Table 1. Age, Striatal SPECT Ratio, and Behavioral Variables According to Genotype Group and Drug.
| Genotype |
All (N=50) |
SPECT subsample (N=35) |
||||||
|---|---|---|---|---|---|---|---|---|
|
10/10 (N=28) |
9R (N=22) |
10/10 (N=16) |
9R (N=19) |
|||||
| Mean | SD | Mean | SD | Mean | SD | Mean | SD | |
| Age (years) | 24.29 | (3.32) | 23.00 | (2.56) | 24.81 | (3.89) | 23.00 | (2.75) |
| Specific striatal binding | — | — | — | — | 2.97 | (0.19) | 3.08 | (0.33) |
| Caudate-specific binding | 3.12 | (0.24) | 3.23 | (0.38) | ||||
| Putamen-specific binding | 2.81 | (0.14) | 2.89 | (0.31) | ||||
| Go/No-Go variables | ||||||||
| Methylphenidate | ||||||||
| Percentage of incorrect no-go | 16.50 | (11.12) | 16.97 | (9.05) | 13.69 | (7.74) | 16.84 | (9.30) |
| Percentage of incorrect go | 0.68 | (0.82) | 0.68 | (1.21) | 0.50 | (0.73) | 0.74 | (1.20) |
| Percentage of incorrect odd | 0.25 | (1.32) | 1.14 | (2.35) | 0 | (0) | 1.32 | (2.50) |
| Mean RT correct go | 316.36 | (30.52) | 321.51 | (44.18) | 319.30 | (35.14) | 319.64 | (42.41) |
| Mean RT incorrect no-go | 395.67 | (140.66) | 417.84 | (238.02) | 426.06 | (163.67) | 384.28 | (202.68) |
| Mean RT correct odd | 380.40 | (49.45) | 376.03 | (53.21) | 382.17 | (42.72) | 372.08 | (48.51) |
| SD RT correct go | 48.07 | (12.63) | 49.71 | (15.17) | 50.42 | (13.81) | 49.74 | (15.33) |
| SD RT incorrect no-goa | 158.88 | (228.45) | 183.54 | (338.41) | 221.01 | (293.26) | 144.83 | (279.49) |
| SD RT correct odd | 81.49 | (25.13) | 82.62 | (28.92) | 78.11 | (16.94) | 80.03 | (24.40) |
| ICV correct go | 0.15 | (0.03) | 0.15 | (0.03) | 0.16 | (0.03) | 0.15 | (0.01) |
| ICV incorrect no-goa | 0.32 | (0.33) | 0.27 | (0.32) | 0.40 | (0.41) | 0.24 | (0.28) |
| ICV correct odd | 0.21 | (0.057) | 0.22 | (0.03) | 0.21 | (0.05) | 0.21 | (0.06) |
| Placebo | ||||||||
| Percentage incorrect no-go | 17.46 | (8.92) | 20.45 | (12.00) | 14.50 | (8.17) | 20.42 | (12.84) |
| Percentage of incorrect go | 0.50 | (0.06) | 1.00 | (1.50) | 0.56 | (0.63) | 1.05 | (1.58) |
| Percentage of incorrect odd | 0.46 | (1.50) | 0.55 | (1.12) | 0.38 | (1.03) | 0.63 | (1.26) |
| Mean RT correct go | 319.10 | (33.13) | 320.07 | (35.19) | 330.20 | (37.81) | 319.96 | (34.68) |
| Mean RT incorrect no-go | 446.71 | (322.47) | 362.94 | (92.60) | 479.95 | (396.45) | 360.40 | (96.04) |
| Mean RT correct odd | 369.35 | (57.99) | 370.80 | (48.62) | 388.16 | (65.43) | 366.58 | (45.29) |
| SD RT correct go | 54.01 | (15.15) | 49.14 | (14.25) | 58.12 | (18.25) | 49.51 | (15.13) |
| SD RT incorrect no-goa | 194.83 | (268.96) | 136.62 | (184.15) | 174.09 | (241.08) | 139.72 | (198.52) |
| SD RT correct odd | 73.51 | (26.64) | 75.46 | (17.33) | 77.88 | (24.95) | 74.64 | (17.89) |
| ICV correct go | 0.17 | (0.03) | 0.15 | (0.03) | 0.17 | (0.04) | 0.15 | (0.03) |
| ICV incorrect no-goa | 0.37 | (0.37) | 0.32 | (0.34) | 0.36 | (0.38) | 0.32 | (0.36) |
| ICV correct odd | 0.19 | (0.05) | 0.20 | (0.03) | 0.20 | (0.04) | 0.20 | (0.04) |
Abbreviations: ICV, intraindividual coefficient of variation; N, number of subjects, RT, reaction time in ms, SD, standard deviation.
a
Owing to the low number of errors of some subjects, their SD values could not be calculated. Therefore, N(10/10)=26 for both drug conditions and N(9R)=21 for methylphenidate for the ICV incorrect no-go trials. For the SPECT sample, the same subjects had to be excluded. Therefore, N(10/10)=14 for both drug conditions and N(9R)=18 for methylphenidate.