-
Paul Kay.
MIT Encyclopedia of the cognitives sciences,
chapter Color categorization.
1999.
Keywords: color,
categorization.
| Abstract: Lexical color categorization consists in the division of the colorsensations into classes corresponding to the significata of the color words of a particular language. Perceptual color categorization consists in the division ofthe color sensations into classes by the perceptual processes of an organism - human or non-human, adult or neonate, possessed of knowledge of alanguage or not so possessed. Conflict among views on the relation of lexical to perceptual color categorization has prevailed for over a century.Nineteenth century classicists, anthropologists and opthalmologists were aware that all languages do not reflect identical lexical classifications of color.Some, such as the classicist (and statesman) William Gladstone, concluded that differences in color lexicons reflect differences in perceptual abilities, e.g.,"... that the organ of color and its impressions were but partially developed among the Greeks of the heroic age" (see Berlin and Kay 1969 [B&K]: 135).Others, like the opthalmologist Hugo Magnus, recognized that failure to distinguish colors lexically need not indicate inability to distinguish themperceptually (see B&K: 144f). These and other late nineteenth century scholars tended strongly to view differences in color lexicons in evolutionaryterms. |
@InBook{kay_99,
author = {Kay, Paul},
editor = {Wilson, A. and Keil, Frank C.},
title = {MIT Encyclopedia of the cognitives sciences},
chapter = {Color categorization},
publisher = {},
year = {1999},
url = {http://www.icsi.berkeley.edu/~kay/color.categorization.ps},
rating = {C},
keywords = {color, categorization},
abstract = {Lexical color categorization consists in the division of the colorsensations into classes corresponding to the significata of the color words of a particular language. Perceptual color categorization consists in the division ofthe color sensations into classes by the perceptual processes of an organism - human or non-human, adult or neonate, possessed of knowledge of alanguage or not so possessed. Conflict among views on the relation of lexical to perceptual color categorization has prevailed for over a century.Nineteenth century classicists, anthropologists and opthalmologists were aware that all languages do not reflect identical lexical classifications of color.Some, such as the classicist (and statesman) William Gladstone, concluded that differences in color lexicons reflect differences in perceptual abilities, e.g.,"... that the organ of color and its impressions were but partially developed among the Greeks of the heroic age" (see Berlin and Kay 1969 [B&K]: 135).Others, like the opthalmologist Hugo Magnus, recognized that failure to distinguish colors lexically need not indicate inability to distinguish themperceptually (see B&K: 144f). These and other late nineteenth century scholars tended strongly to view differences in color lexicons in evolutionaryterms.}
}
-
Laurence T. Maloney.
Color Vision: From Genes to Perception,
chapter Physics-based approaches to modeling surface color perception.
Cambridge University Press,
1999.
Keywords: color constancy.
| Abstract: Surface Color Perception. The study of surface color perception is a proper subset of the study of color perception, and one way to highlight the difference between them is to consider the effective stimulus appropriate to each. The effective stimulus for the study of color perception, broadly construed, is the spectral power distribution of light arriving at each point of the left and right retinas. There is no assumption that the patterns of light correspond to any possible arrangement of surfaces, objects and illuminants in a three-dimensional scene. In contrast, the study of surface color perception presupposes that the light reaching the retinas has a history. The effective stimulus is the result of the interaction of certain light sources (the illuminant) with the surfaces of objects in an environment. It is clear that any stimulus appropriate for the study of surface color perception is also appropriate for the study of color perception but not vice versa. |
| Comments: Excellente review synthétique des différentes approches sur le problème de la constance des couleurs |
@InBook{malo_99,
author = {Maloney, Laurence T.},
editor = {Gegenfurtner, K. R., & Sharpe, L. T.},
title = {Color Vision: From Genes to Perception},
chapter = {Physics-based approaches to modeling surface color perception},
publisher = {Cambridge University Press},
year = {1999},
abstract = {Surface Color Perception. The study of surface color perception is a proper subset of the study of color perception, and one way to highlight the difference between them is to consider the effective stimulus appropriate to each. The effective stimulus for the study of color perception, broadly construed, is the spectral power distribution of light arriving at each point of the left and right retinas. There is no assumption that the patterns of light correspond to any possible arrangement of surfaces, objects and illuminants in a three-dimensional scene. In contrast, the study of surface color perception presupposes that the light reaching the retinas has a history. The effective stimulus is the result of the interaction of certain light sources (the illuminant) with the surfaces of objects in an environment. It is clear that any stimulus appropriate for the study of surface color perception is also appropriate for the study of color perception but not vice versa.},
comments = {Excellente review synthétique des différentes approches sur le problème de la constance des couleurs},
url = {http://www.psych.nyu.edu/maloney/MaloneyColorCambridgeUP1999.pdf},
keywords = {color constancy},
rating = {B}
}
-
L. T. Sharpe,
A. Stockman,
H. Jägle,
and J. Nathans.
Color vision: from genes to perception,
chapter Opsin genes, cone photopigments, color vision and colorblindness,
pages 3-50.
Cambridge: Cambridge University Press,
1999.
Keywords: color,
photopigment,
genetics,
vision.
| Comments: Une bonne présentation des méchanismes molécularies à la base de la vision |
@InBook{shar_99,
author = {Sharpe, L. T. and Stockman, A. and Jägle, H. and Nathans, J.},
editor = {K. Gegenfurtner & L. T. Sharpe},
title = {Color vision: from genes to perception},
chapter = {Opsin genes, cone photopigments, color vision and colorblindness},
publisher = {Cambridge: Cambridge University Press},
year = {1999},
pages = {3-50},
rating = {C},
comments = {Une bonne présentation des méchanismes molécularies à la base de la vision},
keywords = {color, photopigment, genetics, vision},
url = {http://www.allpsych.uni-giessen.de/karl/colbook/sharpe.pdf}
}
-
Shun-Ichi Amari.
Natural Gradient Learning for Over- and Under-Complete Bases in ICA.
Neural Computation,
1999.
Keywords: ICA,
statistics,
neural networks.
| Abstract: Independent component analysis or blind source separation is a new technique of extracting independent signals from mixtures. It is applicable even when the number of independent sources is unknown and is larger or smaller than the number of observed mixture signals. This article extends the natural gradient learning algorithm to be applicable to these overcomplete and undercomplete cases. Here, the observed signals are assumed to be whitened by preprocessing, so that we use the natural Riemannian gradient in Stiefel manifolds. |
| Comments: Expression of the metric associated with the set of rectangular orthogonal matrices, aka the Stiefel manifold, and thus derivation of the natural gradient related to it. |
@Article{amar_99,
author = {Amari, Shun-Ichi},
title = {Natural Gradient Learning for Over- and Under-Complete Bases in ICA},
journal = {Neural Computation},
year = {1999},
Abstract = {Independent component analysis or blind source separation is a new technique of extracting independent signals from mixtures. It is applicable even when the number of independent sources is unknown and is larger or smaller than the number of observed mixture signals. This article extends the natural gradient learning algorithm to be applicable to these overcomplete and undercomplete cases. Here, the observed signals are assumed to be whitened by preprocessing, so that we use the natural Riemannian gradient in Stiefel manifolds.},
comments = {Expression of the metric associated with the set of rectangular orthogonal matrices, aka the Stiefel manifold, and thus derivation of the natural gradient related to it.},
url = {http://gs37.sp.cs.cmu.edu/papers/files/amari-99.pdf},
rating = {B},
keywords = {ICA, statistics, neural networks}
}
-
Lawrence W. Barsalou.
