While the research programs in early cognitive science and artificial intelligence aimed to articulate what cognition was in ideal terms, much research in contemporary computational neuroscience looks at how and why brains fail to function as they should ideally. This focus on impairment affects how we understand David Marr's hypothesized three levels of understanding. In this essay, we suggest some refinements to Marr's distinctions using a population activity model of cortico-striatal circuitry exploring impulsivity and behavioral inhibition as a case study. (...) In particular, we urge that Marr's computational level should be redefined to include a description of how systems break down. We also underscore that feed-forward processing, cognition disconnected from behavioral context, and representations do not always drive cognition in the way that Marr originally assumed. (shrink)

We present a population density and moment-based description of the stochastic dynamics of domain $${\text{Ca}}^{2+}$$ -mediated inactivation of L-type $${\text{Ca}}^{2+}$$ channels. Our approach accounts for the effect of heterogeneity of local $${\text{Ca}}^{2+}$$ signals on whole cell $${\text{Ca}}^{2+}$$ currents; however, in contrast with prior work, e.g., Sherman et al. :985–995, 1990), we do not assume that $${\text{Ca}}^{2+}$$ domain formation and collapse are fast compared to channel gating. We demonstrate the population density and moment-based modeling approaches using a 12-state Markov chain model (...) of an L-type $${\text{Ca}}^{2+}$$ channel introduced by Greenstein and Winslow :2918–2945, 2002). Simulated whole cell voltage clamp responses yield an inactivation function for the whole cell $${\text{Ca}}^{2+}$$ current that agrees with the traditional approach when domain dynamics are fast. We analyze the voltage-dependence of $${\text{Ca}}^{2+}$$ inactivation that may occur via slow heterogeneous domain [ $${\text{Ca}}^{2+}$$ ]. Next, we find that when channel permeability is held constant, $${\text{Ca}}^{2+}$$ -mediated inactivation of L-type channels increases as the domain time constant increases, because a slow domain collapse rate leads to increased mean domain [ $${\text{Ca}}^{2+}$$ ] near open channels; conversely, when the maximum domain [ $${\text{Ca}}^{2+}$$ ] is held constant, inactivation decreases as the domain time constant increases. Comparison of simulation results using population densities and moment equations confirms the computational efficiency of the moment-based approach, and enables the validation of two distinct methods of truncating and closing the open system of moment equations. In general, a slow domain time constant requires higher order moment truncation for agreement between moment-based and population density simulations. (shrink)

"An essential overview of an important intellectual movement, Logical Empiricism in North America offers the first significant, sustained, and multidisciplinary attempt to understand the intellectual, cultural, and political dimensions of ...

Anthony Giddens’ theory of structuration is a theory of social action, which claims that society should be understood in terms of action and structure; a duality rather than two separate entities. This paper introduces some of the central characteristics of structuration theory, presenting a conceptual framework that helps to explore how people produce the systems and structures that shape their practice. By understanding how people produce and reproduce structures, then there is the potential for changing them. Criticisms that have been (...) raised about the theory are introduced, followed by examples of how the theory might be useful to nursing research. Structuration theory can be employed to explore how nurses produce, reproduce, and transform nursing practice through social interaction across time and space. (shrink)

Although this is an impressive piece of modeling work, I worry that the two models that Wright & Liley have created do not yet provide us with useful empirical information regarding brain processing.

