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/9780198521921.003.0013
- Subject:
- Psychology, Cognitive Neuroscience
In a number of tests, D. B. reported an impression of ‘waves’ generated by some visual stimuli, especially in a ‘lively’ part of his field defect (a region between the fovea and about 30° in the ...
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In a number of tests, D. B. reported an impression of ‘waves’ generated by some visual stimuli, especially in a ‘lively’ part of his field defect (a region between the fovea and about 30° in the lower quadrant). The waves could have some ‘sort of form’, or could be ‘quick’, ‘slow’, ‘sharp’, or ‘curved’. When the waves were experienced they were difficult for him to ignore, but they could seriously mislead him when they were used as a basis for differential discriminations. Accordingly, special pains were taken to see whether good discrimination was still possible when conditions were arranged to eliminate the waves. This was done by increasing ambient illumination with bright overhead lamps or by using low contrast stimuli. The results showed that his discrimination was still excellent in a variety of situations, even though he reported ‘nothing there’, ‘absolutely nothing’, or ‘just guessing’. D. B. often seemed to settle into a sort of experience-less ‘blindsight mode’ when he performed well but automatically and without fatigue, in contrast to his good field when long series of discrimination tests produced tiredness.Less
In a number of tests, D. B. reported an impression of ‘waves’ generated by some visual stimuli, especially in a ‘lively’ part of his field defect (a region between the fovea and about 30° in the lower quadrant). The waves could have some ‘sort of form’, or could be ‘quick’, ‘slow’, ‘sharp’, or ‘curved’. When the waves were experienced they were difficult for him to ignore, but they could seriously mislead him when they were used as a basis for differential discriminations. Accordingly, special pains were taken to see whether good discrimination was still possible when conditions were arranged to eliminate the waves. This was done by increasing ambient illumination with bright overhead lamps or by using low contrast stimuli. The results showed that his discrimination was still excellent in a variety of situations, even though he reported ‘nothing there’, ‘absolutely nothing’, or ‘just guessing’. D. B. often seemed to settle into a sort of experience-less ‘blindsight mode’ when he performed well but automatically and without fatigue, in contrast to his good field when long series of discrimination tests produced tiredness.
F. Bermúdez-Rattoni, J. Bures, and T. Yamamoto
- Published in print:
- 1998
- Published Online:
- January 2008
- ISBN:
- 9780198523475
- eISBN:
- 9780191712678
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198523475.003.0009
- Subject:
- Psychology, Neuropsychology
The fact that the CTA triggering stimulus is sometimes forgotten resembles Șblindsightș, when a person with postgeniculate lesion denies being able to see anything, but avoids rapidly approaching ...
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The fact that the CTA triggering stimulus is sometimes forgotten resembles Șblindsightș, when a person with postgeniculate lesion denies being able to see anything, but avoids rapidly approaching objects. Similarly, protein synthesis is considered a prerequisite of learning but its blockade in the CS-US interval does not prevent CTA acquisition, and can even serve as US. CTA elicited by rewarding drugs can be due to a combination of their positive and aversive effects, but also because they precede a highly rewarding US. These possibilities are illustrated by the discovery of the c-fos antisense, the microinjection of which into amygdala several hours before CTA training impaired the taste aversion memory tested 3–5 days later. Attempts to replace the US by electrical taste (50 Hz, 0.1 ms anodal pulses) applied for 4h to the oral cavity elicited reliable CTA learning. CTA opened an important interaction between neurology and immunology by using cyclophosphamide (CPP) as the US in the CTA experiments.Less
The fact that the CTA triggering stimulus is sometimes forgotten resembles Șblindsightș, when a person with postgeniculate lesion denies being able to see anything, but avoids rapidly approaching objects. Similarly, protein synthesis is considered a prerequisite of learning but its blockade in the CS-US interval does not prevent CTA acquisition, and can even serve as US. CTA elicited by rewarding drugs can be due to a combination of their positive and aversive effects, but also because they precede a highly rewarding US. These possibilities are illustrated by the discovery of the c-fos antisense, the microinjection of which into amygdala several hours before CTA training impaired the taste aversion memory tested 3–5 days later. Attempts to replace the US by electrical taste (50 Hz, 0.1 ms anodal pulses) applied for 4h to the oral cavity elicited reliable CTA learning. CTA opened an important interaction between neurology and immunology by using cyclophosphamide (CPP) as the US in the CTA experiments.
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/9780198521921.003.0002
- Subject:
- Psychology, Cognitive Neuroscience
‘D. B.’ is the subject of the book who underwent intensive tests of his blindsight. His visual cortex in one hemisphere was removed surgically to excise an invasive tumour when he was 33 years old. ...
