Review Question - QID 214958

A 2-year-old boy is brought to a geneticist for evaluation of persistent developmental delay. He was born to a G1P1 mother at term via spontaneous vaginal delivery and had APGAR scores of 9 and 9 at 1 and 5 minutes, respectively. Since then, he has consistently missed his developmental milestones and does not appear to respond to verbal stimuli at home. On presentation, he is found to have writhing movements of his hands and arms bilaterally as well as numerous wounds on his hands and wrists. When asked, his parents say that these injuries are due to self-biting activity. Which of the following is the most likely function that is deficient in this patient?