E prime

The SRTT is a well-established experimental paradigm eliciting motor sequence learning over time (Nissen and Bullemer, 1987 (link)). We applied an eight-digit SRTT requiring participants to react with the first four fingers (thumb (1), index (2), middle (3), ring finger (4)) of the right hand using a response button box fitted to the right hand that was connected to a standard Windows PC. Timing of the SRTT as well as recording of reaction times was realized by E-Prime^® (Psychology Software Tools Inc.). Stimuli were projected on a screen in front of the participants. Four blue rectangles were arranged horizontally along the middle of the screen against a black background at a distance of 2.66 m and with a visual angle of 12.87°. Stimuli remained present until the correct button was pressed. The next stimulus appeared after a 1 s delay. The sequence was 1–3–4–2–3–2–3–4 repeated 10 times in the sequential condition. During the random condition, fingers 1–4 were to press with the same number as in the sequential condition but in a random order.

The spatial working memory task was modeled on the classic Sternberg working memory paradigm. Cue stimuli were yellow circles appearing in 1 of 8 possible locations. Each trial began with fixation followed by a presentation of 3 frames (300 ms each) showing one cue stimulus at a time in either the same location or 3 different locations. A blank grid was inserted between the frames for 200 ms to decrease chunking and motion perception. A 1,500 ms (50% of trials), 3,000 ms (25% of trials), or 4,500 ms (25% of trials) delay period was used to minimize habituated preparatory responses.
Following the delay period, subjects made a button press to indicate whether a frame showing 4 circles located among 8 possible locations had occurred in any of the previous cue locations (50% of trials) or were all in novel locations (50% of trials). A total of 144 high load trials and 144 low load trials were distributed across 12 runs, with the order randomized within runs. Intertrial fixation intervals ranged between 1,000 and 4,500 ms, with a short break between runs. The task was designed and run using E-Prime (Psychology Software Tools, Inc., Pittsburgh, PA).

This computer task asked participants to identify which emotion, either happy, sad, fear, anger, disgust or surprise, was represented by the face presented on the computer screen. The faces were acquired from (Ekman & Friesen, 1971 (link)) pictures of facial affect series. These varied by actor, emotion presented, and the intensity of the emotion shown on the face, either 0% (neutral), 25%, 50%, 75%, or 100%. The task was created and presented on a PC via E‐Prime® by Psychology Software Tools (2.0, Psychology Software Tools).
When completing the task, participants were first provided with a trial set of faces to gain familiarity with the process before taking part in the experimental set. For each individual stimulus, the participant was first shown a fixation cross in the center of the screen, followed by the stimulus image for 500 ms, and then, a visual mask which also lasted 500 ms. The six emotions were subsequently displayed on the screen in six boxes to form a circle of options, and participants were instructed to use the computer mouse to select the emotion, which corresponds to the face they had just seen. In total, 144 individual faces were randomly presented, with the entire task taking 15 min. Accuracy of emotional identification and reaction times, plus nominated misattributed emotional category when perceiving neutral faces, were recorded.

In the current study, to investigate sex differences in emotional processing, emotional face pictures were selected from the affect series of Ekman and Friesen (1976 (link)). This series of emotional faces consists of six facial emotions (sad, disgusted, surprised, fearful, angry, and happy) with the intensity of emotions varying from the full emotion (100%) to 25%. In total, there were 144 emotional facial pictures which are equally divided for each emotion, i.e., each facial emotion had 24 pictures. For the experimental presentation, E-Prime (18-2.0.8.22), Psychology Software Tools, Philadelphia, USA) was used to control the appearance of pictures. In the task, emotional faces were displayed for 500 ms on the computer screen. After this time interval, the names of six emotions were presented. Participants were required to respond to the appropriate emotion that described the preceding face by using the mouse provided to click on the emotion. Participants had to make their response in the given time, otherwise missing responses or responses by accident (too fast < 250 ms; too long >6,000 msec) were taken as incorrect responses. Outcome measures were mean response times and the total number of correct trials for each category of emotion.