Perceptual symbols systems.
Behavioral and brain sciences,
22:577-660,
1999.
Keywords: objects,
sensorimotor,
cognition.
| Abstract: Prior to the twentieth century, theories of knowledge were inherently perceptual. Since then, developments in logic, statistics, and programming languages have inspired amodal theories that rest on principles fundamentally different from those underlying perception. In addition, perceptual approaches have become widely viewed as untenable, because they are assumed to implement recording systems, not conceptual systems. A perceptual theory of knowledge is developed here in the contexts of current cognitive science and neuroscience. During perceptual experience, association areas in the brain capture bottom-up patterns of activation in sensory-motor areas. Later, in a top-down manner, association areas partially reactivate sensory-motor areas to implement perceptual symbols. The storage and reactivation of perceptual symbols operates at the level of perceptual components--not at the level of holistic perceptual experiences. Through the use of selective attention, schematic representations of perceptual components are extracted from experience and stored in memory (e.g., individual memories of green, purr, hot). As memories of the same component become organized around a common frame, they implement a simulator that produces limitless simulations of the component (e.g., simulations of purr). Not only do such simulators develop for aspects of sensory experience, they also develop for aspects of proprioception (e.g., lift, run) and for introspection (e.g., compare, memory, happy, hungry). Once established, these simulators implement a basic conceptual system that represents types, supports categorization, and produces categorical inferences. These simulators further support productivity, propositions, and abstract concepts, thereby implementing a fully functional conceptual system. Productivity results from integrating simulators combinatorially and recursively to produce complex simulations. Propositions result from binding simulators to perceived individuals to represent type-token relations. Abstract concepts are grounded in complex simulations of combined physical and introspective events. Thus, a perceptual theory of knowledge can implement a fully functional conceptual system while avoiding what it is becoming increasingly apparent would be problems for amodal symbol systems. Implications for cognition, neuroscience, evolution, development, and artificial intelligence are explored. |
| Comments: Défend l'idée d'une cognition perceptuelle, et non amodale. Perspective historique frappante et très lucide. |
@Article{bars_99,
author = {Barsalou, Lawrence W.},
title = {Perceptual symbols systems},
journal = {Behavioral and brain sciences},
year = {1999},
volume = {22},
pages = {577-660},
abstract = {Prior to the twentieth century, theories of knowledge were inherently perceptual. Since then, developments in logic, statistics, and programming languages have inspired amodal theories that rest on principles fundamentally different from those underlying perception. In addition, perceptual approaches have become widely viewed as untenable, because they are assumed to implement recording systems, not conceptual systems. A perceptual theory of knowledge is developed here in the contexts of current cognitive science and neuroscience. During perceptual experience, association areas in the brain capture bottom-up patterns of activation in sensory-motor areas. Later, in a top-down manner, association areas partially reactivate sensory-motor areas to implement perceptual symbols. The storage and reactivation of perceptual symbols operates at the level of perceptual components--not at the level of holistic perceptual experiences. Through the use of selective attention, schematic representations of perceptual components are extracted from experience and stored in memory (e.g., individual memories of green, purr, hot). As memories of the same component become organized around a common frame, they implement a simulator that produces limitless simulations of the component (e.g., simulations of purr). Not only do such simulators develop for aspects of sensory experience, they also develop for aspects of proprioception (e.g., lift, run) and for introspection (e.g., compare, memory, happy, hungry). Once established, these simulators implement a basic conceptual system that represents types, supports categorization, and produces categorical inferences. These simulators further support productivity, propositions, and abstract concepts, thereby implementing a fully functional conceptual system. Productivity results from integrating simulators combinatorially and recursively to produce complex simulations. Propositions result from binding simulators to perceived individuals to represent type-token relations. Abstract concepts are grounded in complex simulations of combined physical and introspective events. Thus, a perceptual theory of knowledge can implement a fully functional conceptual system while avoiding what it is becoming increasingly apparent would be problems for amodal symbol systems. Implications for cognition, neuroscience, evolution, development, and artificial intelligence are explored.},
comments = {Défend l'idée d'une cognition perceptuelle, et non amodale. Perspective historique frappante et très lucide. },
keywords = {objects, sensorimotor, cognition},
rating = {B},
url = {http://www.bbsonline.org/documents/a/00/00/04/29/bbs00000429-00/bbs.barsalou.html}
}
-
E.J. Chichilisky and Brian A. Wandell.
Trichromatic opponent color classification.
Vision Research,
1999.
Keywords: color,
neuroscience,
psychology.
| Abstract: Stimuli varying in intensity and chromaticity, presented on numerous backgrounds, were classified into red/green, blue/yellow and white/black opponent color categories. These measurements revealed the shapes of the boundaries that separate opponent colors in three-dimensional color space. Opponent color classification boundaries were generally not planar, but their shapes could be summarized by a piecewise linear model in which increment and decrement color signals are combined with different weights at two stages to produce opponent color sensations. The effect of background light on classification was largely explained by separate gain changes in increment and decrement cone signals. |
| Comments: Détermination des frontières rouge/vert et bleu/jaune, qui ne sont pas des plans, mais des morceaux de plan ou des cones. Ils passent généralement pas la couleur du fond, mais pas toujours. |
@Article{chic_wand_99,
author = {Chichilisky, E.J. and Wandell, Brian A.},
title = {Trichromatic opponent color classification},
journal = {Vision Research},
year = {1999},
url = {ftp://white.stanford.edu/users/brian/color/TOCC.pdf},
abstract = {Stimuli varying in intensity and chromaticity, presented on numerous backgrounds, were classified into red/green, blue/yellow and white/black opponent color categories. These measurements revealed the shapes of the boundaries that separate opponent colors in three-dimensional color space. Opponent color classification boundaries were generally not planar, but their shapes could be summarized by a piecewise linear model in which increment and decrement color signals are combined with different weights at two stages to produce opponent color sensations. The effect of background light on classification was largely explained by separate gain changes in increment and decrement cone signals.},
comments = {Détermination des frontières rouge/vert et bleu/jaune, qui ne sont pas des plans, mais des morceaux de plan ou des cones. Ils passent généralement pas la couleur du fond, mais pas toujours.},
keywords = {color, neuroscience, psychology},
rating = {C}
}
-
A. Clark.
An embodied cognitive science?.
