involving cooperative charge interactions as a partial explanation of Adey's results (80), but their

molecular basis still remains speculative (52).

There have been reports of the effects of EMFs on conditioned responses in both operant (44-

51, 74) and respondent paradigms (8, 54-58). In the operant studies, the effect of the EMFs was usually

established on the basis of changes in discrete movement by the test subjects. For example, Thomas

(74) found that a pulsed EMF of 1000 µW/cm2, 2.45 GHz, altered the effect of chlordiazepoxide on

behavior. The drug produced a change in the bar-pressing rate which was potentiated in the presence of

the EMF. In the respondent studies, typically, the field-induced effects were more generalized and

consisted of responses such as impaired endurance (57). The use of EMFs as conditioned stimuli during

periods preceding aversive stimuli has frequently (59-61), but not always (62-64), failed.

Summary

EMFs produced a broad array of impacts on the nervous system, ranging from changes in the

electrical activity of specific areas of the brain, to systematic changes such as clinical zoonosis, enzyme

increases, and alterations in specific and diffuse behavior. The most important characteristic of the

reported effects was that the energy imparted to the organism under study was far too low to have

energetically driven the observed changes via passive or classical processes such as ionization, heating,

or gross alteration in the resting potential of membranes in excitable tissue. It was the metabolism of

the organism, therefore, which furnished the energy, and the applied EMFs functioned primarily as

eliciting, triggering, or controlling factors for the observed biological changes. There have been no

systematic studies with one type of EMF, one organism, and one experimental paradigm.

Consequently, it is difficult to generalize regarding the direction or trend that will likely be exhibited

by specific nervous system parameters when they are measured under conditions which differ from

those already studied. In this sense the present studies are unsatisfactory. But this problem can be

remedied by future studies and it does not detract from the fundamental conclusion that nonthermal

EMFs can cause electrical, biochemical, functional, and histopathological changes in the nervous

system.

The manner and location at which the EMFs were detected and the means by which their

existence was first communicated to the central nervous system-a dear prerequisite for any of the

reported effects- cannot be determined from the present studies. The site of reception may be the

central nervous system itself. Support for this can be found in studies in which brain electrical activity

changes occurred instantaneously with the presentation of the field. By analogy with the modes of

detection of other stimuli such as light, sound, or touch, it might also be suggested that the peripheral

nervous system is the locus of EMF detection. This point can only be resolved by future studies -

carefully designed to eliminate the recognized difficulties in recording electrical activity during EMF

exposure (44) - in which nervous system electrical activity and the DC potentials are recorded during

EMF exposure of the central and peripheral nervous systems separately.

Because the nature of the reception process of EMFs is unknown, it is not possible to determine

whether it is mediated differently for EMFs with different frequency or amplitude characteristics. In

contrast to this, the subsequent physiological events seem to proceed via common pathways regardless

of the frequency of the applied EMF. Thus, altered brain electrical activity was found at 640 Hz (S), 3

GHz (6), and 9.3 GHz (68). Similarly, 50 Hz, (22), and 2.4 GHz (23) fields each produced comparable

c hanges in enzyme levels in the brain. With regard to behavioral endpoints (reaction time, motor

activity, conditioned responses), identical effects were found using EMFs that span the spectrum.

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