FREEMAN, W. J. 
these changes represent fluctuations in the energy level of centers 
in which the electrode has been found to lie. In each case, the elec- 
trode has been used as a focal tool and the interpretation has been 
made in focal terms. 
This fact of technique is crucial. When it was first introduced, 
the term center was simply a label applied to a given part of the 
brain which could produce a discrete response on stimulation, such 
as the eye-opening center, tongue-twitching center, orfinger- moving 
center, and so forth, without any firm commitment on the part of 
the user. But its subsequent application to all other parts of the brain 
was due more to the technology of the electrode than to any rational 
development of the system. Despite many difficulties with this 
doctrine, it has been the bulwark of studies in temperature regulation 
and there is no cliche more firmly entrenched in the medical liter- 
ature than the term "temperature regulation centers." 
I would now like to illustrate some of these assumptions and 
difficulties by describing three experiments. These have one thing 
in common. They failed. They gave negative results, or, perhaps 
better said, "indeterminate" results; and I would like to point out 
what the assumptions of these experiments were and how at least 
in two cases the assumptions were wrong. 
AN INCONCLUSIVE EXPERIMENT INVOLVING 
RECORDING 
The first experiment was to record the electrical activity of 
the hypothalamus in association with changes in body temperature 
(Freeman, 1957). This was a prelude to hypothalamic heating and 
cooling by means of which to evoke electrical changes possibly 
correlated with thermoreceptor activity. As we conceived the prob- 
lem initially, the hypothalamus was composed of a series of nuclei, 
and each nucleus was presumed to have its own characteristic form 
or pattern of electrical activity; one of these nuclei or collections 
of cells, even if it was intermingled with others, was sensitive to 
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