1 id - system id
2 condition - payoff structure in block 2
3 block - experimental block
4 trial - sample #
5 delta_p - true absolute difference in proportions of arrows up between options A and B
6 p1 - true proportion of arrows up for option A
7 p2 - " option B
8 startleft - true if unfolding starts with option A, B otherwise
9 n_both - total number of observed single arrows
10 n_left - # arrows observed for option A
11 n_right - " option B
12 presentation_time - sampling time [ms]
13 response - decision 
14 correct - correctness of choice
15 ecu - summed payoff after this decision
16 rt - response latency for the decision (aside from sampling)
17 t_used - summed time used after this trial 
18 presented_left - actually observed sample of arrows on option A (1 up, 0 down)
19 presented_right - " option B
20 allstim_left - computer generated full sample on option A
21 allstim_right - " option B
22 ecu_to_cent - factor for payoff calculation