Complexity Digest 2001.16

16-Apr-2001

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Content

  1. The Semantic Web, Scientific American
  2. Prion Protein: Evolution Caught En Route, PNAS
  3. The Role Of Chaotic Resonances In The Solar System, Nature
  4. Twin Peeks at Ocean Warming, Science
    1. Greenhouse Warming Passes One More Test, Science
    2. Detection of Anthropogenic Climate Change In The World's Oceans, Science
    3. Climate Response To Orbital Forcing Across The Oligocene-Miocene Boundary, Science
  5. Farm Futures, Science
    1. Forecasting Agriculturally Driven Global Environmental Change, Science
    2. Control of Nitrogen Export From Watersheds By Headwater Streams, Science
  6. Tissue Spreading On Implantable Substrates Is A Competitive Outcome, PNAS
  7. Fundamental Unpredictability In Multispecies Competition, The American Naturalist
  8. Intervening To Achieve Cooperative Ecosystem Management: Towards An Agent Based Model, J. Art Soc & Soc Sim
  9. From Social Monitoring To Normative Influence, J. Art Soc & Soc Sim
    1. Modeling The Emergence Of Resource-Sharing Conventions: An Agent-Based Approach, J. Art Soc & Soc Sim
    2. Creating Artificial Worlds: A Note On Sugarscape And Two Comments, J. Art Soc & Soc Sim
  10. The Creation Of A Reputation In An Artificial Society Organised By A Gift System, J. Art Soc & Soc Sim
  11. Role-Playing Games For Opening The Black Box Of Multi-Agent Systems, J. Art Soc & Soc Sim
  12. Why Mathematicians Now Care About Their Hat Color, NYTimes
  13. Object Processing In The Infant Brain, Science
  14. Location Neurons Do Advanced Math, Science
    1. Be Subthreshold And Multiply, Science
    2. Auditory Spatial Receptive Fields Created By Multiplication, Science
    3. Hyperacute Directional Hearing of the Ormia Ochracea Fly, Cornell News/Science Daily
  15. Genomics Fosters a "Systems Approach" And Collaborations, Plant Cell
  16. Odor-associated Health Complaints, Chem. Senses
    1. Judgement Of Odor Intensity Influenced By Knowledge Of Odor Source, Chem. Senses
  17. Semantic Dementia: Relevance To Connectionist Models Of Long-Term Memory, Brain
  18. Is Schizophrenia Caused By An Enemy Within?, New Scientist
    1. Retroviruses And The Pathogenesis Of Schizophrenia, PNAS
    2. Retroviral RNA Identified In The Cerebrospinal Fluids And Brains Of Individuals With Schizophrenia, PNAS
  19. A Developmental Study Of The Affective Value Of Tempo And Mode In Music, Author Response
  20. Links & Snippets

  1. The Semantic Web, Scientific American Next Article Bookmark and Share

    Excerpts: The Semantic Web will bring structure to the meaningful content of Web pages, creating an environment where software agents roaming from page to page can readily carry out sophisticated tasks for users.(…)

    The Semantic Web is not a separate Web but an extension of the current one, in which information is given well-defined meaning, better enabling computers and people to work in cooperation. The first steps in weaving the Semantic Web into the structure of the existing Web are already under way. In the near future, these developments will usher in significant new functionality as machines become much better able to process and "understand" the data that they merely display at present.

    • The Semantic Web, Tim Berners-Lee, James Hendler, Ora Lassila, Scientific American, May 2001


  2. Prion Protein: Evolution Caught En Route, PNAS Next Article Bookmark and Share

    Abstract: The prion protein displays a unique structural ambiguity in that it can adopt multiple stable conformations under physiological conditions. In our view, this puzzling feature resulted from a sudden environmental change in evolution when the prion, previously an integral membrane protein, got expelled into the extracellular space. Analysis of known vertebrate prions unveils a primordial transmembrane protein encrypted in their sequence, underlying this relocalization hypothesis. Apparently, the time elapsed since this event was insufficient to create a "minimally frustrated" sequence in the new milieu, probably due to the functional constraints set by the importance of the very flexibility that was created in the relocalization. This scenario may explain why, in a structural sense, the prion protein is still en route toward becoming a foldable globular protein.

