Dynamic mechanistic explanation: computational modeling of circadian rhythms as an exemplar for cognitive science

We consider computational modeling in two fields: chronobiology and cognitive science. In circadian rhythm models, variables generally correspond to properties of parts and operations of the responsible mechanism. A computational model of this complex mechanism is grounded in empirical discoveries and contributes a more refined understanding of the dynamics of its behavior. In cognitive science, on the other hand, computational modelers typically advance de novo proposals for mechanisms to account for behavior. They offer indirect evidence that a proposed mechanism is adequate to produce particular behavioral data, but typically there is no direct empirical evidence for the hypothesized parts and operations. Models in these two fields differ in the extent of their empirical grounding, but they share the goal of achieving dynamic mechanistic explanation. That is, they augment a proposed mechanistic explanation with a computational model that enables exploration of the mechanism’s dynamics. Using exemplars from circadian rhythm research, we extract six specific contributions provided by computational models. We then examine cognitive science models to determine how well they make the same types of contributions. We suggest that the modeling approach used in circadian research may prove useful in cognitive science as researchers develop procedures for experimentally decomposing cognitive mechanisms into parts and operations and begin to understand their nonlinear interactions.     

Disciplines,models, and computers: The path to computational quantum chemistry

Many disciplines and scientific fields have undergone a computational turn in the past several decades. This paper analyzes this sort of turn by investigating the case of computational quantum chemistry. The main claim is that the transformation from quantum to computational quantum chemistry involved changes in three dimensions. First, on the side of instrumentation, small computers and a networked infrastructure took over the lead from centralized mainframe architecture. Second, a new conception of computational modeling became feasible and assumed a crucial role. And third, the field of computational quantum chemistry became organized in a market-like fashion and this market is much bigger than the number of quantum theory experts. These claims will be substantiated by an investigation of the so-called density functional theory (DFT), the arguably pivotal theory in the turn to computational quantum chemistry around 1990.     

Constitutive relevance in cognitive science: The case of eye movements and cognitive mechanisms

In this paper I assess whether the recently proposed “No De-Coupling” (NDC) theory of constitutive relevance in mechanisms is a useful tool to reconstruct constitutive relevance investigations in scientific practice. The NDC theory has been advanced as a framework theoretically superior to the mutual manipulability (MM) account of constitutive relevance in mechanisms but, in contrast to the MM account, has not yet been applied to detailed case studies. I argue that the NDC account is also applicable to empirical practice and that it fares better than the MM account on both theoretical and empirical grounds. I elaborate these claims in terms of applications of the NDC theory to two case studies of cognitive science research on the role of eye movements in mechanisms for cognitive capacities.     

Circadian rhythms and their mechanisms

Summary Recent work concerning the number, site(s) and means of adjustment to the 24-h day of internal clocks is reviewed. Work on humans is considered wherever possible though much of the work involving ablation and in vitro techniques necessarily involves other species, particularly rodents. It is concluded that, though recent advances have been impressive and present techniques appear likely to continue to produce results and stimulate discussion, more attention should be directed to considering the circadian system as a whole rather than as an assemblage of individual components.     

Earthquake prediction,biological clocks,and the cold war psy-ops: Using animals as seismic sensors in the 1970s California

A familiar story of seismology is that of a small field originally focused on local studies of earthquakes through diverse disciplinary perspectives being transformed, in the second half of the twentieth century, into a highly specialized field focused on global studies of the earth's deep interior via sophisticated instruments and transnational networks of seismological stations. Against this backdrop, this essay offers a complementing account, highlighting the significance of local circumstances and disciplinary agendas that were contingent not only on transformations in the geophysical sciences but also on the concurrently changing biological sciences during the Cold War. Using examples of the studies of unusual animal behavior prior to earthquakes conducted under the auspices of the US Geological Survey on the West Coast of the United States in the 1970s, this essay examines a variety of motivations behind the attempts to bridge geophysics and biology. These examples illustrate the ways in which earthquake prediction became entangled with concerns over the use of seismological data, pioneering research on biological rhythms, and the troubled field of Cold War-driven military brain studies.