TRENDS in Cognitive Sciences,
3(9):345-351,
1999.
Keywords: embodiment,
cognitive sciences.
| Abstract: The last ten years have seen an increasing interest, within cognitive science, in issues concerning the physical body, the local environment, and the complex interplay between neural systems and the wider world in which they function. Yet many unanswered questions remain, and the shape of a genuinely physically embodied, environmentally embedded science of the mind is still unclear. In this article I will raise a number of critical questions concerning the nature and scope of this approach, drawing a distinction between two kinds of appeal to embodiment: (1) 'Simple' cases, in which bodily and environmental properties merely constrain accounts that retain the focus on inner organization and processing; and (2) More radical appeals, in which attention to bodily and environmental features is meant to transform both the subject matter and the theoretical framework of cognitive science. |
@Article{clar_99,
author = {Clark, A.},
title = {An embodied cognitive science?},
journal = {{TRENDS} in Cognitive Sciences},
volume = {3},
number = {9},
year = {1999},
pages = {345-351},
abstract = {The last ten years have seen an increasing interest, within cognitive science, in issues concerning the physical body, the local environment, and the complex interplay between neural systems and the wider world in which they function. Yet many unanswered questions remain, and the shape of a genuinely physically embodied, environmentally embedded science of the mind is still unclear. In this article I will raise a number of critical questions concerning the nature and scope of this approach, drawing a distinction between two kinds of appeal to embodiment: (1) 'Simple' cases, in which bodily and environmental properties merely constrain accounts that retain the focus on inner organization and processing; and (2) More radical appeals, in which attention to bodily and environmental features is meant to transform both the subject matter and the theoretical framework of cognitive science.},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?holding=npg&cmd=Retrieve&db=PubMed&list_uids=10461197&dopt=Abstract},
rating = {B},
keywords = {embodiment, cognitive sciences}
}
-
Jules Davidoff,
Ian Davies,
and Debi Roberson.
Colour categories in a stone-age tribe.
Nature,
398:203-204,
1999.
Keywords: color,
perception,
linguistic.
| Comments: Critique de la notion de catégories universelles de couleurs, argumenté par l'étude d'une tribu Mélanésienne. |
@Article{davi_davi_robe_99,
author = {Davidoff, Jules and Davies, Ian and Roberson, Debi},
title = {Colour categories in a stone-age tribe},
journal = {Nature},
year = {1999},
volume = {398},
pages = {203-204},
rating = {C},
comments = {Critique de la notion de catégories universelles de couleurs, argumenté par l'étude d'une tribu Mélanésienne.},
url = {http://cognitrn.psych.indiana.edu/rgoldsto/perlearn/berinmo.pdf},
keywords = {color, perception, linguistic}
}
-
Andreas K. Engel,
Pascal Fries,
Peter Konig,
Michael Brecht,
and Wolf Singer.
Temporal binding, binocular rivalry, and consciousness.
Consciousness and Cognition,
8(2):128-151,
1999.
Keywords: binding,
NCC,
awareness.
| Abstract: Cognitive functions like perception, memory, language, or consciousness are based on highly parallel and distributed information processing by the brain. One of the major unresolved questions is how information can be integrated and how coherent representational states can be established in the distributed neuronal systems subserving these functions. It has been suggested that this so-called binding problem may be solved in the temporal domain. The hypothesis is that synchronization of neuronal discharges can serve for the integration of distributed neurons into cell assemblies and that this process may underlie the selection of perceptually and behaviorally relevant information. As we intend to show here, this temporal binding hypothesis has implications for the search of the neural correlate of consciousness. We review experimental results, mainly obtained in the visual system, which support the notion of temporal binding. In particular, we discuss recent experiments on the neural mechanisms of binocular rivalry which suggest that appropriate synchronization among cortical neurons may be one of the necessary conditions for the buildup of perceptual states and awareness of sensory stimuli. |
| Comments: Le "binding problem" : comments un traitement distribué et a priori asynchrone des différents aspects perceptuels peut donner lieu à une perception unifié ? |
@Article{enge_01,
author = {Engel, Andreas K. and Fries, Pascal and Konig, Peter and Brecht, Michael and Singer, Wolf},
title = {Temporal binding, binocular rivalry, and consciousness},
journal = {Consciousness and Cognition},
year = {1999},
volume = {8},
number = {2},
pages = {128-151},
abstract = {Cognitive functions like perception, memory, language, or consciousness are based on highly parallel and distributed information processing by the brain. One of the major unresolved questions is how information can be integrated and how coherent representational states can be established in the distributed neuronal systems subserving these functions. It has been suggested that this so-called binding problem may be solved in the temporal domain. The hypothesis is that synchronization of neuronal discharges can serve for the integration of distributed neurons into cell assemblies and that this process may underlie the selection of perceptually and behaviorally relevant information. As we intend to show here, this temporal binding hypothesis has implications for the search of the neural correlate of consciousness. We review experimental results, mainly obtained in the visual system, which support the notion of temporal binding. In particular, we discuss recent experiments on the neural mechanisms of binocular rivalry which suggest that appropriate synchronization among cortical neurons may be one of the necessary conditions for the buildup of perceptual states and awareness of sensory stimuli.},
comments = {Le "binding problem" : comments un traitement distribué et a priori asynchrone des différents aspects perceptuels peut donner lieu à une perception unifié ?},
url = {http://www.ini.unizh.ch/~peterk/OwnPapers/engel.cc.99.pdf},
keywords = {binding, NCC, awareness}
}
-
Ian Gold and Daniel Stoljar.
A neuron doctrine in the philosophy of neuroscience.
Behavioral and Brain Sciences,
22(5):585-642,
1999.
