John Bickle

Reducing mind to molecular pathways: explicating the reductionism implicit in current cellular and molecular neuroscience

As opposed to the dismissive attitude toward reductionism that is popular in current philosophy of mind, a “ruthless reductionism” is alive and thriving in “molecular and cellular cognition”—a field of research within cellular and molecular neuroscience, the current mainstream of the discipline. Basic experimental practices and emerging results from this field imply that two common assertions by philosophers and cognitive scientists are false: (1) that we do not know much about how the brain works, and (2) that lower-level neuroscience cannot explain cognition and complex behavior directly. These experimental practices involve intervening directly with molecular components of sub-cellular and gene expression pathways in neurons and then measuring specific behaviors. These behaviors are tracked using tests that are widely accepted by experimental psychologists to study the psychological phenomenon at issue (e.g., memory, attention, and perception). Here I illustrate these practices and their importance for explanation and reduction in current mainstream neuroscience by describing recent work on social recognition memory in mammals.

Neuroeconomics, neurophysiology and the common currency hypothesis

We briefly describe ways in which neuroeconomics has made contributions to its contributing disciplines, especially neuroscience, and a specific way in which it could make future contributions to both. The contributions of a scientific research programme can be categorized in terms of (1) description and classification of phenomena, (2) the discovery of causal relationships among those phenomena, and (3) the development of tools to facilitate (1) and (2). We consider ways in which neuroeconomics has advanced neuroscience and economics along each line. Then, focusing on electrophysiological methods, we consider a puzzle within neuroeconomics whose solution we believe could facilitate contributions to both neuroscience and economics, in line with category (2). This puzzle concerns how the brain assigns reward values to otherwise incomparable stimuli. According to the common currency hypothesis, dopamine release is a component of a neural mechanism that solves comparability problems. We review two versions of the common currency hypothesis, one proposed by Read Montague and colleagues, the other by William Newsome and colleagues, and fit these hypotheses into considerations of rational choice.

Psychoneural reduction of the genuinely cognitive: Some accomplished facts

Abstract The need for representations and computations over their contents in psychological explanations is often cited as both the mark of the genuinely cognitive and a source of skepticism about the reducibility of cognitive theories to neuroscience. A generic version of this anti‐reductionist argument is rejected in this paper as unsound, since (i) current thinking about associative learning emphasizes the need for cognitivist resources in theories adequate to explain even the simplest form of this phenomena (Pavlovian conditioning), and yet (ii) the most widely accepted recent theory of associative learning, which utilizes cognitivist resources, has already been reduced to a purely neurophysiological account. Psychoneural reduction of genuinely cognitivist theories is thus already an accomplished scientific fact, despite pronouncements by anti‐reductionists about its conceptual impossibility or empirical implausibility. In addition, the specific form of reduction involved in this case (“combinatorial”...

Has the last decade of challenges to the multiple realization argument provided aid and comfort to psychoneural reductionists

The previous decade has seen renewed critical interest in the multiple realization argument. These criticisms constitute a “second wave” of challenges to this central argument in late-20th century philosophy of mind. Unlike the first wave, which challenged the premise that multiple realization is inconsistent with reduction or type identity, this second wave challenges the truth of the multiple realization premise itself. Since psychoneural reductionism was prominent among the explicit targets of the multiple realization argument, one might think that this second wave of challenges provides important aid and comfort to reductionists. In this paper, however, I provide reasons for thinking it does not. This is not to the detriment of psychoneural reductionism because, as I also argue here, and unrecognized by the current non-reductive orthodoxy in philosophy of mind, one key argument among the first wave of criticisms of the multiple realization argument has never been adequately rejoined.

Connectionism, eliminativism, and the semantic view of theories

Recently some philosophers have urged that connectionist artificial intelligence is (potentially) eliminative for the propositional attitudes of folk psychology. At the same time, however, these philosophers have also insisted that since philosophy of science has failed to provide criteria distinguishing ontologically retentive from eliminative theory changes, the resulting eliminativism is not “principled”. Application of some resources developed within the semantic view of scientific theories, particularly recent formal work on the theory reduction relation, reveals these philosophers to be wrong in this second contention, yet by and large correct in the first.

