Table 8.
Digit symbol substitution task: multilevel model of marijuana high in relation to number of correct responses.
| Effects | DSSTa number of correct responses (n=60) | |||||
|
|
Estimate | SE | 95% CI | P value | ||
| Fixed effects | ||||||
|
|
Person level (level 2) | |||||
|
|
|
Intercept | 5.81 | 9.95 | N/Ab | .56 |
|
|
|
Session | 0.25 | 0.02 | N/A | .001c |
|
|
|
Session2 (quadratic) | −0.00 | 0 | N/A | .001c |
|
|
|
Subjective high (PMd) | −6.83 | 2.38 | N/A | .004c |
|
|
|
Distraction (PM) | 18.78 | 7.66 | N/A | .01e |
|
|
|
Subjective high (PM) × distraction (PM) | 4.62 | 1.81 | N/A | .01e |
|
|
|
Gender (0=male, 1=female) | −0.23 | 1.34 | N/A | .86 |
|
|
|
Age (0=age 20) | −0.40 | 0.38 | N/A | .29 |
|
|
|
Full-scale IQ (0=IQ score of 110) | −0.09 | 0.13 | N/A | .47 |
|
|
Session level (level 1) | |||||
|
|
|
Subjective high (CCf) | −0.18 | 0.07 | N/A | .01e |
|
|
|
Distraction (CC) | −0.86 | 0.22 | N/A | .001c |
|
|
|
Subjective high (CC) × distraction (CC) | 0.08 | 0.04 | N/A | .07 |
| Random effects | ||||||
|
|
Level 1 residual variance | 24.66 | 0.7 | 23.33 to 26.08 | N/A | |
|
|
Intercept | 23.21 | 4.37 | 16.04 to 33.57 | N/A | |
aDSST: digit symbol substitution task.
bNot applicable.
cP<.01.
dPM: person mean scores, reflecting individual differences in subjective marijuana high or distraction across all sessions.
eP<.05.
fCC: constant-centered scores (centered at 0), reflecting session-to-session variation in scores or session-specific scores.