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‘D. B.’ is the subject of the book who underwent intensive tests of his blindsight. His visual cortex in one hemisphere was removed surgically to excise an invasive tumour when he was 33 years old. The findings of Pöppel et al. (1973) were confirmed, in which brain damaged subjects could move their eyes to the location of an ‘unseen’ stimulus in their blind fields. The use of animal testing methods were then applied by asking D. B. to guess the location of stimuli by reaching for them. He was also asked to guess between two alternatives: whether a line was horizontal or not, and whether a stimulus was a particular shape or an alternative shape. Asking him to guess whether a sine-wave grating or a homogenous luminous-matched patch was present or not made it possible to measure his visual acuity and compare it with that of the intact visual hemifield. Following a battery of tests, his verbal commentaries were recorded in which he characteristically said he was just guessing and thought he was ‘at chance’ because he could not see anything, although in some tests he had a ‘feeling’ that something was there.Less
‘D. B.’ is the subject of the book who underwent intensive tests of his blindsight. His visual cortex in one hemisphere was removed surgically to excise an invasive tumour when he was 33 years old. The findings of Pöppel et al. (1973) were confirmed, in which brain damaged subjects could move their eyes to the location of an ‘unseen’ stimulus in their blind fields. The use of animal testing methods were then applied by asking D. B. to guess the location of stimuli by reaching for them. He was also asked to guess between two alternatives: whether a line was horizontal or not, and whether a stimulus was a particular shape or an alternative shape. Asking him to guess whether a sine-wave grating or a homogenous luminous-matched patch was present or not made it possible to measure his visual acuity and compare it with that of the intact visual hemifield. Following a battery of tests, his verbal commentaries were recorded in which he characteristically said he was just guessing and thought he was ‘at chance’ because he could not see anything, although in some tests he had a ‘feeling’ that something was there.
John M. Findlay
- Published in print:
- 2003
- Published Online:
- January 2008
- ISBN:
- 9780198524793
- eISBN:
- 9780191711817
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198524793.003.0008
- Subject:
- Psychology, Cognitive Psychology
This chapter discusses a selected set of neuropsychological disorders and enquires whether analysis of eye movements can help explain the nature of the disorder. It argues that the study of such ...
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This chapter discusses a selected set of neuropsychological disorders and enquires whether analysis of eye movements can help explain the nature of the disorder. It argues that the study of such patients can in turn inform theories of vision and visual cognition. The chapter starts with a discussion of blindsight, visuo-spatial neglect, Balint's syndrome, and disorders that result from damage to the frontal lobe. The second half of the chapter concentrates on a single case, AI, who is not able to generate eye movements and so instead generates saccade-like movements of her head. The case is discussed as an example of peripheral neuropsychology, and the implications for the active vision framework are emphasized.Less
This chapter discusses a selected set of neuropsychological disorders and enquires whether analysis of eye movements can help explain the nature of the disorder. It argues that the study of such patients can in turn inform theories of vision and visual cognition. The chapter starts with a discussion of blindsight, visuo-spatial neglect, Balint's syndrome, and disorders that result from damage to the frontal lobe. The second half of the chapter concentrates on a single case, AI, who is not able to generate eye movements and so instead generates saccade-like movements of her head. The case is discussed as an example of peripheral neuropsychology, and the implications for the active vision framework are emphasized.
Bernard J. Baars
- Published in print:
- 1997
- Published Online:
- May 2009
- ISBN:
- 9780195102659
- eISBN:
- 9780199864126
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195102659.003.0004
- Subject:
- Neuroscience, Sensory and Motor Systems, Behavioral Neuroscience
This chapter argues that sensory consciousness gives us our most vivid moment-to-moment experiences. Mental images seem to be “faint copies” of sensory events, generated from within the brain itself. ...
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This chapter argues that sensory consciousness gives us our most vivid moment-to-moment experiences. Mental images seem to be “faint copies” of sensory events, generated from within the brain itself. As far as the brain is concerned, sensations and images belong together. Abstract ideas, on the other hand, allow us to transcend the limitations of the perceptual world in time and space, to enter the many realms of abstraction. The parts of the human cortex that support abstract thinking seem relatively recent on an evolutionary scale, and may ride on the older functioning of sensory cortex. In language, in interpreting other people, in music and art, we often combine the sensory and the abstract into a single, seamless flow of experience.Less
This chapter argues that sensory consciousness gives us our most vivid moment-to-moment experiences. Mental images seem to be “faint copies” of sensory events, generated from within the brain itself. As far as the brain is concerned, sensations and images belong together. Abstract ideas, on the other hand, allow us to transcend the limitations of the perceptual world in time and space, to enter the many realms of abstraction. The parts of the human cortex that support abstract thinking seem relatively recent on an evolutionary scale, and may ride on the older functioning of sensory cortex. In language, in interpreting other people, in music and art, we often combine the sensory and the abstract into a single, seamless flow of experience.