  3. The Role Of Chaotic Resonances In The Solar System, Nature Next Article Bookmark and Share

    Excerpts: Our understanding of the Solar System has been revolutionized over the past decade by the finding that the orbits of the planets are inherently chaotic. In extreme cases, chaotic motions can (…) eject a planet from a system. Moreover, the spin axis of a planet-Earth's spin axis regulates our seasons-may evolve chaotically, with adverse effects on the climates of otherwise biologically interesting planets. Some of the recently discovered extrasolar planetary systems contain multiple planets, and it is likely that some of these are chaotic as well.

  4. Twin Peeks at Ocean Warming, Science Next Article Bookmark and Share

    Abstract: Although global warming is often framed in terms of atmospheric temperature, the atmosphere contains only a small fraction of the heat supplied by the sun. From an energetic point of view, the oceans are far more important, and it has been shown recently that the heat content of the upper 3000 meters of the ocean has increased during the past 50 years. Two studies show that this observation agrees quite well with what we should expect for an Earth warmed by greenhouse gas emissions (see the news story by Kerr ). Using different climate models, Levitus et al. (p. 267) and Barnett et al. (p. 270) show that changes in the distribution of heat in the world ocean are accurately reproduced when forcing by anthropogenic greenhouse gases and sulfate aerosols are incorporated. The agreement between these different models, which have both successfully simulated observed changes in the climate system that have not been reproduced previously, lends greater confidence to these approaches.

    1. Greenhouse Warming Passes One More Test, Science Next Article Bookmark and Share

      Excerpts: Are humans indeed warming the world? If so, will future warming be big enough to matter· Confident answers depend in large part on the credibility of climate models. Greenhouse critics claim modelers can get any answer they like about warming simply by adjusting any of the numerous inputs whose values in the real world remain uncertain. (…) Modelers have long argued that constraints such as the need to simulate current climate and the history of atmospheric warming keep their models more honest than that. Now a new, independent reality check from the ocean has strengthened their case.

    2. Detection of Anthropogenic Climate Change In The World's Oceans, Science Next Article Bookmark and Share

      Excerpts: Large-scale increases in the heat content of the world's oceans have been observed to occur over the last 45 years. The horizontal and temporal character of these changes has been closely replicated by the state-of-the-art Parallel Climate Model (PCM) forced by observed and estimated anthropogenic gases. (…) model-produced signals are indistinguishable from the observations at the 0.05 confidence level. Further, the chances of either the anthropogenic or observed signals being produced by the PCM as a result of natural, internal forcing alone are less than 5%.

    3. Climate Response To Orbital Forcing Across The Oligocene-Miocene Boundary, Science Next Article Bookmark and Share

      Excerpt: The data presented here, however, indicate that eccentricity-modulated variations in precession must contribute as well, at least during the early Miocene. In examining the orbital curves, we have identified at least two other intervals when low-amplitude nodes align with low eccentricity at 18.2 and 27.0 Ma. Although those nodes are not as long as at 23.0 Ma, characterization of climatic anomalies at these two times would substantiate the orbital anomaly hypothesis, while also serving to confirm the orbital solutions.

  5. Farm Futures, Science Next Article Bookmark and Share

    Abstract: Global change is about more than the effects of greenhouse gases on climate. Tilman et al. (p. 281) recast agriculturally driven changes in global nitrogen and phosphorus fertilization, in pesticide production and trade, and in the extent of agricultural land, for next 50 years. To arrive at their forecasts, they extrapolate the linear increase of these parameters with time, global population, and per capita Gross Domestic Product during the past half-century. They forecast at least twofold increases in most parameters by 2050.

    1. Forecasting Agriculturally Driven Global Environmental Change, Science Next Article Bookmark and Share

      Excerpt: During the next 50 years, which is likely to be the final period of rapid agricultural expansion, demand for food by a wealthier and 50% larger global population will be a major driver of global environmental change. Should past dependences of the global environmental impacts of agriculture on human population and consumption continue, 109 hectares of natural ecosystems would be converted to agriculture by 2050. (…) Significant scientific advances and regulatory, technological, and policy changes are needed to control the environmental impacts of agricultural expansion.

    2. Control of Nitrogen Export From Watersheds By Headwater Streams, Science Next Article Bookmark and Share

      Excerpts: Nitrogen (N) loading of terrestrial and aquatic ecosystems is increasing worldwide as a result of human activities such as fertilizer application, N fixation by legume crops, human and animal waste disposal, and fossil fuel combustion. As terrestrial ecosystems become saturated with N, excess N moves with surface runoff and groundwater flow to streams, lakes, rivers, and coastal oceans. (…) Results from this (…) study (…) demonstrate how watershed-derived N is processed in stream channels and how these transformations affect the export of N to downstream ecosystems.

