In the end, this procedure resulted
in 76 highly educated (bachelor student level or higher) subjects between 18 and 35 years of age (mean = 23.3, standard deviation = 3.2, 39 women, four left handed) of Caucasian origin that reported no history of psychiatric or neurological disorders, and had normal or corrected-to-normal vision. All participants gave BYL719 written informed consent and the study was approved by the local ethics committee. Genotyping Saliva samples Inhibitors,research,lifescience,medical were collected from all subjects using Oragene (DNA Genotek, Kanata, Canada), and DNA extracted from these samples was used for genotyping of the BDNF (rs6265, Val66Met) SNP as described by Franke et al. (2010). The experiment leader in this study was blinded for the genotype of the participants until after data analysis. Experimental procedure We used a digital adaptation Inhibitors,research,lifescience,medical of Preilowski’s (1972) Task, conceptually similar to the task used by
Mueller et al. (2009). In this task, participants have to draw a line at a predetermined angle by simultaneously Inhibitors,research,lifescience,medical rotating two cylinders on a specially developed input device. The ability to accurately draw these lines depends on the coordination of the rotation speed of both cylinders. Participants were seated in a dimly lit room in front of a computer screen and the input device. Following instructions, Inhibitors,research,lifescience,medical the experiment consisted of 15 trials (three blocks of five trials) in which the
participant had to draw a right-bound line at one of five possible angles (20°, 30°, 45°, 60°, and 70°). To indicate the predetermined angle and the length of the line the participants had to draw, a 10-pixel-wide example line was shown on the computer screen during each trial. The order of the angles was pseudorandomized, such that each angle was shown once randomly in a block of five consecutive trials, and the same angle never appeared twice in a row. The order of the angles was the same for each participant. In order to make the task more challenging for healthy participants (the original Preilowski’s Inhibitors,research,lifescience,medical Rutecarpine task was designed for patients), we included a strict time limit of 25 sec in which the 800-pixel line had to be completed, after which a 5-sec break followed. Subjects were instructed to finish drawing in time (see Fig. 1 for example data). Figure 1 Example data of a representative subject. Data are shown for each of the angles (20°, 30°, 45°, 60°, and 70°) present in the experiment. The graph represents the computer screen with the pixels in horizontal and … Data processing To exclude effects caused by the initial learning of the task and to keep the number of trials with a particular angle equal, we removed the first five trials of the experiment from the analysis. We removed any line-drawing data located outside of the endpoints of the example line.