsible for reflexive orienting in humans. The visual grasp reflex (VGR) mediated by the colliculus is modulated by a dynamic interaction between cortical and subcortical systems. Chronic lesions of the frontal eye field (FEF) cause a slowing of visually guided saccades toward the ipsilesional field; whereas parietal lesions cause a bias against making voluntary saccades toward the contralesional field. The FEF and parietal lobes appear to normally have opposing influences on collicular function: the parietal lobe facilitates the VGR and the FEF inhibits it.Less
This chapter uses eye movements as a model system to investigate how midbrain reflex circuits and frontal and parietal systems for eye movement control combine to produce goal-directed behavior. Converging evidence from patients with midbrain lesions and from hemianopic patients reveals that midbrain pathways are responsible for reflexive orienting in humans. The visual grasp reflex (VGR) mediated by the colliculus is modulated by a dynamic interaction between cortical and subcortical systems. Chronic lesions of the frontal eye field (FEF) cause a slowing of visually guided saccades toward the ipsilesional field; whereas parietal lesions cause a bias against making voluntary saccades toward the contralesional field. The FEF and parietal lobes appear to normally have opposing influences on collicular function: the parietal lobe facilitates the VGR and the FEF inhibits it.
Ian P. Howard and Brian J. Rogers
- Published in print:
- 2008
- Published Online:
- May 2009
- ISBN:
- 9780195367607
- eISBN:
- 9780199867264
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195367607.003.0013
- Subject:
- Psychology, Cognitive Neuroscience, Cognitive Psychology
This chapter reviews the effects of early deprivation of sight in one or both eyes. The discussions cover the effects of dark rearing; monocular deprivation; the critical period; amblyopia; and ...
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This chapter reviews the effects of early deprivation of sight in one or both eyes. The discussions cover the effects of dark rearing; monocular deprivation; the critical period; amblyopia; and amblyopia and stereopsis.Less
This chapter reviews the effects of early deprivation of sight in one or both eyes. The discussions cover the effects of dark rearing; monocular deprivation; the critical period; amblyopia; and amblyopia and stereopsis.
Ian P. Howard and Brian J. Rogers
- Published in print:
- 2008
- Published Online:
- May 2009
- ISBN:
- 9780195367607
- eISBN:
- 9780199867264
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195367607.003.0028
- Subject:
- Psychology, Cognitive Neuroscience, Cognitive Psychology
The processing of binocular disparity has temporal as well as spatial characteristics. This chapter discusses the question of how the visual system processes signals that arrive both at different ...
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The processing of binocular disparity has temporal as well as spatial characteristics. This chapter discusses the question of how the visual system processes signals that arrive both at different times and in different locations. Topics covered include the Pulfrich effect, visual-latency spatial-disparity hypothesis, temporal-disparities, effects of luminance and contrast, eye movements and the Pulfrich effect, dynamic visual noise Pulfrich effect, and clinical aspects of the Pulfrich effect.Less
The processing of binocular disparity has temporal as well as spatial characteristics. This chapter discusses the question of how the visual system processes signals that arrive both at different times and in different locations. Topics covered include the Pulfrich effect, visual-latency spatial-disparity hypothesis, temporal-disparities, effects of luminance and contrast, eye movements and the Pulfrich effect, dynamic visual noise Pulfrich effect, and clinical aspects of the Pulfrich effect.
Jan J. Koenderink
- Published in print:
- 2005
- Published Online:
- January 2012
- ISBN:
- 9780197262962
- eISBN:
- 9780191734533
- Item type:
- chapter
- Publisher:
- British Academy
- DOI:
- 10.5871/bacad/9780197262962.003.0011
- Subject:
- Archaeology, Archaeological Methodology and Techniques
When an observer is faced with a straight photograph, the observer can either look at the image or look into the photograph. This manner of observing photographs presents a difference that is ...
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When an observer is faced with a straight photograph, the observer can either look at the image or look into the photograph. This manner of observing photographs presents a difference that is crucial. In the former case, the observer is aware of the photograph as a physical object in a physical space while in the latter, the observer is aware of the pictorial object in a pictorial space. This chapter focuses on the current understanding of pictorial perception and the structure of pictorial space. Pictorial space is different from physical space in that it does not exist outside of the observer's awareness. It is a thread of consciousness and a purely mental object. In contrast, the photograph as a physical object is a mere planar sheet composed of pigments in a certain simultaneous order. The concepts of pictorial object and scene is not limited to the earlier existence of a physical space that figured casually in the present existence of the photograph. The theory of pictorial space is largely derived from psychophysical data. The measurement of it depends on the idiosyncratic movements of the mental eye. It is purely an ‘intentional entity’ that makes its elusive to physiological methods and susceptible to misconception.Less
When an observer is faced with a straight photograph, the observer can either look at the image or look into the photograph. This manner of observing photographs presents a difference that is crucial. In the former case, the observer is aware of the photograph as a physical object in a physical space while in the latter, the observer is aware of the pictorial object in a pictorial space. This chapter focuses on the current understanding of pictorial perception and the structure of pictorial space. Pictorial space is different from physical space in that it does not exist outside of the observer's awareness. It is a thread of consciousness and a purely mental object. In contrast, the photograph as a physical object is a mere planar sheet composed of pigments in a certain simultaneous order. The concepts of pictorial object and scene is not limited to the earlier existence of a physical space that figured casually in the present existence of the photograph. The theory of pictorial space is largely derived from psychophysical data. The measurement of it depends on the idiosyncratic movements of the mental eye. It is purely an ‘intentional entity’ that makes its elusive to physiological methods and susceptible to misconception.
