101 psychology students (72% female; age: M ¼ 23.43, SD ¼ 6.03) enrolled at a university in Germany participated in this research. The
study used a 2 2 factorial experimental design with two factors: External mood-induction (positive [PE] vs. neutral [NE] emotions), and
internal mood-induction (through the design of the learning environment; positive design [PD] vs. neutral design [ND]). Participants were
randomly assigned to one of the four experimental conditions, under consideration of gender and eye sight (to control eyetracking results;
e.g. glasses or contact lenses) to match comparable groups. The control group (NEND) received the neutral mood-induction procedure (NE)
and the material with neutral design (ND). The PEPD group received the positive mood-induction procedure (PE) and material with positive
emotional design (PD). The PEND group received the positive mood-induction procedure (PE) and the material with neutral design (ND). The
NEPD group received a neutral mood-induction procedure (NE) and the material with positive emotional design (PD).