Tag: Philosophy of Neuroscience

“The matrix presents a version of an old philosophical fable: the brain in a vat. a disembodied brain is floating in a vat, inside a scientist’s laboratory. the scientist has arranged that the brain will be stimulated with the same sort of inputs that a normal embodied brain receives. to do this, the brain is connected to a giant computer simulation of a world. the simulation determines which inputs the brain receives. when the brain produces outputs, these are fed back into the simulation. the internal state of the brain is just like that of a normal brain, despite the fact that it lacks a body. from the brain’s point of view, things seem very much as they seem to you and me.”

“Suppose that a team of neurosurgeons and bioengineers were able to remove your brain from your body, suspend it in a life-sustaining vat of liquid nutrients, and connect its neurons and nerve terminals by wires to a supercomputer that would stimulate it with electrical impulses exactly like those it normally receives when embodied. according to this brain-in-a-vat thought experiment, your envatted brain and your embodied brain would have subjectively indistinguishable mental lives. for all you know—so one argument goes—you could be such a brain in a vat right now.”

“This essay argues that the image of the brain in a vat metaphorically encapsulates articulations of the relationship between the corporeal and the technological dimensions found in cyberpunk fiction and cinema. cyberpunk is concurrently concerned with actual and imaginary metamorphoses of biological organisms into machines, and of mechanical apparatuses into living entities. its recurring representation of human beings hooked up to digital matrices vividly recalls the envatted brain activated by electric stimuli, which hilary putnam has theorized in the context of contemporary epistemology. at the same time, cyberpunk imaginatively raises the same epistemological questions instigated by putnam. these concern the cognitive processes associated with the collusion of human and mechanical creatures, and related metaphysical and ethical issues spawned by such processes. as a philosophical trope, the brain in a vat would appear to pivot on the notion of a disembodied subject consisting of sheer mentation. however, literary and cinematic interpretations of the image in cyberpunk persistently foreground the obdurate materiality of the flesh-often in its most grisly and grotesque incarnations. © 2004 elsevier ltd. all rights reserved.”

“M dell’utri (in ‘choosing conceptions of realism’, ‘mind’ 99, 79-90) presents a reconstruction of putnam’s argument to show that the hypothesis that we are brains in a vat is self-refuting. i explain why the argument is problematic and offer a resolution of the difficulty.”

“The brain in a vat thought-experiment is most commonly used to illustrate global or cartesian skepticism. you are told to imagine the possibility that at this very moment you are actually a brain hooked up to a sophisticated computer program that can perfectly simulate experiences of the outside world. here is the skeptical argument. if you cannot now be sure that you are not a brain in a vat, then you cannot rule out the possibility that all of your beliefs about the external world are false. or, to put it in terms of knowledge claims, we can construct the following skeptical argument. let ‘p’ stand for any belief or claim about the external world, say, that snow is white.”

“The brain-in-a-vat argument for skepticism is best formulated, notnusing the closure principle, but using the ‘preference principle,’nwhich states that in order to be justified in believing h on thenbasis of e, one must have grounds for preferring h over each alternativenexplanation of e. when the argument is formulated this way, dretske’snand klein’s responses to it fail. however, the strengthened argumentncan be refuted using a direct realist account of perception. fornthe direct realist, refuting the biv scenario is not a preconditionnon knowledge of the external world, and only the direct realist canngive a noncircular account of how we know we’re not brains in vats.”

“This article indicates some ways in which the fantasy of the brain in the vat has been used in thought experiments to discuss important philosophical problems. the first has to do with scepticism about the external world. the second has to do with hilary putnam’s arguments for the indeterminacy of reference and his rejection of metaphysical realism. the third issue to which the brain in the vat is relevant has to do with the difference between broad and narrow content of beliefs and putnam’s challenging assertion that reference is not ‘in the head’. though there are brief suggestions for dealing with these problems and saving metaphysical realism, the main purpose is to indicate the relevance of the fantasy of the brain in the vat to discussion of these issues. © 2004 elsevier ltd. all rights reserved.”

