Feedback control in neural systems is ubiquitous. Here we study the mathematics of nonlinear feedback control. We compare models in which the input is multiplied by a dynamic gain (multiplicative control) with models in which the input is divided by a dynamic attenuation (divisive control). The gain signal (resp. the attenuation signal) is obtained through a concatenation of an instantaneous nonlinearity and a linear low-pass filter operating on the output of the feedback loop. For input steps, the dynamics of gain (...) and attenuation can be very different, depending on the mathematical form of the nonlinearity and the ordering of the nonlinearity and the filtering in the feedback loop. Further, the dynamics of feedback control can be strongly asymmetrical for increment versus decrement steps of the input. Nevertheless, for each of the models studied, the nonlinearity in the feedback loop can be chosen such that immediately after an input step, the dynamics of feedback control is symmetric with respect to increments versus decrements. Finally, we study the dynamics of the output of the control loops and find conditions under which overshoots and undershoots of the output relative to the steady-state output occur when the models are stimulated with low-pass filtered steps. For small steps at the input, overshoots and undershoots of the output do not occur when the filtering in the control path is faster than the low-pass filtering at the input. For large steps at the input, however, results depend on the model, and for some of the models, multiple overshoots and undershoots can occur even with a fast control path. (shrink)

A naturalistic theory of intentionality is proposed that differs from previous evolutionary and tracking theories. Full-blown intentionality is constructed through a series of evolvable refinements. A first, minimal version of intentionality originates from a conjectured internal process that estimates an organism’s own fitness and that continually modifies the organism. This process produces the directedness of intentionality. The internal estimator can be parsed into intentional components that point to components of the process that produces fitness. It is argued that such intentional (...) components can point to mistaken or non-existing entities. Different Fregian senses of the same reference correspond to different components that have different roles in the estimator. Intentional components that point to intentional components in other organisms produce directedness towards semi-abstract entities. Finally, adding a general, population-wide means of communication enables intentional components that point to fully abstract entities. Intentionality thus naturalized has all of its expected properties: being directed; potentially making errors; possibly pointing to non-existent, abstract, or rigid entities; capable of pointing many-to-one and one-to-many; distinguishing sense and reference; having perspective and grain; and having determinate content. Several examples, such as ‘swampman’ and ‘brain-in-a-vat’, illustrate how the theory can be applied. (shrink)

Living organisms appear to have agency, the ability to act freely, and humans appear to have free will, the ability to rationally decide what to do. However, it is not clear how such properties can be produced by naturalistic processes, and there are indeed neuroscientific measurements that cast doubt on the existence of free will. Here I present a naturalistic theory of agency, consciousness, and free will. Elementary forms of agency evolved very early in the evolution of life, utilizing an (...) extension of the basic Darwinian scheme that combines and entangles deterministic and stochastic causation. The extension effectively produces an active form of causation, as well as meaning intrinsic to the organism. Consciousness arose when animals evolved advanced nervous systems and social lifestyles that enabled communication mutually affecting each animal’s intrinsic meaning. I argue that various forms of agency that subsequently arose in evolution, preconscious, conscious, intelligent, symbolic, and rational agency, still coexist in humans. This coexistence, combined with the fact that agency is not instantaneous but takes time to build up, makes simple interpretations of neuroscientific results on free will problematic. The conclusion of the study is that conscious free will, including a form of agent causation, is fully consistent with a naturalistic world-view and can be produced by the specific processes discussed. The result closely resembles existing approaches to life and mind that are inspired by phenomenology. (shrink)

Biological organisms appear to have agency, goals, and meaningful behaviour. One possibility is that this is mere appearance, where such properties are not real, but only ‘as if’ consequences of the physiological structure of organisms. Another possibility is that these properties are real, as emerging from the organism's structure and from how the organism interacts with its environment. Here I will discuss a recent theory showing that the latter position is most likely correct, and argue that the theory is largely (...) consistent with the basics of the field of biosemiotics. The theory can be represented as a triad that resembles the semiotic triad proposed by Peirce, which connects a sign with its object through a process of interpretation. In the theory presented, the sign is an internalized version of fitness which refers to the true fitness through a feedback loop that in effect produces interpretation. The feedback loop entangles deterministic and stochastic forms of causation in such a way that genuine agency, goal-directedness, and their associated meaning emerge. It produces a strong form of emergence not reducible to its constituents. The result is that novel phenomena arise that are real and necessary components for a complete understanding of living organisms. (shrink)

The causal efficacy of a material system is usually thought to be produced by the law-like actions and interactions of its constituents. Here, a specific system is constructed and explained that produces a cause that cannot be understood in this way, but instead has novel and autonomous efficacy. The construction establishes a proof-of-feasibility of strong emergence. The system works by utilizing randomness in a targeted and cyclical way, and by relying on sustained evolution by natural selection. It is not vulnerable (...) to standard arguments against strong emergence, in particular ones that assume that the physical realm is causally closed. Moreover, it does not suffer from epiphenomenalism or causal overdetermination. The system uses only standard material components and processes, and is fully consistent with naturalism. It is discussed whether the emergent cause can still be viewed as ‘material’ in the way that term is commonly understood. (shrink)

