Toward a brain-based theory of beauty

We wanted to learn whether activity in the same area(s) of the brain correlate with the experience of beauty derived from different sources. 21 subjects took part in a brain-scanning experiment using functional magnetic resonance imaging. Prior to the experiment, they viewed pictures of paintings and listened to musical excerpts, both of which they rated on a scale of 1-9, with 9 being the most beautiful. This allowed us to select three sets of stimuli--beautiful, indifferent and ugly--which subjects viewed and heard in the scanner, and rated at the end of each presentation. The results of a conjunction analysis of brain activity showed that, of the several areas that were active with each type of stimulus, only one cortical area, located in the medial orbito-frontal cortex (mOFC), was active during the experience of musical and visual beauty, with the activity produced by the experience of beauty derived from either source overlapping almost completely within it. The strength of activation in this part of the mOFC was proportional to the strength of the declared intensity of the experience of beauty. We conclude that, as far as activity in the brain is concerned, there is a faculty of beauty that is not dependent on the modality through which it is conveyed but which can be activated by at least two sources--musical and visual--and probably by other sources as well. This has led us to formulate a brain-based theory of beauty.     

Toward a geographical theory of hypocritical decision-making

When a community authorizes the development of a controversial project which may produce adverse ecological effects, the decision may be made on the basis of a differing geographical distribution of costs and benefits. Local benefits may exceed local costs while overall costs exceed overall benefits. This paper attempts, through a mathematical theoretical exposition, to show that this situation provides a rational incentive for hypocritical public behavior. Possible solutions are considered. One set of solutions implies return to laissez-fairetype capitalism and the maintenance of a taut, spatial economic system which is sensitive to shock. Another set of solutions implies the development of a socialist economy. Mixed solutions are presented as unstable and tending to environmental deterioration. The mirrorimage problem — of concentrated costs and diffused benefits in the United States, and the State of New Jersey specifically — is also considered, leading to similar conclusions.     

Toward a self-similar theory of microbial populations

A fresh quest is made of segregated cell models of microbial populations with a view to determine whether the multivarite distribution of physiological states, during transient growth, can attain self-similar forms (i.e., become time invariant) when each physiological state variable is scaled with respect to its population average. Such self-similar growth situations are believed to be more general than those of balanced growth. The conditions under which self-similarity is possible are investigated. Thus conditions are stipulated on the synthesis rates of different physiological entities, cell division rate, and the partitioning of the parent cell's components among the daughter cells (assuming binary division) in order for self-similar growth to be attained. Subject to the attainment of self-similar growth, it is shown that cytometric data can be analyzed systematically to determine how the rates of syntheses of various biochemical entities and cell division rates vary with the physiological entities that are measured. Inverse problems, represented by algebraic systems, are identified which will potentially allow flow cytometric data to be inverted to yield quantitative information on the absolute rates of cellular growth and reproductory processes as a function of the cell states chosen for measurement. It is suggested that the methods become more effective when cytometry can be used to make direct observations on dividing cells so that the number of unknowns in the inverse problem can be reduced, thus facilitating its more complete solution. Preliminary analysis of cytometric data obtained in the literature show promise of self-similarity and thus the possibility of application of the methods discussed here. (c) 1994 John Wiley & Sons, Inc.     

Toward a theory of intracrine hormone action

A growing body of evidence indicates that in some cases, peptide hormones can function in the intracellular space. These findings are reviewed. In addition, this laboratory has made proposals regarding the origin, nature and function of intracrines--that is, intracellularly acting peptide hormones that also function in an autocrine, paracrine or endocrine manner. Here, these hypotheses are developed, and potential implications/applications of this point of view are discussed. Possible implications for cellular differentiation, cellular memory and hormonal responsiveness, as well as for the assumption of novel functions by intracellular regulatory proteins are discussed.     

Middle-class residential mobility in Mexico City: Toward a cross-cultural theory

Few social-psychological theories of intraurban residential mobility have been offered, despite a number of empirical studies of personal motives. A complete explanation of residential mobility would interrelate macroscopic economic factors with household preferences. A cross-cultural socio-psychological model is presented as a step toward a comprehensive theory. Data from an exploratory study of middle-class Mexico City residents are used to test the model. Results suggest that middle-class Mexicans decide to move because of space needs accompanying life-cycle changes, desire for home ownership, and environmental reasons. Home selection was primarily a function of availability, cost, and terms. Unlike North Americans, suburban Mexicans were uninterested in community activities and maintained close contact with relatives; central-city respondents enjoyed living in the city despite dissatisfaction with residence or neighborhood. Most would avoid the suburbs because of communication problems and distance from relatives. Results support the model and justify further testing and development.I am grateful to the University of Alabama Research Grants Committee and Center for International Studies for financial support to carry out this study.An earlier version of this paper was presented at the annual meeting of the American Sociological Society in New York, August 1976.     

