Biomedical subjects
Publications and source records attributed to A H Frey.
Exposure of the head to pulse-modulated microwaves induces the perception of a sound. It has been hypothesized that the electromagnetic energy is converted to acoustic energy in the skull and then conducted through the bone. Dynamic time-averaged interferometric holography showed that the predicted motion of head tissue did not occur. An alternative locus for this hearing effect is suggested.
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Rats spent more time in the halves of shuttle boxes that were shielded from illumination by 1.2 GHz microwave energy than in the unshielded. In Experiment 1, rats avoided the energy when it was presented as 30-musec pulses with a pulse repetition rate of 100 pulses per second (pps). The average power density was about .6 mW/cm2, and the peak power density was about 200 mW/cm2. In Experiment 2, the energy was presented both continuously and in pulse-modulated form, i.e., .5-msec exponentially decaying pulses at a rate of 1,000 pps. The average power density of the continuous energy was 2.4 mW/cm2, and the average power density of the pulse-modulated energy was .2 mW/cm2. The peak power density of the modulated energy was 2.1 mW/cm2. The rats avoided the pulsed energy, but not the continuous energy.
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A psychophysical study of the perception of "sound" induced by illumination with pulse-modulated, ultrahigh-frequency electromagnetic energy indicated that perception was primarily dependent upon peak power and secondarily dependent upon pulse width. The average power did not significantly affect perception. Perceived characteristics of pitch and timbre appeared to be functions of modulation.
An evaluative review of the electrosensing literature was pursued with the intention of determining the nature of the electrosensing mechanism and its sensitivity. The biological data base, although weak, was useful in development of a mathematical model and in analyses of the sense mechanisms and their functions. During the analyses, we suggest a working hypothesis on the nature of the sense mechanism. We also collapse the various sensor coding schemes that have been proposed into one scheme. The function of the mathematical model of the sensor that was developed was explored with the use of a computer. The fishes' function at the system level was also considered and possible mechanisms defined.
In recent years there has been experimental work and speculation bearing upon the significance in neural functioning of electromagnetic energy in the region of the spectrum between 0.3 and 10 mu. We demonstrate, in this experiment, micron wavelength electromagnetic emission from active live crab nerves as compared to inactive live and dead nerves. Further, the data indicate that the active nerve emission is caused by specific biophysical reactions rather than being simply black-body radiation.
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