Insert a code component on the next routine (from the “custom” components panel). Make sure it is above the text component on that routine where you want to give the feedback. In the “begin routine” tab of that code component, insert something like this:
if response.keys == 'left': # or whatever key corresponds to this choice
feedback = left
else:
feedback = right
Then in your text component, simply insert $feedback
in the “text” file, set to update “every repeat”.