Cognition

The general issue that we address in this chapter is whether and how, from the autonomous perspective, cognitive phenomena can be understood as a specific and highly complex class of interactive capacities, stemming from the evolutionary complexification of agency.

1. 1.

   It is worth noting that there are other authors belonging to the autonomous perspective, such as Hooker, Bickhard, Christensen, and Collier, who do not identify life with cognition. In very broad terms this group seeks, as we do, to characterise cognition in more restrictive organisational terms than just the possession of agency. However, whereas they look to increased behavioural capacities as the primary discriminating dimension, our focus is on understanding the increasing functional capacity and complexity of the underlying biological organisation. The approaches are compatible with one another in principle. Yet, because of the specificity of the constraints imposed by the embodiment of functional capacities, we consider our own approach the more fundamental and do not pursue behavioural alternatives here.

2. 2.

   This is not to say that an increase in complexity implies an evolutionary advantage; viruses and bacteria are “as adaptive” as, for instance, large primates. We just assume that evolution has explored new forms of organisation, and some of these are more complex. Increase in organismic complexity during the course of evolution can be explained by the fact that, starting from a simple base, there was nowhere else to go (Gould 1988, 2002).

3. 3.

   Many of the ideas of this section are taken from Arnellos and Moreno (in press).

4. 4.

   The path followed by organisms to grow in size is multicellularity because cells seem to be unable to overcome certain size limits. According to Bonner, this has to do with energy considerations: “if one thinks of the rates of different chemical processes occurring within the cell, the distances needed for diffusion, the surface boundaries needed for isolating different chemical components of the motor, and so forth, all of these lead to the conclusion that there is an optimal size with sharp upper and lower limits, which is the size found in nature” (Bonner 1988: 61). For others (Vogel 1988), it has to do with the appropriate size for transmitting genetic products via diffusion. In fact, both arguments point to a similar problem, namely, the progressive difficulty of maintaining a molecularly based metabolic and reproductive organisation as size increases. (Moreno and Exteberria 2005)

5. 5.

   Actually, the constitutive cells of M. xanthus could live independently. When they do not find sufficient nutrients, they aggregate to form raised pigmented mounds, termed fruiting bodies.

6. 6.

   This is three times slower than unicellular paramecia, which move by means of numerous cilia beating in a coordinated way at rates of up to 2 mm/s.

7. 7.

   Actually, this is a convenient simplification, because in fact the metabolic system sustains the neuro-muscular system; moreover, it also affects it (e.g. when exercise, skeletal growth, or injury demands an adaptation of the neural system), and is affected by it, directly via the neuro-endocrine system and indirectly via directing behaviour (e.g. forcing exertion until organs start to dissolve).

8. 8.

   Neurons are different from other cells in that they are capable of forming branches that are interconnected through plastic electrochemical pathways and are capable of propagating and modulating potential electrical variability (see next section).

9. 9.

   This is not to say that neurons only establish connections among themselves. In fact, neurons connect with practically all other types of cell in the body.

10. 10.

    It is commonly accepted that the primary operational primitives of the nervous system are the changes of neuron membrane action potentials over time (generally in the form of spikes), which conserve dynamic variability in terms of spike frequencies and time distance between spikes. Synaptic connections, on the other hand, specify a connectivity matrix (the transformation functions between primary operational primitives). Actually, the basic connectivity matrix is modulated by neural modulators (local and global synaptic modulators and action potential threshold modulators), which operate at a slower speed (neural modulators are secondary operational primitives because they become operational primitives in virtue of their effect on the spikes). These primitives (spike rates, inter-spike intervals, time of arrival, gas-net modulation, synaptic modulators, axonal growth, etc.) constitute the neural domain.

11. 11.

    In fact, neural dynamics depend not only on inter-neural relations. In the neural system, indeed, there are many other non-neuronal cells (glia, astrocytes…) that also influence the inter-neuronal processes. It seems that these influence is much more important in vertebrate’s neural system (Bullock et al. 2005).

12. 12.

    A body plan is the set of constraints harnessing the development of the structural features of a whole phylum of multicellular organisms. It is the framework that guides the way its body is laid out. Once fixed, a body plan becomes a constraining (in the sense of either “limiting” or “enabling”) factor in the evolution of a given line of animals, since adaptations only take place inside the architectural limits of the ancestral body plan (Hickman et al. 2001).

13. 13.

    In comparison with the nervous system, the functioning of the neuroendocrine system is slower and more durable. As we will see in the next section, in certain animals, in addition to the neuroendocrine system, there is also a direct takeover by the nervous system of some body functions.

14. 14.

    In fact, the big nervous system of certain cephalopods is much more evenly distributed than in vertebrates: for example, more than half of the neurons of the big octopus’ nervous system are located in the arms themselves.

15. 15.

    Lacking fine-tuned control of blood circulation, large invertebrates (pogonophores, giant cephalopods, and others now extinct) tire easily and their vascular system is forced to work close to its physiological limits (Abbott 1995). As we have emphasised, like other large invertebrates, large octopuses do not display motility that is as efficient as that of vertebrates. They rely on a system involving three hearts and permanently high blood pressure.