Keywords: philosophy,
neuroscience,
reductionnism.
| Abstract: Many neuroscientists and philosophers endorse a view about the explanatory reach of neuroscience which we will call the neuron doctrine to the effect that the framework for understanding the mind will be developed by neuroscience; or, as we will put it, that a successful theory of the mind will be solely neuroscientific. It is a consequence of this view that the sciences of the mind that cannot be expressed by means of neuroscientific concepts alone count as indirect sciences that will be discarded as neuroscience matures. This consequence is what makes the doctrine substantive, indeed, radical. We ask, first, what the neuron doctrine means and, second, whether it is true. In answer to the first question, we distinguish two versions of the doctrine. One version, the trivial neuron doctrine, turns out to be uncontroversial but unsubstantive because it fails to have the consequence that the non-neuroscientific sciences of the mind will eventually be discarded. A second version, the radical neuron doctrine, does have this consequence, but, unlike the first doctrine, is highly controversial. We argue that the neuron doctrine appears to be both substantive and uncontroversial only as a result of a conflation of these two versions. We then consider whether the radical doctrine is true. We present and evaluate three arguments for it, based either on general scientific and philosophical considerations or on the details of neuroscience itself; arguing that all three fail. We conclude that the evidence fails to support the radical neuron doctrine. |
@ARTICLE{gold_stol_99,
AUTHOR = {Gold, Ian and Stoljar, Daniel},
TITLE = {A neuron doctrine in the philosophy of neuroscience},
JOURNAL = {Behavioral and Brain Sciences},
Volume = {22},
Number = {5},
YEAR = {1999},
pages = {585-642},
url = {http://www.bbsonline.org/documents/a/00/00/05/53/bbs00000553-00/bbs.gold.html},
keywords = {philosophy, neuroscience, reductionnism},
rating = {B},
abstract = {Many neuroscientists and philosophers endorse a view about the explanatory reach of neuroscience which we will call the neuron doctrine to the effect that the framework for understanding the mind will be developed by neuroscience; or, as we will put it, that a successful theory of the mind will be solely neuroscientific. It is a consequence of this view that the sciences of the mind that cannot be expressed by means of neuroscientific concepts alone count as indirect sciences that will be discarded as neuroscience matures. This consequence is what makes the doctrine substantive, indeed, radical. We ask, first, what the neuron doctrine means and, second, whether it is true. In answer to the first question, we distinguish two versions of the doctrine. One version, the trivial neuron doctrine, turns out to be uncontroversial but unsubstantive because it fails to have the consequence that the non-neuroscientific sciences of the mind will eventually be discarded. A second version, the radical neuron doctrine, does have this consequence, but, unlike the first doctrine, is highly controversial. We argue that the neuron doctrine appears to be both substantive and uncontroversial only as a result of a conflation of these two versions. We then consider whether the radical doctrine is true. We present and evaluate three arguments for it, based either on general scientific and philosophical considerations or on the details of neuroscience itself; arguing that all three fail. We conclude that the evidence fails to support the radical neuron doctrine.}
}
-
Karin L. Harman,
G. Keith Humphrey,
and Melvyn A. Goodale.
Active manual control of object views facilitates visual recognition.
Current Biology,
9:1315-1318,
1999.
Keywords: motor control,
objects,
perception.
@Article{harm_hump_good_99,
author = {Harman, Karin L. and Humphrey, G. Keith and Goodale, Melvyn A.},
title = {Active manual control of object views facilitates visual recognition},
journal = {Current Biology},
year = {1999},
volume = {9},
pages = {1315-1318},
url = {http://www.psy.vanderbilt.edu/postdocs/jameskh/PDFs/CurrBioPap.pdf},
abstract = {},
rating = {C},
keywords = {motor control, objects, perception}
}
-
Mitsuo Kawato.
Internal models for motor control and trajectory planning.
Current Opinion in Neurobiology,
9:718-727,
1999.
Keywords: neuroscience,
motor control,
internal models.
| Abstract: A number of internal model concepts are now widespread in neuroscience and cognitive science. These concepts are supported by behavioral, neurophysiological, and imaging data; furthermore, these models have had their structures and functions revealed by such data. In particular, a specific theory on inverse dynamics model learning is directly supported by unit recordings from cerebellar Purkinje cells. Multiple paired forward inverse models describing how diverse objects and environments can be controlled and learned separately have recently been proposed. The 'minimum variance model' is another major recent advance in the computational theory of motor control. This model integrates two furiously disputed approaches on trajectory planning, strongly suggesting that both kinematic and dynamic internal models are utilized in movement planning and control. |
@Article{kawa_99,
author = {Kawato, Mitsuo},
title = {Internal models for motor control and trajectory planning},
journal = {Current Opinion in Neurobiology},
year = {1999},
volume = {9},
pages = {718-727},
keywords = {neuroscience, motor control, internal models},
rating = {C},
comments = {review},
abstract = {A number of internal model concepts are now widespread in neuroscience and cognitive science. These concepts are supported by behavioral, neurophysiological, and imaging data; furthermore, these models have had their structures and functions revealed by such data. In particular, a specific theory on inverse dynamics model learning is directly supported by unit recordings from cerebellar Purkinje cells. Multiple paired forward inverse models describing how diverse objects and environments can be controlled and learned separately have recently been proposed. The 'minimum variance model' is another major recent advance in the computational theory of motor control. This model integrates two furiously disputed approaches on trajectory planning, strongly suggesting that both kinematic and dynamic internal models are utilized in movement planning and control. },
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?holding=npg&cmd=Retrieve&db=PubMed&list_uids=10607637&dopt=Abstract}
}
-
G. K. Klute,
J. M. Czerniecki,
and B. Hannafor.
McKibben Artificial Muscles: Pneumatic Actuators with Biomechanical Intelligence.
IEEE/ASME 1999 International Conference on Advanced Intelligent Mechatronics (AIM'99),
1999.
Keywords: motor control,
physiology.
| Abstract: Un petit papier sur les muscles de McKibben (ballon dans une gaine), surtout intéressant pour ses référence aux modèles de muscles naturels (Hill). |
@Article{klut_czer_hann_99,
author = {Klute, G. K. and Czerniecki, J. M. and Hannafor, B.},
title = {McKibben Artificial Muscles: Pneumatic Actuators with Biomechanical Intelligence},
journal = {IEEE/ASME 1999 International Conference on Advanced Intelligent Mechatronics (AIM'99)},
year = {1999},
abstract = {Un petit papier sur les muscles de McKibben (ballon dans une gaine), surtout intéressant pour ses référence aux modèles de muscles naturels (Hill).},
url = {http://crim.ece.ncsu.edu/projects/muscles/papers/klute,czerniecki,hannaford_mckibben_muscles_pneumatic_actuators.pdf},
rating = {D},
keywords = {motor control, physiology}
}
-
Jan J. Koenderink,
Andrea J. van Doorn,
Dana J. Kristin,
and Shree Nayar.
Bidirectional reflection distribution function of thoroughly pitted surfaces.
International Journal of Computer Vision,
31(2/3):129-144,
1999.
