3/25/16 Decision Making Finances: Save money or spend it? The - PDF document

3/25/16 Decision Making ¤ Finances: Save money or spend it? The Neural Mechanisms of ¤ Eating: Indulge in a second Risky Decision Making dessert? ¤ Medical: Medication with side effects? Rebecca Weldon ¤ Underage drinking: Risk of getting caught ¤ Drugs: Risk of overdose Laboratory for Rational Decision Making ¤ Unprotected sex: Risk of HIV Human Neuroscience Institute Cornell University Multidisciplinary Science Adolescent Risk Taking Number of Drownings 800 600 400 200 0 5-9 10-14 15-24 25-34 35-44 Age 25 Accidents per 100 drivers 20 15 10 5 0 Age Lindquist & Wager, 2015 1

3/25/16 MRI + Cognitive Science Multidisciplinary Science Lindquist & Wager, 2015 Lindquist & Wager, 2015 Human neuroimaging Functional brain imaging ¤ Functional brain imaging can be used to study both cognitive and affective processes. ¤ Modalities include: ¤ Positron emission tomography (PET) ¤ Functional magnetic resonance imaging (fMRI) ¤ Electroencephalography (EEG) Lindquist & Wager, 2015 Lindquist & Wager, 2015 2

3/25/16 Magnetic Resonance Imaging (MRI) MRI Principles Principles: • An MR scanner consists 1. Tissues are full of protons (H + ) of an electromagnet with a very strong 2. Protons in a magnetic field align magnetic field (1.5-7.0 themselves and oscillate in an Tesla) equilibrium state • Earth’s magnetic field 3. Protons exposed to a directed = .000005 Tesla radiofrequency (RF) pulse of magnetism absorb energy • 3 Tesla magnet is ~60,000 times stronger 4. When the RF pulse is removed, than the Earth’s protons release energy as they relax toward their equilibrium magnetic field. state Lindquist & Wager, 2015 From: William W. Seeley, MD; UCSF fMRI data fMRI data ¤ Each image consists of ~100,000 'voxels' (cubic volumes that span the 3D space of the brain). ¤ During the course of an experiment several hundred images are acquired (~ one every ¤ Each voxel corresponds to a spatial location (x, y, z) in the brain. 2s). Lindquist & Wager, 2015 Lindquist & Wager, 2015 3

3/25/16 fMRI data BOLD fMRI ¤ Tracking the intensity over time gives us a ¤ fMRI uses the Blood Oxygenation Level time series. Dependent (BOLD) signal. ¤ BOLD fMRI measures the ratio of oxygenated to deoxygenated hemoglobin in the blood. ¤ BOLD fMRI does not measure neuronal activity directly--it measures the metabolic demands (oxygen consumption) of active neurons. Lindquist & Wager, 2015 Lindquist & Wager, 2015 Data Processing Pipeline fMRI = Functional Magnetic Resonance Imaging Increase in blood flow Increase in neuronal Stimulus to that neuronal re g io n activity = hemodynamic response function Lindquist & Wager, 2015 4

3/25/16 Problem 1 A disease outbreak is expected to kill 600 people. You must choose between two programs Risky Choice Framing Problems (A or B) to fight the disease: A = 200 people will be saved B = 1/3 probability that 600 people will be saved, 2/3 probability that no one will be saved Basic paradigm (Tversky & Kahneman, 1986) Risky Choice Framing Problems Problem 2 A disease outbreak is expected to kill 600 Disease outbreak expected to kill 600 people. people. You must choose between two programs You must choose between two programs (A or B) to fight the disease: (A or B) to fight the disease: 200 saved A = 200 people will be saved (sure) GAIN A = 400 people will die B = 1/3 probability that 600 people will be saved, 2/3 probability that no one will be saved (risky) B = 2/3 probability that 600 people will die, 1/3 probability that no one will die 600-400 = 200 saved A = 400 people will die (sure) LOSS B = 2/3 probability that 600 people will die, 1/3 probability that no one will die (risky) Basic paradigm (Tversky & Kahneman, 1986) Basic paradigm (Tversky & Kahneman, 1986) 5