16. 16.

    During evolution, the ANS has been associated to other neural structures (like the limbic system), all of them performing fine-tuned control over body functions. Together, these structures constitute what the neurobiologist Gerald Edelman (1989) calls the “Nervous System of the Interior”.

17. 17.

    As mentioned, the basic way for the nervous system to control the functioning of the body is through the neuroendocrine system, which operates through highly specific substances (hormones) distributed by the circulatory system. Unlike the neuroendocrine system, which is based on diffusion and is largely distributed, a vertebrate’s ANS is a centralised system, which operates mainly through fast, direct, and targeted neurally-channelled control.

18. 18.

    The concentration of neurons – for example, in ganglia – is associated to the realisation of tasks that require a certain degree of complexity. As we have said, invertebrates’ nervous systems are in general much more distributed than vertebrates’, where we find an evolutionary tendency to concentrate neurons in the head.

19. 19.

    Alongside the SMNS, there are the structures that coordinate the sensorimotor tasks performed by the SMNS and the internal organ control tasks performed by the ANS. In particular, coinciding with the appearance of reptiles (about 310 mya) another specific structure appeared in the brain, the limbic system, which is a system of interconnected nuclei that bridge the ANS and the SMNS (Gloor 1997). The limbic system organises the flow from the ANS to the SMNS of both neural connectivity and the secretion of peptides (as well as other neuromodulator substances) that can modify qualitative aspects, such as speed, in the operation of many brain circuits. The limbic system organises the flow back from the SMNS to the ANS as well, by means of neural connectivity.

20. 20.

    Many neuroscientists have defended a similar view to Damasio’s (see for instance Ledoux 1996; Lewis 2005), postulating that emotions arise as the result of the complex interplay between the ANS and the SMNS and the functioning of the viscera.

21. 21.

    As Christensen argues, this hierarchical scheme is supported by classical experiments involving the sectioning of the central nervous systems of cats (Brown 1911; Sherrington 1947). When the brain stem and spinal cord are isolated from the forebrain, a cat is still able to breathe, swallow, stand, walk, and run. However, the movements are produced in a highly stereotyped, robotic fashion. The animal is not goal-directed, nor does it respond to the environment. Thus, the brain stem and spinal cord are responsible for producing basic movement coordination, but not higher-level environmental sensitivity or goal-directedness. Instead, a cat with intact basal ganglia and hypothalamus, but a disconnected cortex, will move around spontaneously and avoid obstacles. The animal can perform relatively complex tasks such as eating and drinking and can also display emotions. Evidently, this level of motor control is responsible for the core elements of motivated behaviour. The hypothalamus plays an especially prominent role in integrating the activity of the autonomic and somatic motor systems. But the experiment shows that the most complex forms of behaviour involve the cortex. This area of the brain performs “episodic control”, adjusting goal-directed action in relation to local contingencies. And for that, what is needed is not only highly integrated perceptions, but also perceptions that are associated with the animal’s goals, values, and environmental context.

22. 22.

    Edelman uses the term “primary consciousness” to refer to the varieties of perceptual awareness that humans share with many animals, thanks to which they are able to integrate observed events into memory so as to create a subjectively “aware” perception of the present and immediate past of the world around them.

23. 23.

    This kind of neurodynamic organisation in thalamocortical areas occurs in the gamma frequency band (Llinás et al. 1998). This has led some authors to suggest that timing in this frequency band in the visual areas may be the correlate of conscious visual experience (Crick and Koch 1990) or of perceptual consciousness (Engel and Singer 2001).

24. 24.

    http://news.harvard.edu/gazette/story/2010/10/thinking-like-an-octopus/

25. 25.

    In the mentioned studies, the concept of dynamic structure is defined as “the subset of internal variables and their relationships involved in a certain sensorimotor coupling. A dynamic structure emerges when (for a given time window) we can systematically reduce the dimensionality of the internal operational organization of the NS to predict the behavior of the system” (Barandiaran and Moreno 2006: 177)

26. 26.

    This does not mean that communication between animals is established only through sensorial signals. In fact, in many cases, chemical interactions are also very important. For example, the members of an ant colony share food and other fluids, thus inducing socially coherent patterns in a phenomenon known as Trophallaxis.

27. 27.

    See: http://learn.genetics.utah.edu/content/epigenetics/rats/

Authors and Affiliations

1. IAS-Research Centre for Life, Mind and Society Departamento de Lógica y Filosofía, Universidad del País Vasco, Donostia – San Sebastian, Guipúzcoa, Spain

   Alvaro Moreno

2. Institut d’Histoire et de Philosophie des Sciences et des Techniques (IHPST), CNRS/Université Paris I/ENS, Paris, France

   Matteo Mossio

Reprints and permissions

© 2015 Springer Science+Business Media Dordrecht

Policies and ethics