Charles Siewert
- Published in print:
- 2010
- Published Online:
- September 2010
- ISBN:
- 9780199556182
- eISBN:
- 9780191721014
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199556182.003.0003
- Subject:
- Philosophy, Philosophy of Mind, Metaphysics/Epistemology
This chapter takes as its target ‘ambitious physicalism’: an approach that aims to provide an explanatory reduction of consciousness to a physical and functional base. The chapter uses a range of ...
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This chapter takes as its target ‘ambitious physicalism’: an approach that aims to provide an explanatory reduction of consciousness to a physical and functional base. The chapter uses a range of cases involving the phenomenon of ‘blindsight’ to argue for the reality of phenomenal appearances of such a kind that cannot be accounted for by the standard physicalist theories, whether eliminativist, functionalist, or representationalist. It argues that the physicalist faces a dilemma: either denying the reality of phenomenal appearances by trying to identify those appearances with something manifest and describable in non-phenomenal terms, or facing an unavoidable arbitrariness in deciding which hidden features should be assigned metaphysically necessary and constitutive status with respect to conscious phenomena. The chapter argues that the cost of abandoning ambitious, reductive physicalism is not high, since we can still study the systematic relations between phenomenal appearances and physical conditions. The persistent failure to find an ultimate explanation of the real ‘nature’ of consciousness does not threaten the explanatory completeness of science.Less
This chapter takes as its target ‘ambitious physicalism’: an approach that aims to provide an explanatory reduction of consciousness to a physical and functional base. The chapter uses a range of cases involving the phenomenon of ‘blindsight’ to argue for the reality of phenomenal appearances of such a kind that cannot be accounted for by the standard physicalist theories, whether eliminativist, functionalist, or representationalist. It argues that the physicalist faces a dilemma: either denying the reality of phenomenal appearances by trying to identify those appearances with something manifest and describable in non-phenomenal terms, or facing an unavoidable arbitrariness in deciding which hidden features should be assigned metaphysically necessary and constitutive status with respect to conscious phenomena. The chapter argues that the cost of abandoning ambitious, reductive physicalism is not high, since we can still study the systematic relations between phenomenal appearances and physical conditions. The persistent failure to find an ultimate explanation of the real ‘nature’ of consciousness does not threaten the explanatory completeness of science.
Robert Kirk
- Published in print:
- 2005
- Published Online:
- February 2006
- ISBN:
- 9780199285488
- eISBN:
- 9780191603150
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/0199285489.003.0010
- Subject:
- Philosophy, Philosophy of Mind
Any system with the basic package is a decider; any decider with directly active perceptual information has the ‘basic package-plus’ and is a ‘decider-plus’. This chapter argues that being a ...
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Any system with the basic package is a decider; any decider with directly active perceptual information has the ‘basic package-plus’ and is a ‘decider-plus’. This chapter argues that being a decider-plus is logically sufficient for perceptual consciousness. First, on the provisional assumption that the basic package-plus includes all the purely functional conditions necessary for perceptual-phenomenal consciousness, the sole-pictures argument of Chapter 4 is extended to cover any decider-plus, not just zombies; then that assumption is defended. No merely natural or nomological or brute necessity has to be invoked. Among numerous likely objections discussed are those relating to blindsight; automatism; the usual objections to functionalist accounts of consciousness; the ‘explanatory gap’; and Carruthers’s critique of rival accounts to his own.Less
Any system with the basic package is a decider; any decider with directly active perceptual information has the ‘basic package-plus’ and is a ‘decider-plus’. This chapter argues that being a decider-plus is logically sufficient for perceptual consciousness. First, on the provisional assumption that the basic package-plus includes all the purely functional conditions necessary for perceptual-phenomenal consciousness, the sole-pictures argument of Chapter 4 is extended to cover any decider-plus, not just zombies; then that assumption is defended. No merely natural or nomological or brute necessity has to be invoked. Among numerous likely objections discussed are those relating to blindsight; automatism; the usual objections to functionalist accounts of consciousness; the ‘explanatory gap’; and Carruthers’s critique of rival accounts to his own.