“In this paper we offer an exegesis of hilary putnam’s classic argument against the brain-in-a-vat hypothesis offered in his reason, truth and history (1981). in it, putnam argues that we cannot be brains in a vat because the semantics of the situation make it incoherent for anyone to wonder whether they are a brain in a vat. putnam’s argument is that in order for ‘I am a brain in a vat’ to be true, the person uttering it would have to be able to refer successfully to those things: the vat, and the envatted brain. putnam thinks that reference can’t be secured without relevant kinds of causal relations, which, if envatted, the brain would lack, and so, it fails to be able to meaningfully utter ‘i am a brain in a vat’. we consider the implications of putnam’s arguments for cartesian scepticism and suggest that there may yet be some ways out of putnam’s arguments for the traditional sceptic. in conclusion, we discuss the role of putnam’s arguments against the brain in a vat hypothesis in his larger defense of his own internal realism against metaphysical realism. © 2004 elsevier ltd. all rights reserved.”

“Recent literature in epistemology has focused on the following argument for skepticism (sa): i know that i have two hands only if i know that i am not a handless brain in a vat. but i don’t know i am not a handless brain in a vat. therefore, i don’t know that i have two hands. part i of this article reviews two responses to skepticism that emerged in the 1980s and 1990s: sensitivity theories and attributor contextualism. part ii considers the more recent textquoteleft{}neo-mooreantextquoteright response to skepticism and its development in textquoteleft{}safetytextquoteright theories of knowledge. part iii argues that the skeptical argument set out in sa is not of central importance. specifically, sa is parasitic on skeptical reasoning that is more powerful and more fundamental than that displayed by sa itself. finally, part iv reviews a pyrrhonian argument for skepticism that is not well captured by sa, and considers a promising strategy for responding to it.”

“I reply to some recent comments by brian weatherson on my ‘simulation argument’. i clarify some interpretational matters, and address issues relating to epistemological externalism, the difference from traditional brain-in-a-vat arguments, and a challenge based on ‘grue’-like predicates.”

“The modern vat-brain debate is an epistemological one, and it focuses on the point of view of a putatively deceived subject. semantic externalists argue that we cannot coherently wonder whether we are brains in vats. this paper examines a new experimental paradigm for cognitive neuroscience-the neurally-controlled animat (nca) paradigm-that seems to have a great deal in common with the vat-brain scenario. neural cells are provided with a simulated body within an artificial world in order to study the brain both in vitro and in vivo. given the similarity between the nca scenario and the vat-brain scenario, semantic externalism seems to undermine the utility of the nca methodology. three initial responses to the externalist challenge are offered. a fourth response clarifies the distinctive theoretical background to the nca in ‘artificial life’ and, in doing so, we uncover an anti-representationalist conception of the nca. this distances the nca paradigm from externalist objections and casts cognitive neuroscience, and the vat-brain debate, in a new light. © 2004 published by elsevier ltd.”

“Phi losophe r s lov e to ta l k a bout k nowl edge. a whole field is devoted to reflection on the topic, with product tie-ins to professor- ships and weighty conferences. epistemology is serious business, taught in academies the world over: there is ‘moral’ and ‘social’ epistemology, epistemology of the sacred, the closet, and the family. there is a compu- tational epistemology laboratory at the university of waterloo, and a center for epistemology at the free university in amsterdam. a google search turns up separate websites for ‘constructivist,’ ‘feminist,’ and ‘evolutionary’ epistemology, of course, but also ‘libidinal,’ ‘android,’ ‘quaker,’ ‘internet,’ and (my favorite) ‘erotometaphysical’ epistemol- ogy. harvard offers a course in the field (without the erotometaphysical part), which (if we are to believe its website) explores the epistemic status of weighty claims like ‘the standard meter is 1 meter long’ and ‘i am not a brain in a vat.’1 we seem to know a lot about knowledge.2”