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Mean age of acquisition and word frequency (With Standard Deviations) as a Function of Task and Group.
| Groups | ||
|---|---|---|
| Task | Normal Elderly | AD Patients |
| Age of Acquisition1 | ||
| Letter | 366.9 (44.7) | 358.6 (54.1) |
| Semantic | 332.6 (18.7) | 299.5 (17.8) |
| Cumulative Word Frequency | ||
| Letter | 13.4 (.63) | 13.8 (.73) |
| Semantic | 11.9 (.83) | 12.5(.43) |
Age of acquisition units are age on a 7 point scale (1=0–2 years…7=age 13 years and over) multiplied by 100. Thus, a score of 300 nominally corresponds to 5.5 years of age
