<!-- TITLE: Neuroecon --> <!-- SUBTITLE: A quick summary of Neuroecon --> # Neural responses to taxation Distinguishing the "hedonistic" neural responses to 'pure altruism' and 'warm glow' motives. **pure altruism** satisfaction from increases in public good. free-riding very common. taxation typical solution **warm glow** agency associated with voluntary giving. taxation doesn't produce this. their benefit derives from amount of gift. ventral striatum and insulae *connected to* reward processing (money, food, drugs). but also to charitable giving, deciding to trust others, punishing unfair players **Dictator game** You have $100 and decide what to give to charity (different balances of your loss and their game), as well as mandatory taxes ## Results + Larger activation in response to *the participant* getting money decreases likelihood of giving + Larger activation in response to *the charity *getting money increases likelihood of giving # Using TMS to disrupt DLPFC and diminish reciprocal fairness [Supplementary material](http://www.sciencemag.org/cgi/content/full/1129156/DC1) **Ultimatum game** is where one proposes a split of e.g. $20, and if refused both players earn $0. **Previous research** shows unfair ultimatums are rejected, even if it's a considerable amount of money. Anterior insula and DLPFC activate when responders make the decision of acceptance. Competing theories about whether participants are resisting the temptation to accept (self-interest) or to reject (norm-maintenance). These are both consistent with dual-systems approaches. They think it's not one or the other, but the balancing of the two aims. ## Claims in the abstract + Right (but not left) DLPFC disruption matters + Participants still judge unfair offers as unfair, despite accepting them + Implication: DLPFC plays a role in implementation of fairness-related behaviors ## Their hypotheses + Disruption to right DLPFC should be more influential than left, based on previous work on inhibitory control + Should see a difference between human- and computer- conditions, as norm-enforcing doesn't make sense for computers ## The study, logic and procedure + We don't really know the DLPFC is instrumental in this decision process, or what exactly it's doing if it is (what impulse is it modulating?) + 52 subjects, no prior TMS experience + only options are 10, 8, 6, or 4 out of 20. + each plays 20 times. 10 times with distinct others, 10 times with randomly generated (deciders know) + repeditive transcranial magnetic stimulation (rTMS) applied for 15 minutes to right or left DLPFC (19/17 subjects) + control condition (16 subjects) + this brain area will be deactivated for another ~7min after stimulation stops + fairness assessments took place roughly 4-5 minutes after the 15-minute offline stimulation with rTMS + DLPFC "very likely" to still be disrupted ## Results + 24% acceptance for human offers of 4 + *acceptance of most unfair*: 9.3% (sham rTMS), 14.7% (rTMS of left), 44.7% (rTMS of right) + 37% accepted all unfair offers after rTMS right, *none* in the other conditions + rTMS of right $\to$ same response time 16/4 as 10/10 + given rTMS of right, no effect of offer on probability to accept + gave questionairres afterwards trying to assess individual differences + no effect of rTMS on fairness judgments (measured immediately after Ultimatum Game) + no differences in acceptance of computer-offer conditions across stimulus conditions # Others' ## Wills et al. 2018