58 The Rice Institute Pamphlet
panzees who had been trained to open problem boxes with
those limbs. Even though movement was curtailed by a
severe temporary paralysis, the monkeys used their feet to
help their arms open the boxes. The results of these and
other studies involving tissue destruction or removal in the
sensory and motor areas increase our uncertainty about the
functions performed by those areas.
The recent neurophysiological research on somatic sensory
and motor processes discussed in this section does substanti-
ate the presence of specific areas in the cortex which when
stimulated result in sensations or motor movements Just as
neurophysiologists in 1900 had claimed. However, studies de-
signed to clarify the significance of these areas for the way
the central nervous system mediates between environment
and behavior preclude the acceptance of any simple, me-
chanical model. There is too much variability in response to
stimulation for one subject, in cortical location and amount
of tissue for a particular part of the body in different sub-
jects, and in anatomical and histological characteristics. The
kinds of sensory and motor processes which result from
stimulation are crade and stereotyped; their relation to com-
plex behavior sequences or sensory discriminations is ob-
scure. The effects of tissue removal in the sensory and motor
areas are variable and often only temporary. The available
neurophysiological data require a much more complicated
model for the explanation of the sensory and motor aspects
of behavior than the one available to psychologists at the
beginning of this century.
INTELLECTUAb PROCESSES
The technique of electrical stimulation introduced by
Fritsch & Hitzig left more than half of the cortex unidentified
(Ferrier, 1886, Ch. VIII; Sherrington, 1906, Lecture VIII;