Toward an improved discrimination of outer membrane proteins using a sequence-based approach

This article offers a novel sequence-based approach to discriminate outer membrane proteins (OMPs). The first step is to use a new representation approach, factor analysis scales of generalized amino acid information (FASGAI) representing hydrophobicity, alpha and turn propensities, bulky properties, compositional characteristics, local flexibility and electronic properties, etc., to characterize sequences of OMPs and non-OMPs. The subsequent data is then transformed into a uniform matrix by the auto cross covariance (ACC). The second step is to develop discrimination predictors of OMPs from non-OMPs using a support vector machine (SVM). The SVM predictors thus successfully produce a high Matthews correlation coefficient (MCC) of 0.916 on 208 OMPs from non-OMPs including 206 α-helical membrane proteins and 673 globular proteins by a fivefold cross validation test. Meanwhile, overall MCC values of 0.923 and 0.930 are obtained for the discrimination OMPs from the α-helical membrane proteins and the globular proteins, respectively. The results demonstrate that the FASGAI-ACC-SVM combination approach shows great prospect of application in the field of bioinformatics or proteomics studies.     

Toward a unified theory of visual area V4

Visual area V4 is a midtier cortical area in the ventral visual pathway. It is crucial for visual object recognition and has been a focus of many studies on visual attention. However, there is no unifying view of V4's role in visual processing. Neither is there an understanding of how its role in feature processing interfaces with its role in visual attention. This review captures our current knowledge of V4, largely derived from electrophysiological and imaging studies in the macaque monkey. Based on recent discovery of functionally specific domains in V4, we propose that the unifying function of V4 circuitry is to enable selective extraction of specific functional domain-based networks, whether it be by bottom-up specification of object features or by top-down attentionally driven selection.     

The species–energy theory: a role for energy variability

Species–energy theory posits that energy availability regulates population sizes, extinction rates and ultimately species richness. This theory has focused mostly on total energy as a measure of energy availability. However, because energy variation can also influence population sizes and extinction rates, species–energy theory should arguably consider simultaneously both total energy and its variation. Using data on species richness of land birds and mammals, we compared the fit of three species–energy models including total energy, energy variation or both combined. We show that the combination of total energy and energy variation has greater predictive power than any of them considered separately. We also evaluate three crucial assumptions of this modified species–energy theory and show that they are supported by available data. These results illuminate the current debate on climate change, given that both average conditions and variability of climatic conditions are likely to change in the future.     

Behavioural plasticity and sex differences in host finding of a specialized bee species

Many animals feed on flowers, and visual as well as olfactory cues are considered as most important mediators in animal–plant interactions. However, the relative importance of these cues is not well understood. Bees are the most important animal pollinators worldwide and here, we determined the importance of decoupled and combined visual and olfactory cues of Lysimachia punctata (Primulaceae) for host plant location in both sexes of the specialized, solitary bee, Macropis fulvipes (Melittidae). Lysimachia-inexperienced female bees preferred olfactory over visual cues though visual cues increased the attractiveness of olfactory ones. In experienced females, the importance of visual cues was increased. Both Lysimachia-naive and -experienced males relied more on visual cues as compared to females. This study demonstrates that the relative weighting of cues used for host plant finding depends on the sex and experience of M. fulvipes. The latter finding reveals the presence of learning-induced behavioural plasticity in host plant finding for a bee species. It may allow the bee to forage highly efficient. Visually guided female detection on flowers by males is a likely functional explanation for the differences in the weighting of visual and olfactory cues between the sexes.     

Statistical theory of combinatorial libraries of folding proteins: energetic discrimination of a target structure

A self-consistent theory is presented that can be used to estimate the number and composition of sequences satisfying a predetermined set of constraints. The theory is formulated so as to examine the features of sequences having a particular value of Delta=E(f)-(u), where E(f) is the energy of sequences when in a target structure and (u) is an average energy of non-target structures. The theory yields the probabilities w(i)(alpha) that each position i in the sequence is occupied by a particular monomer type alpha. The theory is applied to a simple lattice model of proteins. Excellent agreement is observed between the theory and the results of exact enumerations. The theory provides a quantitative framework for the design and interpretation of combinatorial experiments involving proteins, where a library of amino acid sequences is searched for sequences that fold to a desired structure.     

How to evade a coevolving brood parasite: egg discrimination versus egg variability as host defences

Arms races between avian brood parasites and their hosts often result in parasitic mimicry of host eggs, to evade rejection. Once egg mimicry has evolved, host defences could escalate in two ways: (i) hosts could improve their level of egg discrimination; and (ii) negative frequency-dependent selection could generate increased variation in egg appearance (polymorphism) among individuals. Proficiency in one defence might reduce selection on the other, while a combination of the two should enable successful rejection of parasitic eggs. We compared three highly variable host species of the Afrotropical cuckoo finch Anomalospiza imberbis, using egg rejection experiments and modelling of avian colour and pattern vision. We show that each differed in their level of polymorphism, in the visual cues they used to reject foreign eggs, and in their degree of discrimination. The most polymorphic host had the crudest discrimination, whereas the least polymorphic was most discriminating. The third species, not currently parasitized, was intermediate for both defences. A model simulating parasitic laying and host rejection behaviour based on the field experiments showed that the two host strategies result in approximately the same fitness advantage to hosts. Thus, neither strategy is superior, but rather they reflect alternative potential evolutionary trajectories.     

The heuristics of biologic theory: the case of self-nonself discrimination

Mel Cohn has responded to our critique of the minimal model of self-nonself discrimination proposed by Langman and him. In this response to Mel Cohn, we summarize the essential differences between our points of view and highlight one criterion (of many) for preferring one theory to another in the complex field of biology: a preferred theory, rather than solving a problem, is heuristic. A good theory is one that activates a scientist to perform experiments that are novel and productive.