This paper provides new insights into the food security performance of long and short food chains, through an analysis of the resilience of such chains during the severe weather events that occurred in the Australian State of Queensland in early 2011. Widespread flooding cut roads and highways, isolated towns, and resulted in the deaths of people and animals. Farmlands were inundated and there were food shortages in many towns. We found clear evidence that the supermarket-based food chain delivery system experienced (...) significant difficulties in supplying food to flood-affected towns. In contrast, more localized food supply chains—which relied upon supply from growers in peri-urban areas and community-based food initiatives—remained largely intact, and provided food at a time when the supermarkets were limited in their ability to respond to consumer demand. However, on closer examination of food distribution during flooding in the regional city of Rockhampton and in the State capital, Brisbane, the demarcation of success between “long” and “short” food chains became blurred. Both types of food supply chains shared some key resilience characteristics in responding to crisis but diverged in other important ways. We argue that conceptualizing food chains in terms of key elements of resilience—scale, diversity, flexibility and cohesion—may be more fruitful than the short-long dichotomy alone. This approach is particularly useful when prioritizing food security as the basis for evaluating food system sustainability in a context of predicted increases in extreme weather events and future climate change. (shrink)

On the one hand, consciousness seems to be utterly the wrong sort of phenomenon to capture in a scientific theory. On the other hand, theorizing about consciousness does not seem to be beyond the pale of science. This dissertation tries to resolve this dilemma of consciousness for the cognitive sciences by answering the three following questions: What are the appropriate properties of the mind and the brain to study in order to develop a theory of consciousness? What informational role does (...) consciousness play in our psychological life? How does the underlying neurophysiological structure of consciousness relate to higher-level information processing descriptions of consciousness? In discussing these issues, I defend the viability of the project against popular philosophical objections and then develop my own framework for approaching the scientific study of consciousness based on work in neurophysiology, developmental psychology, neurology, cognitive neuropsychology, and cognitive psychology. In particular, this dissertation argues that consciousness is actually a structural property of the brain relative to higher level information processing. ;I argue that qualitative states are aligned with a single and distinct memory system. Understanding how that system works, and how it differs from other systems, should allow us to "decompose" consciousness in a naturalistic framework. Though the operations of our different memory systems are not completely understood, it is clear that our "semantic" memory system can be identified with conscious experience. The study of semantic memory across the various investigative domains within the cognitive sciences bounds the phenomena of consciousness such as to make it amenable to scientific scrutiny. This then gives us a solid interdisciplinary framework in which to begin a thorough study of qualitative experience. (shrink)

To be a philosopher of science means, among other things, to have an account of what scientific explanation is, or, at the very least, to have a response to various accounts of scientific explanation on offer from other philosophies of science while earnestly working toward what one hopes will be one’s own, original account. One presumption clearly and often lying behind such work is that science provides two kinds of knowledge. There is propositional knowledge, “knowledge that” or “knowledge what,” and (...) there is some other kind of knowledge, something beyond propositional knowledge, usually called “knowing why.” We can know that the moon will have such a phase at this or that time, that home sales will always slump following a rise in interest rates, or that probably no two snowflakes are the same shape, without knowing why the moon will have that phase, home sales will fall as interest rates rise, or no two snowflakes have the same shape. But science, so the common contemporary presumption continues, fills in the missing knowledge — it tells us why. How science does this, when it can’t, and what the nature of this sort of knowledge is are precisely the issues that separate theorists of explanation. There are, of course, deflationary views of explanation, which reduce explanation to other properties or eliminate explanation altogether , but these are a decided minority. The vast majority of the work on scientific explanation takes itself to be addressing a certain, distinct, kind of knowledge. This is, moreover, a familiar and introductory point made in philosophical discussions of explanation. I rehearse it here because it has a role to play later, in my discussion of Carl Hempel and Paul Oppenheim’s 1948 article, “Studies in the Logic of Explanation”. (shrink)

Spelling out in detail what we do and do not know about phenomenological experience, this book denies the common view of consciousness as a central decision...

This book is perhaps the first to open a dialogue between the two disciplines.

