The name is absent

56 The Rice Institute Pamphlet

of which tlιe adult fingers are capable. The mouth is never
used to form a word” (Penfield & Rasmussen, 1950, p. 217).

It should be obvious from the quotations that although
cortical stimulation of the sensory and motor areas produces
effects which may be described as sensory or motor, these
effects are so simple and so specific that they bear little rela-
tion to skilled behavior patterns or complex sensory discrimi-
nations. In further cortical explorations Penfield has found
some evidence for secondary or even supplementary sensory
and motor areas which seem related to more complex be-
havior patterns for the mouth and hand. However, the effects
of stimulation in these areas can be noted only if the region
stimulated is already active. Penfield’s tentative conclusion
is that, although the sensory and motor areas in the cortex
may be way stations in the development of complex behavior
patterns, they are clearly neither terminals nor points of
origin.

(3) Another group of studies explored the effect on be-
havior resulting from the removal of tissue in the sensory and
motor areas. The research on animals has been designed to
determine the consequences of destroying individual nerve
cells and fibers and of removing larger amounts of tissue.
Lashley (1958) reports that more than one thousand cuts
have been made in the cortex of the monkey without any
discoverable changes in its behavior. In other studies knife
cuts have been made in criss-cross patterns across the sen-
sory and motor areas of a monkey’s cortex and deep into
the white matter of the hemisphere producing not only cell
destruction but also severing the connections between cells;
again, little or no defects have been reported in learning or
the retention of habits (Sperry, 1958). The removal of larger
amounts of tissue has been shown to have an effect on an
animal’s behavior. In Lashley’s (1929) work on maze learning

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