Head to the Memory Den in Goodneighbor. Approach Irma and if you persuaded/bribed her for a trial run on their memory lounger, the quest “The Memory Den” will become available. Sit in the memory lounger and you’ll get to see the memory of your son and wife. You won’t be able to do anything so just let the cutscene play and the sequence will end automatically. Talk to Irma afterward and the quest will be complete.