Figure 1.

Study flow. At the screening session, subjects underwent medical examination and donated blood samples for genotyping analyses. After identification of 16 female BDNF Met carriers and 16 age- and education-matched BDNF Val/Val carriers, these subjects were tested on cognitive performance using standard neuropsychological tests (day 1; for details, see Materials and Methods). In a randomized order on day 2 or 3, subjects underwent assessment of plasticity of the motor cortex, using a PAS₂₅ protocol (adapted from Stefan et al., 2000). On the other day, implicit motor and grammar learning were assessed using a SRTT and an AGL task.