  6. Tissue Spreading On Implantable Substrates Is A Competitive Outcome, PNAS Next Article Bookmark and Share

    Excerpts: Tissue spreading over a substratum is a fundamental process in animal development, wound healing, and malignancy. Understanding the process of tissue spreading is critically important for the emerging field of tissue engineering and for the future use of biomaterials scaffolds for tissue or organ regeneration. Because spreading of a three-dimensional tissue over a surface must come at the expense of associations between cells, greater cell-cell cohesivity should restrain cell emigration.

    (…) either decreasing substratum adhesivity or increasing cell-cell cohesivity dramatically slowed the spreading rate of cell aggregates.


  7. Fundamental Unpredictability In Multispecies Competition, The American Naturalist Next Article Bookmark and Share

    Abstract: One of the central goals of ecology is to predict the distribution and abundance of organisms. Here, we show that, in ecosystems of high biodiversity, the outcome of multispecies competition can be fundamentally unpredictable. We consider a competition model widely applied in phytoplankton ecology and plant ecology in which multiple species compete for three resources. We show that this competition model may have several alternative outcomes, that the dynamics leading to these alternative outcomes may exhibit transient chaos, and that the basins of attraction of these alternative outcomes may have an intermingled fractal geometry. As a consequence of this fractal geometry, it is impossible to predict the winners of multispecies competition in advance.

  8. Intervening To Achieve Cooperative Ecosystem Management: Towards An Agent Based Model, J. Art Soc & Soc Sim Next Article Bookmark and Share

    Abstract: Ecosystem management is quite a complex challenge, but very important and it needs to be addressed if we want to preserve our environment. This paper presents an alternative for ecosystem management based on agent-based modeling, solving the problem in a decentralized, co-operative fashion. The presented model is focused in integrated watershed management, task which may have potentially conflicting requirements such as: water supply (for domestic, agricultural and industrial uses), pollution control, fisheries management, flood control, hydropower production, navigation and wetlands management, and recreation provision. Computer simulations proposed ecosystem management strategies, some of which were similar to actual strategies.

    Excerpt: The central argument of this paper is that here is an opportunity to assess possible ecosystem intervention strategies, and perhaps to generate new and effective ones, from a computer model alone. We might even hope to discover new and useful concepts in terms of which to discuss and formulate ecosystem intervention. A prospect is thus opened up that, although technically challenging, is exciting and goes well beyond the present limited use of agent-based models.


  9. From Social Monitoring To Normative Influence, J. Art Soc & Soc Sim Next Article Bookmark and Share

    Abstract: This paper is intended to analyse the concepts involved in the phenomena of social monitoring and norm-based social influence for systems of normative agents. These are here defined as deliberative agents, representing norms and deciding upon them. Normative agents can use the norms to evaluate others' behaviours and, possibly, convince them to comply with norms. Normative agents contribute to the social dynamics of norms, and more specifically, of norm-based social control and influence. In fact, normative intelligence allows agents to
    1. Check the efficacy of the norms (the extent to which a norm is applied in the system in which it is in force), and possibly
    2. Urge their fellows to obey the norms.

    The following issues are addressed:


    1. Modeling The Emergence Of Resource-Sharing Conventions: An Agent-Based Approach, J. Art Soc & Soc Sim Next Article Bookmark and Share

      In this note, the author first reviews the well-known book of Epstein and Axtell "Growing Artificial Societies" and positive and negative reviews of it, discussing the "validity" of computer simulations. He then gives arguments against reductionism and organicism, and in favor of complex systems, in the context of multi-agent systems. In his final comment, the author proposes a object-oriented methodology for developing computer simulations that facilitate the modification and reutilization of source code.

    2. Creating Artificial Worlds: A Note On Sugarscape And Two Comments, J. Art Soc & Soc Sim Next Article Bookmark and Share

      Abstract: This paper describes simulations in an artificial society in which autonomous agents exchange gifts. In this society agents perform simple acts that are looked at by the others and are analysed so that a common image is created for each agent (a reputation). The model is based on numerous descriptions of non-merchant exchange systems, which are very interesting for ethnologists as well as for economists: they appear to be important for circulation of goods and to insure the reproduction of social links and values. In the system built the agents must make a gift at each time-step. There exist two kinds of gifts and two corresponding kinds of reputation: the agents either give to share or to be prestigious. Since gifts are received according to status, receiving a gift is as important for a reputation as making one. Each agent is characterised by its ''motivation'' to acquire the reputation of being a sharing agent or a prestigious agent. It is also characterised by its ''esteem'', to decide if it will be able to do the gift it wants to do for a time-step. These two characteristics of an agent can be stable during the simulation, but can also evolve according to its history. We study here the different patterns that can appear in the societies, in terms of generation of reputation, and of histories over time. A huge range of these patterns can be observed, depending on the choice made for the parameters. In some cases the agents cannot be individually distinguished, in other cases they can: but, in any case any individual behaviours that emerge have to be sustained by a collective specification that points out more or less the way agents value each reputation.

