Normative data for the Turkish version of the pyramids and palm trees test

In this study, we aimed to establish Turkish normative data for two versions of The Pyramids and Palm Trees Test (PPTT), pictorial (PPTT-P), and verbal (PPTT-V) using Turkish culture-specific items.

The study sample involves 181 participants stratified into three age groups and further stratified into three education levels and gender. The participants were given the PPTT versions along with a neuropsychological battery. Participants in the aged group were further screened for cognition and depression. The internal consistency, the convergent and discriminant validity of the PPTT versions, and predictors of the performance in the PPTT versions are statistically analyzed.

The Cronbach's alpha coefficients for PPTT-P and PPTT-V were found as 0.48. and 0.42, respectively. Among the demographic variables, only education had an effect on the performances of both versions. Education level explained 21.2% of the variance in PPTT-P performance and 13.7% of the variance in PPTT-V performance. A cutoff score of 45 is proposed for the individuals with primary school education and 47 for those with higher education. Results suggested that both versions had moderate convergent but no discriminant validity.

Present findings suggest that PPTT is a useful neuropsychological instrument for assessing semantic memory in the Turkish population.