Browsing by Author "O'Callaghan, Casey"

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    Can You Believe It? A Case for Meaningful Control of Belief
    (2015-04-29) Phillips, Heather Anne; O'Callaghan, Casey; Grandy, Richard; Bradford, Gwendolyn; Schneider, David
    Within the doxastic control debate it is often unclear whether, and if so why, doxastic control is important or valuable. Of course, the importance or insignificance of doxastic control is irrelevant to the question of whether or not we have it. However, if whether we possess control is an important issue, which many philosophers believe it is, then it seems fruitful to specify why it is important and frame the debate around the question whether we possess the type of control necessary to secure that which we value. I employ this approach and subsequently argue that we exercise what I call meaningful control of belief. I describe this control as “meaningful” for two reasons. First, I want to make clear that my interests (and what I maintain should inform the interests of the doxastic control debate generally) go beyond mere demonstration of control. Second, when I claim that we can exercise meaningful control, I am claiming not only that a certain kind of control of belief is possible, but also that the available form of control is valuable. Though I make several claims and respond to numerous potential objections throughout the dissertation, I face two primary challenges, both of which involve taking minority positions in long-standing and ongoing debates. First, I argue that we can exert doxastic control. Second, and in support of the former, I argue against the claim that alternate possibilities are required for voluntary control. Doxastic control is most frequently denied because we lack the ability to believe at-will. Particularly prominent within the debate is a form of at-will control brought to the fore by Bernard Williams. On this conception, one acts at-will when the action performed is basic or immediate in the sense of having no intermediate steps, i.e. voluntarily winking, smiling or raising one’s arm (the most frequently used example). The other form of at-will control I address is articulated by Pamela Hieronymi. On her view, one acts at-will when one’s decision to act is sensitive to practical reasons. Examples of this form of at-will control include any action that is performed in order to make someone happy or because a practical reason such as this could have served as a reason to do so. Belief falls short of the at-will standard in the first sense because belief cannot voluntarily be brought about without intermediate steps. That is, you cannot, right now, believe that you are eight feet tall. In the second sense, belief falls short of at-will control because the decision whether to believe that p is not responsive to practical reasons. In fact, in both cases the only thing relevant to answering the question whether to believe that p is evidence speaking for or against p, and therein lies the rub. I, however, develop and advocate for a sense of at-will control that not only aligns with our intuitions about voluntary and non-voluntary actions, but also does justice to the fact that belief is not an action. My account builds on one of the candidate conceptions of at-will Hieronymi considers and discards, namely a sense of at-will similar to the one used in the phrase “fire at will.” When soldiers fire at-will, they fire (or don’t) based on what they judge called for given any commands, instructions or information they have received, the objective pursued and the context in which they find themselves. Similarly, when one believes at will in this (the judged called for) sense, one forms a belief based on what one judges called for given one’s background information, the objective pursued and the context in which one finds oneself. Interestingly, while she discards the other candidate conceptions because they do not align with typical intuitions regarding what actions are voluntary, Hieronymi casts this candidate aside solely because it would not rule out the possibility of at-will control of belief. Given that she aims at explaining why (instead of proving that) at-will control of belief is impossible, her decision to reject the fire-at-will conception makes sense. However, in the context of the doxastic control debate, such a reason is highly question-begging. This does not mean, however, that the judged called for (JCF) conception is without potential objections. During my development and defense of this conception, a difference emerges between this sense of at-will in the context of action and belief. Put most simply, while one can judge an action called for and refrain from so acting, one cannot judge it called for to believe that p and refrain from so believing. This is because on my account of belief, one believes that p when one is satisfied that p, and if one judges it called for to believe that p, then one is satisfied that p and, thereby, believes that p. This asymmetry between the contexts of action and belief raises concerns about one’s ability to do otherwise (or in this case believe otherwise), which is often considered a requirement of voluntary action. While I do not subscribe to the alternate-possibilities account of free action, I recognize both that many do and that responding to their objection is important. I utilize John Martin Fischer’s work in the area of free will to shape my response. Fischer distinguishes between what he calls regulative control and guidance control. Regulative control requires that one be able to do otherwise; guidance control does not. I argue that JCF control of belief is an instance of guidance control and that such control—in the form of doxastic deliberation—is sufficient for meaningful control of belief.
