Preferences and beliefs about financial risk taking mediate the association between anterior insula activation and self-reported real-life stock trading

Figures

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  Figure 1. The investing paradigm and regions of interest. There were eight blocks in each domain (gain and loss), consisting of eight trials each (thus 96 total trials, one trial of each domain is shown here). In the beginning of a block, participants were shown in which domain they were. They chose between a risky (stock) or non-risky (bond) option and the choice implementation (button press) was highlighted with a green frame. Next, participants saw the stock payoff feedback, regardless of the previous choice. The participants then estimated the probability of the stock being good and finally, a balance feedback was shown.

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  Figure 2. Group-level brain activation and regions of interest. (a) Whole-brain reward prediction error (RPE) activation (whole-brain corrected p(FWE) <0.05, k > 10, n = 165). (b) Regions of interest used to extract weighted beta estimates (see Figs 2–4, as well as Supplementary Figs S1, S2, and Supplementary Table S4). The right (turquoise) and left (pink) anterior insula (AI) masks, as well as bilateral ventral striatum (VS, magenta) masks were obtained from previous neuroeconomic studies on risk processing1,6. The ventromedial prefrontal cortex (vmPFC) mask (yellow) and the fusiform face area (FFA) mask (blue, used as a control region) were obtained from meta-analyses of valuation9 and emotional face processing31, respectively.

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  Figure 3. Data distribution of all variables used in the analysis (all n = 157, Tables 1–3). Kernel density graphs are shown for continuous variables, histograms for ordinal and interval variables, and bar graphs for binary variables. 1During stock versus bond choice (gain domain). 2Bins: 1 (<500€), 2 (500€–1000€), 3 (1000€–2000€), 4 (2000€–3000€), 5 (3000€–4000€), 6 (4000€–5000€), 7 (5000€–6000€), 8 (>6000€).

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  Figure 4. The association between the activation in the anterior insula (AI, independent variable, when choosing between a stock and a bond) and active stock trading (dependent variable) is mediated through risk tolerance and risk optimism (mediator variable, see Supplementary Table S10). The Sobel-Goodman (SG) Mediation test was used with subsequent bootstrapping of the effect (all n = 157, seed set at 10, 10,000 repetitions). Observed coefficients are shown with 95% (bias-corrected and accelerated) confidence intervals in parentheses. An effect is considered significant if the confidence interval does not include the null hypothesis (i.e. zero is not included) and is visualized in bold. (a) Mediation of left AI activation and active stock trading through risk tolerance (at least 17.7%). (b) Mediation of left AI activation and active stock trading through risk optimism (at least 22.9%). (c) Mediation of right AI activation and active stock trading through risk tolerance (at least 25.0%).