Inserting images into a code when certain conditions are being met?

I'm very very new to coding & currently trying to edit a code for an experiment I'm running at the end of this month. I'd appreciate any guidance (like what I should be looking into... general direction help. I feel very lost).

Basically, I'm trying to edit this code so that I can assign subjects to one of 3 conditions (Upward, Lateral, Downward). After block 2, I need to insert 3 possible jpeg images associated with 3 experimental conditions (U, L, D). I'm attaching the part of the code I assume I need to edit below.

Q1: Without really understanding coding, my assumption's that it'll be something like "if block == 2" (to insert the possible conditions if block 2 has been completed), "elseif block < nblock" (typical block ending message if the block isn't 2, or the last one), "else" (end of experiment).

Am I on the right track?

Q2: I need to have a way to link these 3 images to the 3 conditions, then a way to assign subjects these conditions (U, L, D) before the experiment begins. Where should I look to learn how to do this?

Hope this makes sense, thank you for any guidance you can offer!

 if (block > 0)
            if UseEL == 1
                Eyelink('StopRecording');
            end
            blockacc = round(blockacc/trial*100);
            Screen('TextSize', w,30);
            if block < nblock
                message = strcat('In this block, your accuracy was\n',num2str(blockacc),'%.\n\nHave a short break.\n\nPress SPACE to start the next block');
            else
                message = strcat('In this block, your accuracy was\n',num2str(blockacc),'%.\n\nGreat job! You have finished the experiment!');
            end
            DrawFormattedText(w, message, 'center', 'center', white);
            Screen('Flip', w);
            WaitSecs(.5);
            while (1)
                [~,~,keyCode ] = KbCheck;
                if keyCode(spaceKey)
                    break
                elseif keyCode(escapeKey)
                    if UseEL == 1
                        Eyelink('StopRecording');
                        Eyelink('CloseFile');
                        Eyelink('ReceiveFile');
                        Eyelink('Shutdown');
                    end
                    ListenChar(1);
                    Screen('CloseAll');
                    ShowCursor;
                    fclose('all');
                    Priority(0);
                    clear all
                    break;
                end
            end
            FlushEvents('keyDown');
        end

Answer 1

[Samay Sagar]

To add the functionality for displaying specific images after block 2 and to assign subjects to one of the three conditions, you can follow these steps:

You can insert a check for block == 2 to display the images associated with the experimental conditions. Here's how you can modify the code:

if (block > 0) 

    % ... [existing code] ... 
    if block == 2 
        % Get the image associated with the subject's condition 
        conditionImage = GetConditionImage(subjectCondition);  
        image(conditionImage);% Display the image) 
    elseif block < nblock 
        % ... [existing code] ... 
    else 
        % ... [existing code] ... 
    end 
    % ... [existing code ] 
end 

To assign subjects to conditions and link images to those conditions, you can follow these steps:

1. Define Conditions and Images: At the beginning of your script, define a mapping between conditions and image file paths. You can use “struct” for this.

conditionImages = struct('U', 'upward.jpg', 'L', 'lateral.jpg', 'D', 'downward.jpg')

2. Create the GetConditionImage Function: This function will return the image associated with the condition

function image = GetConditionImage(condition) 
    conditionImages = struct('U', 'upward.jpg', 'L', 'lateral.jpg', 'D', 'downward.jpg'); 
    image = imread(conditionImages.(condition)); 
end 

3. You can now assign subject to conditions based on your use case. Here’s how you can assign it randomly

onditions = {'U', 'L', 'D'}; 
subjectCondition = conditions{randi(numel(conditions))}; 

Read more about “imread” and “struct” here:

https://www.mathworks.com/help/releases/R2019a/matlab/ref/imread.html

https://www.mathworks.com/help/releases/R2019a/matlab/ref/struct.html