A. Peripheral:
(1) External.
(2) Internal.
B. Central.
3. Show by a diagram how one cortical center arouses another. Compare the diagram in Fig. 9, p. 37.
4. Facilitation of the patellar reflex or "knee jerk". Let your subject sit with one leg hanging freely from the knee down. With the edge of your hand strike the patellar tendon just below the knee cap. (a) Compare the reflex movement so obtained with a voluntary imitation by the subject. Which is the quicker and briefer? (b) Apply a fairly strong auditory stimulus (a sudden noise) a fraction of a second before the tap on the tendon, and see whether the reflex response is reinforced, (c) Ask the subject to clench his fists or grit his teeth, and tap the tendon as he does so. Reinforcement? (d) Where is the reflex center for the patellar reflex, and whence comes the reinforcing influence?
5. Construct a diagram showing the different centers and connections involved in making the skilled movement of writing; and consider what loss of function would result from destruction of each of the centers.
REFERENCES
Herrick's Introduction to Neurology, 1918, Chapter XX, on the "Functions of the Cerebrum".
Stile's Nervous System and Its Conservation, Chapters X, XI and XII.