Supplemental Materials

Do Adolescents With ADHD Show Risk Seeking? Disentangling Probabilistic Decision Making by Equalizing the Favorability of Alternatives

by Y. Pollaket al., 2016, Journal of Abnormal Psychology

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(B)

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Figure S1: (A) A typical display from the Gamble task. Subjects chose between 21 pairs of certain and risky monetary alternatives presented as pie charts. Certain alternatives showed only one monetary value. Risky alternatives presented two monetary values and their associated probabilities. Outcome probabilities of the risky gambles ranged from 0 to 1 in 0.25 increments. Expected values for the certain and risky gambles were matched within 20% for all gamble pairs. Subjects indicated their choice on each trial via button press. (B) A typical display from the description version of the Clicking Paradigm. The task consisted of four problems in which subjects had to choose between certain and low probability alternatives, equalized for expected value. Problems were different in terms of valence of the rare event and in order of magnitude of the gamble (ones or tens). In the description condition, participants were presented with two cards, each of which is associated with different outcomes and probabilities, and were instructed to choose one of the cards. At this example, the participant was provided with information regarding the outcomes of the alternatives, and she chose the risky alternative. (C) A typical display from the experience version of the Clicking Paradigm. In the experience condition, participants saw four pairs of two decks of cards on the computer screen, representing distributions not known to them. By clicking on the decks, cards were drawn, providing feedback according to the corresponding distribution. Subjects drew 100 cards on each of the four problems, resulting in overall 400 trials. At this example, the participant drew a card from the left deck and won 20.2 points.

Experiment 1:

Payoff matrix for risk aversion problems

Problem / Certain / Risky
Vc / V1 / P(V1) / V2 / EV
1 / 7 / 16 / .40 / 0 / 6.4
2 / 13 / 23 / .66 / 0 / 15.18
3 / 11 / 17 / .60 / 0 / 10.2
4 / 11 / 17 / .66 / 0 / 11.22
5 / 14 / 29 / .44 / 0 / 12.76
6 / 11 / 23 / .43 / 0 / 9.89
7 / 10 / 20 / .66 / 0 / 13.2
8 / 300 / 400 / .80 / 0 / 320
9 / 225 / 300 / .80 / 0 / 240
10 / 240 / 250 / .66 / 240 / 246.6
11 / 360 / 375 / .66 / 360 / 369.9

Note. Vc, the value of certain outcome. V1 is the value (points) for the more probable outcome, V2 is the value of the less probable outcome, and EV is the expected value of the risky alternative.

Payoff matrix for loss aversion problems

Problem / Certain / Risky
Vc / V1 / P(V1) / V2 / EV
1 / 0 / 10 / .50 / −10 / 0
2 / 0 / 20 / .50 / −10 / 5
3 / 0 / 30 / .50 / −10 / 10
4 / 0 / 40 / .50 / −10 / 15
5 / 0 / 50 / .50 / −10 / 20
6 / 0 / 100 / .50 / −100 / 0
7 / 0 / 200 / .50 / −100 / 50
8 / 0 / 300 / .50 / −100 / 100
9 / 0 / 400 / .50 / −100 / 150
10 / 0 / 500 / .50 / −100 / 200

Note. Vc, the value of certain outcome. V1 is the value (points) for the more probable outcome, V2 is the value of the less probable outcome, and EV is the expected value of the risky alternative.

Experiment 2:

Payoff matrix for decision problems

Problem / Certain / Risky
Vc / V1 / P(V1) / V2 / EV
1 / 2.3 / 3 / .93 / −7.2 / 2.29
2 / 11.2 / 15.2 / .92 / −34.5 / 11.2
3 / 0 / −2 / .91 / 20.2 / 0
4 / 7.4 / 6.9 / .94 / 15 / 7.39

Note.Vc, the value of certain outcome. V1 is the value (points) for the more probable outcome, V2 is the value of the less probable outcome, and EV is the expected value of the risky alternative.

Experiment 3:

Payoff matrix for decision problem

Problems / Certain / Risky
Vc / V1 / P(V1) / V2 / EV
1 / 3 / 4 / .75 / 0 / 3
2 / 15.4 / 18.8 / .7 / 7.6 / 15.4
3 / −3.8 / −5 / .75 / 0 / −3.8
4 / −7.7 / −9.3 / .7 / −4 / −7.7
5 / 2 / 17 / 0.5 / −13 / 2
6 / 1.75 / 16 / 0.5 / −12.5 / 1.75
7 / 1.5 / 10 / 0.5 / −7 / 1.5
8 / 1.25 / 7.5 / 0.5 / −5 / 1.25
9 / 2.3 / 3 / 0.93 / −7.2 / 2.3
10 / 11.2 / 15.2 / 0.92 / −34.5 / 11.2
11 / 0 / −2 / 0.91 / 20.2 / 0
12 / 7.4 / 6.9 / 0.94 / 15 / 7.4
13 / 12 / 20 / .6 / 0 / 12
14 / 27 / 30 / .8 / 15 / 27
15 / −7.5 / −10 / .75 / 0 / −7.5
16 / −20 / −24 / .75 / −8 / −20
17 / 4 / 28 / 0.5 / −20 / 4
18 / 5 / 32 / 0.5 / −25 / 5
19 / 3 / 22 / 0.5 / −16 / 3
20 / 5 / 30 / 0.5 / −20 / 5
21 / 15 / 18 / 0.9 / −12 / 15
22 / 24.4 / 30 / 0.92 / −40 / 24.4
23 / 0 / −4 / 0.91 / 40.5 / 0
24 / 14.5 / 15 / 0.95 / 5 / 14.5

Note.Vc, the value of certain outcome. V1 is the value (points) for the more probable outcome, V2 is the value of the less probable outcome, and EV is the expected value of the risky alternative.