Keywords: physics,
reflectance,
BRDF,
vision,
computer graphics.
| Abstract: We derive the BRDF (Bidirectional Reflection Distribution Function) at the mega scale of opaque surfaces that are rough on the macro and micro scale. The roughness at the micro scale is modeled as a uniform, isotropically scattering, Lambertian surface. At the macro scale the roughness is modeled by way of a distribution of spherical concavities. These pits influence the BRDF via vignetting, cast shadow, interreflection and interposition, causing it to differ markedly from Lambertian. Pitted surfaces show strong backward scattering (so called opposition effect ). When we assume that the macro scale can be resolved, the radiance histogram and the spatial structure of the textons of the textured surface (at the mega scale) can be calculated. This is the main advantage of the model over previous ones: One can do exact (numerical) calculations for a surface geometry that is physically realizable. |
@article{koen_door_99,
author = {Koenderink, Jan J. and van Doorn, Andrea J. and Kristin, Dana J. and Nayar, Shree},
title = {Bidirectional reflection distribution function of thoroughly pitted surfaces},
journal = {International Journal of Computer Vision},
volume = {31},
number = {2/3},
pages = {129-144},
year = {1999},
keywords = {physics, reflectance, BRDF, vision, computer graphics},
rating = {C},
url = {http://www.cs.columbia.edu/CAVE/publinks/koenderink_IJCV_1999.pdf},
abstract = {We derive the BRDF (Bidirectional Reflection Distribution Function) at the mega scale of opaque surfaces that are rough on the macro and micro scale. The roughness at the micro scale is modeled as a uniform, isotropically scattering, Lambertian surface. At the macro scale the roughness is modeled by way of a distribution of spherical concavities. These pits influence the BRDF via vignetting, cast shadow, interreflection and interposition, causing it to differ markedly from Lambertian. Pitted surfaces show strong backward scattering (so called opposition effect ). When we assume that the macro scale can be resolved, the radiance histogram and the spatial structure of the textons of the textured surface (at the mega scale) can be calculated. This is the main advantage of the model over previous ones: One can do exact (numerical) calculations for a surface geometry that is physically realizable.}
}
-
D. D. Lee and H. S. Seung.
Learning the Parts of Objects by Non-negative Matrix Factorization.
Nature,
401:788,
october 1999.
Keywords: mathematics,
ingeneering,
artificial vision,
decomposition.
| Abstract: Is perception of the whole based on perception of its parts? There is psychological and physiological evidence for parts-based representations in the brain, and certain computational theories of object recognition rely on such representations. But little is known about how brains or computers might learn the parts of objects. Here we demonstrate an algorithm for non-negative matrix factorization that is able to learn parts of faces and semantic features of text. This is in contrast to other methods, such as principal components analysis and vector quantization, that learn holistic, not parts-based, representations. Non-negative matrix factorization is distinguished from the other methods by its use of non-negativity constraints. These constraints lead to a parts-based representation because they allow only additive, not subtractive, combinations. When non-negative matrix factorization is implemented as a neural network, parts-based representations emerge by virtue of two properties: the firing rates of neurons are never negative and synaptic strengths do not change sign. |
| Comments: Learning basis function with a constraint of additive participation to reconstruction amount to the problem of non-negative matrix factorization. This method is compared with PCA and vector quantization. |
@Article{lee_seun_99,
author = {Lee, D. D. and Seung, H. S.},
title = {Learning the Parts of Objects by Non-negative Matrix Factorization},
journal = {Nature},
year = {1999},
volume = {401},
pages = {788},
month = {october},
abstract = {Is perception of the whole based on perception of its parts? There is psychological and physiological evidence for parts-based representations in the brain, and certain computational theories of object recognition rely on such representations. But little is known about how brains or computers might learn the parts of objects. Here we demonstrate an algorithm for non-negative matrix factorization that is able to learn parts of faces and semantic features of text. This is in contrast to other methods, such as principal components analysis and vector quantization, that learn holistic, not parts-based, representations. Non-negative matrix factorization is distinguished from the other methods by its use of non-negativity constraints. These constraints lead to a parts-based representation because they allow only additive, not subtractive, combinations. When non-negative matrix factorization is implemented as a neural network, parts-based representations emerge by virtue of two properties: the firing rates of neurons are never negative and synaptic strengths do not change sign.},
comments = {Learning basis function with a constraint of additive participation to reconstruction amount to the problem of non-negative matrix factorization. This method is compared with PCA and vector quantization.},
keywords = {mathematics, ingeneering, artificial vision, decomposition},
rating = {B},
url = {http://hebb.mit.edu/people/seung/papers/ls-lponm-99.pdf}
}
-
David A. Leopold and Nikos K. Logothetis.
Multistable phenomena: changing views in perception.
Trends in Cognitive Sciences,
3(7),
1999.
Keywords: neuroscience,
vision,
rivalry.
| Abstract: Traditional explanations of multistable visual phenomena (e.g. ambiguous figures, perceptual rivalry) suggest that the basis for spontaneous reversals in perception lies in antagonistic connectivity within the visual system. In this review, we suggest an alternative, albeit speculative, explanation for visual multistability that spontaneous alternations reflect responses to active, programmed events initiated by brain areas that integrate sensory and non-sensory information to coordinate a diversity of behaviors. Much evidence suggests that perceptual reversals are themselves more closely related to the expression of a behavior than to passive sensory responses: (1) they are initiated spontaneously, often voluntarily, and are influenced by subjective variables such as attention and mood; (2) the alternation process is greatly facilitated with practice and compromised by lesions in non-visual cortical areas; (3) the alternation process has temporal dynamics similar to those of spontaneously initiated behaviors; (4) functional imaging reveals that brain areas associated with a variety of cognitive behaviors are specifically activated when vision becomes unstable. In this scheme, reorganizations of activity throughout the visual cortex, concurrent with perceptual reversals, are initiated by higher, largely non-sensory brain centers. Such direct intervention in the processing of the sensory input by brain structures associated with planning and motor programming might serve an important role in perceptual organization, particularly in aspects related to selective attention. |
| Comments: Les phénomènes de multistabilité de la perception seraient plus l'expression d'un process top-down que d'un réflexe sensoriel passif. Arguments neuros convainquants et approche générale d'une vrai pertinence. |
@Article{leop_logo_99,
author = {Leopold, David A. and Logothetis, Nikos K.},
title = {Multistable phenomena: changing views in perception},
journal = {Trends in Cognitive Sciences},
year = {1999},
volume = {3},
number = {7},
url = {http://www.kyb.tuebingen.mpg.de/publications/pdfs/pdf201.pdf},
abstract = {Traditional explanations of multistable visual phenomena (e.g. ambiguous figures, perceptual rivalry) suggest that the basis for spontaneous reversals in perception lies in antagonistic connectivity within the visual system. In this review, we suggest an alternative, albeit speculative, explanation for visual multistability that spontaneous alternations reflect responses to active, programmed events initiated by brain areas that integrate sensory and non-sensory information to coordinate a diversity of behaviors. Much evidence suggests that perceptual reversals are themselves more closely related to the expression of a behavior than to passive sensory responses: (1) they are initiated spontaneously, often voluntarily, and are influenced by subjective variables such as attention and mood; (2) the alternation process is greatly facilitated with practice and compromised by lesions in non-visual cortical areas; (3) the alternation process has temporal dynamics similar to those of spontaneously initiated behaviors; (4) functional imaging reveals that brain areas associated with a variety of cognitive behaviors are specifically activated when vision becomes unstable. In this scheme, reorganizations of activity throughout the visual cortex, concurrent with perceptual reversals, are initiated by higher, largely non-sensory brain centers. Such direct intervention in the processing of the sensory input by brain structures associated with planning and motor programming might serve an important role in perceptual organization, particularly in aspects related to selective attention.},
comments = {Les phénomènes de multistabilité de la perception seraient plus l'expression d'un process top-down que d'un réflexe sensoriel passif. Arguments neuros convainquants et approche générale d'une vrai pertinence.},
keywords = {neuroscience, vision, rivalry},
rating = {B}
}
-
Jeremy Nathans.
