II. A Model of the Interest System
The model is based on the concept of an interest. The word is used with its everyday meaning. It has however the implication of concern rather than advantage, and it covers all deployment of attention, from desire to wonder.
The system comprises two spatially discretised differential equations (X(i,j) and Y,(i,j) arranged as the elements of a Volterra-Lotka equation. Similar to a chemical diffusion reaction model. The state space is closed (toroid). Its metric is cognitive map space with the addition of perception and imagination. Emotion is reduced to a single aversive/attractive value which, in combination with the state of the matrix provides the value of X(i,j). The differential equations are fluctuated to simulate an unknown environment. The brain is modeled as a noisy far from equilibrium network. The dynamic modeled conforms with present psycho-neurological findings.
The quotidian mind is apparently occupied with interests and these interests compete for attention which is Conserved and finite, ie N = supply of metabolites.
Interests are aroused and depressed both by autocatalysis, sensory input and by the state of the rest of the system.
The arousal of an intrest is its emotional content ie the value of X(i,j).
Emotions are modeled by the extreme reduction of all emotion to a single variable which models an attraction/revulsion spectrum.
In everyday life expression of an interest tends to lower its arousal. Ie the VL part of the equations .
N =metabolic rescources-> X(i,j)
Arousal -> Y(i,j) Action.
The authors of this model propose that mind is a noisy far from equilibrium dynamical system of competing interests and that imagination is an emergent property of the system.
The image of the imaginer is an emergent property of the imagination.
The output of the system need bear no simple relationship to the input.
The equations were implemented as a computer program in C language. The program was run on a Cray computer at the, then, SERC Atlas Computer Centre Didcot Oxon. and on a MasPar multi CPU array at the NASA Goddard Jet Propulsion Laboratories Washington DC. Visualisations of the data produced by these computer simulations demonstrated that the system did indeed have emergent properties. Which is to say that the model would not only produce interests that were present in its initial state. Furthermore the model also produces interests that had no immediate connection with any other interests. (See purple cloud graphic) This can be viewed as analogous to the creative function in a human mind.
Computer graphic of development of interest system showing sudden events A. With added language system B and ego C .
There is an area of solution space in which the structural attractors generated by the model are few, slow to change and very aroused. This corresponds with the monotropic (attention tunneled) state found in people described as autistic. (This is what the last paper was about) This area of state space is contiguous with the rest of the space suggesting that autism is part of a normal distribution of personality types.
This is not a model of autism it is a theory about human beings in which autism has a natural role as contributing to essential diversity. The interest model of mind is a new way (graphic, mathematical) of conceiving of people as transient collections of desires/directed energies affecting and being affected by perception, imagination, cognition and action. We think it makes psychological data (people) easier to analyse.
We provide two interactive animation of the interest system on this website that allow experimental testing of predicted behaviour of the interest system. A webbased 2D model and an advanced 3D model are available for download. We plan to release the sourcecode under a common license. Click here for our interactice animation mind as an interest system!
See Mind as a Dynamical System: Implications for Autism for more information on mind as an interst system.