Adaptive system

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An adaptive system is a set of interacting or interdependent entities, real or abstract, forming an integrated whole that together are able to respond to environmental changes or changes in the interacting parts, in a way analogous to either continuous physiological homeostasis or evolutionary adaptation in biology. Feedback loops represent a key feature of adaptive systems, such as ecosystems and individual organisms; or in the human world, communities, organizations, and families.

Artificial adaptive systems include robots with control systems that utilize negative feedback to maintain desired states.

The law of adaptation[edit]

The law of adaptation can be stated informally as:

Every adaptive system converges to a state in which all kind of stimulation ceases.[1]

Formally, the law can be defined as follows:

Given a system , we say that a physical event is a stimulus for the system if and only if the probability that the system suffers a change or be perturbed (in its elements or in its processes) when the event occurs is strictly greater than the prior probability that suffers a change independently of :

Let be an arbitrary system subject to changes in time and let be an arbitrary event that is a stimulus for the system : we say that is an adaptive system if and only if when t tends to infinity the probability that the system change its behavior in a time step given the event is equal to the probability that the system change its behavior independently of the occurrence of the event . In mathematical terms:

  1. -
  2. -

Thus, for each instant will exist a temporal interval such that:

Benefit of self-adjusting systems[edit]

In an adaptive system, a parameter changes slowly and has no preferred value. In a self-adjusting system though, the parameter value “depends on the history of the system dynamics”. One of the most important qualities of self-adjusting systems is its “adaptation to the edge of chaos” or ability to avoid chaos. Practically speaking, by heading to the edge of chaos without going further, a leader may act spontaneously yet without disaster. A March/April 2009 Complexity article further explains the self-adjusting systems used and the realistic implications.[2] Physicists have shown that adaptation to the edge of chaos occurs in almost all systems with feedback.[3]

Practopoiesis[edit]

Practopoiesis, a term due to its originator Danko Nikolić, is a reference to a kind of adaptive or self-adjusting system in which autopoiesis of an organism or a cell occurs through allopoietic interactions among its components.[4] The components are organized into a poietic hierarchy: one component creates another. For example, according to this proposal, in the brain this hierarchy leads to the capability of learning to learn. The theory proposes that living systems exhibit a hierarchy of four such poietic operations in total:

   evolution (i) → gene expression (ii) → non gene-involving homeostatic mechanisms (anapoiesis) (iii) → cell function (iv)

Practopoiesis challenges current neuroscience doctrine by asserting that mental operations primarily occur at the anapoietic level (iii) — i.e., that minds emerge from fast homeostatic mechanisms. This contrasts the widespread belief that thinking is synonymous with neural activity (level iv).

See also[edit]

Notes[edit]

  1. ^ José Antonio Martín H., Javier de Lope and Darío Maravall: "Adaptation, Anticipation and Rationality in Natural and Artificial Systems: Computational Paradigms Mimicking Nature" Natural Computing, December, 2009. Vol. 8(4), pp. 757-775. doi
  2. ^ Hübler, A. & Wotherspoon, T.: "Self-Adjusting Systems Avoid Chaos". Complexity. 14(4), 8 – 11. 2008
  3. ^ Wotherspoon, T.; Hubler, A. "Adaptation to the edge of chaos with random-wavelet feedback.". J Phys Chem A. doi:10.1021/jp804420g. 
  4. ^ Danko Nikolić (2015). "Practopoiesis: Or how life fosters a mind.". Journal of Theoretical Biology. 373: 40–61. doi:10.1016/j.jtbi.2015.03.003. 

References[edit]

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