The Evolution and Physiology of Human Color Vision: Insights from Molecular Genetic Studies of Visual Pigments.
Neuron,
24:299-312,
1999.
Keywords: neuroscience,
genetics,
color,
photopigments.
| Comments: review assez détaillée des méchanismes moléculaires à la base de la vision en couleur |
@Article{nath_99,
author = {Nathans, Jeremy},
title = {The Evolution and Physiology of Human Color Vision: Insights from Molecular Genetic Studies of Visual Pigments},
journal = {Neuron},
year = {1999},
volume = {24},
pages = {299-312},
url = {http://mbb.harvard.edu/evolution_of_mind_and_brain/Livingstone.pdf},
comments = {review assez détaillée des méchanismes moléculaires à la base de la vision en couleur},
rating = {C},
keywords = {neuroscience, genetics, color, photopigments}
}
-
J. Kevin O'Regan,
Ronald A. Rensink,
and James J. Clark.
Blindness to scene changes caused by mudsplashes.
Nature,
34:398,
1999.
Keywords: change blindness,
vision.
| Abstract: Change-blindness, occurs when large changes are missed under natural viewing conditions because they occur simultaneously with a brief visual disruption, perhaps caused by an eye movement,, a flicker, a blink, or a camera cut in a film sequence. We have found that this can occur even when the disruption does not cover or obscure the changes. When a few small, high-contrast shapes are briefly spattered over a picture, like mudsplashes on a car windscreen, large changes can be made simultaneously in the scene without being noticed. This phenomenon is potentially important in driving, surveillance or navigation, as dangerous events occurring in full view can go unnoticed if they coincide with even very small, apparently innocuous, disturbances. It is also important for understanding how the brain represents the world. |
@Article{oreg_rens_clar_99,
author = {O'Regan, J. Kevin and Rensink, Ronald A. and Clark, James J.},
title = {Blindness to scene changes caused by mudsplashes},
journal = {Nature},
year = {1999},
volume = {34},
pages = {398},
url = {http://nivea.psycho.univ-paris5.fr/Mudsplash/mudsplash.html},
rating = {B},
abstract = {},
keywords = {change blindness, vision},
abstract = {Change-blindness, occurs when large changes are missed under natural viewing conditions because they occur simultaneously with a brief visual disruption, perhaps caused by an eye movement,, a flicker, a blink, or a camera cut in a film sequence. We have found that this can occur even when the disruption does not cover or obscure the changes. When a few small, high-contrast shapes are briefly spattered over a picture, like mudsplashes on a car windscreen, large changes can be made simultaneously in the scene without being noticed. This phenomenon is potentially important in driving, surveillance or navigation, as dangerous events occurring in full view can go unnoticed if they coincide with even very small, apparently innocuous, disturbances. It is also important for understanding how the brain represents the world. }
}
-
Stephen E. Palmer.
Color, Counsciousness, and the Isomorphism Constraint.
Behavioral and Brain Sciences,
22(6),
1999.
Keywords: color,
perception,
qualia.
| Abstract: The relations among consciousness, brain, behavior, and scientific explanation are explored within the domain of color perception. Current scientific knowledge about color similarity, color composition, dimensional structure, unique colors, and color categories is used to assess Locke's "inverted spectrum argument" about the undetectability of color transformations. A symmetry analysis of color space shows that the literal interpretation of this argument -- reversing the experience of a rainbow -- would not work. Three other color-to-color transformations might, however, depending on the relevance of certain color categories. The approach is then generalized to examine behavioral detection of arbitrary differences in color experiences, leading to the formulation of a principled distinction, called the isomorphism constraint, between what can and cannot be determined about the nature of color experience by objective behavioral means. Finally, the prospects for achieving a biologically based explanation of color experience below the level of isomorphism are considered in light of the limitations of behavioral methods. Within-subject designs using biological interventions hold the greatest promise for scientific progress on consciousness, but objective knowledge of another person's experience appears impossible. The implications of these arguments for functionalism are discussed. |
@ARTICLE{palm_99,
AUTHOR = {Palmer, Stephen E.},
TITLE = {Color, Counsciousness, and the Isomorphism Constraint},
JOURNAL = {Behavioral and Brain Sciences},
YEAR = {1999},
volume = {22},
number = {6},
abstract = {The relations among consciousness, brain, behavior, and scientific explanation are explored within the domain of color perception. Current scientific knowledge about color similarity, color composition, dimensional structure, unique colors, and color categories is used to assess Locke's "inverted spectrum argument" about the undetectability of color transformations. A symmetry analysis of color space shows that the literal interpretation of this argument -- reversing the experience of a rainbow -- would not work. Three other color-to-color transformations might, however, depending on the relevance of certain color categories. The approach is then generalized to examine behavioral detection of arbitrary differences in color experiences, leading to the formulation of a principled distinction, called the isomorphism constraint, between what can and cannot be determined about the nature of color experience by objective behavioral means. Finally, the prospects for achieving a biologically based explanation of color experience below the level of isomorphism are considered in light of the limitations of behavioral methods. Within-subject designs using biological interventions hold the greatest promise for scientific progress on consciousness, but objective knowledge of another person's experience appears impossible. The implications of these arguments for functionalism are discussed.},
url = {http://bbsonline.cup.cam.ac.uk/Preprints/OldArchive/bbs.palmer.html},
rating = {B},
keywords = {color, perception, qualia}
}
-
Zenon Pylyshyn.
Is Vision Continuous With Cognition? The Case for Cognitive Impenetrability of Visual Perception.
Behavioral and Brain Sciences,
22(3),
1999.
