The thermodynamic cost of fast thought

After more than sixty years, Shannon's research [1-3] continues to raise fundamental questions, such as the one formulated by Luce [4,5], which is still unanswered: "Why is information theory not very applicable to psychological problems, despite apparent similarities of concepts?" On this topic, Pinker [6], one of the foremost defenders of the computational theory of mind [6], has argued that thought is simply a type of computation, and that the gap between human cognition and computational models may be illusory. In this context, in his latest book, titled Thinking Fast and Slow [8], Kahneman [7,8] provides further theoretical interpretation by differentiating the two assumed systems of the cognitive functioning of the human mind. He calls them intuition (system 1) determined to be an associative (automatic, fast and perceptual) machine, and reasoning (system 2) required to be voluntary and to operate logical- deductively. In this paper, we propose an ansatz inspired by Ausubel's learning theory for investigating, from the constructivist perspective [9-12], information processing in the working memory of cognizers. Specifically, a thought experiment is performed utilizing the mind of a dual-natured creature known as Maxwell's demon: a tiny "man-machine" solely equipped with the characteristics of system 1, which prevents it from reasoning. The calculation presented here shows that [...]. This result indicates that when the system 2 is shut down, both an intelligent being, as well as a binary machine, incur the same energy cost per unit of information processed, which mathematically proves the computational attribute of the system 1, as Kahneman [7,8] theorized. This finding links information theory to human psychological features and opens a new path toward the conception of a multi-bit reasoning machine.

Ag-dependent (in silico) approach implies a deterministic kinetics for homeostatic memory cell turnover

Verhulst-like mathematical modeling has been used to investigate several complex biological issues, such as immune memory equilibrium and cell-mediated immunity in mammals. The regulation mechanisms of both these processes are still not sufficiently understood. In a recent paper, Choo et al. [J. Immunol., v. 185, pp. 3436-44, 2010], used an Ag-independent approach to quantitatively analyze memory cell turnover from some empirical data, and concluded that immune homeostasis behaves stochastically, rather than deterministically. In the paper here presented, we use an in silico Ag-dependent approach to simulate the process of antigenic mutation and study its implications for memory dynamics. Our results have suggested a deterministic kinetics for homeostatic equilibrium, what contradicts the Choo et al. findings. Accordingly, our calculations are an indication that a more extensive empirical protocol for studying the homeostatic turnover should be considered.