A new theory that naturalizes biological function is explained and compared with earlier etiological and causal role theories. Etiological theories explain functions from how they are caused over their evolutionary history. Causal role theories analyze how functional mechanisms serve the current capacities of their containing system. The new proposal unifies the key notions of both kinds of theories, but goes beyond them by explaining how functions in an organism can exist as factors with autonomous causal efficacy. The goal-directedness and normativity (...) of functions exist in this strict sense as well. The theory depends on an internal physiological or neural process that mimics an organism’s fitness, and modulates the organism’s variability accordingly. The structure of the internal process can be subdivided into subprocesses that monitor specific functions in an organism. The theory matches well with each intuition on a previously published list of intuited ideas about biological functions, including intuitions that have posed difficulties for other theories. (shrink)

The causal structure of Darwinian evolution by natural selection is investigated. Its basic scheme is reproduction resulting from a feedback loop driven by internal and external causes. Causation internal to the loop connects genotype, development, phenotype, and fitness, with environmental constraints on the latter preventing runaway reproduction. External causes driving the core loop are environmental change and genetic change. This basic causal structure is complicated by modern additions such as control of mutation rate, niche construction, interactions between evolution and development, (...) and epigenetic effects. In this article it is argued that at least one of these additions, control of mutation rate, produces an additional feedback loop incorporating a continual, targeted modulation of stochasticity, and thereby produces an unusual form of causation. This form of causation entangles deterministic and stochastic causation in such a way that it imposes, in effect, an active, goal-driven role on the organisms in a line of descent. The goal is defined by the factor driving the stochasticity, which must be regarded as an intrinsic estimate made implicitly by the organism of its own fitness. The estimator itself is an evolved property of the organism, and is aligned with the apparent goal-directedness of natural selection. (shrink)

Recently developed extensions of evolutionary theory are used to explain the human self as an evolved, unitary, and purposeful phenomenon. A basic mechanism that can generate life's agency and goal-directedness is combined with mechanisms that can account for awareness by and of the self, and for the social characteristics of humans. The new theory is largely consistent with major existing theories of the self, in particular theories centred on self-esteem, self-determination theory, and terror management theory. It can therefore be regarded (...) as a meta-theory that brings these theories, and related ones, within a common evolutionary framework. The theory suggests two primary dimensions of the self, the depth of awareness of the self and the social extent of the self. A revised and updated version of this paper can be found as Chapter 13 ('The human self') in my book 'The estimator theory of life and mind: how agency and consciousness can emerge', see VANTET-8 at philpapers . (shrink)

This book provides a comprehensive overview of my recent theoretical work that aims to explain some of the more puzzling properties of life and mind, in particular agency, goal-directedness and consciousness. It contains published papers as well as new material. Table of contents: Preface - PART I: GROUNDWORK - 1. Introduction - 2. The basic mechanism - 3. Inclusive and extensive fitness - 4. Components of F and X - 5. The consequences: a preview - PART II: LIFE - 6. (...) What qualifies as life? - 7. Biological meaning - 8. Biological functions - PART III: MIND - 9. Minimal agency, goal-directedness and value - 10. Intentionality and meaning - 11. Language - 12. Consciousness - 13. The human self - PART IV: PHILOSOPHY - 14. Strong emergence - 15. The real, the true and the good - 16. Philosophical problems of consciousness - Epilogue - Appendix A: Summaries of computational simulations - Appendix B: Examples of minimal intentionality - References. -/- . (shrink)

A recently developed computational and neurobiological theory of phenomenal consciousness is applied to a series of persistent philosophical problems of consciousness (in recent formulations by Tye, Searle, and Chalmers). Each problem has a clear solution according to this theory, as is briefly explained here. A slightly modified version of this paper can be found as Chapter 16 ('Philosophical problems of consciousness') in my book 'The estimator theory of life and mind: how agency and consciousness can emerge', see VANTET-8 at philpapers (...) . (shrink)

The origin and development of consciousness is poorly understood. Although it is clearly a naturalistic phenomenon evolved through Darwinian evolution, explaining it in terms of physicochemical, neural, or symbolic mechanisms remains elusive. Here I propose that two steps had to be taken in its evolution. First, living systems evolved an intrinsic goal-directedness by internalizing Darwinian fitness as a self-estimated fitness. The self-estimated fitness participates in a feedback loop that effectively produces intrinsic meaning in the organism. Second, animals with advanced nervous (...) systems evolved a special form of communication that modifies the way each partner estimates fitness. The resulting change in intrinsic meaning is experienced subjectively as a primary form of consciousness. This primary form is subsequently used to generate, partly through internalized dialogue, more complex forms of consciousness, such as consciousness of the natural and social worlds, consciousness of the self, and language-dependent forms of consciousness. An updated version of the theory in this paper can be found as Chapter 12 ('Consciousness') in my book 'The estimator theory of life and mind: how agency and consciousness can emerge', see VANTET-8 at philpapers . (shrink)