Keywords: vision,
cognition,
perception.
| Abstract: Although the study of visual perception has made more progress in the past 40 years than any other area of cognitive science, there remain major disagreements as to how closely vision is tied to cognition. This target article sets out some of the arguments for both sides (arguments from computer vision, neuroscience, psychophysics, perceptual learning and other areas of vision science) and defends the position that an important part of visual perception, corresponding to what some people have called early vision, is prohibited from accessing relevant expectations, knowledge and utilities in determining the function it computes - in other words, it is cognitively impenetrable. That part of vision is complex and involves top-down interactions that are internal to the early vision system. Its function is to provide a structured representation of the 3-D surfaces of objects sufficient to serve as an index into memory, with somewhat different outputs being made available to other systems such as those dealing with motor control. The paper also addresses certain conceptual and methodological issues raised by this claim, such as whether signal detection theory and event-related potentials can be used to assess cognitive penetration of vision. A distinction is made among several stages in visual processing, including, in addition to the inflexible early-vision stage, a pre-perceptual attention-allocation stage and a post-perceptual evaluation, selection, and inference stage which accesses long-term memory. These two stages provide the primary ways in which cognition can affect the outcome of visual perception. The paper discusses arguments from computer vision and psychology showing that vision is "intelligent" and involves elements of "problem solving". The cases of apparently intelligent interpretation sometimes cited in support of this claim do not show cognitive penetration; rather, they show that certain natural constraints on interpretation, concerned primarily with optical and geometrical properties of the world, have been compiled into the visual system. The paper also examines a number of examples where instructions and "hints" are alleged to affect what is seen. In each case it is concluded that the evidence is more readily assimilated to the view that when cognitive effects are found, they have a locus outside early vision, in such processes as the allocation of focal attention and the identification of the stimulus. |
@Article{pyly_99,
author = {Pylyshyn, Zenon},
title = {Is Vision Continuous With Cognition? The Case for Cognitive Impenetrability of Visual Perception},
journal = {Behavioral and Brain Sciences},
year = {1999},
number = {3},
volume = {22},
abstract = {Although the study of visual perception has made more progress in the past 40 years than any other area of cognitive science, there remain major disagreements as to how closely vision is tied to cognition. This target article sets out some of the arguments for both sides (arguments from computer vision, neuroscience, psychophysics, perceptual learning and other areas of vision science) and defends the position that an important part of visual perception, corresponding to what some people have called early vision, is prohibited from accessing relevant expectations, knowledge and utilities in determining the function it computes - in other words, it is cognitively impenetrable. That part of vision is complex and involves top-down interactions that are internal to the early vision system. Its function is to provide a structured representation of the 3-D surfaces of objects sufficient to serve as an index into memory, with somewhat different outputs being made available to other systems such as those dealing with motor control. The paper also addresses certain conceptual and methodological issues raised by this claim, such as whether signal detection theory and event-related potentials can be used to assess cognitive penetration of vision. A distinction is made among several stages in visual processing, including, in addition to the inflexible early-vision stage, a pre-perceptual attention-allocation stage and a post-perceptual evaluation, selection, and inference stage which accesses long-term memory. These two stages provide the primary ways in which cognition can affect the outcome of visual perception. The paper discusses arguments from computer vision and psychology showing that vision is "intelligent" and involves elements of "problem solving". The cases of apparently intelligent interpretation sometimes cited in support of this claim do not show cognitive penetration; rather, they show that certain natural constraints on interpretation, concerned primarily with optical and geometrical properties of the world, have been compiled into the visual system. The paper also examines a number of examples where instructions and "hints" are alleged to affect what is seen. In each case it is concluded that the evidence is more readily assimilated to the view that when cognitive effects are found, they have a locus outside early vision, in such processes as the allocation of focal attention and the identification of the stimulus.},
url = {http://bbsonline.cup.cam.ac.uk/Preprints/OldArchive/bbs.pylyshyn.html},
rating = {B},
keywords = {vision, cognition, perception}
}
-
Michael T. Rosenstein and Paul R. Cohen.
Continuous Categories for a mobile robot.
1999.
Keywords: artificial intelligence.
| Comments: Article faible. Construction de clusters dans les inputs sensoriels sur la base de séries temporelles prototypiques. |
@ARTICLE{rose_cohe_99,
AUTHOR = {Rosenstein, Michael T. and Cohen, Paul R.},
TITLE = {Continuous Categories for a mobile robot},
year = {1999},
comments = {Article faible. Construction de clusters dans les inputs sensoriels sur la base de séries temporelles prototypiques.},
url = {http://citeseer.nj.nec.com/rosenstein99continuous.html},
rating = {D},
keywords = {artificial intelligence}
}
-
Ramesh Srinivasan,
D. Patrick Russell,
Gerald M. Edelman,
and Guilio Tononi.
Increased Synchronization of Neuromagnetic Responses during Conscious Perception.
The Journal of Neuroscience,
19(13):5435-5448,
1999.
Keywords: binding,
NCC.
| Abstract: In binocular rivalry, the observer views two incongruent images, one through each eye, but is conscious of only one image at a time. The image that is perceptually dominant alternates every few seconds. We used this phenomenon to investigate neural correlates of conscious perception. We presented a red vertical grating to one eye and a blue horizontal grating to the other eye, with each grating continuously flickering at a distinct frequency (the frequency tag for that stimulus). Steady-state magnetic fields were recorded with a 148 sensor whole-head magnetometer while the subjects reported which grating was perceived. The power of the steady-state magnetic field at the frequency associated with a grating typically increased at multiple sensors when the grating was perceived. Changes in power related to perceptual dominance, presumably reflecting local neural synchronization, reached statistical significance at several sensors, including some positioned over occipital, temporal, and frontal cortices. To identify changes in synchronization between distinct brain areas that were related to perceptual dominance, we analyzed coherence between pairs of widely separated sensors. The results showed that when the stimulus was perceived there was a marked increase in both interhemispheric and intrahemispheric coherence at the stimulus frequency. This study demonstrates a direct correlation between the conscious perception of a visual stimulus and the synchronous activity of large populations of neocortical neurons as reflected by stimulus-evoked steady-state neuromagnetic fields. |
@Article{srin_russ_edel_tono_99,
author = {Srinivasan, Ramesh and Russell, D. Patrick and Edelman, Gerald M. and Tononi, Guilio},
title = {Increased Synchronization of Neuromagnetic Responses during Conscious Perception},
journal = {The Journal of Neuroscience},
year = {1999},
volume = {19},
number = {13},
pages = {5435-5448},
url = {http://www.jneurosci.org/cgi/content/full/19/13/5435},
rating = {C},
keywords = {binding, NCC},
abstract = {In binocular rivalry, the observer views two incongruent images, one through each eye, but is conscious of only one image at a time. The image that is perceptually dominant alternates every few seconds. We used this phenomenon to investigate neural correlates of conscious perception. We presented a red vertical grating to one eye and a blue horizontal grating to the other eye, with each grating continuously flickering at a distinct frequency (the frequency tag for that stimulus). Steady-state magnetic fields were recorded with a 148 sensor whole-head magnetometer while the subjects reported which grating was perceived. The power of the steady-state magnetic field at the frequency associated with a grating typically increased at multiple sensors when the grating was perceived. Changes in power related to perceptual dominance, presumably reflecting local neural synchronization, reached statistical significance at several sensors, including some positioned over occipital, temporal, and frontal cortices. To identify changes in synchronization between distinct brain areas that were related to perceptual dominance, we analyzed coherence between pairs of widely separated sensors. The results showed that when the stimulus was perceived there was a marked increase in both interhemispheric and intrahemispheric coherence at the stimulus frequency. This study demonstrates a direct correlation between the conscious perception of a visual stimulus and the synchronous activity of large populations of neocortical neurons as reflected by stimulus-evoked steady-state neuromagnetic fields.}
}
-
S. Zeki.
Toward a theory of visual consciousness.
