Berit Brogaard

The phenomenon of synesthesia has undergone an invigoration of research interest and empirical progress over the past decade. Studies investigating the cognitive mechanisms underlying synesthesia have yielded insight into neural processes behind such cognitive operations as attention, memory, spatial phenomenology and inter-modal processes. However, the structural and functional mechanisms underlying synesthesia still remain contentious and hypothetical. The first section of the present paper reviews recent research on grapheme-color synesthesia, one of the most common forms of synesthesia, and addresses the ongoing debate concerning the role of selective attention in eliciting synesthetic experience. Drawing on conclusions of the first half, the paper’s second half examines the various models proposed to explain the cognitive mechanisms behind grapheme-color synesthesia, and discusses the explanatory virtues of a new model suggesting that grapheme-color synesthesia is grounded in memory. The last section offers an examination of some of the broader philosophical implications of synesthesia.

Russell's new theory of denoting phrases introduced in "On Denoting" in Mind 1905 is now a paradigm of analytic philosophy. The main argument for Russell's new theory is the so-called 'Gray's Elegy' argument, which purports to show that the theory of denoting concepts promoted by Russell in the 1903 Principles of Mathematics is incoherent. The 'Gray's Elegy' argument rests on the premise that if a denoting concept occurs in a proposition, then the proposition is not about the concept. I argue that the premise is false. The 'Gray's Elegy' argument does not exhaust Russell's ammunition against the theory of denoting concepts. Another reason Russell rejects the theory is, as he says, that it cannot provide an adequate account of non-uniquely denoting concepts. In the last section of the paper, I argue that even though Russell was right in thinking that the theory of denoting concepts cannot provide an adequate account of non-uniquely denoting concepts, Russell's new theory does not succeed in eliminating the occurrence of all denoting concepts, as it requires a commitment to the existence of variables that indirectly denote their values. However, the view that variables are denoting concepts is unproblematic once the 'Gray's Elegy' argument is blocked.

Studies have shown that both serotonin and glutamate receptor systems play a crucial role in the mechanisms underlying drug-induced synesthesia. The specific nature of these mechanisms, however, continues to remain elusive. Here we propose two distinct hypotheses for how synesthesia triggered by hallucinogens in the serotonin-agonist family may occur. One hypothesis is that the drug-induced destabilization of thalamic projections via GABAergic neuronal circuits from sensory areas leads to a disruption of low-level, spontaneous integration of multisensory stimuli. This sort of integration regularly occurs when spatial and temporal attributes match. Destabilization of feedback loops, however, can result in incongruent experiences or binding of random thalamus activation with sensory input in a particular sensory modality. The second hypothesis builds on embodied cognition, cases in which visual images of external stimuli activate task-related neural regions. On this proposal, binding processes that do not normally generate awareness become accessible to consciousness as a result of decreased attentional discrimination among incoming stimuli.

Back when researchers thought about the various forms that color vision could take, the focus was primarily on the retinal mechanisms. Since that time, research on human color vision has shifted from an interest in retinal mechanisms to cortical color processing. This has allowed color research to provide insight into questions that are not limited to early vision but extend to cognition. Direct cortical connections from higher-level areas to lower-level areas have been found throughout the brain. One of the classic questions in cognitive science is whether perception is influenced, and if so to what extent, by cognition and whether a clear distinction can be drawn between perception and cognition. Since perception is seen as providing justification for our beliefs about properties in the external world, these questions also have metaphysical and epistemological significance. The aim of this paper is to highlight some of the areas where research on color perception can shed new light on questions in the cognitive sciences. A further aim of the paper is to raise some questions about color research that are in dire need of further reflection and investigation.

It is sometimes argued that the fact that possession of perfect knowledge about the future is impossible, means that it is impossible for decisions to be rational. This reasoning is fallacious. If rationality is given a new interpretation, then decisions can be considered rational. A theory of decision that has as its basis Peirce’s theory of abduction can provide a new way of understanding decisions as rational processes. The Peircean theory of decision (i) considers decisions as part of a complete strategy, and (ii) shows that decision making is governed by the same rules as scientific abduction. These rules are neither permissive rules like rules of deductive inference nor predictive like laws of nature, but rather genuine laws of conduct that determine what step should be made, if a given end is to be reached.

I argue that McDowell-style disjunctivism, as the position is often cashed out, goes wrong because it takes the good epistemic standing of veridical perception to be grounded in “manifest” facts which do not necessarily satisfy any epistemic constraints. A better form of disjunctivism explains the difference between good and bad cases in terms of epistemic constraints that the states satisfy. This view allows us to preserve McDowell’s thesis that good cases make facts manifest, as long as manifest facts must satisfy epistemic constraints.