Mohan Matthen
- Published in print:
- 2005
- Published Online:
- April 2005
- ISBN:
- 9780199268504
- eISBN:
- 9780191602283
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/0199268509.003.0002
- Subject:
- Philosophy, Philosophy of Mind
Sensory systems are automatic sorting machines which assign external sensed objects (distal stimuli) to classes on the basis of useful commonalities found in them. The results of a system=s sorting ...
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Sensory systems are automatic sorting machines which assign external sensed objects (distal stimuli) to classes on the basis of useful commonalities found in them. The results of a system=s sorting activities are made available to the perceiver in the form of a sensation, which can be held in memory or later recalled. Appearance thus follows classification as the record thereof. It follows (a) that sensory qualities are prior to experience and hence cannot be defined in terms of it, and (b) that all variations in the appearance of the stimulus are representationally significant (but not that all phenomenal variation is representationally significant).Less
Sensory systems are automatic sorting machines which assign external sensed objects (distal stimuli) to classes on the basis of useful commonalities found in them. The results of a system=s sorting activities are made available to the perceiver in the form of a sensation, which can be held in memory or later recalled. Appearance thus follows classification as the record thereof. It follows (a) that sensory qualities are prior to experience and hence cannot be defined in terms of it, and (b) that all variations in the appearance of the stimulus are representationally significant (but not that all phenomenal variation is representationally significant).
Gerry Canavan
- Published in print:
- 2016
- Published Online:
- April 2017
- ISBN:
- 9780252040665
- eISBN:
- 9780252099106
- Item type:
- book
- Publisher:
- University of Illinois Press
- DOI:
- 10.5406/illinois/9780252040665.001.0001
- Subject:
- Literature, 20th-century and Contemporary Literature
“I began writing about power because I had so little,” Octavia E. Butler once said. Butler's life as an African American woman—an alien in American society and among science fiction writers—informed ...
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“I began writing about power because I had so little,” Octavia E. Butler once said. Butler's life as an African American woman—an alien in American society and among science fiction writers—informed the powerful works that earned her an ardent readership and acclaim both inside and outside science fiction. This book offers a critical and holistic consideration of Butler's career. Drawing on Butler's personal papers, the book tracks the false starts, abandoned drafts, tireless rewrites, and real-life obstacles that fed Butler's frustrations and launched her triumphs. The book departs from other studies to approach Butler first and foremost as a science fiction writer working within, responding to, and reacting against the genre's particular canon. The result is an illuminating study of how an essential SF figure shaped themes, unconventional ideas, and an unflagging creative urge into brilliant works of fiction that include novels and short stories, including the early Patternist series, Kindred, Blindsight, Clay's Ark, the Xenogenesis and Parables series, and Fledgling.Less
“I began writing about power because I had so little,” Octavia E. Butler once said. Butler's life as an African American woman—an alien in American society and among science fiction writers—informed the powerful works that earned her an ardent readership and acclaim both inside and outside science fiction. This book offers a critical and holistic consideration of Butler's career. Drawing on Butler's personal papers, the book tracks the false starts, abandoned drafts, tireless rewrites, and real-life obstacles that fed Butler's frustrations and launched her triumphs. The book departs from other studies to approach Butler first and foremost as a science fiction writer working within, responding to, and reacting against the genre's particular canon. The result is an illuminating study of how an essential SF figure shaped themes, unconventional ideas, and an unflagging creative urge into brilliant works of fiction that include novels and short stories, including the early Patternist series, Kindred, Blindsight, Clay's Ark, the Xenogenesis and Parables series, and Fledgling.
Brian O'Shaughnessy
- Published in print:
- 2003
- Published Online:
- November 2003
- ISBN:
- 9780199256723
- eISBN:
- 9780191598135
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/0199256721.003.0016
- Subject:
- Philosophy, Philosophy of Mind
Does ‘blindsight’ show that seeing is only inessentially an experience? The data is examined, and difficulties raised. Why always low‐key examples? How do we know it is not a borderline example of ...
