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Supplemental Materials
Emotion Regulation and Behavior in an Individual-Decision Trading Experiment: Insights From Psychophysiology
by A. Hariharan et al., 2015, Journal of Neuroscience, Psychology, and Economics
http://dx.doi.org/10.1037/npe0000040
This material provides screenshots of the experiment interface for the information of the reviewers. Moreover, we include English translations of the instructions and the comprehension questions. Please note that the instructions are only translations for information; they are not intended to be used in the lab. The instructions in the original language were carefully polished in grammar, style, comprehensibility, and avoidance of strategic guidance.
Appendix A
Experiment Instructions
General
Welcome to today’s experiment and thank you for your participation. In this experiment, you can earn cash, depending on your decisions. Please read these instructions carefully.
When you have questions, please raise your hand and direct your questions directly and as quietly as possible to the experimenter. Please do not communicate with the other participants for the entire duration of the experiment.
The experiment consists of 16 repetitive rounds, in which the first round is test round. In the test round, you can familiarize yourself with the procedure. In each round you will make a decision, by which you are bestowed with a share. Following this, you can decide to either keep or sell the stock.
Course of a round
Each of the 16 independent rounds consists of 4 individual, independent stock investments.
During a stock investment you will go through 2 trading periods. Your payment for the stock is then calculated according to the gain or loss you have achieved in these two periods.
The steps of a stock investment are described in more detail below.
Stock Investment
First, you have the option of choosing from one of four stocks.
Each stock is worth 100 €, and must be selected once per round. A stock which is already chosen is highlighted with a red background (see figure), such that you can no longer select this in the same round.
Trading Period 0 - Display of Stock Properties
In the second step, you receive information about the selected stock in terms of their possible change in value (possible values: + / -2 €, + / -10 €), the probability of winning (possible values: 45%, 55%) and the corresponding probability of loss, on the left side of the screen. The display is made with a short time gap. On the right side of the screen is a graph depicting the stock value (the initial value is always 100 €) for each trading period.
In the illustrated example, the possible change is the amount of 10 €. Then you will be shown how high the probability to win, which in this example is 55%. Thus, you could win a stock of 10€ with a probability of 55%. However, this also means that you could lose €10 with a probability of 45%.
Trading Period 0 - Stock trend & Decision
At the end of the first trading period, the actual development of your stock will be presented. In this example, the stock price has increased by 10 €. Now it's your decision, to sell this stock and realize a profit of 10 €, or to hold the stock. In the case of "Hold", you play another trading period, and the stock is automatically sold. You have 55% probability of gaining an additional 10 €. The stock price will rise or fall in each period; it is not possible for the value to remain at the same state.
Trading Period 2 - Final Information & short questionnaire
Now you see the result of the stock investment: if you had held the stock in Period 1, you can see how the stock performed, and your total realized profit. If you had sold the stock in Period 1, you will see the further trend of the stock only for your information. Through this, you will see the amount of profit or loss you would have made if you had held the stock. Through a red color trend, you will be signaled the stock’s gain/loss information, and its current value.
In this example you have sold your shares in the first trading period, so you have realized a total loss of € 10. In the second trading period, you can observe that the stock has fallen further. Had you held the stock, your total loss would have been €20.
After a short delay you will be prompted to evaluate your experienced emotions immediately after the stock trading at the bottom of the screen, on a scale of 1 to 7.
Payoff Calculation
Your personal payoff is calculated using the total gain/loss of a single stock trading round! You choose this stock trading round yourself at the end of the experiment by rolling a die. First you will pull out a number from 1 to 15 from the envelope, that determines your round (test round is excluded), and then you will roll a 4-sided die, to choose the individual stock within this round.
At the beginning, you will receive a credit of 22 €, so that in the worst case you still receive a payment of 2 € even with a loss of 20 € (10 € Period 1 loss + 10 € Period 2 loss). In the best case, you get a maximum of 42 € (10 € Period 1 profit + 10 € Period 2 profit + 22 € credit).
In the example shown, the stock has increased by € 10 in the first trading period, but declined in the second trading period 10 €, so your final value is equal to the initial value of 100 € . But since you have sold the stock after period 1, you make a gain of € 10. This gain is added to the initial € 22 credit, so your total payment would be 32 € in this example. Schematically, this would be described as:
Concluding Remarks
Please fill out an understanding questionnaire after a short prompt now on the PC in front of you. Then wait until the experimenter prompts you to start the experiment on the PC in front of you. Upon completion of this experiment on the computer, we will ask you to complete a questionnaire. At the end of it, you will be individually requested by the experimenter determine your payoff by rolling your die and the amount will be paid in cash. The experiment process is then complete for you.
If you have a question, please remain seated quietly and raise your hand. The experimenter will then come to you and answer your question.
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Appendix B
Factor Loadings of Physiological Parameters With Varimax Rotation
Feature / Description / CronbachAlpha / Factor loadings for Component
1 (Arousal_Fac_HR) / 2 (Arousal_Fac_SCR)
Heart Rate 10 : avghr_pre10 / Normalized Heart rate 1 s before event / .98 / .987 / .133
Heart Rate 9 : avghr_pre9 / Normalized Heart rate .9 s before event / .987 / .145
Heart Rate 8 : avghr_pre8 / Normalized Heart rate .8 s before event / .990 / .120
Heart Rate 7 : avghr_pre7 / Normalized Heart rate .7 s before event / .992 / .085
Heart Rate 6 : avghr_pre6 / Normalized Heart rate .6 s before event / .991 / .117
Heart Rate 5 : avghr_pre5 / Normalized Heart rate .5 s before event / .991 / .114
Heart Rate 4 : avghr_pre4 / Normalized Heart rate .4 s before event / .996 / .044
Heart Rate 3: avghr_pre3 / Normalized Heart rate .3 s before event / .997 / .025
Heart Rate 2 : avghr_pre2 / Normalized Heart rate .2 s before event / .995 / .045
Heart Rate 1 : avghr_pre1 / Normalized Heart rate .1 s before event / .995 / .050
SCR 1 : avg_cda_tonic / Mean tonic activity within response window (wrw) / .696 / -.381
SCR 2 : avg_cda_nscr / Number of significant (= above-threshold) SCRs wrw / .85 / .191 / .967
SCR 3 : avg_cda_ampsum / Sum of SCR-amplitudes of significant SCRs wrw [muS] / -.101 / .952
SCR 4 : avg_cda_scr / Average phasic driver wrw. Represents phasic activity wrw most accurately, not correlated to SCR amplitudes [muS] / -.396 / .888
SCR 5 : avg_cda_iscr / Area (i.e. time integral) of phasic driver wrw [muS*s] / -.396 / .888
SCR 6 : avg_ttp_latency / Response latency of first significant SCR wrw [s] / -.337 / .704
Eigenvalue / 10.915 / 4.704
Variance Explained (%) / 63.60 / 28.27
Cumulative Variance (%) / 63.60 / 91.87
Note: Average Phasic Heart Rate was computed in the time frame of 1s before E2.
SCR features were calculated using Ledalab (Benedek & Kaernbach, 2010) for Matlab on E2.