All four groups of individuals were first trained in how to solve different spatial rotation tasks (training session) and then asked to solve similar tasks (test session) to those they have previously learned. The spatial rotation tasks were based on a well-established Slovene intelligence test–BTI (Mihelič, 1972), on the spatial-temporal animation reasoning tasks (STAR) designed by Peterson (2000), and on the PF & C subtest of the Stanford–Binet IQ measure (Rideout and Laubach, 1996). The training session consisted of 45 items which in a stepwise presentation showed the solution principles (see lower part of Fig. 1). The test also consisted of 45 items (see upper part of Fig. 1). Respondents had to judge which of the four figures on the right corresponded to the figure in the left frame. All items were presented on a computer screen positioned about 100 cm in front of the respondent. The tasks were presented at fixed 11 s interstimulus intervals. They were exposed for 7 s following a 2 s interval, when a cross was presented. During this time the students were instructed to press a button (1–4) which indicated their answer. All pictures were generated by the STIM stimulator.