3/25/16 Risky Choice Framing Problems Fuzzy-Trace Theory Adults derive the gist! Disease outbreak expected to kill 600 people. Gist Verbatim You must choose between two programs A lot of quarters 92 quarters (A or B) to fight the disease: A = 200 people will be saved (sure) GAIN B = 1/3 probability that 600 people will be saved, 2/3 probability that no one will be saved (risky) (Saving some people better than saving none. ) Age LOSS A = 400 people will die (sure) Verbatim Gist B = 2/3 probability that 600 people will die, 1/3 probability that no one will die (risky) (None dying is better than some dying.) Reyna, 2012 Fuzzy-Trace Theory fMRI Experiment: Adolescent Risk Survey example Taking ¤ Risk of contracting HIV from unprotected sex = “a 1/2000 chance” ¤ Risk of contracting HIV from unprotected sex = “a small chance” ¤ How does representation of risk and reward information affect risky Gist processing leads to better decision decision making? making! ¤ Adolescents versus adults ¤ Relationship between reward Can we cue gist-based processing in sensitivity and risky choice adolescents to make their decision making resemble adult decision making? 6

3/25/16 Fuzzy-Trace Theory Manipulation Decisions task completed in MRI scanner: Condition Sure Option Risky Option Prediction Experimental Design Win $20 for 2/3 probability of ¤ Between-subjects factors: Gist sure. winning nothing. ¤ Age (adolescents, adults) LARGE Framing Effect ¤ Hunger (non-hungry, hungry) SOME NONE Win $20 for 1/3 probability of ¤ Within-subjects factors: Mixed sure. winning $60; 2/3 probability of winning NORMAL ¤ Frame (gain, loss) nothing. Framing Effect ¤ Fuzzy-trace truncation (verbatim, mixed, gist) ¤ Reward type (candy, money) SOME SOME or NONE ¤ Magnitudes (1, 6, 20) Win $20 for 1/3 probability of Verbatim sure. winning $60. NO Framing Effect SOME SOME Whole Brain Contrasts Stimulus Presentation You have entered a raffle and $60 is at stake. Which would you choose? ¤ Activation in one experimental condition – A: Win $30 for sure. activation in another experimental condition B: 50% probability you 4 seconds win $60 and 50% PREAMBLE probability you win nothing. Risky > Sure 7 seconds CHOICE 4 seconds Risky CONFIDENCE RATING 4, 6, 8 seconds INTERTRIAL INTERVAL 7

3/25/16 Verbatim No Framing > Framing > No Framing Individual Differences May Gist Framing Affect Decision Making Adolescents (n=24) Adults (n=51) Postcentral IPL Precentral Dorsolateral PFC Dorsomedial PFC Right Right Superior Middle Occipital Cingulate Lobule Middle Cortex Right Right Cingulate Supramar Precentral Cortex ginal Gyrus Gyrus Left dorsal striatal/insular area activation for Individual Difference Measure: Mixed + Verbatim Gain Risk > Mixed + Sensation Seeking Verbatim Gain Sure is correlated with ¤ 19-item Impulsive Sensation Seeking Score Sensation Seeking Subscale - Zuckerman- Left Putamen 1.2 Kuhlman Personality Beta Value for Putamen Questionnaire (Zuckerman 0.8 r=.725 et al., 1993) 0.4 P < .001 ¤ I like doing things just for 0 0.00 0.50 1.00 1.50 the thrill of it. -0.4 ¤ I sometimes like to do -0.8 things that are a little -1.2 Sensation Seeking Score frightening. ¤ I like “wild” uninhibited 1/3 chance of winning parties. Win $20 for sure OR $60 and a 2/3 chance of winning nothing. 8

3/25/16 Thank you! Summary ¤ fMRI is an incredibly powerful tool that allows us to examine activation in the entire brain in a matter of seconds. ¤ Risky decisions can be modulated as a function of the way information about risks and rewards is presented. ¤ There are specific gist-based processing areas (dorsolateral prefrontal cortex) and verbatim-based processing areas (dorsomedial prefrontal cortex) in the brain. ¤ People higher in sensation seeking show greater putamen activation during risky choice for gains. 9