Table 1.
Participants' characteristics and behavioral performance in the SST
| IGD (n = 21) | HC (n = 21) | t/χ 2 /U | P | |
| mean ± SD | mean ± SD | |||
| Clinical assessments | ||||
| Age (years) | 22.29 ± 1.42 | 21.82 ± 1.85 | 0.84 | 0.405 |
| Education (years) | 16.14 ± 1.32 | 16.00 ± 1.82 | 0.29 | 0.772 |
| YIAT score | 69.62 ± 12.48 | 25.19 ± 6.74 | 14.35 | <0.001*** |
| Internet gaming (h/wk) | 31.83 ± 9.64 | – | 5.59a | <0.001*** |
| Alcohol use (at least once/month) | 6b/0.29c | 13b/0.62c | 4.71d | 0.030* |
| Cigarette use (at least once/month) | 0b/0.00c | 0b/0.00c | – | – |
| BAI score | 4.57 ± 4.82 | 1.81 ± 2.80 | 2.27 | 0.030* |
| BDI score | 6.38 ± 7.69 | 3.38 ± 4.50 | 1.54 | 0.131 |
| SST performance | ||||
| Mean number of trials (per session) | 78.09 ± 1.92 | 77.46 ± 1.55 | 1.16 | 0.252 |
| Mean number of G (per session) | 52.39 ± 5.70 | 48.35 ± 9.36 | 1.69 | 0.099 |
| Mean number of F (per session) | 5.14 ± 3.91 | 8.88 ± 7.63 | −2.00 | 0.053 |
| Mean number of SS (per session) | 11.02 ± 1.03 | 11.21 ± 1.33 | −0.54 | 0.591 |
| Mean number of SE (per session) | 9.54 ± 1.81 | 9.02 ± 1.07 | 1.14 | 0.261 |
| GS % | 91.10 ± 6.91 | 84.41 ± 13.62 | 2.00 | 0.054 |
| SS % | 53.78 ± 4.39 | 55.76 ± 2.32 | −2.71 | 0.073 |
| Mean GoRT (ms) | 690.42 ± 109.94 | 721.94 ± 77.37 | −1.07 | 0.289 |
| Critical SSD | 473.63 ± 133.07 | 495.89 ± 113.83 | −0.58 | 0.563 |
| SSRT | 212.41 ± 56.12 | 226.80 ± 61.77 | −0.79 | 0.434 |
| PES effect (ms) | 32.92 ± 61.54 | 47.8 ± 81.67 | −0.66 | 0.512 |
| Sequential effect | 0.15 ± 0.19 | 0.09 ± 0.14 | 1.23 | 0.225 |
| Mean FD | 0.13 ± 0.05 | 0.12 ± 0.06 | 0.38 | 0.704 |
Abbreviations: SD = standard deviation; IGD = Internet gaming disorder; HC = healthy control; YIAT = Young's online Internet addiction test; Internet gaming (hrs/wk) = Internet gaming hours per week; BAI = Back Anxiety Inventory; BDI = Beck Depression Inventory; Mean number of trials (per session) = the average number of trials per session; Mean number of G (per session) = the average number of successful go trials per session; Mean number of F (per session) = the average number of failed go trials per session; Mean number of SS (per session) = the average number of successful stop trials per session; Mean number of SE (per session) = the average number of stop error trials per session; GS (%) and SS (%) = percentage of successful go and stop trials; Mean GoRT (ms) = the mean reaction time of successful go trials; PES effect (ms) = the RT difference between the go trials that followed a stop error (pSE) and those that followed another go trial (pG); Critical SSD = Critical stop-signal delay; SSRT = Stop-signal reaction time; Sequential effect= Pearson correlation between P(Stop) and RT on go trials for individual subjects; Mean FD = the frame-wise displacement (FD) of head position.
U value.
the number of participants.
the rate of alcohol and cigarette use.
χ2 value.