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126  Some Bad Habits of Reacting
     To Stress Can Be Unlearned
     The Washington Post  Saturday, November 30, 1968

     Conditioned reflexes have been a favorite subject of psychological
experimentation for 50 years. The starting point is usually a
simple, already established reflex, like pulling back from a painful
electric shock. When the stimulus is applied at the same time as or
just after another signal, say a flash of light, the experimental 
animal is promptly conditioned. That is, it "learns" to retreat from the
signal flash in the same way as it does from the shock.

     Human subjects show very similar behavior, and the conditioned
reflex played a large part in psychologists' earlier thinking about
the process of learning in man.  More recently, more emphasis has been
placed on the observation and imitation of others' behavior as a 
central element in human intellectual development. Nevertheless, 
conditioned behavior may still play an important role in body functions
and in emotions which are not always so plainly under conscious control.

     More recent studies have made increasing use of "instrumental
conditioning." Particular responses to a signal are directly rewarded
or discouraged so that the technique need to be attached to a 
pre-existing reflex.

     The discovery of the reward centers in the brain has further
advanced such work.  When electrodes are implanted in these regions
and animals are given the opportunity to press a lever that will send
electrical impulses into them, they will self-stimulate these centers
almost to the exclusion of any other behavior, ignoring drives like
hunger, thirst and fatigue that would otherwise dominate.

     It is then possible to set up an apparatus that will respond to
some particular behavior whose learning the psychologist wishes to
study and to reward the animal for "correct" behavior with an electrical
pulse to his reward center.  Similar circuits have presumably been
evolved within the animal and human brains to facilitate the learning
and maintenance of social behavior essential for the preservation of
the species.

     The most striking results from such experiments have been reported
by Drs. Leo V. DiCara and Neal E. Miller of Rockefeller University
New York.  Their earlier work had established that rats could be
trained, with reinforcement by electric stimulation, to change their 
heart rate either up or down in response to a tone signal.

     This was very difficult without the use of a drug, curare, to
dampen the general changes in muscle tension that would accompany
changes in heart rate.  However, once the animals had learned to make
their heart rate change with the tone, the behavior could also be 
demonstrated without the curare and despite the inappropriateness of
changing heart rate without a bodily demand for it.

     In one of their most spectacular experiments, they showed that
the rats could regulate a difference in blood flow to the right ear
vs. the left ear, and without changing blood flow in other parts of
the body.  Dr. Miller and his colleagues have also shown "learned" 
responses in kidney function and in contractions of the intestine.

     These experiments show beyond doubt that neural circuits exist by
which the brain can influence body functions long held to be autonomous.
Furthermore, the brain can learn the most inappropriate programs
that may still be implemented through these circuits.

     The analogy to psychosomatic disease is obvious. In fact, some of
these experimenters' rats died of insufficient circulation when they
overresponded to stimuli to which a slowing of the heart had been 
conditioned. Some recent innovations in psychotherapy, so-called 
behavior therapy, emphasize the importance of unlearning the patient's 
established bad habits of bodily responses to stressful stimuli.
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