Table 2.
Mean DKM parameter κ (s-1), mean reproduced length (s) and coefficient of variation of the duration reproduction task for three durations, as well as discounting parameter k compared between stimulant-using, impulsive subjects as well as stimulant-naïve controls.
| Ever used Popular types |
Stimulant users (n = 10) | Impulsive (n = 5) | Controls (n = 12) | |||
|---|---|---|---|---|---|---|
| Mean | S.D. | Mean | S.D. | Mean | S.D. | |
| BIS non-planning | 25.2 | 6.6 | 26 | 0.7 | 21 | 4 |
| BIS motor | 24.8 | 6.2 | 32 | 5.6 | 21 | 4.1 |
| BIS attention/cognition | 16.6 | 3.8 | 21.4 | 4.4 | 15 | 3.2 |
| ZTPI present-hedonistic | 54.3 | 4.5 | 59.2 | 5.8 | 54.8 | 6.4 |
| ZTPI present fatalistic | 22 | 5.2 | 27.2 | 3.7 | 21 | 5.1 |
| ZTPI future | 40.9 | 7.7 | 35.6 | 9.8 | 44.6 | 6.3 |
| DKM parameter κ | 0.0128 | 0.0052 | 0.0302 | 0.0141 | 0.0092 | 0.0007 |
| 3-s mean reproduction | 2.821 | 0.312 | 2.706 | 0.762 | 3.004 | 0.523 |
| 3-s CV reproduction | 30.6 | 11.1 | 24.3 | 9.1 | 19.6 | 4.6 |
| 9-s mean reproduction | 8.042 | 1.238 | 7.178 | 1.982 | 8.209 | 1.249 |
| 9-s CV reproduction | 26.9 | 10.1 | 30.1 | 10.2 | 22.7 | 9.0 |
| 18-s mean reproduction | 13.760 | 1.940 | 11.939 | 5.503 | 13.360 | 2.455 |
| 18-s CV reproduction | 29.9 | 13.6 | 23.2 | 5.0 | 30.5 | 12.2 |
| Discounting parameter k | 0.488 | 0.473 | 0.053 | 0.036 | 0.188 | 0.119 |