Reaction Time Study - Psychology

This is a psychological reaction time study. Participants will complete a series of 48 trials in which they see a picture and press one of four keyboard keys to register their response. The order in which the stimuli are presented will need to be randomized. The program will need to generate an output file for each participant. Each line of the data file should represent one trial. Four values need to be recorded for each trial: the ID of the picture that was shown, what number that picture was in the presentation sequence (e.g. #7 in the sequence of 48), the participant’s response time in milliseconds, and the response key that was pressed. ## Deliverables This program will collect data for the first in a series of psychological studies. This is a reaction time study in which participants will see a series of pictures on the screen, and they will be asked to press one of four keys to identify the emotion displayed in each of the pictures. Participants will first read paper instructions about the task. Participants will be assigned an ID number when they enter the lab. Participants should first be presented with a text box in which they enter their ID number. The instructions should read “Please enter your laboratory ID number.?? There should be a button to advance the screen after the number is entered. There will first be eight practice trials for participants to familiarize themselves with the keyboard response keys. The practice trials need not be recorded in the output file, and they will look exactly like the study trials. The first screen after the participants enter their ID number should be labeled “Practice Trials.?? At the bottom of the screen, participants should see the following instructions: “Press any of the arrow keys to begin the practice trials.?? The practice trials should begin when one of the arrow keys is pressed. Participants should then see a blank screen for two seconds. Next, a fixation cross (a small plus sign) will appear in the middle of the screen for one second. Then, a picture will appear in the middle of the screen. Each picture will remain on the screen until a response is registered. Once a response is made, the sequence will begin again with a blank screen for two seconds. The timing of each of these events is an important element of the design and should be consistent for each trial. Participants will press one of four keys to identify the emotion shown in the picture (Up arrow = happy; down arrow = sad; right arrow = angry; left arrow = neutral expression). The response keys will be marked on the keyboard and do not need to be labeled on the screen. The sequence of blank screen, fixation cross, picture, will be repeated 8 times during the practice trials. After a response is made to the eighth practice picture, a screen should appear that is labeled “Study Trials.?? At the bottom of the screen, participants should see the following instructions: “Press any of the arrow keys to begin the study trials.?? The study trials should begin when one of the arrow keys is pressed. The study trials will follow the same sequence as the practice trials: blank screen, fixation cross, picture. The only difference will be that participants’ responses to the Study Trials will be recorded. A separate data file should be created for each participant. The name for the data file should be the participant’s lab assigned ID number. The file should include the date and the times at which the study trials began and ended. Each line of the data file should represent one trial. Four values need to be recorded for each trial: the ID of the picture that was shown, what number that picture was in the presentation sequence (e.g. #7 in the sequence of 48), the participant’s response time in milliseconds, and the response key that was pressed. The 48 pictures in the Study Trials will need to be presented in a random order. After the response to 48th picture has been registered, instructions should appear on the screen that read:“This part of the study is over. Please open Packet #2 and follow the instructions.