Table 8.
Patient performance on complex and component executive function tasks. Patient and control values show means and ranges (in parentheses). Shading identifies tasks that were combined into composites, as discussed in the Results (see also Table 2).
| Complex Executive Function Tasks | Patients | Controls |
|---|---|---|
| WCST (categories completed) | 10 (1-15) | 15 (14-15)a |
| WCST (perseverative errors) | 20 (3-38) | 7 (0-21)b |
| TOH (number of moves) | 95 (60-176) | 88 (54-163)b |
| Simple Executive Function Tasks | ||
| Inhibition Tasks | ||
| Verbal Stroop (interference effect,ms) | 1017 (131-2794) | 244 (56-492)b |
| Spatial Stroop (interference effect, ms) | 209 (10-865) | 63 (−100-260)b |
| PWI (interference effect, ms) | 199 (−286-676) | 38 (−18-185)a |
| Recent negatives (interference effect, ms) | 664 (−489-2835) | 115 (−9-260)a |
| Updating Tasks | ||
| Verbal 1-back (percent correct) | 93 (62-100) | 86 (65-97)b, c |
| Nonverbal 1-back (percent correct) | 82 (52-96) | 76 (41-98)b, c |
| Verbal keep track (percent correct) | 84 (50-100) | 93 (79-100)b, c |
| Nonverbal keep track (percent correct) | 87 (5-100) | 89 (51-100)b, c |
| Shifting Tasks | ||
| Plus-minus (switch cost, sec) | 86 (−1-284) | 41 (27-74)b, d |
| Cued shifting (switch cost, ms) | 1033 (19-3197) | 155 (−55-468)a |
Control data collected at Rice University. WCST (categories): N = 18, Mage = 67 years. PWI: N = 9, Mage = 66 years. Recent negatives: N = 10, Mage = 67 years. Cued shifting: N = 16, Mage = 64 years.
Control data from Hull et al. (2008).
The updating tasks used by Hull et al. (2008) required subjects to update two items (e.g., keeping track of 2 colors in the nonverbal keep track task), as opposed to one item as used for the patients tested in the present study. Thus, the control data reflect 2-item updating; we assume accuracy would be very high were controls to complete the 1-item updating tasks.
The plus-minus task used by Hull et al. (2008) required subjects to add or subtract 3 from each two-digit number (as opposed to adding or subtracting 1, as used in the present study). Thus, the control data reflect this task variation.