Table 2.
Reaction times and accuracy
| Controls (n = 23) | Alzheimer's disease (n = 23) | LBD (n = 32) | Between group Anova (df = 2,75) comparison (P‐value) | Tukey Post hoc between group comparisons | |
|---|---|---|---|---|---|
| ANT trials responded % [range] | 99.6 (0.89) [96.8 – 100] | 95.9 (6.6) [74.5–100] | 96.7 (4.72) [78.7–100] | P = 0.024 | Con › AD =LBD |
| RT for correct trials (ms) | |||||
| No cue | 928 (177) | 1,152 (247) | 1,395 (300) | P < 0.001 | Con ‹ AD « LBD |
| Neutral cue | 896 (159) | 1,133 (261) | 1,391 (322) | P < 0.001 | Con « AD « LBD |
| Directional cue | 816 (178) | 1,060 (241) | 1,325 (330) | P < 0.001 | Con « AD « LBD |
| Congruent | 714 (121) | 897 (210) | 1,125 (262) | P < 0.001 | Con ‹ AD « LBD |
| All Incongruent | 1,044 (233) | 1,347 (312) | 1,652 (410) | P < 0.001 | Con « AD « LBD |
| Incongruent easy | 1,005 (217) | 1,229 (274) | 1,521 (391) | P < 0.001 | Con ‹ AD « LBD |
| Incongruent hard | 1,084 (265) | 1,477 (384) | 1,800 (486) | P < 0.001 | Con « AD ‹ LBD |
| Correct responses (%) | |||||
| No cue | 98.4 (1.9) | 91.0 (8.3) | 89.2 (7.6) | P < 0.001 | Con » AD = LBD |
| Neutral cue | 98.6 (1.3) | 90.7 (9.2) | 87.7 (9.3) | P < 0.001 | Con » AD = LBD |
| Directional cue | 98.9 (1.5) | 91.8 (9.2) | 88.1 (8.4) | P < 0.001 | Con » AD = LBD |
| Congruent | 98.8 (1.3) | 94.9 (6.3) | 94.0 (6.3) | P = 0.004 |
Con › AD; Con » LBD; AD = LBD |
| All incongruent | 98.4 (1.4) | 87.4 (12.1) | 82.7 (12.3) | P < 0.001 | Con » AD = LDB |
| Incongruent easy | 98.2 (2.3) | 88.2 (13.1) | 84.6 (13.3) | P < 0.001 | Con » AD = LDB |
| Incongruent hard | 98.6 (1.5) | 86.7 (13.5) | 80.9 (14.5) | P < 0.001 | Con » AD = LDB |
| RT differences (ms) | |||||
| Alerting | 32.1 (48)* | 19.8 (93)† | 4.7 (88)† | 0.5 | – |
| Orienting | 79.9 (55)** | 72.7 (83)** | 66.1 (95)** | 0.8 | – |
| Executive | 330 (151)** | 451 (191)** | 527 (203)** | 0.001 | LBD « Con; AD=Con; AD=LBD |
| Conflict | 79 (129)* | 248 (228)** | 279 (249)** | 0.003 | Con « LBD; Con « AD; AD=LBD |
| Error rate differences (%) | |||||
| Alerting | −0.17 (1.85) | 0.31 (6.35) | 1.48 (4.36) | 0.383 | – |
| Orienting | 0.25 (1.38) | 1.07 (3.44) | 0.39 (3.96) | 0.648 | – |
| Executive | 0.39 (1.25) | 7.50 (9.61)** | 11.24 (10.84)** | <0.001 | Con « LBD; Con « AD; AD=LBD |
| Conflict | −0.40 (2.73) | 1.46 (10.98) | 3.71 (13.02) | 0.347 | – |
Group means for reaction times (RT) and accuracy within and between different conditions (alerting = no cue – neutral cue, orienting = neutral cue – directional cue, executive = incongruent – congruent, conflict = hard — easy). The standard deviations are presented in brackets.
Within group one sample t test for difference between cues/targets:.
*P < 0.05.
**P < 0.001.
†Not significant (P > 0.15).
For the Tukey Post hoc comparisons in RT, AD, Alzheimer's disease; Con, controls.
‹ indicates P < 0.05; « P < 0.01; = indicates P >=0.0.5