Do you have a strategy? Multimodal brain signatures of social bargaining in neurodegeneration and frontal stroke

MELLONI MARGHERITA; BILLEKE PABLO; BAEZ SANDRA; HESSE EUGENIA; DE LA FUENTE LAURA; FORNO GONZALO; BIRBA AGUSTINA; GARCÍA CORDERO INDIRA; SIGMAN MARIANO; HUEPE DAVID; SLACHEVSKY ANDREA; MANES FACUNDO; GARCIA ADOLFO; SEDEÑO LUCAS; IBAÑEZ AGUSTIN

Congreso; 18thInternational Organization of Psychophysiology (IOP) World Congress; 2016

Recursive social decision making requires the use of flexible, context-sensitive long-term strategies for negotiation. To succeed in social bargaining, participants? own perspectives must be dynamically integrated with those of interactors to maximize self-benefits and adapt to the other?s preferences, respectively. This is a pre-requisite to develop a successful long-term self-other integration strategy (SOIS). To investigate strategic interaction we analyzed social bargaining behavior in relation to its structural correlates, ongoing brain dynamics (oscillations and related source space), and functional connectivity signatures in healthy subjects and patients offering contrastive lesion models of neurodegeneration and focal stroke: behavioral variant frontotemporal dementia (bvFTD), Alzheimer?s disease (AD), and frontal lesions (FL). All groups showed preserved basic bargaining indexes. However, impaired SOIS was found in bvFTD and FL patients, suggesting that social bargaining critically depends on the integrity of prefrontal regions. Also, structural results revealed a critical role of prefrontal regions in value integration and strategic decisions for SOIS. Furthermore, SOIS was predicted by anticipatory activity (alpha/beta oscillations with sources in fronto-temporal regions) associated with expectations about others? decisions. This pattern was reduced in all clinical groups, with greater impairments for bvFTD and FL. Finally, fMRI connectivity analysis highlighted a fronto-temporo-parietal network involved in successful SOIS, with selective compromise of long-distance connections in both frontal disorders. Findings offer (i) unprecedented evidence of convergent behavioral and neurocognitive signatures of strategic social bargaining in different lesion models, (ii) new insights into the critical roles of frontal hubs and associated temporo-parietal networks for strategic social negotiation.