Michael Land and Benjamin Tatler
- Published in print:
- 2009
- Published Online:
- March 2012
- ISBN:
- 9780198570943
- eISBN:
- 9780191693878
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198570943.001.0001
- Subject:
- Psychology, Cognitive Psychology
The cooperative action of different regions of human brains gives an amazing capacity to perform activities as diverse as playing the piano and hitting a tennis ball. Somehow, without conscious ...
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The cooperative action of different regions of human brains gives an amazing capacity to perform activities as diverse as playing the piano and hitting a tennis ball. Somehow, without conscious effort, eyes find the information that is needed to operate successfully in this world. The development of head-mounted eye trackers over recent years has made it possible to record where we look during different active tasks, and so work out what information the eyes supply to the brain systems that control limbs. The strategies that the eye movement system uses in the initiation and guidance of action are explored. This book examines a wide range of visually guided behaviour, from sedentary tasks like reading and drawing, to dynamic activities such as driving and playing cricket. A central theme is that the eye movement system has its own knowledge about where to find the most appropriate information for guiding action — information not usually available to conscious scrutiny. Thus, each type of action has its own specific repertoire of linked eye movements, acquired in parallel with the motor skills themselves. Starting with a brief background to eye movement studies, the book then reviews a range of observations and analyses of different activities. It ends with discussions of the nature of visual representation, the neurophysiology of the systems involved, and the roles of attention and learning.Less
The cooperative action of different regions of human brains gives an amazing capacity to perform activities as diverse as playing the piano and hitting a tennis ball. Somehow, without conscious effort, eyes find the information that is needed to operate successfully in this world. The development of head-mounted eye trackers over recent years has made it possible to record where we look during different active tasks, and so work out what information the eyes supply to the brain systems that control limbs. The strategies that the eye movement system uses in the initiation and guidance of action are explored. This book examines a wide range of visually guided behaviour, from sedentary tasks like reading and drawing, to dynamic activities such as driving and playing cricket. A central theme is that the eye movement system has its own knowledge about where to find the most appropriate information for guiding action — information not usually available to conscious scrutiny. Thus, each type of action has its own specific repertoire of linked eye movements, acquired in parallel with the motor skills themselves. Starting with a brief background to eye movement studies, the book then reviews a range of observations and analyses of different activities. It ends with discussions of the nature of visual representation, the neurophysiology of the systems involved, and the roles of attention and learning.
Ian P. Howard and Brian J. Rogers
- Published in print:
- 2008
- Published Online:
- May 2009
- ISBN:
- 9780195367607
- eISBN:
- 9780199867264
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195367607.003.0008
- Subject:
- Psychology, Cognitive Neuroscience, Cognitive Psychology
This chapter discusses the ways in which images into the eyes facilitate or suppress each other. Under certain circumstances, binocular images are perceived more readily and appear brighter than ...
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This chapter discusses the ways in which images into the eyes facilitate or suppress each other. Under certain circumstances, binocular images are perceived more readily and appear brighter than monocular images. Under other circumstances, superimposed, neighbouring, or successively presented binocular images engage in mutual suppression. The chapter also deals with interocular transfer. A visual phenomenon shows interocular transfer when an aftereffect generated by presenting a stimulus to one eye shows when only the other eye is open. The study of interocular transfer reveals how and, to some extent, where inputs from the two eyes are combined.Less
This chapter discusses the ways in which images into the eyes facilitate or suppress each other. Under certain circumstances, binocular images are perceived more readily and appear brighter than monocular images. Under other circumstances, superimposed, neighbouring, or successively presented binocular images engage in mutual suppression. The chapter also deals with interocular transfer. A visual phenomenon shows interocular transfer when an aftereffect generated by presenting a stimulus to one eye shows when only the other eye is open. The study of interocular transfer reveals how and, to some extent, where inputs from the two eyes are combined.
