Table 2.
Experimental task performance data for participants.
| Experimental measure | Healthy control group | Alzheimer’s disease | ||
|---|---|---|---|---|
| Case 1 | Case 2 | Case 3 | ||
| Inter-personal reactivity index | ||||
| Perspective Taking (/28) | 17.1 (3.7) | 16 (z = -0.31) | 2 (z = -4.11) | 6 (z = -3.02) |
| Empathic Concern (/28) | 19.3 (4.4) | 22 (z = 0.63) | 15 (z = -0.97) | 14 (z = -1.19) |
| Personal Distress (/28) | 9.6 (6.1) | 14 (z = 0.72) | 23 (z = 2.20) | 23 (z = 2.20) |
| Tactile discrimination | ||||
| Threshold (mm) | 11.0 (2.3) | 7.5 (z = -1.51) | 15.0 (z = 1.73) | 14.2 (z = 1.37) |
| Rubber hand illusion | ||||
| Mean score target items (/7)∗ | 5.8 (0.9) | 2.7 (z = -3.41) | 7.0 (z = 1.38) | 5.7 (z = -0.09) |
| Self/non-self touch attribution | ||||
| Self (/10) | 9.8 (0.7) | 10 | 10 | 9 |
| Non-self synchronous (/10) | 4.5 (2.6) | 2 | 10 | 4 |
| Non-self asynchronous (/10) | 9.1 (1.2) | 9 | 10 | 9 |
| Self/non-self voice memory † | ||||
| Overall recognition | 0.83 (0.10) | 0.67 (z = -1.56) | 0.63 (z = -1.96) | 0.44 (z = -3.77) |
| Own voice | 0.84 (0.09) | 0.56 (z = -3.18) | 0.56 (z = -3.18) | 0.56 (z = -3.18) |
| Non-self: same gender | 0.82 (0.12) | 0.88 (z = 0.46) | 0.75 (z = -0.60) | 0.38 (z = -3.78) |
| Non-self: opposite gender | 0.82 (0.15) | 0.56 (z = -1.65) | 0.56 (z = -1.65) | 0.38 (z = -2.66) |
| Overall attribution | 0.36 (0.05) | 0.38 | 0.20 | 0.38 |
| Own voice | 0.48 (0.11) | 0.22 | 0.56 | 0.33 |
| Non-self: same gender | 0.31 (0.08) | 0.43 | 0.08 | 0.50 |
| Non-self: opposite gender | 0.29 (0.18) | 0.44 | 0.00 | 0.33 |
Group mean (standard deviation) performance scores are reported for the healthy control group; for individual patients, raw scores are presented along with z-scores (in parentheses) indexing each patient’s performance on neuropsychological tests relative to the control group (individual z-score > 1.96 standard deviations beyond healthy control mean in bold). z-scores are not displayed for the source attribution tasks (action and voice memory) as floor or ceiling effects rendered their use inappropriate. See text for further details. Maximum scores for neuropsychological tests where appropriate are in parentheses. ∗Likert scale 1 = no percept to 7 = strong percept. bbbData in the self/non-self voice memory task are presented as proportion of items in each condition correct (chance level performance 0.5 for recognition task, 0.33 for attribution task).