While much has been written about whether visual perception is cognitively penetrable, the analogous question with respect to auditory perception has received very little attention. Here we argue that instances of top-down modulation of auditory processing, although extensive, do not constitute cases of cognitive penetration of auditory perception since the changes in the phenomenology of auditory perception caused by top-down influences cannot plausibly be attributed to the listeners’ discursive thoughts.

0. Relativistic Content In standard semantics, propositional content, whether it be the content of utterances or mental states, has a truth-value relative only to a possible world. For example, the content of my utterance of ‘Jim is sitting now’ is true just in case Jim is sitting at the time of utterance in the actual world, and the content of my belief that Alice will give a talk tomorrow is true just in case Alice will give a talk on the day following the occurrence of my belief state in the actual world. Let us call propositional content which has a truth-value relative only to a possible world ‘non-relativistic content’. Non-relativistic content can be treated as either structured or unstructured. On the unstructured-content view, non-relativistic content is a set of possible worlds and bears the truth-value true just in case the actual world is a member of that set. For example, the content of my utterance of ‘Jim is working now’ at time t is the set of worlds in which Jim is working at t, and this content is true just in case the actual world is among those worlds. On the structured-content view, non-relativistic content is a set or conglomeration of properties and/or objects, where properties are features which objects possess regardless of who considers or observes them and regardless of when they are being considered or observed. Such properties are said to be (or represent) functions from possible worlds to extensions. Relative to a possible world they determine a set of objects instantiating the property. For example, relative to the actual world the property of being human determines the set of actual humans. Not all content is non-relativistic. Let us say that propositional content is relativistic just in case it possesses a truth-value only relative to a centered world. A centered world is a possible world in which an individual and a time are marked, where the marked individual..

Determiner phrases embedded under a propositional attitude verb have traditionally been taken to denote answers to implicit questions. For example, 'the capital of Vermont' as it occurs in 'John knows the capital of Vermont' has been thought to denote the proposition which answers the implicit question 'what is the capital of Vermont?' Thus, where 'know' is treated as a propositional attitude verb rather than an acquaintance verb, 'John knows the capital of Vermont' is true iff John knows that Montpelier is the capital of Vermont. The traditional view lost its popularity long ago, because it was thought to rest on the controversial assumption that determiner phases embedded under a propositional attitude verb function semantically in the same way as the corresponding wh-clauses. Here we defend the traditional assumption against objections. We then argue that wh-clauses are not to be given a uniform treatment as indirect questions. When occurring under a propositional attitude verb, wh-clauses are better treated as having a predicate-type semantic value. We conclude by considering some possible objections to the predicate view.

Despite the recent surge in research on, and interest in, synesthesia, the mechanism underlying this condition is still unknown. Feedforward mechanisms involving overlapping receptive fields of sensory neurons as well as feedback mechanisms involving a lack of signal disinhibition have been proposed. Here I show that a broad range of studies of developmental synesthesia indicate that the mechanism underlying the phenomenon may involve reinstatement of brain activity in different sensory or cognitive streams in a way that is similar to what happens during memory retrieval of semantically associated items. In the paper’s final sections I look at the relevance of synesthesia research, given the memory model, to our understanding of multisensory perception and common mapping patterns.

Blindsight is a kind of residual vision found in people with lesions to V1. Subjects with blindsight typically report no visual awareness, but they are nonetheless able to make above-chance guesses about the shape, location, color and movement of visual stimuli presented to them in their blind field. A different kind of blindsight, sometimes called type 2 blindsight, is a kind of residual vision found in patients with V1 lesions in the presence of some residual awareness. Type 2 blindsight differs from ordinary visual experience in lacking the particularity, transparency and fine-grainedness often taken to be essential to visual experience, at least in veridical cases. I argue that the case of type 2 blindsight provides a counterexample to the view that these characteristics are essential to veridical visual experience and that this gives us reason to resist the view that visual experience is essentially a perceptual relation to external objects. In the second part of the paper I argue that the case of type 2 blindsight yields important insights into the effects of attentional modulation on perceptual content and that cases of attentional modulation of appearance are not at odds with the view that the phenomenology of visual experience flows from its content.