  10. The Creation Of A Reputation In An Artificial Society Organised By A Gift System, J. Art Soc & Soc Sim Next Article Bookmark and Share

    Abstract: Multi-agent systems and role playing games have both been developed separately and offer promising potential for synergetic joint use in the field of renewable resource management, for research, training and negotiation support. While multi-agent systems may give more control over the processes involved in role playing games, role playing games are good at explaining the content of multi-agent systems. The conversion of one tool to another is quite easy but organisation of game sessions is more difficult.

    Both these tools have been used jointly in a fully described experiment in the Senegal river valley for issues of co-ordination among farmers. Role-playing games first enabled us to work on the validation of the MAS. Subsequently, the combination of both tools has proved to be an effective discussion support tool.


  11. Role-Playing Games For Opening The Black Box Of Multi-Agent Systems, J. Art Soc & Soc Sim Next Article Bookmark and Share

    Excerpt: The reason this problem is so captivating, mathematicians say, is that it is not just a recreational puzzle to be solved and put away.

    Rather, it has deep and unexpected connections to coding theory, an active area of mathematical research with broad applications in telecommunications and computer science.

    In their attempts to devise a complete solution to the problem, researchers are proving new theorems in coding theory that may have applications well beyond mathematical puzzles.


  12. Why Mathematicians Now Care About Their Hat Color, NYTimes Next Article Bookmark and Share

    Abstract: Object Processing in the Infant Brain Csibra et al. (Reports, 24 Nov. 2000, p. 1582) found that 8-month-old infants showed electroencephalogram responses in the gamma band (40 Hz) when presented with Kanizsa figures, illusory-square diagrams known to be perceived by infants of that age, but that 6-month-olds, who do not perceive the squares, did not show such gamma-band activity (GBA). The study thus underscored the link between GBA and the process by which "the brain 'binds' together separately coded stimulus features to form unitary representations of objects." Comments by Muller and by Herrmann and Friederici point out significant differences between the Csibra et al. infant study and studies in adults--particularly with respect to the location of the GBA increase in the brain and the detailed patterns of event-related potential (ERP) data presented by Csibra et al.--and question the proposed relation between the ERPs and perceptual binding. Csibra and Johnson respond that "in light of . . . variable findings in adults, we need to keep an open mind when interpreting the data from infants.

  13. Object Processing In The Infant Brain, Science Next Article Bookmark and Share

    Abstract: An owl knows where to aim its talons to catch a mouse even in the dark, thanks in part to a precise map of auditory space engraved in its brain's inferior colliculus, located in the brainstem. Now researchers report on page 249 that space-specific neurons in this map can perform more sophisticated computations than are commonly credited to neurons: Most neurons simply add incoming signals to come up with an answer, but neurons in the owl's auditory map multiply.

  14. Location Neurons Do Advanced Math, Science Next Article Bookmark and Share

    The auditory system of the barn owl has provided numerous valuable models for neurobiology. Pena and Konishi (p. 249; see the cover and the news story by Helmuth ) used intracellular recording from many identified space-specific neurons in the inferior colliculus of the barn owl to determine what computational processes could account for the emergence of space specificity. They compared multiplication and addition in the space-specific cells and present clear evidence in favor of multiplication of subthreshold inputs. The need for multiplicative combination was predicted by previous modeling studies but not shown conclusively. The results in this study will allow the mechanisms in those models to be tested experimentally.

    1. Be Subthreshold And Multiply, Science Next Article Bookmark and Share

      Excerpt: Examples of multiplication by neurons or neural circuits are scarce, although many computational models use this basic operation. The owl's auditory system computes interaural time (ITD) and level (ILD) differences to create a two-dimensional map of auditory space. (…) A multiplication of separate postsynaptic potentials tuned to ITD and ILD, rather than an addition, can account for the subthreshold responses of these neurons to ITD-ILD pairs. Other nonlinear processes improve the spatial tuning of the spike output and reduce the fit to the multiplicative model.

