Table 1. Means (and Standard Errors) of Subject Characteristics.
| Experiment 1 | ||||
|---|---|---|---|---|
| Measure | YoungStandard | YoungVigilance | OldStandard | OldVigilance |
| Education | 12.85 (0.18) | 12.98 (0.20) | 15.22 (0.39) | 15.62 (0.36) |
| Medicationa | 0.66 (0.18) | 0.77 (0.16) | 2.39 (0.27) | 2.64 (0.33) |
| Vocabularya | 28.05 (0.44) | 28.26 (0.48) | 33.63 (0.47) | 34.20 (0.44) |
| Digit symba | 60.62 (1.32) | 63.65 (1.82) | 51.14 (1.89) | 50.40 (1.73) |
| DS memorya | 7.93 (0.19) | 7.67 (0.23) | 5.80 (0.31) | 5.92 (0.33) |
| Experiment 2 | ||||
| Measure | Young1-back | Young2-back | Old1-back | Old2-back |
|
| ||||
| Education | 12.41 (0.11) | 12.70 (0.15) | 15.58 (0.38) | 15.00 (0.42) |
| Medicationa | 0.70 (0.14) | 0.82 (0.16) | 2.35 (0.25) | 3.12 (0.34) |
| Vocabularya | 27.96 (0.43) | 27.84 (0.47) | 33.86 (0.43) | 33.05 (0.56) |
| Digit symba | 61.76 (1.49) | 62.21 (1.25) | 49.00 (1.81) | 46.14 (2.04) |
| DS memorya | 7.65 (0.25) | 7.59 (0.23) | 5.23 (0.38) | 4.93 (0.37) |
Note. Education = number of years education completed; medication = self-reported number of medications taken daily; vocabulary = number correct out of 40 on the Shipley Vocabulary Test (Zachary, 1986); digit symb = WAIS Digit-Symbol subtest (Wechsler, 1981); DS memory = symbol recall following the WAIS Digit-Symbol subtest (Wechsler, 1981); Standard = subjects completing the standard, go/no-go, version of the SART; Vigilance = subjects completing the vigilance version of the SART; 1-back = subjects completing the 1-back task; 2-back = subjects completing the 2-back task.
Age comparison p < .05. No comparisons of, or interactions with, the task-condition variables were significant. No statistical comparison of education was made because the young adults were currently enrolled at a university.