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Does ‘blindsight’ show that seeing is only inessentially an experience? The data is examined, and difficulties raised. Why always low‐key examples? How do we know it is not a borderline example of seeing (since they are theoretically guaranteed)? The argument pro the view that seeing occurs and experience does not is examined. The likelihood of these twin possibilities is counterbalanced against alternative interpretations of the data, and on the whole found wanting. But assuming that they are both realized, what theoretical account of seeing is open to one? That it is a cerebral phenomenon endowed with suitable input and output causal properties? But is this a statement of real essence? If so, it is not a viable theory. Presumably, it is a functionalist statement of nominal essence. However, while seeing has necessary origin properties, the cognitive effects of seeing are inessential. Then why believe that ‘seeing’ names any phenomenon at all? And why neglect its actual experiential function? The conclusion is that the experiential status of seeing is part of its essence, and that the standard interpretation of ‘blindsight’ is tantamount to jettisoning the very concept.Less
Does ‘blindsight’ show that seeing is only inessentially an experience? The data is examined, and difficulties raised. Why always low‐key examples? How do we know it is not a borderline example of seeing (since they are theoretically guaranteed)? The argument pro the view that seeing occurs and experience does not is examined. The likelihood of these twin possibilities is counterbalanced against alternative interpretations of the data, and on the whole found wanting. But assuming that they are both realized, what theoretical account of seeing is open to one? That it is a cerebral phenomenon endowed with suitable input and output causal properties? But is this a statement of real essence? If so, it is not a viable theory. Presumably, it is a functionalist statement of nominal essence. However, while seeing has necessary origin properties, the cognitive effects of seeing are inessential. Then why believe that ‘seeing’ names any phenomenon at all? And why neglect its actual experiential function? The conclusion is that the experiential status of seeing is part of its essence, and that the standard interpretation of ‘blindsight’ is tantamount to jettisoning the very concept.
Melvyn Goodale and David Milner
- Published in print:
- 2013
- Published Online:
- May 2013
- ISBN:
- 9780199596966
- eISBN:
- 9780191753008
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199596966.003.0006
- Subject:
- Psychology, Cognitive Psychology, Vision
In this chapter, recent fMRI studies of activity in the ventral and dorsal streams of Dee Fletcher and other individuals with visual deficits are discussed. The results of neuroimaging studies of ...
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In this chapter, recent fMRI studies of activity in the ventral and dorsal streams of Dee Fletcher and other individuals with visual deficits are discussed. The results of neuroimaging studies of visual form agnosia, optic ataxia, and other disorders converge nicely with the earlier behavioural work discussed earlier chapters. We learn about ‘blindsight’, spared visual abilities in patients with large lesions of primary visual cortex.Less
In this chapter, recent fMRI studies of activity in the ventral and dorsal streams of Dee Fletcher and other individuals with visual deficits are discussed. The results of neuroimaging studies of visual form agnosia, optic ataxia, and other disorders converge nicely with the earlier behavioural work discussed earlier chapters. We learn about ‘blindsight’, spared visual abilities in patients with large lesions of primary visual cortex.
Naomi Eilan
- Published in print:
- 2011
- Published Online:
- September 2011
- ISBN:
- 9780199692040
- eISBN:
- 9780191729713
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199692040.003.0004
- Subject:
- Philosophy, Metaphysics/Epistemology, Philosophy of Mind
Contra sense datum theories, most philosophers hold that perceptions have immediate ‘objective import'. How should the possession by a perception of such import be explained? The paper suggests that ...
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Contra sense datum theories, most philosophers hold that perceptions have immediate ‘objective import'. How should the possession by a perception of such import be explained? The paper suggests that two important dimensions along which accounts of perceptual objectivity divide turn on answers to the following questions. (1) The Division of Labour Question: should the full content of our commonsense realism about the world we perceive be thought of as part of the actual content of perception itself or something the theorist of perception assumes? (2) The Consciousness Question: is it possible to derive explanations of the objectivity of conscious perceptions from an account of the objectivity possessed by non-conscious perceptions? The paper argues that a relational theory of perceptual consciousness delivers a negative answer (with Burge and contra Strawson) to the first, and a negative answer(with Strawson and contra Burge) to the second, exploiting the key insights in each of these philosophers approaches.Less
Contra sense datum theories, most philosophers hold that perceptions have immediate ‘objective import'. How should the possession by a perception of such import be explained? The paper suggests that two important dimensions along which accounts of perceptual objectivity divide turn on answers to the following questions. (1) The Division of Labour Question: should the full content of our commonsense realism about the world we perceive be thought of as part of the actual content of perception itself or something the theorist of perception assumes? (2) The Consciousness Question: is it possible to derive explanations of the objectivity of conscious perceptions from an account of the objectivity possessed by non-conscious perceptions? The paper argues that a relational theory of perceptual consciousness delivers a negative answer (with Burge and contra Strawson) to the first, and a negative answer(with Strawson and contra Burge) to the second, exploiting the key insights in each of these philosophers approaches.
Danielle Spencer
- Published in print:
- 2020
- Published Online:
- December 2020
- ISBN:
- 9780197510766
- eISBN:
- 9780197510797
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780197510766.001.0001
- Subject:
- Psychology, Cognitive Psychology
This book identifies and names the phenomenon of metagnosis: the experience of newly learning in adulthood of a long-standing condition. It can occur when the condition has remained undetected (e.g., ...