      Editor's note: If owls can multiply one can expect that dolphin can do that as well. In sea water sound travels about five times as fast as in air (with correspondingly shorter ITDs) but on the other hand a dolphin's head is more than five times bigger than an owl's head. Maybe they can do more than multiply.


    2. Auditory Spatial Receptive Fields Created By Multiplication, Science Next Article Bookmark and Share

      Excerpts: Cornell University neuroscientists knew they had one amazing fly on their hands when they testedOrmia ochracea , a tiny insect parasite with such acute directional hearing that it has inspired a new generation of hearing aids and nanoscale listening devices.

      But it wasn't until the scientists ran an experiment on a fly-sized treadmill that they fully appreciated Ormia's talent for sound localization: Not only can the fly match the species thought to have the best directional hearing --Homo sapiens -- but it does so with a fraction of the head space, a boon to miniaturization of man-made devices, Andrew C. Mason, Michael L. Oshinsky and Ron R. Hoy report in the April 5, 2001, issue of Nature .

      "We thought humans were the champions at sound localization, thanks to our highly evolved auditory apparatus and the fact that our ears are up to six inches apart, a separation that allows for ample localization cues. Ormia's ears are a minuscule half millimeter apart, but it has evolved a system for localizing sounds very different from any other animal. (...)

      Sound waves cause each fly eardrum to beat out of phase with the other.

      "The near ear, the one closest to the sound source, responds more vigorously, compared to the far ear, " Hoy explains. Then the fly's nervous system (its fused neural ganglia and a tiny brain) instantaneously calculates the difference in pressure between the two ears and signals the fly's muscles to respond to the sound source. With human ears about 6 inches apart, we have about 10 microseconds to make the same calculation that the Ormia fly, with its half-millimeter head, makes in about 50 nanoseconds -- a thousand times faster.


    3. Hyperacute Directional Hearing of the Ormia Ochracea Fly, Cornell News/Science Daily Next Article Bookmark and Share

      Excerpt: Genomics is changing the face of biology. At first glance, it is largely a change of scale: we move from considering the function of one or a few genes to considering hundreds or thousands of genes at once. The technological advances that brought about this change of scale are leading to the rapid development of still more tools for experimentation and data analysis at the genomic level. We move beyond the genome to consideration of the transcriptome, proteome, and metabolome (all of the transcripts, proteins, and metabolites, respectively, within a cell, tissue, or organism). Looking deeper, we also find that this change of scale is having a dramatic effect on the structure of the scientific community, the manner in which scientific investigation is conducted (and by whom), and how information is disseminated.

  15. Genomics Fosters a "Systems Approach" And Collaborations, Plant Cell Next Article Bookmark and Share

    Abstract: Physical symptoms may be reported in workplace and community settings in which odorous airborne chemicals are present. Despite the relative frequency of such reports, clinicians, public health authorities and sensory scientists often experience difficulty interpreting odor-associated symptoms. The approach to interpretation advocated in this review involves: (i) understanding the toxicology of the agent(s) involved (in particular their relative irritant and odorant potencies); (ii) assessing exposure parameters (i.e. concentration and duration). Depending upon exposure concentration, duration and relative irritant and odorant potencies, a variety of pathophysiological mechanisms may be invoked in explaining odor-associated health symptoms. Some of these imputed mechanisms fall under the traditional scope of toxicology and others involve attitudinal and/or behavioral responses to odors.

  16. Odor-associated Health Complaints, Chem. Senses Next Article Bookmark and Share

    Abstract: Odor perception, including intensity, is affected by knowledge of odor source. For 76 subjects tested with 24 everyday odorants, ratings of intensity, pleasantness and familiarity were enhanced when subjects either could identify the odor source themselves or were provided with the name by the experimenter. Ratings were highest when subjects judged that the names provided matched their own perception, suggesting an interaction between individuals’ cognitive representation of odors and their immediate perceptual experience.