Robert Wilson (1994) maintains that many interesting and fundamental aspects of psychology are non-individualistic because large chunks of psychology depend upon organisms being deeply embedded in some environment. I disagree and present one version of narrow content that allows enough reference to the environment to meet any wide challenge. I argue that most psychologists are already this sort of narrow content theorist and that these narrow content explanations of psychological phenomena meet Wilson's criteria for being a good explanation better than (...) any wide explanation of the same event. (shrink)

Farah argues that nonlocal models explain clinical data better. However, the locality assumption does not seem so implausible if different sorts of data are taken into account. In particular, priming experiments using evoked response potentials support modularity. I describe some ERP studies relevant to this issue.

Passive frame theory is compatible with modern complexity theory and the idea that conflict drives the emergence of a novel structural organization. After describing new developmental data, we suggest that this conflict needs to be expanded to include not only conflict between action options, but also between action and perception.

While schizophrenia may be genetically determined up to a point, neither it nor its nearest relatives offer any sort of reproductive advantage to its sufferers. Instead, from an evolutionary point of view, schizophrenia is benign – it neither promotes nor inhibits survival to reproduction. Because it is benign, its rate of occurrence should remain fairly constant over time.

or Browse over 3500 reviews in " by Valerie Hardcastle, Ph.D. " _Metapsychology_.

In this essay, I hope to make clearer what the points of division between the materialists and the sceptics are. I argue that the rifts are quite deep and turn on basic differences in understanding the scientific enterprise. In section I, I outline the disagreements between David Chalmers and me, arguing that consciousness is not a brute fact about the world. In section II, I point out the fundamental difference between the materialists and the sceptics, suggesting that this difference is (...) not something that further discussion or argumentation can overcome. In the final section, I outline one view of scientific explanation and conclude that the source of conflict really turns on a difference in the rules each side has adopted in playing the game. (shrink)

There are three basic skeptical arguments against developing a scientific theory of consciousness: theory cannot capture a first person perspective; consciousness is causally inert with respect to explaining cognition; and the notion "consciousness" is too vague to be a natural kind term. Although I am sympathetic to naturalists' counter-arguments, I also believe that most of the accounts given so far of how explaining consciousness would fit into science are incorrect. In this essay, I indicate errors my colleagues on both sides (...) of the fence make in thinking about this issue, as well as outline data relevant to distinguishing conscious states from unconscious ones empirically. (shrink)

On the one hand, we think that our conscious perceptions are tied to some stage of whatever processing stream we have. On the other hand, we think that our conscious experiences have to resemble the computational states that instantiate them. However, nothing in our alleged stream resembles our experienced perceptions. Hence, a conflict. The question is: How can we go from what we know about neurons, their connections, and firing patterns, to explaining what conscious perceptual experiences are like? No intuitive (...) answer seems plausible. Our perceptual experiences are complex and unified; however, brains divide their processing tasks into small chunks and segregate those smaller pieces across the gray matter. In this essay, I conjecture that what corresponds to our visual perceptions are higher order patterns of bifurcation in an attractor phase space. If I am correct, then the problem of the explanatory gap in philosophy, the binding problem in psychology, and the problem of perception in neuroscience disappear. If the traditional computational perspective is wrong, and sensory processing is not piece-meal, step-wise, and segregated, then there is no need for something in the head to tie things together. (shrink)

The data discussed strongly suggest that neural imaging does not unduly sway judges and jurors; in fact, it is often counterproductive. The percentage of appellate cases in which the decision was favorable to defendants with brain scan data mirrored those of decisions without such proffered evidence. Moreover, fully two-thirds of the scans admitted were either inconclusive or showed normal brain structures. In decisions referencing brain scans, judges mentioned defendant behavior significantly more often than they referred to the defendant’s brain. Finally, (...) in the actual decisions themselves, judges often ignored relevant imaging data in favor of case precedent or misinterpreted the data so that they would fit with the judges’ initial reactions and opinions. (shrink)

In Sisyphus's Boulder, Eric Dietrich and Valerie Hardcastle argue that we will never get such a theory because consciousness has an essential property that..

What is required to be an interdisciplinary theory in cognitive science is for it to span more than one traditional domain. Generally speaking, as I discuss ...

