I have a homework problem about writing a Matlab program that collects data in a discrimination experiment, calculates detection indices for user performance and write a file containing the data for each participant tested.

Create a visual discrimination task where the user discriminates between two types of visually presented stimuli. You can decide what type of discrimination task to implement. There needs to be a distinction between a noise trial and a signal trial. Your program should:

1. Ask for the id of the user.

2. Ask for the number of trials n in the discrimination task. The number n should be an even number.

3. The program should randomly allocate n/2 signal events and n/2 noise events to the n trials.

4. The randomization should be the same for each user id. If we restart the program with the same user id, we should get the same sequence of trials.

5. On each trial, an image should be presented and the user has to respond with a signal decision using letters or numbers as responses. You do not have to implement a graphical user interface for the task. Simply use the command window to present feedback and receive user input from the keyboard.

6. The user should receive feedback after each trial (correct or incorrect)

7. After n trials are completed, calculate the following:

a. The probability of a hit.

b. The probability of a false alarm.

c. Sensitivity (d') and the bias(beta) index from Signal Detection Theory. One solution you can use is to replace the empirical hit or false alarm rates of 0 or 1 with fixed value of 0.01 and .99 respectively.

8. Show these performance numbers to the user.

9. The data should be saved to a .mat Matlab file. The filename should be constructed in such a way that it is unique. The filename should have the user id in the file. You should save all the data that is need to reconstruct what happened in the discrimination task including all individual decisions.