Semantic memory for actions as assessed by the Kissing and Dancing Test: Education and age effects in cognitively healthy individuals

Action semantics is a relevant part of cognitive-linguistic assessment and the "Kissing and Dancing Test" (KDT) has been used extensively for this purpose, evidencing clinical distinctions among brain-damaged patients. To enhance its use, reference values are necessary, especially for populations with heterogeneous educational levels and socioeconomic backgrounds. Objective To analyze the effects of schooling and age on the KDT in cognitively unimpaired individuals. Methods The KDT was applied to seventy-four healthy subjects. Sociodemographic factors were investigated through correlational and between-group analyses. Reference values according to age and schooling were provided. Results KDT performance correlated significantly with schooling (r=0.757, p<0.01), age (r=-0.496, p<0.01) and socioeconomic status (r=0.418 p<0.01) but these variables were intercorrelated. Correlation with schooling and age remained significant when controlling for age and socioeconomic status (r=0.530, p<0.01), and for schooling (-0.305,<0.01), respectively. When controlling for schooling, correlation between socioeconomic status and KDT was not significant (p=0.164). Between-group analyses revealed no age effects. Significant differences were found in performance according to educational level. Scores below 39/52 and below 47/52 (percentile 25) for individuals with 8 or less years of schooling and for individuals with 9 or more years of schooling, respectively, seem suggestive of an impairment in Action Semantics Processing and shall be further investigated. Conclusion KDT performance was influenced both by age and schooling, indicating the need to consider these demographic features as covariates when analyzing performance on the test and to adjust cut-off scores according to these demographic characteristics in clinical practice.