Periodic Reporting for period 5 - BRAINCODES (Brain networks controlling social decisions)
Okres sprawozdawczy: 2023-03-01 do 2024-02-29
Humans do not act in a social vacuum, but our decisions always affect the people around us. We therefore need to consider other people's goals, beliefs, and emotions when making decisions. This social decision-making is fundamental to uniquely human traits such as trust, sharing, strategizing, and adhering to social norms. These behaviours are crucial for both individual and societal well-being, and disruptions of them can lead to significant personal and societal costs, particularly in cases of brain disorders or criminal activities. Understanding how we make social decisions is thus crucial for maintaining peaceful and productive societies and is a key focus of various scientific fields, including psychology, economics, the social sciences, biology, and medicine.
The project BRAINCODES seeks to understand the brain mechanisms that control our social decisions, particularly in areas like cooperation, strategic behaviour, adherence to norms, and sharing. Characterizing these brain mechanisms is challenging because such behaviours are primarily human and therefore cannot be studied in animal models. It is particularly unclear (1) what neural computations are carried out to steer these behaviours, (2) how the involved brain areas interact as a network, (3) which aspects of neural processing in the network indeed control behaviour in a causal sense, and (4) how changes in these processes lead to pathological behaviour if disrupted in brain disorders.
BRAINCODES addresses these four open questions by employing a unique multi-method approach that integrates computational modelling of social decisions with new combinations of multimodal neuroimaging and brain stimulation methods. Thus, BRAINCODES aims to generate a causal understanding of the brain network mechanisms that allow humans to control their social decisions, thereby elucidating a biological basis for individual differences in social behaviour and paving the way for new perspectives on how disordered social behaviour may be identified and hopefully remedied.
The project BRAINCODES seeks to understand the brain mechanisms that control our social decisions, particularly in areas like cooperation, strategic behaviour, adherence to norms, and sharing. Characterizing these brain mechanisms is challenging because such behaviours are primarily human and therefore cannot be studied in animal models. It is particularly unclear (1) what neural computations are carried out to steer these behaviours, (2) how the involved brain areas interact as a network, (3) which aspects of neural processing in the network indeed control behaviour in a causal sense, and (4) how changes in these processes lead to pathological behaviour if disrupted in brain disorders.
BRAINCODES addresses these four open questions by employing a unique multi-method approach that integrates computational modelling of social decisions with new combinations of multimodal neuroimaging and brain stimulation methods. Thus, BRAINCODES aims to generate a causal understanding of the brain network mechanisms that allow humans to control their social decisions, thereby elucidating a biological basis for individual differences in social behaviour and paving the way for new perspectives on how disordered social behaviour may be identified and hopefully remedied.
To identify neural computations and brain network mechanisms that underlie social behaviour, we conducted several studies with functional magnetic resonance imaging (fMRI) and/or electroencephalography (EEG). These studies focused on different types of social behaviours, such as leadership, trust, altruism, moral decisions, norm compliance, and strategic choice. Together, these studies highlight various shared types of neural computations and functional interactions in the social brain network that underlie distinct aspects of social behaviour. Moreover, they highlight some key areas that appear to implement these computations and interact with one another (among them the temporo-parietal junction, TPJ, and the lateral and medial prefrontal cortex, lPFC and mPFC). In one notable study, we identified a truly multivariate pattern of neural activity across the whole brain network that can predict how flexibly people can adapt to other people’s behavioural strategies. We have established computational models that allow researchers to investigate, for all these types of behaviour, how the information about social context can be integrated with non-social information to control action.
We tested the causal relevance of these identified neural processes by means of brain stimulation studies. Key findings of these studies are that the TPJ is causally relevant for moral decisions and for computations that allow people to incorporate other’s perspectives into their own behaviour, that the lPFC is causally relevant for compliance with social norms, that neural coherence between frontal and parietal areas facilitates altruism.
