Table 1.
Effect of stimulation on stop-signal task performance
| Trial type | 20Hz Unstimulated | 20Hz Stimulated | 70Hz Unstimulated | 70Hz Stimulated | LME statistics |
|||
|---|---|---|---|---|---|---|---|---|
| df, Error df | Main effect of frequency (20Hz, 70Hz) | Main effect of stimulation (ON, OFF) | Interaction | |||||
| Go | ||||||||
| % early response | 0.0 | 0.0 | 0.0 | 0.0 | NA | NA | NA | NA |
| % no response | 1.7 ± 2.29 | 1.57 ± 2.46 | 1.56 ± 2.24 | 1.53 ± 2.48 | 1, 102 | F = 0.14 p = 0.705 | F = 0.04 p = 0.851 | F = 0.16 p = 0.694 |
| goRT (ms) | 17.96 ± 43.64 | 16.90 ± 43.73 | 18.10 ± 42.4 | 17.15 ± 42.6 | 1, 28,138 | F = 0.69 p = 0.407 | F = 3.71 p = 0.054 | F = 0.0 p = 0.968 |
| Stop | ||||||||
| Stop fail RT (ms) | −1.5 ± 34.09 | −2.40 ± 34.14 | −2.47 ± 33.74 | −2.00 ± 33.24 | 1, 6937 | F = 0.27 p = 0.606 | F = 0.05 p = 0.818 | F = 0.72 p = 0.395 |
| % inhibit | 51.26 ± 0.58 | 51.75 ± 0.69 | 51.38 ± 0.64 | 51.78 ± 0.7 | 1, 102 | F = 0.8 p = 0.359 | F = 26.8 p < 0.0001 | F = 0.3 p = 0.611 |
| SSRT (ms) | 189.4 ± 12.42 | 191.1 ± 11.24 | 193.36 ± 12.22 | 192.4 ± 12.3 | 1, 102 | F = 5.36 p = 0.023 | F = 0.1 p = 0.748 | F = 1.37 p = 0.244 |
GoRT and stop fail RT are expressed relative to the target (i.e. response – 800 ms). Mean ± SD is reported. LME = linear mixed model. Results for LME models are given as Type III sums of squares for sequentially fitted fixed effects. Statistically significant findings are highlighted in bold.