SUPPLEMENTARY INFORMATION

Transcription

1 SUPPLEMENTARY INFORMATION 1. Supplementary Tables 2. Supplementary Figures 1/12

2 Supplementary tables TABLE S1 Response to Expected Value: Anatomical locations of regions correlating with the expected value on each trial, having accounted for mean changes in activity due to the target level. Data are thresholded at p<0.005, uncorrected. We report areas reaching a peak voxel-level significance p and cluster size of >5 voxels only. Area L/R MNI coordinates T value Extent x y z (voxels) mid-orbital gyrus - ventromedial orbitofrontal cortex R fusiform gyrus L ventral striatum - nucleus accumbens R superior medial gyrus L /12

3 TABLE S2 Response to Target Level: Anatomical locations of regions correlating with the target level. We report areas reaching a peak voxel-level significance p and cluster size of >5 voxels only. Area L/R MNI coordinates T value Extent x y z middle frontal gyrus, BA6 R anterior cingulate cortex R middle occipital gyrus L superior frontal gyrus L paracentral lobule/ supplementary motor area, BA6 L L precentral gyrus L postcentral gyrs L middle occipital gyrus R /12

4 TABLE S3 Response to Variance: Anatomical locations of regions correlating with the expected variance on each trial, having accounted for mean changes in activity due to the target level and expected value. Data are thresholded at p<=0.005, uncorrected. We report areas reaching a peak voxel-level significance p and cluster size of >5 voxels only. Area L/R MNI coordinates T value Extent x y z (voxels) Putamen R middle frontal gyrus R inferior frontal gyrus R superior orbital gyrus R inferior parietal lobe L inferior temporal gyrus R ventral striatum L postcentral gyrus, BA6 R anterior cingulate cortex R anterior insula L anterior insula R middle frontal gyrus L inferior frontal gyrus / anterior insula R /12

5 TABLE S4 Response to Skewness: Anatomical locations of regions correlating with the expected skewness on each trial, having accounted for mean changes in activity due to the target level, expected value, and variance. Data are thresholded at p<0.005, uncorrected. We report areas reaching a peak voxel-level significance p and cluster size of >5 voxels only. Area L/R MNI coordinates T value Extent x y z postcentral gyrus, BA 1 L superior parietal lobe, BA2 L mid-orbital gyrus, medial orbitofrontal cortex L inferior frontal gyrus L medial temporal pole R superior frontal gyrus L middle temporal gyrus L precentral gyrus, BA 6 R /12

6 TABLE S5 Response to Integrated Utility: Anatomical locations of regions correlating with the overall utility of choice on each trial. We report areas reaching a peak voxellevel significance p and cluster size of >5 voxels only. Area L/R MNI coordinates T value Extent x y z corpus callosum / mid-cingulate gyrus R primary somatosensory cortex R prmary motor cortex L medial prefrontal cortex L R Thalamus L Thalamus L pre-supplementary motor area L anterior insula L /12

7 Previous studies identifying regions of interest for expected value and variance-related activity TABLE S6 EXPECTED VALUE Study reference Description Regions MNI coordinate [x, y, z] - peak Knutson 2005 EV Ventral striatum + 11,11,-3-8,-11,-2 mofc + -4,51,3 Yacubian 2006 Gain related EV Ventral striatum -12, 9, -3 12, 9, -3 R OFC 36, 63, 0 Probability* R mofc 3, 51, -6 Ventral striatum -12, 15, -3 15, 15, -6 Abler 2006 Probability** Ventral striatum 9, 0, -12-9, 9, -12 Plassmann 2007 Willlingness to pay*** mofc 6, 30, -17 Elliot 2008 Relative value mofc 6, 48, -12 Rolls 2008 EV mofc 19, 51, -3 EV and magnitude mofc 2, 38, -14 De Martino 2009 Willingness to pay*** mofc -4, 40, indicates that coordinates have been transformed from reported Talairach to MNI space for comparison (using tal2mni (Brett 2001)) *reward probability was collinear with relative gain-related EV, as there were only two magnitudes of gain (high or low), and these were cued by an image of a coin or a banknote, which sets the context similarly to our target manipulation **collinear with EV as fixed value of outcome ***subjective value. EV expected value; mofc medial orbitofrontal cortex Mean coordinates of interest based on average coordinates from above studies: Ventral striatum: right: [12, 9, -6], left: [-10, 6, -5] mofc: right: [12, 47, -9], left [-4, 46, -7] 7/12