This Letter to the Editor is a comment on a paper by Rodríguez Higuera (Biosemiotics 9, 155–167, 2016) that refers to a paper by van Hateren (Biosemiotics 8, 403–419, 2015). The comment argues that semiosis (i.e., the making of meaning) has biological roots in an internal process X occurring within all forms of life. This internal process produces, in effect, an approximation (i.e., an estimate) of the fitness of an organism. X subsequently drives a purely stochastic process of structural (...) change within the organism. This results in primordial forms of semiosos, agency, and aboutness. It is argued that the way this is produced should be regarded as a form of strong emergence, because it results in novel causal powers that are not equivalent to the combined causal powers of the composing parts of the system. -/- . (shrink)

Invited book review of R. P. Thompson, A remarkable journey: The story of evolution (Reaktion Books, 2015).

The objective of the new series, "Molecular Biology, Biochemistry and Biophysics", of which this brochure forms the first volume, is to produce more than another compilation of data. It is hoped that the new series will help the individual "specialist" keep abreast of important developments in the natural sciences at the molecular and subcellular level in fields complementary to his own. The predominant aim is not so much to increase the ever-growing body of information in an encyclopedic fashion but rather (...) to give, in addition to a well rounded factual presentation of subjects which have reached a degree of maturation, a leitmotiv developed by the individual authors from a more personal point of view. The reader should thus be able to use these mono graphs not only for acquisition of knowledge but as a source of further motiva tion in his own work. This latter and more consequential aim of the monograph series is one of the reasons for presenting here a most unusual talk which should enable the reader to sit back and view his own efforts in the context of science and creative attempts as a whole. The lecture is the virtually unknown inaugural address of the Dutch physical chemist JACOBUS HENRICUS VAN'T HOFF. As is shown in his short biography presented on pages 3 and 4 the principal thoughts of the molecular biologist of today are akin to his own and he clearly recognized the universality of molecular life processes. (shrink)

Results of two survey studies are presented. It is shown that attitudes of the public about "technology in general" are not stable and can easily be affected by how the subject is introduced. Eight areas of technology are compared on the basis of empirical relations in attitudinal judgments, in attribute ratings, in self- assigned importance weights of attributes, and in importance of reference groups and persons. On the basis of similarities in these four kinds of judgments, three clusters of technology (...) areas were identified: a cluster of modern reproductive technologies, an information cluster containing automation, computer, and communication technologies, and a cluster containing nuclear energy and military technology. The attitude toward "technology in general" can not be considered as an aggregation of attitudes toward these areas of technology: The relations between general attitude and specific attitudes are only moderate to negligible. (shrink)

The Dutch law states that a physician may perform euthanasia according to a written advance euthanasia directive when a patient is incompetent as long as all legal criteria of due care are met. This may also hold for patients with advanced dementia. We investigated the differing opinions of physicians and members of the general public on the acceptability of euthanasia in patients with advanced dementia.

In this article, an ethical analysis of an educational programme on renal replacement therapy options for patients and their social network is presented. The two main spearheads of this approach are: (1) offering an educational programme on all renal replacement therapy options ahead of treatment requirement and (2) a home-based approach involving the family and friends of the patient. Arguments are offered for the ethical justification of this approach by considering the viewpoint of the various stakeholders involved. Finally, reflecting on (...) these ethical considerations, essential conditions for carrying out such a programme are outlined. The goal is to develop an ethically justified and responsible educational programme. (shrink)

Objectives: To investigate why physicians label end-of-life acts as either ‘euthanasia/ending of life’ or ‘alleviation of symptoms/palliative or terminal sedation’, and to study the association of such labelling with intended reporting of these acts. Methods: Questionnaires were sent to a random, stratified sample of 2100 Dutch physicians. They were asked to label six hypothetical end-of-life cases: three ‘standard’ cases and three cases randomly selected, that varied according to type of medication, physician’s intention, type of patient request, patient’s life expectancy and (...) time until death. We identified the extent to which characteristics of cases are associated with physician’s labelling, with multilevel multivariable logistic regression. Results: The characteristics that contributed most to labelling cases as ‘euthanasia/ending of life’ were the administration of muscle relaxants or disproportional morphine. Other important factors were an intention to hasten death and a life expectancy of several months. Physicians were much more willing to report cases labelled as ‘euthanasia’ or ‘ending of life’ than other cases. Conclusions: Similar cases are not uniformly labelled. However, a physicians’ label is strongly associated with their willingness to report their acts. Differences in how physicians label similar acts impede complete societal control. Further education and debate could enhance the level of agreement about what is physician-assisted dying, and thus should be reported, and what not. (shrink)