    1. Judgement Of Odor Intensity Influenced By Knowledge Of Odor Source, Chem. Senses Next Article Bookmark and Share

      Abstract: Semantic dementia is a recently documented syndrome associated with non-Alzheimer degenerative pathology of the polar and inferolateral temporal neocortex, with relative sparing (at least in the early stages) of the hippocampal complex. Patients typically show a progressive deterioration in their semantic knowledge about people, objects, facts and the meanings of words. Yet, at least clinically, they seem to possess relatively preserved day-to-day (episodic) memory. Neuropsychological investigations of semantic dementia provide, therefore, a unique opportunity to investigate the organization of human long-term memory and, more specifically, to determine the relationship between semantic memory and other cognitive systems, such as episodic memory. In this review, we summarize recent empirical findings from patients with semantic dementia and discuss whether the neuropsychological phenomena of the disease are consistent with current cognitive and computational models of human long-term memory and amnesia. Six specific issues are addressed: (i) the relative preservation of category-level (superordinate) compared with fine-graded (subordinate) semantic knowledge as the disease progresses; (ii) the better recall of recent autobiographical and semantic memories compared with those in the distant past; (iii) the preservation of new learning, as measured by recognition memory, early in the disease; (iv) the interaction between autobiographical experience and semantic knowledge in the current, but not the distant, time-period; (v) increased long-term forgetting of newly learned material; and (vi) impaired implicit memory. It is concluded that recent findings from semantic dementia offer strong support for the view that memory consolidation in humans is dependent upon interactions between the hippocampal complex and neocortex. Furthermore, these investigations have provided computational modellers of human memory with a novel set of neuropsychological data to be simulated and tested.

  17. Semantic Dementia: Relevance To Connectionist Models Of Long-Term Memory, Brain Next Article Bookmark and Share

    Excerpts: Some cases of schizophrenia may be caused by viruses activating ancient viral DNA lurking in our genome, claim researchers in the US. If so, it might be possible to treat or even prevent the disease with antiviral drugs.

    Yolken says he thought retroviruses might be involved because schizophrenia seems to depend on environmental as well as genetic factors. (…)

    Support for the idea comes from anecdotal evidence that patients often suffer a fever immediately before the onset of schizophrenia.


  18. Is Schizophrenia Caused By An Enemy Within?, New Scientist Next Article Bookmark and Share

    Excerpts: Schizophrenia is a complex disorder characterized by disturbances in multiple domains of brain functioning, including cognitive, emotional, and perceptual processes. Although the diagnostic criteria for schizophrenia have high diagnostic reliability, affected individuals may differ substantially in the specific profile of signs and symptoms that they manifest as well as in the severity and course of their illness. (…) In this issue of PNAS, Karlsson et al. (2) provide intriguing data suggestive of a possible role for retroviruses in the etiology and/or pathogenesis of schizophrenia in some individuals.

    1. Retroviruses And The Pathogenesis Of Schizophrenia, PNAS Next Article Bookmark and Share

      Excerpt: Schizophrenia is a serious brain disease of uncertain etiology. A role for retroviruses in the etiopathogenesis of some cases of schizophrenia has been postulated on the basis of clinical and epidemiological observations. We found sequences homologous to retroviral pol genes in the cell-free cerebrospinal fluids (CSFs) of 10 of 35 (29%) individuals with recent-onset schizophrenia or schizoaffective disorder. Retroviral sequences also were identified in the CSFs of 1 of 20 individuals with chronic schizophrenia.

    2. Retroviral RNA Identified In The Cerebrospinal Fluids And Brains Of Individuals With Schizophrenia, PNAS Next Article Bookmark and Share

      ComDig Question: Do you have a theory why the modifications (in tempo/mode) would be perceived as "happy" or "sad"?

      Simone Dalla Bella: In our article we did not interpret why reducing tempo and changing mode from major to minor make music less happy. What we can conclude from our study is simply that tempo and mode are the most important parameters (perhaps the only one) who determine whether a piece of Western music is happy or sad in adults and 6-8-year-olds (5-year-olds use only tempo).

      However, we can speculate about that. It is possible that children learn to link fast tempo to happy music simply because, by analogy, a happy reaction is often associated with rapid actions reflecting excitement. In contrast, a slow tempo would be considered as sad, since sadness implies more slow/passive actions, indicating less excitement. But this is a mere speculation. It is much more difficult to justify why a major mode conveys a happy mood and a minor mode conveys a sad mood. Another possibility is that all these associations are simply arbitrary, as well as the words we use to designate objects are arbitrary related to the properties of those objects (e.g. why do we use the word "dog" do designate a dog? Not because it has four legs, a tail, etc.)

      Editor's note: The author kindly made sound examples available that were used in the study. They are four examples of "L'autunno" (1st movement, allegro) by Vivaldi: Original, Tempo-Change, Mode-Change, Tempo+Mode-Change


  19. A Developmental Study Of The Affective Value Of Tempo And Mode In Music, Author Response Next Article Bookmark and Share

  20. Links & Snippets Bookmark and Share


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