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This book identifies and names the phenomenon of metagnosis: the experience of newly learning in adulthood of a long-standing condition. It can occur when the condition has remained undetected (e.g., colorblindness) and/or when the diagnostic categories themselves have shifted (e.g., ADHD). More broadly, it can occur with unexpected revelations bearing upon selfhood, such as surprising genetic test results. This phenomenon has received relatively scant attention, yet learning of an unknown condition is frequently a significant and bewildering revelation, subverting narrative expectations and customary categories. In addressing the topic this book deploys an evolution of narrative medicine as a robust research methodology comprising interdisciplinarity, narrative attentiveness, and creating a writerly text. Beginning with the author’s own experience of metagnosis, it explores the issues it raises—from communicability to narrative intelligibility to different ways of seeing. Next, it traces the distinctive metagnostic narrative arc through the stages of recognition, subversion, and renegotiation, discussing this trajectory in light of a range of metagnostic experiences, from Blade Runner to real-world midlife diagnoses. Finally, it situates metagnosis in relation to genetic revelations and the broader discourses concerning identity. Proposing that the figure of blindsight—drawn from the author’s metagnostic experience—offers a productive model for negotiating such revelations, the book suggests that better understanding metagnosis will not simply aid those directly affected but will also serve as a bellwether for how we will all navigate advancing biomedical and genomic knowledge, and how we may fruitfully interrogate the very notion of identity.Less
This book identifies and names the phenomenon of metagnosis: the experience of newly learning in adulthood of a long-standing condition. It can occur when the condition has remained undetected (e.g., colorblindness) and/or when the diagnostic categories themselves have shifted (e.g., ADHD). More broadly, it can occur with unexpected revelations bearing upon selfhood, such as surprising genetic test results. This phenomenon has received relatively scant attention, yet learning of an unknown condition is frequently a significant and bewildering revelation, subverting narrative expectations and customary categories. In addressing the topic this book deploys an evolution of narrative medicine as a robust research methodology comprising interdisciplinarity, narrative attentiveness, and creating a writerly text. Beginning with the author’s own experience of metagnosis, it explores the issues it raises—from communicability to narrative intelligibility to different ways of seeing. Next, it traces the distinctive metagnostic narrative arc through the stages of recognition, subversion, and renegotiation, discussing this trajectory in light of a range of metagnostic experiences, from Blade Runner to real-world midlife diagnoses. Finally, it situates metagnosis in relation to genetic revelations and the broader discourses concerning identity. Proposing that the figure of blindsight—drawn from the author’s metagnostic experience—offers a productive model for negotiating such revelations, the book suggests that better understanding metagnosis will not simply aid those directly affected but will also serve as a bellwether for how we will all navigate advancing biomedical and genomic knowledge, and how we may fruitfully interrogate the very notion of identity.
L. Weiskrantz
- Published in print:
- 2003
- Published Online:
- March 2012
- ISBN:
- 9780198505822
- eISBN:
- 9780191686900
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198505822.003.0009
- Subject:
- Psychology, Neuropsychology
This chapter shows that blindsight illustrates that at least a limited analysis of visual signals continues in some patients even in those parts of their visual field for which they are subjectively ...
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This chapter shows that blindsight illustrates that at least a limited analysis of visual signals continues in some patients even in those parts of their visual field for which they are subjectively blind. It begins by presenting categories of residual visual capacities. There are two general approaches to indirect methods of testing for residual visual function that allow an inference without requiring the subject to guess ‘without seeing’: (1) reflexes to visual stimuli in the blind hemifield; (2) interactions between the intact and impaired hemifields. There can be no doubt that parallel extrastriate visual pathways can mediate visual discriminations, in humans as well as in other primates, but it is the dissociations that emerge, suggesting a segregation of functions, that we are only beginning to characterize.Less
This chapter shows that blindsight illustrates that at least a limited analysis of visual signals continues in some patients even in those parts of their visual field for which they are subjectively blind. It begins by presenting categories of residual visual capacities. There are two general approaches to indirect methods of testing for residual visual function that allow an inference without requiring the subject to guess ‘without seeing’: (1) reflexes to visual stimuli in the blind hemifield; (2) interactions between the intact and impaired hemifields. There can be no doubt that parallel extrastriate visual pathways can mediate visual discriminations, in humans as well as in other primates, but it is the dissociations that emerge, suggesting a segregation of functions, that we are only beginning to characterize.
