Browsing by Author "Neander, Karen L"

Working memory—the mental capacity to “hold on to” information after it ceases to be perceptually available—is one of the most discussed topics in psychology and neuroscience. Despite the importance of working memory in the sciences, however, there is only a small amount of philosophical research on the topic. The aim of my dissertation is to provide a philosophically-informed account of working memory, and to assess its relationship to other mental phenomena, including attention and consciousness.

In chapter one, I provide a broad historical overview of working memory. I begin by outlining William James’ original distinction between “primary” and “secondary” memory, and work my way up to present-day neuroscientific investigations of working memory. One of the main conclusions of this chapter is that there is no single working memory “module” in the brain. Instead, working memory is best conceptualized as a functionally-defined process that is potentially realized by multiple neural mechanisms.

In chapter two, I explore the link between working memory and attention. Recent evidence from psychology and neuroscience indicates that attention is (to some extent) involved in the process of working memory maintenance. However, it remains unclear whether the contents of working memory are always attended, or if working memory representations can be dynamically shifted in and out of the focus of attention. Drawing on empirical and phenomenological data, I argue that the second view is correct. Although attention plays an important role in working memory maintenance, working memory representations can persist—at least temporarily—outside the focus of attention.

Chapter three addresses a related question: namely, how working memory relates to consciousness. I distinguish three possible positions on this score: (i) working memory representations are always conscious; (ii) working memory representations can be either conscious or unconscious, but they are all accessible to consciousness; and (iii) working memory representations can be either conscious or unconscious, and some are inaccessible to consciousness. Based on the available empirical data, I argue in favor of position (ii). Evidence suggests that working memory representations can be unconscious, but such unconscious representations still appear to be consciously accessible, in the sense that they can be brought to consciousness at will.

Finally, in chapter four, I provide a critique of Peter Carruthers’ recent sensory-based account of working memory. According to Carruthers, attention only targets “mid-level” sensory areas, and thus the representations held in working memory will necessarily be sensory based in nature. I disagree. I point out that there is some evidence for attentional modulation outside of modality-specific sensory areas. I also highlight several empirical studies which provide preliminary support for the existence of non-sensory (i.e., amodal) working memory representations.

In this thesis, I take up two important issues for understanding neurobiological systems: normative functions and information. After introducing the topic and my methodology in chapters 1 and 2, chapter 3 contains an extended critique of the most prominent theory of biological functions, the selected-effects theory of functions. My arguments center on the influential recent selected-effects theory arguing that it has trouble accounting for certain cases and does not seem to capture the sense of malfunction employed in the neurosciences. Chapter 4 defends an alternative theory of normative biological functions that I label the statistical fitness theory. Roughly, this theory holds that tokens of a trait type have the normative function to do something y if it is typical for tokens of that type of trait to y and their doing y contributes to the inclusive fitness of the organism that possesses the trait. In turn, this theory defines malfunctioning trait tokens as those whose effects that typically make positive contributions to fitness fall below the "normal" range in the population. Chapter 5 argues that several other recently popular theories of normative functions have significant flaws.

Chapter 6 takes up the issue of a certain kind of information, namely natural, propositional information. I provide a general framework that explains when signals carry this kind of information about their signifieds based upon stable, perfect correlations holding between the two. Hence, I label this the "stable correlation theory". I also argue that there are good reasons to think that neurons in our brains carry natural, propositional information and that their ability to do so is also grounded in stable correlations.

This dissertation seeks to bring together two philosophical literatures: the functions literature from the philosophy of biology, and the functionalist literature in naturalistic metaethics. Biological function suggests both objectivity and normativity: “the function of the heart is to pump blood” is an objective fact, and yet, hearts may malfunction—and malfunctioning is normative. Many ethicists wish to naturalize ethics—to help find a place for human normative lives in the objective natural world. In order to do so, they need tools to analyze humans as the products of evolutionary processes. Humans have a dual inheritance system involving both cultural and genetic inheritance that makes analysis of function for them particularly complex. In this dissertation, I develop a set of conceptual tools for those who wish to naturalize. I begin by developing an account of inheritance that can handle culture. Then, I elaborate the selected effects account of function so that it can handle all the evolutionary strangeness of culture. I then introduce the monolith fallacy—an error often committed by those studying human evolution—a tendency to oversimplify—to emphasize the high degree of complexity involved in any naturalizing project. Finally, I introduce the notion of value-guided functions—a kind of functioning not tied to our intentions, but to our values to round out the picture. I then apply the whole framework to the work of the functional metaethicists: Allan Gibbard, David Wong, Richard Joyce, and Philip Kitcher.

One popular characterization of physicalism is as an empirical prediction about the theoretical objects and properties of future science. It is argued that physicalism so characterized cannot be justified unless an individual has idiosyncratic standards of inductive evidence. An alternative to this characterization of physicalism is a project that justifies physicalism according to the current science: all theoretical objects and properties can either be reduced to or eliminated in favor of the objects and properties of the current physical sciences. The extent to which this type of physicalism can be justified depends on an individual's epistemic rules and prioritization thereof.