1999.
Keywords: philosophy,
neuroscience,
consciousness,
vision.
| Abstract: The visual brain consists of several parallel, functionally specialized processing systems, each having several stages (nodes) which terminate their tasks at different times; consequently, simultaneously presented attributes are perceived at the same time if processed at the same node and at different times if processed by different nodes. Clinical evidence shows that these processing systems can act fairly autonomously. Damage restricted to one system compromises specifically the perception of the attribute that that system is specialized for; damage to a given node of a processing system that leaves earlier nodes intact results in a degraded perceptual capacity for the relevant attribute, which is directly related to the physiological capacities of the cells left intact by the damage. By contrast, a system that is spared when all others are damaged can function more or less normally. Moreover, internally created visual percepts illusions, afterimages, imagery, and hallucinations activate specifically the nodes specialized for the attribute perceived. Finally, anatomical evidence shows that there is no final integrator station in the brain, one which receives input from all visual areas; instead, each node has multiple outputs and no node is recipient only. Taken together, the above evidence leads us to propose that each node of a processing-perceptual system creates its own microconsciousness. We propose that, if any binding occurs to give us our integrated image of the visual world, it must be a binding between microconsciousnesses generated at different nodes. Since any two microconsciousnesses generated at any two nodes can be bound together, perceptual integration is not hierarchical, but parallel and postconscious. By contrast, the neural machinery conferring properties on those cells whose activity has a conscious correlate is hierarchical, and we refer to it as generative binding, to distinguish it from the binding that might occur between the microconsciousnesses. |
@article{zek_99,
author = {Zeki, S.},
title = {Toward a theory of visual consciousness},
text = {Consciousness and Cognition 8:225-259 (1999) (with A. Bartels).},
year = {1999},
url = {http://www.ini.unizh.ch/~kiper/consc_articles/zeki_bartels_99_consciousness.pdf},
keywords = {philosophy, neuroscience, consciousness, vision},
abstract = {The visual brain consists of several parallel, functionally specialized processing systems, each having several stages (nodes) which terminate their tasks at different times; consequently, simultaneously presented attributes are perceived at the same time if processed at the same node and at different times if processed by different nodes. Clinical evidence shows that these processing systems can act fairly autonomously. Damage restricted to one system compromises specifically the perception of the attribute that that system is specialized for; damage to a given node of a processing system that leaves earlier nodes intact results in a degraded perceptual capacity for the relevant attribute, which is directly related to the physiological capacities of the cells left intact by the damage. By contrast, a system that is spared when all others are damaged can function more or less normally. Moreover, internally created visual percepts illusions, afterimages, imagery, and hallucinations activate specifically the nodes specialized for the attribute perceived. Finally, anatomical evidence shows that there is no final integrator station in the brain, one which receives input from all visual areas; instead, each node has multiple outputs and no node is recipient only. Taken together, the above evidence leads us to propose that each node of a processing-perceptual system creates its own microconsciousness. We propose that, if any binding occurs to give us our integrated image of the visual world, it must be a binding between microconsciousnesses generated at different nodes. Since any two microconsciousnesses generated at any two nodes can be bound together, perceptual integration is not hierarchical, but parallel and postconscious. By contrast, the neural machinery conferring properties on those cells whose activity has a conscious correlate is hierarchical, and we refer to it as generative binding, to distinguish it from the binding that might occur between the microconsciousnesses.}
}
-
S. Zeki,
S. Aglioti,
D. McKeefry,
and G. Berlucchi.
The neurological basis of conscious color perception in a blind patient.
Proceedings of the National Academy of Sciences,
96(24),
1999.
Keywords: neuroscience,
blind,
vision,
perception,
NCC.
| Abstract: We have studied patient PB, who, after an electric shock that led to vascular insufficiency, became virtually blind, although he retained a capacity to see colors consciously. For our psychophysical studies, we used a simplified version of the Land experiments [Land, E. (1974) Proc. R. Inst. G. B. 47, 23-58] to learn whether color constancy mechanisms are intact in him, which amounts to learning whether he can assign a constant color to a surface in spite of changes in the precise wavelength composition of the light reflected from that surface. We supplemented our psychophysical studies with imaging ones, using functional magnetic resonance, to learn something about the location of areas that are active in his brain when he perceives colors. The psychophysical results suggested that color constancy mechanisms are severely defective in PB and that his color vision is wavelength-based. The imaging results showed that, when he viewed and recognized colors, significant increases in activity were restricted mainly to V1-V2. We conclude that a partly defective color system operating on its own in a severely damaged brain is able to mediate a conscious experience of color in the virtually total absence of other visual abilities. |
@Article{zeki_99,
author = {Zeki, S. and Aglioti, S. and McKeefry, D. and Berlucchi, G.},
title = {The neurological basis of conscious color perception in a blind patient},
journal = {Proceedings of the National Academy of Sciences},
year = {1999},
volume = {96},
number = {24},
url = {http://www.pnas.org/cgi/content/full/96/24/14124},
abstract = {We have studied patient PB, who, after an electric shock that led to vascular insufficiency, became virtually blind, although he retained a capacity to see colors consciously. For our psychophysical studies, we used a simplified version of the Land experiments [Land, E. (1974) Proc. R. Inst. G. B. 47, 23-58] to learn whether color constancy mechanisms are intact in him, which amounts to learning whether he can assign a constant color to a surface in spite of changes in the precise wavelength composition of the light reflected from that surface. We supplemented our psychophysical studies with imaging ones, using functional magnetic resonance, to learn something about the location of areas that are active in his brain when he perceives colors. The psychophysical results suggested that color constancy mechanisms are severely defective in PB and that his color vision is wavelength-based. The imaging results showed that, when he viewed and recognized colors, significant increases in activity were restricted mainly to V1-V2. We conclude that a partly defective color system operating on its own in a severely damaged brain is able to mediate a conscious experience of color in the virtually total absence of other visual abilities.},
rating = {C},
keywords = {neuroscience, blind, vision, perception, NCC}
}