Lawrence Weiskrantz
- Published in print:
- 1999
- Published Online:
- March 2012
- ISBN:
- 9780198524588
- eISBN:
- 9780191689222
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198524588.003.0002
- Subject:
- Psychology, Cognitive Psychology
Typically, those types of damages which cause serious loss of mental and physical capacities are what most people associate with brain damage. Surprisingly, in virtually all of the major cognitive ...
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Typically, those types of damages which cause serious loss of mental and physical capacities are what most people associate with brain damage. Surprisingly, in virtually all of the major cognitive categories that are disturbed by brain damage, there can be remarkably preserved functioning – without the patients themselves being aware of this. Examples of this ‘performance without awareness’ is the severe themory disorder known as amnesic syndrome and the phenomenon of blindsight, in which patients can make visual discriminations even though they are ‘blind’ as a result of damage to the visual cortex of the brain. This chapter attempts to give an indication of the type of evidence that exists for residual, so-called implicit, processing. The chapter concentrates on amnesia and blindsight. The chapter focuses on neural pathways and visual attributes on the former and the nature of the psychological disorder and patients’ commentaries on the latter.Less
Typically, those types of damages which cause serious loss of mental and physical capacities are what most people associate with brain damage. Surprisingly, in virtually all of the major cognitive categories that are disturbed by brain damage, there can be remarkably preserved functioning – without the patients themselves being aware of this. Examples of this ‘performance without awareness’ is the severe themory disorder known as amnesic syndrome and the phenomenon of blindsight, in which patients can make visual discriminations even though they are ‘blind’ as a result of damage to the visual cortex of the brain. This chapter attempts to give an indication of the type of evidence that exists for residual, so-called implicit, processing. The chapter concentrates on amnesia and blindsight. The chapter focuses on neural pathways and visual attributes on the former and the nature of the psychological disorder and patients’ commentaries on the latter.
Lawrence Weiskrantz
- Published in print:
- 1999
- Published Online:
- March 2012
- ISBN:
- 9780198524588
- eISBN:
- 9780191689222
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198524588.003.0003
- Subject:
- Psychology, Cognitive Psychology
Disentangling deficits by dissociations, and the constructing of hypotheses about independence and hierarchical structure, is the very meat of day-to-day neuropsychological analysis and theorizing. ...
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Disentangling deficits by dissociations, and the constructing of hypotheses about independence and hierarchical structure, is the very meat of day-to-day neuropsychological analysis and theorizing. This chapter examines its importance in revealing aspects of mental structure that may not be easily seen in normal function. Further, the chapter explores how the various examples: blindsight, agnosia, aphasia, and neglect, are not only doubly dissociable but multiply dissociable and how each can occur as separate, isolated deficits that may demand theoretical speculation within its own domain.Less
Disentangling deficits by dissociations, and the constructing of hypotheses about independence and hierarchical structure, is the very meat of day-to-day neuropsychological analysis and theorizing. This chapter examines its importance in revealing aspects of mental structure that may not be easily seen in normal function. Further, the chapter explores how the various examples: blindsight, agnosia, aphasia, and neglect, are not only doubly dissociable but multiply dissociable and how each can occur as separate, isolated deficits that may demand theoretical speculation within its own domain.
Lawrence Weiskrantz
- Published in print:
- 2000
- Published Online:
- March 2012
- ISBN:
- 9780198524823
- eISBN:
- 9780191689246
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198524823.003.0021
- Subject:
- Psychology, Cognitive Psychology
This chapter is concerned with the most advanced state of cognition, consciousness. It reviews some of the classic studies of performance without awareness. For instance, it is now a well-known ...
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This chapter is concerned with the most advanced state of cognition, consciousness. It reviews some of the classic studies of performance without awareness. For instance, it is now a well-known phenomenon in amnesic patients that they can often perform certain tasks very well, but they have no recollection of ever having done the task. By presenting part of the training stimuli, the performance of amnesic patients in recognition tasks can be improved markedly, a phenomenon which is now known as ‘priming’. The chapter describes a phenomenon was discovered which this chapter terms ‘blindsight’, where patients with extensive damage to their visual cortex nevertheless are able to respond to stimuli in their blind fields. Interestingly, a similar phenomenon has been found in monkeys with lesions to the striate cortex. This chapter discusses the implications of these and related phenomena for the understanding of consciousness.Less
This chapter is concerned with the most advanced state of cognition, consciousness. It reviews some of the classic studies of performance without awareness. For instance, it is now a well-known phenomenon in amnesic patients that they can often perform certain tasks very well, but they have no recollection of ever having done the task. By presenting part of the training stimuli, the performance of amnesic patients in recognition tasks can be improved markedly, a phenomenon which is now known as ‘priming’. The chapter describes a phenomenon was discovered which this chapter terms ‘blindsight’, where patients with extensive damage to their visual cortex nevertheless are able to respond to stimuli in their blind fields. Interestingly, a similar phenomenon has been found in monkeys with lesions to the striate cortex. This chapter discusses the implications of these and related phenomena for the understanding of consciousness.
