Comment on Gallistel: Behavior theory and information theory: Some parallels

In this article, Gallistel proposes information theory as an approach to some enduring problems in the study of operant and classical conditioning.     

A note on imitative behavior and information

The equations for imitative behavior developed previously indicate that the imitation effect increases with the numberN ₀ of individuals in the social group. In this note it is pointed out that the above conclusion holds only for not too large values ofN ₀. The above conclusion is based on the tacit assumption that each individual is completely informed about the behavior adopted by every other individual. If, however,N ₀ becomes very large, the information per individual decreases. As a result of this, the effects of imitation either increase withN ₀ less rapidly or actually become independent ofN ₀.     

Language evolution and information theory

This paper places models of language evolution within the framework of information theory. We study how signals become associated with meaning. If there is a probability of mistaking signals for each other, then evolution leads to an error limit: increasing the number of signals does not increase the fitness of a language beyond a certain limit. This error limit can be overcome by word formation: a linear increase of the word length leads to an exponential increase of the maximum fitness. We develop a general model of word formation and demonstrate the connection between the error limit and Shannon's noisy coding theorem.     

Genetic information and insurance: some ethical issues.

Life is risky, and insurance provides one of the best developed ways of controlling risks. By pooling, and so transferring risks, those who turn out to suffer antecedently uncertain harms can be assured in advance that they will be helped if those harms arise; they can then plan their lives and activities with confidence that they are less at the mercy of ill fortune. Both publicly organized and commercial insurance can organize the pooling of risk in ways that are beneficial for all concerned. They provide standard ways of securing fundamental ethical values such as solidarity and mutuality. Although policy holders do not know or contract with one another, each benefits from the contribution of others to a shared scheme for pooling and so controlling risk. Although there is a limit to the degree to which commercially-based insurance, where premiums depend on risk level, can go beyond mutuality towards solidarity, in practice it too often achieves a measure of solidarity by taking a broad brush approach to pooling risk. However, the ordinary practices of insurance, and in particular of commercial insurance, also raise ethical questions. These may be put in simple terms by contrasting the way in which an insurance market discriminates between different people, on the basis of characteristics that (supposedly) determine their risk level, and our frequent abhorrence of discrimination, in particular on the basis on religious, racial and gender characteristics. Are the discriminations on which insurance practice relies upon as standard acceptable or not? The increasing availability of genetic information, which testing (of individuals) and screening (of populations) may provide, could lend urgency to these questions. Genetic information may provide a way of obtaining more accurate assessment of individual risks to health and life. This information could be used to discriminate more finely between the risk levels of different individuals, and then to alter the availability and the costs of health, life and unemployment insurance to them. Since all of these forms of insurance bear very directly on the way most people live, it will matter to them how (if at all) insurers take account of genetic information. Will use of this information improve or damage the capacity of insurance to provide confidence in the face of uncertain harms, and help if they happen? Will it discriminate in acceptable or in unacceptable ways? Will it support or damage the sorts of mutuality and solidarity various sorts of insurance schemes have successfully institutionalized?     

Interrelationships among some ectomycorrhizal trees,hypogeous fungi and small mammals: Western Australian and northwestern American parallels

Species of the hypogeous fungus genus. Mesophellia have been shown to form ectomycorrhiza with Eucalyptus diversicolor and improve seedling growth. Since the morphology of these fungi increases their dependence on animal mycophagy for spore dispersal, these results imply a tripartite interrelationship between eucalypts, hypogeous fungi and marsupials which parallels the North American interrelationship between ectomycorrhizal pine, hypogeous fungi and rodents. An understanding of the independent but analogous interrelationships on the two continents has implications for forest management, especially in regard to the effects of forest conversion on other members of the ecosystem.     

Note on the theory of mass behavior

A differential equation has been derived by A. Rapoport,Bull. Math. Biophysics,14, 159 (1952), giving the time course of the fraction of the population who have performed a given act. The general solution of this equation is obtained, some properties of the solution are deduced, and a special case presented in detail.     

Bacterial chemotaxis: information processing,thermodynamics, and behavior

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Nervous vascular parallels: axon guidance and beyond

The vascular and nervous systems are organized with well defined and accurate networks, which represent the anatomical structure enabling their functions. In recent years, it has been clearly demonstrated that these two systems share in common several mechanisms and specificities. For instance, the networking properties of the nervous and vascular systems are governed by common cues that in the brain regulate axon connections and in the vasculature remodel the primitive plexus towards the vascular tree. Here, we summarize the role of semaphorins as a paradigmatic example of the role of axon guidance molecules in physiological and pathological angiogenesis. Finally, we discuss the presence in blood vessels of neurexin and neuroligin, two proteins that finely modulate synaptic activity in the brain. This observation is suggestive of an intriguing new class of molecular and functional parallels between neurons and vascular cells.     

Type A behavior and job performance: some suggestive findings

This study examined Type A and Type B differences in job performance, psychosomatic complaints, and career progression among white-collar employees (N = 218) in a field setting. Significant differences were found between Type A's and Type B's in quality of performance, effort exerted at the job, and psychosomatic complaints. Employees' cultural background and sex moderated some of the relationships observed in the study. Implications of the findings for future research on the topic are discussed.     

Ecological networks: information theory meets Darwin's entangled bank

Is it possible to untangle the 'entangled bank'--Darwin's metaphor for the complexity and connectedness of species in the natural world? Studies on webs of species interactions suggest so, but a major question remains unanswered: how specialized are different ecological networks? By considering how strongly species interact with each other, information theory may give the answer.     

Life,information theory,and topology

The information content of an organism determines to a large extent its ability to perform the basic vital functions: selection of food, breaking up of the food molecules into appropriate parts, selection of those parts, and their assimilation. The information content needed is very large and requires a sufficiently large complexity of the organism. The information content of an organism is largely determined by the information content of the constituent organic molecules. The information content of the latter is in its turn determined by the number of physically distinguishable atoms or radicals of which the molecule is composed. The different arrangements of atoms in a molecule are represented by the structural formula, which is basically a graph. It is shown that the topology of this graph also determines to a large extent the information content. Different points of a graph may be physically indistinguishable; in general, however, they are different in regard to their topological properties. A study of the relations between the topological properties of graphs and their information content is suggested, and several theorems are demonstrated. A relation between topology and living processes is thus found also on the molecular level.     

Sustainable plant disease control: biotic information flow and behavior manipulation

<正>Crop pests and diseases are a major threat to agricultural production worldwide. Farmers utilize massive quantities of chemical pesticides, herbicides, and fungicides for secure crop production. Following the extensive use of pesticides and other chemicals, serious problems regarding human and animal poisoning, agricultural product pollution, and ecological and environmental damage can no longer be ignored