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Science of “contrarian” using diverse models and approaches
Science of “contrarian” using diverse models and approaches
Four model organisms having different social structures
Four model organisms having different social structures
Contrary individuals that behave differently from others are found in a wide variety of species and even in genetically homogeneous populations in the laboratory. However, contrarians have been regarded as outliers so they have not been studied systematically. Here, this project challenges to establish a common, cross-species behavioral paradigm to evaluate contrarians in collaboration with researchers working with four model organisms-flies, medaka fish, monkeys, and humans.
Flies, medaka fish, monkeys, and humans all form social groups, but their degrees vary greatly: simple gathering, well-organised collective behaviors, social hierarchies, and multifaceted and complex social structures. Using these model animals, we aim to test that contrarians are universally present in a variety of animals that form social groups, and we aim to elucidate the biological significance of contrarians.
Multifaceted approach by integrating ecology and neuroscience
Multifaceted approach by integrating ecology and neuroscience
Contrarians may arise in various circumstances and time scales as long as they have a structure of “group and individuals.” In the four model organisms that we use, a variety of experimental techniques have been developed that take advantage of the characteristics of each organism. The use of these model organisms allows us to investigate the diverse nature of contrarians, from the neural basis that manipulates the micro-time scale of changing one’s behavior instantaneously in response to the behavior of others, to the molecular genetic basis on the macro-time scale of changing the composition of a group from generation to generation.
Our project combines ecology and neuroscience to study contrarians from both top-down and bottom-up perspectives. The specialized fields of the research members are diverse, including animal behavior, molecular biology, neurophysiology, ecology, and clinical psychology. By integrating the technologies, knowledge, and research philosophies across members, the researchers will work together to provide a multifaceted character to each research project.
Three major goals of the project
Three major goals of the project
- To establish a behavioral paradigm for evaluating contrarians
- To examine what contrarians and population gain by manipulating the characteristics of the environment, population, and individuals in behavioral experiments
- To elucidate the neural and genetic basis of contrarians
Based on these goals, four research projects will be conducted that take advantage of the biological and experimental technical characteristics of each model organism.
Reserach projects
Reserach projects
Group A01 Social and ecological effects of contrarian behavior on populations and their genetic basis
Group A01 Social and ecological effects of contrarian behavior on populations and their genetic basis
Are individuals that do not follow the majority just bad for society?
Are individuals that do not follow the majority just bad for society?
We sometimes find ourselves wanting to make choices that are different from those of others. The same seems to be true for insects. By using Drosophila, we are studying what genetic characteristics shape such behavior and how such individuals affect the performance of the population.
Yuma Takahashi (Chiba Univ.)
Yuma Takahashi (Chiba Univ.)
Evolutionary biology
Daiki Sato (Chiba Univ.)
Daiki Sato (Chiba Univ.)
Evolutionary genomics
There is a rich diversity within a population of any organism. The main factors for generating diversity within a population are genetic diversity and phenotypic plasticity which is dependent on the environment in which one was born and raised. We have experimentally demonstrated that genetic variation within a population increases the growth rate of the population, walking speed, and comprehensiveness of food search. In addition to genetic and plastic changes within a population, diversity within a population may be created through momentary decision-making that depends on the moment-to-moment social environment, such as “contrarian behavior”. However, it is unknown how such diversity emerges and what ripple effects it has on society. We will first quantify the frequency of occurrence of contrarian behavior in a population of Drosophila melanogaster and explore the genetic basis of the behavior through genome analysis. We will also explore the social impact of contrarian behavior by comparing the movement speed and efficiency in food search and spawning between the entire population of strains that tend to exhibit contrarian behavior and those that do not. Through these studies, we hope to gain an overall picture of diversity and its role in society.
Group A02 Analysis of molecular neural basis of contrarian behavior using novel bold strains and inbred Medaka fish
Group A02 Analysis of molecular neural basis of contrarian behavior using novel bold strains and inbred Medaka fish
Individual personality and social interaction of Medaka fish
Individual personality and social interaction of Medaka fish
If you look carefully when feeding the fish in a task, you might find one who swimming at a distance from others. Consisting a group of Medaka by mixing some strains that have genetically different personalities will elucidate what contrarians bring to society and what molecular mechanism generates behaviors of contrarians/followers.
Saori Yokoi (Hokkaido Univ.)
Saori Yokoi (Hokkaido Univ.)
