Table 3.
Correlation between processing speed and selected psychological and physiological measurements with and without controlling for sex, education, and medication
| Digit Symbol Coding | Symbol Search | Processing Speed Index | Controlling for sex, education, and medication | |||
|---|---|---|---|---|---|---|
| DS | SS | PSI | DS | SS | PSI | |
| Age | − 0.03 | − 0.06 | − 0.04 | − 0.09 | − 0.08 | − 0.09 |
| Height | − 0.16 | 0.03 | − 0.07 | 0.16 | 0.29** | 0.25** |
| Weight | − 0.20* | 0.01 | − 0.08 | − 0.07 | 0.08 | 0.02 |
| Body-mass index | − 0.15 | − 0.01 | − 0.09 | − 0.18 | − 0.03 | − 0.09 |
| Education | 0.26* | 0.12 | 0.21* | |||
| Medication | 0.15 | 0.02 | 0.09 | |||
| Beck Depression Index | − 0.09 | − 0.03 | − 0.04 | − 0.07 | − 0.03 | − 0.05 |
| WAIS Block Design | 0.50*** | 0.30** | 0.50*** | 0.54*** | 0.48*** | 0.54*** |
| WAIS Matrix reasoning | 0.35** | 0.21 | 0.37** | 0.37** | 0.29* | 0.38** |
| WAIS Perceptual reasoning index | 0.47*** | 0.36*** | 0.47*** | 0.49*** | 0.38*** | 0.48*** |
| WAIS Similarities | 0.35*** | 0.19 | 0.28** | 0.32** | 0.17 | 0.25* |
| WMS Digit Span | 0.30* | 0.28* | 0.30* | 0.37*** | 0.30*** | 0.36*** |
| WMS Logical memory immediate | 0.46*** | 0.34*** | 0.43*** | 0.43*** | 0.35*** | 0.42*** |
| WMS Logical memory delayed | 0.49*** | 0.38*** | 0.47*** | 0.28* | 0.27* | 0.28* |
| Box and Block Dominant hand | 0.25* | 0.12 | 0.20 | 0.21 | 0.10 | 0.16 |
| Box and Block Nondominant hand | 0.33** | 0.21 | 0.31** | 0.31** | 0.22 | 0.28* |
| Box and Block combined | 0.28* | 0.16 | 0.24* | 0.26* | 0.15 | 0.22 |
| Grooved Pegboard DH | − 0.43*** | − 0.20 | − 0.39*** | − 0.42*** | − 0.34** | − 0.39** |
| Grooved Pegboard NDH | − 0.47*** | − 0.30* | − 0.46*** | − 0.47*** | − 0.40** | − 0.46*** |
| Grooved Pegboard combined | − 0.47*** | − 0.39*** | − 0.45*** | − 0.47*** | − 0.39** | − 0.45*** |
| Grip strength DH | − 0.09 | 0.02 | − 0.09 | 0.20 | 0.12 | 0.15 |
| Grip strength NDH | − 0.10 | − 0.03 | − 0.09 | 0.14 | 0.13 | 0.13 |
| Grip strength combined | − 0.13 | − 0.10 | − 0.14 | 0.18 | 0.08 | 0.13 |
| One foot stand | 0.16 | 0.13 | 0.15 | 0.14 | 0.14 | 0.14 |
| PRF Dominance | 0.30** | 0.18 | 0.25* | 0.39*** | 0.27* | 0.33* |
| PRF Exhibition | 0.24* | 0.06 | 0.15 | 0.31* | 0.09 | 0.21 |
| PRF Achievement | 0.01 | − 0.06 | − 0.02 | 0.10 | − 0.01 | 0.05 |
| PRF Succorance | 0.07 | 0.06 | 0.06 | − 0.06 | 0.00 | − 0.04 |
| PRF Affiliation | 0.09 | − 0.04 | 0.02 | 0.06 | − 0.06 | − 0.01 |
| PRF Nurturance | 0.15 | 0.10 | 0.13 | 0.04 | 0.03 | 0.04 |
| PRF Cognitive structure | − 0.16 | − 0.04 | − 0.10 | − 0.19 | − 0.05 | − 0.12 |
| PRF Order | 0.13 | 0.16 | 0.15 | 0.06 | 0.11 | 0.09 |
| PRF Impulsivity | 0.10 | 0.03 | 0.07 | 0.06 | − 0.01 | 0.02 |
| PRF Defendence | 0.19 | 0.22* | 0.22* | 0.17 | 0.20 | 0.20 |
| PRF Anxiety | 0.03 | 0.09 | 0.07 | − 0.01 | 0.06 | 0.03 |
| PRF Guilt | 0.03 | 0.01 | 0.02 | − 0.01 | − 0.06 | − 0.03 |
| PRF Aggression | 0.10 | 0.12 | 0.12 | 0.11 | 0.12 | 0.12 |
| PRF Harm avoidance | − 0.07 | 0.01 | − 0.03 | − 0.22* | − 0.06 | − 0.15 |
| PRF Sentience | 0.30** | 0.12 | 0.23* | 0.18 | 0.04 | 0.11 |
| PRF Desirability | − 0.11 | − 0.08 | − 0.11 | − 0.15 | − 0.10 | –0.14 |
***p < .001; **p < .01; *p < .05