In lieu of an abstract, here is a brief excerpt of the content:Philosophy, Psychiatry, & Psychology 10.4 (2003) 353-355 [Access article in PDF] Emotions and Narrative Selves Valerie Gray Hardcastle In their commentaries, both Phillips (2003) and Woody (2003) agree that the affective side of personhood needs to be better addressed in narrative views of self. In their arguments, they focus mainly on how a patient or a subject is here and now. In contrast, Kennett and Matthews (2003) take (...) a longer view and argue for the importance of a diachronic unity for selfhood. This commentary seeks to integrate these views by discussing how emotions are central to building our personal sense of unified agency. 1Phillips and Woody are right: most philosophical discussions of the narrative view of self are overly cognitive and focus too much attention on our linguistic story-telling abilities and not enough on what it is like to be a person experiencing the world. This is too bad, for it is our affective reactions that drive our personal life narratives. Consider: of all the experiences in the world, we only chose a small subset to become or represent who we are. I regularly eat cold cereal for breakfast before heading off to work, but if you ask me to describe myself, I describe my work or my children, not my breakfast-eating habits. Why is this? I identify with my work, my family life, or my play, but not with my sleeping patterns, the trajectories I chose when I drive, or how I brush my teeth. How is it that I have selected the former activities to highlight in my self-stories, but not the latter?I maintain that I choose the former because I have strong affective ties to them, ties that I do not have to driving routes or personal hygiene. And these ties are what determine what gets into our narratives of self. Actually, my claim is stronger than that. I believe that our emotions not only color what we do but they also allow us to act in the first place (this discussion is greatly expanded in my forthcoming book).Humans delight in pretending that our most prized and most humanly attribute is our forebrain, which houses, we also pretend, our capacity for rational thought. Since Plato at least we have held that subduing our passions to the iron rule of reason is our supreme aspiration; it is the ideal for human cognition. Ironically, we think that the more we are like Star Trek's alien Mr. Spock, the more human we really are.But what would life really be like with an overdeveloped forebrain and without emotion? Let us consider more carefully what it is we really prize about being human. We can rationalize well, it is true, but we do so in the service of personal goals. As Aristotle reminds us, we have practical rationality; we have means-ends reasoning with a point. This is just another way of saying that it is imperative that we identify what is important to us prior to cognizing.Obviously, one might scoff, we need an end to engage in means-ends reasoning. But often, I think, what having an end entails is not well appreciated. These days it is fashionable to believe that our fundamental ends—survival and reproduction—are set by our biology and that all [End Page 353] other ends (or most other ends) derive from them in some fashion. Maybe this story is true, but it obscures how ends—whether they be hardwired in or they come later—function in the human psyche.At a bare minimum, that we have particular ends tells us that we have to tag our abstractions, interpretations, and matched patterns with valances—some things are good, some things are bad, and some are indifferent. Tagging our experiences thus is just what it means to have emotions; we are reacting affectively to our world around us. And it is these reactions that determine which inputs we respond to and which we ignore. We literally cannot move about in our world without emotion. I think, perhaps, that this fact is what Phillips and Woody are... (shrink)

Given what we know about the segregated nature of the brain and the relative absence of multi-modal association areas in the cortex, how percepts become unified is not clear. However, if we could work out how and where the brain joins together segregated outputs, we would have a start in localizing the neuronal processes that correlate with conscious perceptual experiences. In this essay, I critically examine data relevant for understanding the neurophysiological underpinnings of perception. In particular, I examine the possibility (...) that 40 Hz. oscillatory firing patterns in cortex are important lower-level neuronal events related to perceptual experiences. I suggest that `binding' - understood as a process of hooking together disparate psychological units - reduces to a property inherent in the structure of our brain's firing patterns. However, this reduction may not reflect the firing rates of individual cells, but instead a `higher level' order superimposed on individual cells' activity. (shrink)