A. David Milner and Melvyn A. Goodale
- Published in print:
- 2006
- Published Online:
- March 2012
- ISBN:
- 9780198524724
- eISBN:
- 9780191689239
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198524724.003.0003
- Subject:
- Psychology, Cognitive Psychology
Damage to the primary visual cortex can cause a profound loss of awareness of the visible world. However, surviving pathways appear to provide sufficient visual information to allow the brain to ...
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Damage to the primary visual cortex can cause a profound loss of awareness of the visible world. However, surviving pathways appear to provide sufficient visual information to allow the brain to mediate a range of visual tasks in the absence of such awareness. In this chapter, the authors discuss how ‘blindsight’ should not be characterized as ‘unconscious perception’. Instead, it should be more correctly seen as a collection of residual visuomotor responses that may depend on a variety of relatively independent circuits in the superion colliculus and dorsal stream. Further, this chapter contends that ‘blindsight’ only becomes paradoxical if one regards vision as a unitary process. If it is accepted that the mechanisms capable of providing perceptual experience are separate from those underlying the visual control of action, the paradox disappears.Less
Damage to the primary visual cortex can cause a profound loss of awareness of the visible world. However, surviving pathways appear to provide sufficient visual information to allow the brain to mediate a range of visual tasks in the absence of such awareness. In this chapter, the authors discuss how ‘blindsight’ should not be characterized as ‘unconscious perception’. Instead, it should be more correctly seen as a collection of residual visuomotor responses that may depend on a variety of relatively independent circuits in the superion colliculus and dorsal stream. Further, this chapter contends that ‘blindsight’ only becomes paradoxical if one regards vision as a unitary process. If it is accepted that the mechanisms capable of providing perceptual experience are separate from those underlying the visual control of action, the paradox disappears.
Lawrence Weiskrantz
- Published in print:
- 2008
- Published Online:
- March 2012
- ISBN:
- 9780199233151
- eISBN:
- 9780191696596
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199233151.003.0012
- Subject:
- Psychology, Cognitive Psychology
This chapter discusses some examples of neuropsychological defects in which awareness is disconnected from a capacity to discriminate or to remember or to attend or to read or to speak. Some of these ...
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This chapter discusses some examples of neuropsychological defects in which awareness is disconnected from a capacity to discriminate or to remember or to attend or to read or to speak. Some of these are prosopagnosia, acquired dyslexia, aphasia, split-brain, and blindsight.Less
This chapter discusses some examples of neuropsychological defects in which awareness is disconnected from a capacity to discriminate or to remember or to attend or to read or to speak. Some of these are prosopagnosia, acquired dyslexia, aphasia, split-brain, and blindsight.
Robert Audi
- Published in print:
- 2020
- Published Online:
- April 2020
- ISBN:
- 9780197503508
- eISBN:
- 9780197503539
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780197503508.003.0001
- Subject:
- Philosophy, Metaphysics/Epistemology
This chapter shows how perception is experiential, relational, and representational: in broad terms, a phenomenally representational, discriminative, non-deviant causal relation to an object. In ...
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This chapter shows how perception is experiential, relational, and representational: in broad terms, a phenomenally representational, discriminative, non-deviant causal relation to an object. In seeing, we have visual experience; in visual experience that is perceptual and not merely sensory, as in hallucinations, some object is visually represented as having certain properties; and genuinely seeing an object entails that it exists. This view of perception is a version of realism. It is realistic about both the objects of perception and the phenomenal properties we instantiate in perceptual experience. The view leaves open, however, the ultimate ontological status of those objects and properties. The properties, however, must be understood to have a character that enables us both to experience what, phenomenologically, it is like to see and what, externally, the things seen are like physically.Less
This chapter shows how perception is experiential, relational, and representational: in broad terms, a phenomenally representational, discriminative, non-deviant causal relation to an object. In seeing, we have visual experience; in visual experience that is perceptual and not merely sensory, as in hallucinations, some object is visually represented as having certain properties; and genuinely seeing an object entails that it exists. This view of perception is a version of realism. It is realistic about both the objects of perception and the phenomenal properties we instantiate in perceptual experience. The view leaves open, however, the ultimate ontological status of those objects and properties. The properties, however, must be understood to have a character that enables us both to experience what, phenomenologically, it is like to see and what, externally, the things seen are like physically.