Behavioral Genetics
We will look at what occurs if mixing individuals from different strains to make a group, especially when they forage in a novel environment. We have found that, even in closed colonies with nearly identical genetic backgrounds, there are some individuals that stay at the bottom of the water when feeding where there is little food although many others flock to the water surface where a lot of food is floating. We hope to elucidate the molecular mechanisms of contrarian by comparing the levels of contrarian emergence among various strains, performing genome-wide association studies, and RNA sequencing analyses. We will also compare the findings of this study with those of other research projects to discuss commonalities and peculiarities in contrarian strategy.
Group A03 Contrarian’s decision making in monkeys
Group A03 Contrarian’s decision making in monkeys
What is the key to surviving in a competitive society of monkeys?
What is the key to surviving in a competitive society of monkeys?
As you know, monkeys are highly intelligent and skilled at observing the facial complexions of others to read the “atmosphere.” In order to survive the intense competition and hierarchical relationships within a herd, one must take advantage of the “atmosphere” and outperform others with a different behavioral strategy. This project will examine the effectiveness of such a “contrarian” behavior.
Hironori Ishii (Kansai Medical University)
Hironori Ishii (Kansai Medical University)
Behavioral neuroscience
Taku Hasegawa (RIKEN)
Taku Hasegawa (RIKEN)
Neurophysiology
Koji Kuraoka (Kansai Medical University)
Koji Kuraoka (Kansai Medical University)
Neurophysiology
Akane Nagano (RIKEN)
Akane Nagano (RIKEN)
Comparative cognitive science
The Monkey Group will conduct two behavioral experiments: one in a real environment and the other in a virtual environment. The collective Y-maze experiment with giant cages, which will be conducted mainly by the RIKEN Group, will comprehensively explore factors that generate contrarian behavior (distance between individuals, power balance, etc.) by focusing on bargaining that involves contact between individuals. The Kansai Medical University Group will parametrically determine the relationship between the behavioral strategies of contrarians and other individuals. This experiment will use a Multiplayer Gambling game that incorporates the collective Y-maze into a virtual environment to allow each monkey to choose based on free will, regardless of the strength of the individuals. Through these two behavioral experiments, we aim to elucidate the principles of contrarian behavior in advanced and diverse decision-making that is unique to monkeys (and humans). We will also conduct fitness simulations based on the obtained behavioral data, investigating the ecological significance of contrarians in terms of ripple effects on the individual and population levels in a long-term perspective. In addition, we plan to advance our understanding with bottom-up approaches by examining the neural mechanisms that generate contrarian behavior and the neuroplasticity associated with changes in the degree of contrarian behavior.
Group A04 Flexible contrarian behavior based on social metacognition in humans
Group A04 Flexible contrarian behavior based on social metacognition in humans
Elucidating the mechanism of contrarian strategy based on the prediction of the thoughts and behaviors of others
Elucidating the mechanism of contrarian strategy based on the prediction of the thoughts and behaviors of others
Humans form far more complex and developed societies than do other animal species. We aim to elucidate how the ability to “read the atmosphere” -adjusting one’s own thoughts and behaviors by imagining the thoughts of others- contributes to the emergence of contrarian strategy and social stability.
Kentaro Miyamoto (RIKEN)
Kentaro Miyamoto (RIKEN)
Cognitive psychology
Mingming Lin (RIKEN)
Mingming Lin (RIKEN)
Cognitive psychology
The Human Group will examine the role of contrarian strategy in society by focusing on the metacognitive ability to accurately evaluate their own cognitive state and advanced social cognitive ability. We will design an online experimental task that mimics the reward-searching/ foraging behaviors of animals in groups and acquire data under conditions where a large number of experimental participants respond simultaneously. Through these, we aim to identify environmental factors, such as predictability of reward amount and probability, as well as in vivo factors, such as temperament, that are involved in the generation of contrarian strategy. To flexibly switch between follower and contrarian strategies in response to changes in social environment, the ability of “social metacognition,” which coordinates cognitive adjustments based on interactions with others, is particularly important, in addition to the ability to engage in the “theory of mind,” which estimates the mental states of others. Using brain function imaging (functional magnetic resonance imaging [MRI] method) and brain stimulation (transcranial magnetic stimulation [TMS] method), we will identify the causal neural basis that produces contrarian behavior. Thus, we will elucidate the sharing and visibility of information with others, the occurrence of contrarian strategy, and the relationship between the benefit and equality as a group over a medium- to long-term time span, aiming to extend the research to sociology, behavioral economics, public policy studies, and other fields in the humanities and social sciences.
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