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    Perceptual Links: Attention, Experience, and Demonstrative Thought
    (2015-04-22) Barkasi, Michael; O'Callaghan, Casey; Siewert, Charles; Grandy, Richard; Zammito, John
    Perception is conscious: perceiving involves a first-person experience of what’s perceived. It’s widely held that these perceptual experiences are independent of what's perceived. Viewing two visually indiscriminable #2 pencils would involve the same experience, despite viewing different objects. It’s also widely held that conscious perception enables thinking about what's perceiving. When you see one of those pencils you can think, THAT is a pencil. Some philosophers, including John McDowell and John Campbell, have suggested that these two features engender a puzzle: how can perceptual experiences make perceived objects available for thought when they’re independent of those objects? This dissertation is a collection of four papers which address this question. The first (chapter 2) argues that, under two minimal assumptions, conscious perception makes objects available for thought only if experience is not object independent. The second (chapter 3) argues that conscious perception makes objects available for thought by enabling voluntarily attention to them. The third (chapter 4) integrates empirical work on multiple-object tracking and philosophical work on attention to argue that conscious perception isn’t mediated by the construction of representations within the visual system. The fourth (chapter 5) uses philosophical methods and neurophysiology to give an account of the role of experience itself in how perception makes objects available for thought. A concluding chapter combines and extends results from the previous chapters to give a naive realist (vs representationalist) account of perceptual experience. The questions about perceptual experience addressed in this dissertation (object dependent or independent? naive realist or representationalist?) are fundamental to our understanding of experience. Not only do they get at its basic nature, but their answers constrain how we might give scientifically respectable, or naturalistic, explanations of experience as well as how we might explain perceptual hallucinations and illusions.
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    Relative Salience of Emergent Features in Vision
    (2013-11-26) Cragin, Anna; Pomerantz, James R.; Byrne, Michael D.; O'Callaghan, Casey; Dannemiller, James L.
    What exactly are the ``parts'' that make up a whole object, and how and when do they group? The answer that is proposed hinges on Emergent Features: features that materialize from the configuration and that make the object more discriminable from other objects. EFs are not possessed by any individual part and are processed as or more quickly than are the properties of the parts. The present experiment focuses on visual discrimination of two-line configurations in an odd-quadrant task. Stimuli were created so as to isolate each EF in order to measure its contribution to speed of discrimination. Previous results suggest that the EFs most responsible for the variations in RT might be Lateral Endpoint Offset, Intersections, Parallelism, Connectivity, Terminator Count, Pixel Count, Closure, and Inside /Outside Relationship. The present study determined the boost or detriments in performance due to each EF and ranked them in terms of their relative salience. The most salient features were: Connectivity, Parallelism, Closure, Intersections, and Inside/Outside Relationship.
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    Semantic interference in language production and comprehension: Same or separable loci?
    (2014-04-22) Harvey, Denise Y.; Schnur, Tatiana T.; Martin, Randi C.; Fischer-Baum, Simon; O'Callaghan, Casey
    The ability to speak and understand language is consciously a fast and easy process. However, the language system can err, either in normal processes or as a result of neural damage following stroke. Often, in both production and comprehension, errors are semantically related to the intended word, such as saying or understanding “cat” when the intended meaning is “dog”. This semantic interference (SI) effect suggests that the processing stages involved in language production and comprehension overlap to some extent. However, because language production and comprehension are usually investigated separately, this has led to different conclusions about how SI arises in each language modality. By most accounts, SI in production occurs at the lexical-semantic level, whereas SI in comprehension arises within the semantic system itself. In this dissertation, I distinguish between SI in production and comprehension by examining how (cognitive mechanisms) and where (neural loci) SI arises during picture naming and word-picture matching tasks that elicit SI by manipulating the semantic context with which target items appear. Aim I of my dissertation directly compared the behavioral characteristics of SI in healthy participants’ production and comprehension performance in order to elucidate the level and cognitive mechanism by which SI arises in each language modality. Aim II explored patients’ susceptibility to SI as it related to cortical gray matter and subcortical white matter damage. The results provided converging evidence that not only do the SI characteristics differ in production and comprehension, but also the neural locus of SI differs across language modality. However, the time course of SI is similar in both language modalities. Accordingly, I conclude SI arises when mapping meanings with words in production vs. mapping words with meanings in comprehension, but that the same cognitive mechanism operates over lexical-semantic processes across modalities. In the end, I argue that because of inherent differences between the order with which lexical and semantic representations are accessed in production vs. comprehension, the mechanism produces different behavioral manifestations of SI in each language modality and places differential demands on cognitive control mechanisms required to resolve interference.