8 TABLE S7 VARIANCE Study reference Description Regions MNI coordinate [x y z] - peak Critchley 2001 Risk* Anterior cingulate 8, 22, 28-6, 28, 20 latofc / Anterior insula 30, 24, , 14, -4 Huettel 2005 Uncertainty*** Anterior insula 35, 26, 4-30,20,5 IFG 55, 10, 35 MFG -44, -4, 36 IPL IPS , -77, 48 Preuschoff 2006 Variance** Anterior insula + -32, 17, 2 34, 13, 2 PHG + -17, -29, , -22, -18 TTG + 58, -14, 10-53, -8, 3 Dreher 2006 Variance Putamen 23, 8, , 0, -11 Tobler 2007 Variance latofc -42, 30, -20 Rolls 2008 Variance Anterior insula 46, 16, 6 Preuschoff 2009 Variance** Anterior insula , 15, -2 Posterior insula + 49, -12, 6 IPL Angular gyrus + 52, -55, 24 IFG + 48, 17, 18 STG + -38, -8, 22 + indicates that coordinates have been transformed from reported Talairach to MNI space for comparison (using tal2mni (Brett 2001)) *risk expressed as probability of most likely outcome in a task with binary outcomes, which is highly correlated with expected variance. **immediate response to variance. ***uncertainty expressed as the 1-p(corr), where p(corr) is the probability of being correct in a decision task with binary outcomes. This correlates with outcome variance latofc lateral orbitofronal cortex; IFG inferior frontal gyrus; MFG middle frontal gyrus; IPL inferior parietal lobe; IPS inferior parietal sulcus; STG superior temporal gyrus; TTG; transverse temporal gyrus; PHG parahippocampal gyrus. Mean coordinates of interest based on above average coordinates of regions reported more than once in above studies: Anterior insula: right: [35, 19, -2] left: [-31, 17, 0] Inferior frontal gyrus: [52, 14, 27] Inferior parietal lobe: [51, -17, 33] 8/12

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12 Figure S3 Legend Model comparison including 3 utility models. EUT expected utility, MVS meanvariance-skewness, PT prospect theory-type. ACV average continuation value, OCV optimal continuation value, SCV sure continuation value. To illustrate relative model fits, we plot the inverse of the average criterion function (mean D) -1, where D is the criterion value (the distance between simulated and actual choice frequencies)). Larger values for D -1 indicate a better model fit, however the 3 utility models are not directly comparable as they have different numbers of parameters. Power utility (EUT) was specified as: V h n, t ( θ ) = V h n, t ( j) h 1 B = Ε n, t ( ρ) 1 ρ ρ h Where B ( ) indexes the jth outcome from the set of discrete outcomes B, from strategy n, t j s n, and ρ reflects the curvature of the power utility function, and hence risk aversion. Prospectic utility (PT) was specified as : V h n, t ( θ ) = V h n, t Δ ( ρ) = Ε h ( ) ( ), } n, t j j m R h B { B n, t 1 ρ R 1 ρ Where Δ {A} is a step function (=1 if A is true, = -1 if A is false), R is the reference point (we set R = 10, the summed expected value of the five lottery proposals within a block), and ρ reflects the curvature of the utility function. In this simplified version of prospect theory, we have no probability weighting and risk seeking for losses is of the same level as risk aversion for gains. 12/12