Precision in neuropsychology. Four challenges when using simplified assumptions

Cognition comprises all thought processes, from perception to memory. Neuropsychological tests are the gold standard (= best way) to measure cognition. However, clinical assessment may at times have to rely on simplified assumptions. This work addresses potential risks of four such assumptions through neuropsychological tests and statistical analysis from: a case report (Paper I); participant data from the Gothenburg Mild Cognitive Impairment study (Papers II, III); and the Swedish Cardio Pulmonary bioImage Study (SCAPIS Pilot, Paper IV). Paper I showed transfer effects from memory training may affect memory tests. Paper II showed that giving free credits for items not administered inflated the scores of those most impaired in the Boston Naming Test (BNT). Paper III showed practice effects could not be ruled out in mild cognitive impairment, and that mean Δ-scores described change better than isolated Δ-scores. Paper IV showed that administering neuropsychological tests in Swedish to non-native speakers gave lower results in tests tapping speed and attention, and that vocabulary testing may enhance precision. Conclusion: the four assumptions save time at the cost of precision. In the greatest need for precision, (e.g. for detection of gradual change before manifest loss), considering the above findings will improve assessments