Table 2.
Data from the peak effects battery as function of phase and drug condition
| Placebo | Zolpidem | Placebo | Zolpidem | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Baseline phase | Baseline phase | Chronic phase | Chronic phase | Significance | |||||
| Mean | (SE) | Mean | (SE) | Mean | (SE) | Mean | (SE) | ||
| Episodic Memory | |||||||||
| Test 2 | |||||||||
| Recognition task | |||||||||
| Hit rate* | 0.76 | (0.03) | 0.65 | (0.04) | 0.76 | (0.04) | 0.63 | (0.06) | Z < P |
| d'* | 1.24 | (0.14) | 0.37 | (0.11) | 1.37 | (0.16) | 0.51 | (0.17) | Z < P |
| False alarm rate* | 0.33 | (0.05) | 0.52 | (0.05) | 0.30 | (0.04) | 0.47 | (0.07) | Z > P |
| C/Response bias | −0.13 | (0.11) | −0.25 | (0.13) | −0.10 | (0.11) | −0.07 | (0.24) | - |
| Gamma* | 0.49 | (0.07) | 0.16 | (0.10) | 0.44 | (0.09) | 0.23 | (0.11) | Z < P |
| Free Recall | |||||||||
| Number recalled* | 2.07 | (0.55) | 0.27 | (0.12) | 3.53 | (0.86) | 0.93 | (0.46) | Z < P |
| Test 3 | |||||||||
| Recognition task | |||||||||
| Hit rate* | 0.74 | (0.03) | 0.56 | (0.05) | 0.71 | (0.06) | 0.57 | (0.04) | Z < P |
| d'* | 1.14 | (0.17) | 0.42 | (0.07) | 1.17 | (0.20) | 0.58 | (0.09) | Z < P |
| False alarm rate | 0.35 | (0.04) | 0.42 | (0.05) | 0.33 | (0.05) | 0.36 | (0.04) | - |
| C/Response bias* | −0.13 | 0.09 | 0.03 | 0.14 | −0.06 | 0.14 | 0.09 | 0.11 | Z > P |
| Gamma* | 0.46 | (0.08) | 0.22 | (0.10) | 0.47 | (0.08) | 0.26 | (0.10) | Z < P |
| Free Recall | |||||||||
| Number recalled* | 2.73 | (0.84) | 0.93 | (0.66) | 2.40 | (1.09) | 0.20 | (0.20) | Z < P |
| Psychomotor | |||||||||
| Balance* | 92.85 | (12.81) | 30.85 | (5.60) | 99.38 | (6.75) | 35.96 | (6.65) | Z < P |
| Circular Lights+ | 100.54 | (3.93) | 77.31 | (2.79) | 90.19 | (3.19) | 81.91 | (2.77) | Z1 < P1 |
| Attention | |||||||||
| Digit Symbol Substitition Task | |||||||||
| Attempted+ | 102.92 | (3.07) | 71.76 | (3.15) | 94.73 | (1.79) | 79.34 | (3.11) | Z1<P1, Z2<P2 |
| Proportion Correct* | 99.62 | (1.24) | 90.77 | (2.56) | 98.51 | (1.32) | 92.90 | (2.22) | Z < P |
| Divided Attention | |||||||||
| Accuracy (cross hair/cursor overlap; tracking)* | 98.24 | (1.51) | 64.93 | (3.64) | 95.31 | (3.67) | 68.72 | (3.28) | Z < P |
| Mean RT (monitoring)* | 115.09 | (5.37) | 148.53 | (10.90) | 109.67 | (4.78) | 124.68 | (7.05) | Z > P |
| Working Memory | |||||||||
| Nback task # | |||||||||
| 1-back Task | |||||||||
| d' | 98.69 | (3.55) | 76.65 | (6.94) | 94.05 | (5.02) | 61.69 | (11.01) | - |
| Median response time | 93.19 | (2.99) | 144.77 | (9.22) | 109.36 | (4.86) | 127.16 | (6.17) | Z > P |
| 2-back Task | |||||||||
| d' | 105.31 | (7.02) | 56.20 | (8.80) | 78.57 | (8.79) | 63.73 | (10.49) | - |
| Median response time | 101.86 | (3.86) | 138.31 | (8.45) | 98.12 | (3.87) | 123.82 | (3.83) | Z > P |
| 3-back Task | |||||||||
| d' | 114.19 | (11.72) | 61.50 | (10.15) | 62.69 | (14.34) | 73.12 | (11.02) | Z1, P2 < P1 |
| Median response time | 100.83 | (2.65) | 124.20 | (6.87) | 104.88 | (4.45) | 115.67 | (5.83) | - |
| Sternberg task | |||||||||
| Proportion correct | 99.54 | (2.16) | 90.57 | (3.33) | 93.82 | (3.27) | 95.38 | (2.90) | - |
| Median Response Time* | 103.73 | (3.23) | 136.78 | (6.34) | 107.24 | (5.33) | 132.07 | (4.28) | Z > P |
| Performance estimation | |||||||||
| DSST | |||||||||
| Speed | −11.43 | (2.92) | 12.01 | (4.71) | −0.94 | (2.09) | 11.29 | (3.97) | Z > P |
| Accuracy | −9.62 | (3.94) | 0.62 | (16.06) | −0.94 | (2.62) | 14.25 | (4.29) | - |
| Recognition task | |||||||||
| Test 2 d' | 5.70 | (7.11) | 54.70 | (6.24) | 6.79 | (7.36) | 45.43 | (9.12) | Z > P |
Note. SE = standard error. Significance column: P = Placebo, Z = Zolpidem, 1 = baseline phase, 2 = chronic phase.
Symbols:
dash (-) = not significant,
asterisk (*) = main effect of drug condition,
plus sign (+) = drug by phase interaction;
number sign (#) = drug by task interaction observed for all N-back outcomes except false alarm rate; additionally, a significant interaction of drug by task condition by phase was observed for N-back hit rate, d', and C.
Sternberg: data are collapsed across delay condition. Performance estimation: data are collapsed across time of testing (pre/post) and peak % of predrug values; difference scores between ratings and actual performance were calculated as follows: Speed = speed rating minus actual trials attempted, Accuracy = accuracy rating minus actual proportion correct, Test 2 d' = accuracy rating minus actual d'.