“When a speaker says something of the form A and B, he may take it for granted that A (or at least that his audience recognizes that he accepts that A) after he has said it. The proposition that A will be added to the background of common assumptions before the speaker asserts that B. Now suppose that B expresses a proposition that would, for some reason, be inappropriate to assert except in a context where A, or something entailed by A, is presupposed. Even if A is not presupposed initially, one may still assert A and B since by the time one gets to saying that B, the context has shifted, and it is by then presupposed that A” (Stalnaker 1974).

According to the extended knowledge account of assertion, we should only assert and act on what we know. Call this the ‘Knowledge Norm’. Because moral and prudential rules prohibit morally and prudentially unacceptable actions and assertions, they can, familiarly, override the Knowledge Norm. This, however, raises the question of whether other epistemic norms, too, can override the Knowledge Norm. The present chapter offers an affirmative answer to this question and then argues that the Knowledge Norm is derived from a more fundamental norm that demands that we do not hinder intellectual flourishing. As the fundamental epistemic norm can come into conflict with the Knowledge Norm, it is sometimes permissible to assert and act on what we don’t know. The chapter concludes with a discussion of the consequences of this insight for the extended knowledge account of assertion.

There is no question that the constituents of cells and organisms are joined together by the part-whole relation. Genes are part of cells, and cells are part of organisms. Species taxa, however, have traditionally been conceived of, not as wholes with parts, but as classes with members. But why does the relation change abruptly from part-whole to class-membership above the level of organisms? Ghiselin, Hull and others have argued that it doesn't. Cells and organisms are cohesive mereological sums, and since species taxa are like cells and organisms in the relevant respects, they, too, are cohesive mereological sums. I provide further reasons in support of the thesis that species are mereological sums. I argue, moreover, that the advocate of this thesis is committed to a form of pluralism with respect to the species concept.

Relativism offers an ingenious way of accommodating most of our intuitions about 'know': the truth-value of sentences containing 'know' is a function of parameters determined by a context of use and a context of assessment. This sort of double-indexing provides a more adequate account of the linguistic data involving 'know' than does standard contextualism. However, relativism has come under recent attack: it supposedly cannot account for the factivity of 'know', and it entails, counterintuitively, that circumstances of evaluation have features that cannot be shifted by any intensional operator. I offer replies to these objections on behalf of the relativist. I then argue that a version of contextualism can account for the same data as relativism without relativizing sentence truth to contexts of assessment. This version of contextualism is thus preferable to relativism on methodological grounds.

The chapter distinguishes between a weak and a strong form of ontological naturalism. Strong ontological naturalism is the view that all truths can be deduced, at least in principle, from truths about physical entities at the lowest level of organization, for example, truths about the elementary particles and forces. Weak ontological naturalism is the view that only physical properties can be causally efficacious. Strong ontological naturalism entails weak ontological naturalism but not vice versa. I then argue that the existence of a truth property is consistent with weak ontological naturalism, as truth is not causally efficacious. After considering several prominent theories of truth, I argue that the only theories of truth that are consistent with strong ontological naturalism are deflationary doctrines that deny that there is a substantial truth property but these theories are not suitable adjoints to strong naturalism, as folks with strong naturalist inclinations normally want to posit the existence of substantial natural properties. Yet if the truth property itself is insubstantial, so are claims about the existence of substantial natural properties. I conclude by arguing that the result that there cannot be a naturalistic theory of truth is unsurprising, as there are independent reasons for thinking that the basic semantic notions must be treated an irreducible, primitive properties.

Scott Soames has recently argued that traditional accounts of propositions as n-tuples or sets of objects and properties or functions from worlds to extensions cannot adequately explain how these abstract entities come to represent the world. Soames’ new cognitive theory solves this problem by taking propositions to be derived from agents representing the world to be a certain way. Agents represent the world to be a certain way, for example, when they engage in the cognitive act of predicating, or cognizing, an act that takes place during cognitive events, such as perceiving, believing, judging and asserting. On the cognitive theory, propositions just are act types involving the act of predicating and certain other mental operations. This theory, Soames argues, solves not only the problem of how propositions come to represent but also a number of other difficulties for traditional theories, including the problem of de se propositions and the problems of accounting for how agents are capable of grasping propositions and how they come to stand in the relation of expression to sentences. I argue here that Soames’ particular version of the cognitive theory makes two problematic assumptions about cognitive operations and the contents of proper names. I then briefly examine what can count as evidence for the nature of the constituents of the cognitive operation types that produce propositions and argue that the common nature of cognitive operations and what they operate on ought to be determined empirically in cross-disciplinary work. I conclude by offering a semantics for cognitive act types that accommodates one type of empirical evidence.