62 The Rice Institute Pamphlet
alternate in the literature with those which fail to record any
behavioral changes. The clinical value of the operation for
the particular patient usually has determined the kinds of
observations that were made, and few, if any, kinds of con-
trols or systematic comparisons have been used to evaluate
the conclusions. (Cf. Franz, 1907, pp. 16-24; Hebb, 1945;
Sholl, 1956, pp. 73-76.) Even more carefully designed studies
could not be accepted without reservation. Rylander (1939a,
1939b) used a comprehensive battery of tests in his study;
besides intelligence tests, he had techniques designed to
measure, among other things, attention, memory, the ability
to abstract common characteristics from a set of objects, and
the formation and use of abstract ideas. For each patient a
“normal” control subject was chosen of the same age, sex,
education, occupation, and social background. Rylander
found changes in test performance for twenty-one of his
thirty-two patients. On the basis of his data he concluded
that the surgical removal of tissue from the frontal lobes
causes intellectual deficit. A re-evaluation of the studies of
Rylander and others by Hebb (1945) makes it impossible to
accept this conclusion.
Hebb (1945) prepared a critical view of neurosurgical re-
ports on the functions of the frontal lobes as a result of his
observations on a patient who had had both frontal lobes
removed. The operation was done to correct epileptic attacks
attributed to a skull fracture some ten years before which as
it turned out had destroyed both frontal poles. Before the
operation tire man was childish, violent, stubborn, and de-
structive; afterwards it was impossible to demonstrate psy-
chological defects. All of the effects of the removal of a large
portion of his frontal lobes seemed to be positive. Intelli-
gence test scores indicated that his IQ had changed from 70
to 96, this last index well within the normal range. Social ad-