The animal sensorimotor organization: a challenge for the environmental complexity thesis

Abstract

Godfrey-Smith’s environmental complexity thesis (ECT) is most often applied to multicellular animals and the complexity of their macroscopic environments to explain how cognition evolved. We think that the ECT may be less suited to explain the origins of the animal bodily organization, including this organization’s potentiality for dealing with complex macroscopic environments. We argue that acquiring the fundamental sensorimotor features of the animal body may be better explained as a consequence of dealing with internal bodily—rather than environmental complexity. To press and elucidate this option, we develop the notion of an animal sensorimotor organization (ASMO) that derives from an internal coordination account for the evolution of early nervous systems. The ASMO notion is a reply to the question how a collection of single cells can become integrated such that the resulting multicellular organization becomes sensitive to and can manipulate macroscopic features of both the animal body and its environment. In this account, epithelial contractile tissues play the central role in the organization behind complex animal bodies. In this paper, we relate the ASMO concept to recent work on epithelia, which provides empirical evidence that supports central assumptions behind the ASMO notion. Second, we discuss to what extent the notion applies to basic animal architectures, exemplified by sponges and jellyfish. We conclude that the features exhibited by the ASMO are plausibly explained by internal constraints acting on and within this multicellular organization, providing a challenge for the role the ECT plays in this context.

Bodily Processing: The Role of Morphological Computation

“…We can start by assuming that mentioned neuroethological studies indicate that various morphologies and senses, and their placements determine differing solutions to environmental problems. This approach is compatible with Keijzer and Arnellos' [32] research on the evolution of the nervous system. Differing morphologies lead to differing kinds of perception and action control or, using Keijzer and Arnellos' [32] terminology, differing animal sensorimotor organization (I refer to this organization in the definition of cognition, introduced above), and can be informative about various kinds of embodied computational cognition (I should note that despite our references to the work of Keijzer and his colleagues, he defends an embodied but not computational approach to cognition [11]).…”

“…This approach is compatible with Keijzer and Arnellos' [32] research on the evolution of the nervous system. Differing morphologies lead to differing kinds of perception and action control or, using Keijzer and Arnellos' [32] terminology, differing animal sensorimotor organization (I refer to this organization in the definition of cognition, introduced above), and can be informative about various kinds of embodied computational cognition (I should note that despite our references to the work of Keijzer and his colleagues, he defends an embodied but not computational approach to cognition [11]). Keijzer and colleagues [33,34] study the evolution of the nervous system, mainly after Pantin [35], describing the basic neuronal unit as a multicellular, neuromuscular sheet, from which all more complex nervous systems evolved.…”

“…Here, I choose the case of vision, which is present only in highly organized systems. Keijzer and Arnellos [32] describe vision as a sensory sensitivity available only for a multicellular organism, a characteristic for multicellular embodiment:…”

Modelling the effects of short and random proto-neural elongations

“…In contrast, we focus here on an alternative Internal Coordination (IC) view (Jékely et al, 2015), which stresses the need to acquire multicellular (bodily) coordination as an initial key task for early-and modern-nervous systems. Coordinating contractile (muscle) tissue for motility and reversible changes in body-shape is a central example here (Pantin, 1956;Keijzer et al, 2013;Keijzer and Arnellos, 2017) that imposes different functional demands on early nervous systems and neural elongations. Rather than focusing on neural elongations as a way to provide specifically targeted connections, an IC view opens up the possibility of acquiring neural elongations in a more gradual way.…”

Evolutionary convergence and biologically embodied cognition

“…For example, IC models allow a different approach to animal sensing that uses an animal body's movements produced by muscle contractions as a means to detect environmental structure at the scale of the animal's body (Keijzer, 2015;Keijzer & Arnellos, 2017). 5 The animal body itself becomes a multicellular effector and sensing device in one.…”