A Functional Hypothesis for LGN-V1-TRN Connectivities Suggested by Computer Simulation

We employ computer simulation to investigate the function of neural circuitries between thalamic sensory relay nuclei, primary sensory cortices, and the thalamic reticular nucleus (TRN). Computational similarities exist between these circuits and the architecture of a simple artificial neural network. We impose processing parameters on this network architecture in keeping with anatomical and physiological details of the mammalian geniculo-cortical visual pathway, and then run the simulation on a task involving multiple simultaneous inputs from the simulated visual field. After two to three loops through the simulation, activity in cortical and thalamic units whose receptive fields include the stronger stimulus remains constant, while activity in other cortical and thalamic units activated by weaker stimuli declines toward resting values. These results suggest that the modeled neural circuitry functions to “prime” selective attentional mechanisms further up the visual streams toward specific portions of the total visual stimulus. Besides extending existing models and evidence about the function of these neural circuits, our results also provide physiologists with predicted activity profiles of thalamic and cortical elements of the modeled neural system for a task not yet studied experimentally.

Mental Anomaly and the New Mind-Brain Reductionism

Davidsons principle of the anomalousness of the mental was instrumental in discrediting once-popular versions of mind-brain reductionism. In this essay I argue that a novel account of intertheoretic reduction, which does not require the sort of cross-theoretic bridge laws that Davidsons principle rules out, allows a version of mind-brain reductionism which is immune from Davidsons challenge. In the final section, I address a second worry about reductionism, also based on Davidsons principle, that survives this response. I argue that new reductionists should revise some significant details of the program, particularly the conception of theories, to circumvent this more potent Davidson-inspired worry.

Revolutions in Neuroscience: Tool Development

Thomas Kuhn’s famous model of the components and dynamics of scientific revolutions is still dominant to this day across science, philosophy, and history. The guiding philosophical theme of this article is that, concerning actual revolutions in neuroscience over the past 60 years, Kuhn’s account is wrong. There have been revolutions, and new ones are brewing, but they do not turn on competing paradigms, anomalies, or the like. Instead, they turn exclusively on the development of new experimental tools. I adopt a metascientific approach and examine in detail the development of two recent neuroscience revolutions: the impact of engineered genetically mutated mammals in the search for causal mechanisms of “higher” cognitive functions; and the more recent impact of optogenetics and designer receptors exclusively activated by designer drugs (DREADDs). The two key metascientific concepts, I derive from these case studies are a revolutionary new tool’s motivating problem, and its initial and second-phase hook experiments. These concepts hardly exhaust a detailed metascience of tool development experiments in neuroscience, but they get that project off to a useful start and distinguish the subsequent account of neuroscience revolutions clearly from Kuhn’s famous model. I close with a brief remark about the general importance of molecular biology for a current philosophical understanding of science, as comparable to the place physics occupied when Kuhn formulated his famous theory of scientific revolutions.

Molecular neuroscience to my rescue (again): Reply to looren de jong & schouten

In their review essay (published in this issue), Looren de Jong and Schouten take my 2003 book to task for (among other things) neglecting to keep up with the latest developments in my favorite scientific case study (memory consolidation). They claim that these developments have been guided by psychological theorizing and have replaced neurobiologys traditional ‘static’ view of consolidation with a ‘dynamic’ alternative. This shows that my ‘essential but entirely heuristic’ treatment of higher-level cognitive theorizing is a mistaken view of actual scientific practice. In response I contend that, on the contrary, a closer look at the memory reconsolidation following reactivation experiments and data suggests (1) a less revolutionary judgment about the proposed alternative, and (2) a now-complete reliance on ruthlessly reductive experimental methods from cellular and molecular neuroscience. These conclusions save the heuristic status I propose for higher-level investigations of behavior and brain. I close with a brief comment on their further charge that I ‘sell out’ philosophy of science to factual developments in science itself.

Integration of Nanoscale Science and Technology into Undergraduate Curricula

An interdisciplinary group at the University of Cincinnati was recently awarded an NSF Nanotechnology Undergraduate Education grant, Integration of Nanoscale Science and Engineering into Undergraduate Curricula. The faculty come from Engineering, Physics, Chemistry, and Philosophy departments. The overall goal of this project is to incorporate nanotechnology education into undergraduate curricula in the Colleges of Engineering and Arts & Sciences. This paper will discuss the material taught in the two courses and the reaction of the students to highly interdisciplinary team teaching of nanotechnology. The lectures provide an overview of nanoscale science and engineering, with applications in nanomaterials, nanophotonics, nanoelectronics, nanomechanics, and bionanosystems. We also include lectures on societal and ethical implications of the nanoscale. The laboratory modules give students hands-on experience including synthesis of nanoparticles and nanotubes, and subsequent characterization with multiple stations of atomic force microscopes and laser spectrometers.