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social networks) BTK inhibitor solubility dmso may emerge from a rich tapestry of previous experiences. Here, we provide an overview of the experimental tasks and the procedures used to analyze the fMRI data; full details are provided in the Supplemental Experimental Procedures. Twenty-six healthy, right-handed individuals who were currently undertaking or had completed a university degree, participated in this experiment (age range 19–31; 12 female). One of these participants failed to fully learn either person or galaxy hierarchies and was therefore excluded from the fMRI analyses. All participants gave informed written consent to participation in accordance with the local research ethics committee. Face pictures were obtained from a widely used database (Stirling database: http://pics.stir.ac.uk). Pictures of galaxies (source: various sites on the internet including http://hubblesite.org/gallery/album/nebula) were chosen to be distinct from one another. Prior to each scanning session, participants briefly performed a simple one-back task where they viewed each individual face and galaxy three times, in order to minimize stimulus novelty effects during scanning. Participants

were instructed that they would STAT inhibitor be playing a simple science-fiction computer game, acting as an investor in the future. They were told they would first (“Learn” phase) need to learn about which individuals have more power within a fictitious space mining company and which galaxies have

more precious mineral. In phase two (“Invest” phase), they were told that they would need to use knowledge acquired during phase one to decide how much they would be willing to pay for potential projects on offer—where a project constituted the combination of a particular person and a particular galaxy (i.e., as if the person would be heading up a mission to go to the galaxy to harvest minerals). The Learn phase paradigm is grounded in classic implementations of the transitive inference task (Bryant and Trabasso, 1971), where dimensions such as length and weight were emphasized (c.f. mineral content 3-mercaptopyruvate sulfurtransferase in our study). In this phase, participants acquired knowledge about the seven-item person and galaxy hierarchies in parallel with blocks of training trials (i.e., six training pairs, presented in pseudorandom order: e.g., P1 versus P2, P2 versus P3, P3 versus P4, P4 versus P5, P5 versus P6, P6 versus P7; see Figure 1A for details) interleaved with blocks of test trials (i.e., six inference pairs, presented in pseudorandom order: e.g., P2 versus P4, P2 versus P5, P2 versus P6, P3 versus P5, P3 versus P6, P4 versus P6; see Figure 1B; for details, see Supplemental Experimental Procedures).