Finally, to establish the clinical relevance of these processes, we tested various groups of people with impaired brain function due to aging, stroke, Borderline Personality Disorder, Autism Spectrum Disorder, and Post-Traumatic Stress Disorder. Our results show that healthy aging leads to a decrease in the use of the neural computations underlying the ability to take strategic decisions, that Asperger’s syndrome is associated with an inflexibility in adapting to other people’s changing strategies, and that Borderline Personality Disorder is associated with biases and instabilities in the way beliefs about others are adapted in response to information about their behaviour.
The results of all studies have been shared at numerous conferences with scientific audiences and at events for decision makers and the interested public, and have been (or are being submitted to be) published in peer-reviewed journals. Moreover, to summarise the aims and findings of the project, we have outlined our theoretical approach in literature reviews, and we have provided an overview of our methodical approach in review papers that provide the field with clear guidelines for conducting and assessing brain stimulation studies on the neural computations and network mechanisms underlying behaviour.
We tested the causal relevance of these identified neural processes by means of brain stimulation studies. Key findings of these studies are that the TPJ is causally relevant for moral decisions and for computations that allow people to incorporate other’s perspectives into their own behaviour, that the lPFC is causally relevant for compliance with social norms, that neural coherence between frontal and parietal areas facilitates altruism.
Finally, to establish the clinical relevance of these processes, we tested various groups of people with impaired brain function due to aging, stroke, Borderline Personality Disorder, Autism Spectrum Disorder, and Post-Traumatic Stress Disorder. Our results show that healthy aging leads to a decrease in the use of the neural computations underlying the ability to take strategic decisions, that Asperger’s syndrome is associated with an inflexibility in adapting to other people’s changing strategies, and that Borderline Personality Disorder is associated with biases and instabilities in the way beliefs about others are adapted in response to information about their behaviour.
The results of all studies have been shared at numerous conferences with scientific audiences and at events for decision makers and the interested public, and have been (or are being submitted to be) published in peer-reviewed journals. Moreover, to summarise the aims and findings of the project, we have outlined our theoretical approach in literature reviews, and we have provided an overview of our methodical approach in review papers that provide the field with clear guidelines for conducting and assessing brain stimulation studies on the neural computations and network mechanisms underlying behaviour.
The work conducted in our project has established and validated sensitive measures of specific social decision mechanisms, at the level of neural computations and underlying brain processes. We have not only established the experimental protocols, computational models, and analysis methods that allow researchers to index these processes, but we have already established that they are indeed causally relevant for behaviour, and that they are altered in healthy aging, Asperger’s Syndrome, Borderline Personality Disorder, and Post-Traumatic Stress Disorder. Thus, the measures established by the work conducted in this project go beyond the state of the art because they do more than simply indicate a correlation between brain activity and behaviour: They index precisely defined neural computations that are demonstrated to be causally relevant for successful control of behaviour in the healthy brain and that are altered by aging and brain pathologies in ways that correlate with the corresponding behavioural symptoms.
These measures will therefore be useful for many academic disciplines: They can be used by neuroscientists to study how social and non-social information is combined during decision making, by psychologists to understand individual differences in and the development of social decision making throughout the lifespan, by social scientists to compare predictions of different theories about human social behaviour, by neurobiologists to identify precursors of social brain networks in animals, by forensic scientists to study the origins of pathologically dishonest or rule-violating behaviour, and by physicians to diagnose and monitor maladaptive social decision making in psychiatric disorders.
These measures will therefore be useful for many academic disciplines: They can be used by neuroscientists to study how social and non-social information is combined during decision making, by psychologists to understand individual differences in and the development of social decision making throughout the lifespan, by social scientists to compare predictions of different theories about human social behaviour, by neurobiologists to identify precursors of social brain networks in animals, by forensic scientists to study the origins of pathologically dishonest or rule-violating behaviour, and by physicians to diagnose and monitor maladaptive social decision making in psychiatric disorders.