Biomedical subjects

M A Persinger

Publications and source records attributed to M A Persinger.

At least 37 records · Page 2Linked to original sources

PubMed2004

Power increases within the gamma range over the frontal and occipital regions during acute exposures to cerebrally counterclockwise rotating magnetic fields with specific derivatives of change.

A total of 11 men and women were exposed for 5 min each to six different temporal configurations of pulsed magnetic fields that were delivered through serial activation of 8 solenoids in a counterclockwise direction around the head within the horizontal plane above the ears. Twenty-second samples of quantitative electroencephalographic activity within the delta, theta, lower alpha, upper alpha, beta, and gamma regions were collected after each configuration had been activated for 2.5 min. Only the circumcerebral presentation of the first pulse for 25 ms followed by an acceleration of +2 ms to each of the other 7 solenoids (the last duration = 11 ms) resulted in a significant increase in power within the gamma range (35 Hz to 45 Hz) over both frontal and occipital lobes but not over the parietal or temporal lobes. These results suggest topical application of specific spatial-temporal configurations of magnetic fields may affect the recursive creation of the rostral-caudal waves of cohesive fields that might produce consciousness.

Adult↗

PubMed2004

Influence of a complex magnetic field application in rats upon thermal nociceptive thresholds: the importance of polarity and timing.

The application of a weak (1 microTesla) complex magnetic field pattern with a relevant electrophysiological signature produced an analgesic response in rats to thermal stimuli when the pattern was presented once every 4 sec for 30 min through iron-core solenoids. In one experiment, the burst-firing pattern was presented once every 4 s for 30 min and restricted to the positive polarity, negative polarity or a bipolar equivalent. The strongest analgesia occurred when the burst-firing pattern was presented with positive polarity or as the typical bipolar signal. Administrations of the burst-firing pattern once per week for four consecutive weeks produced analgesia that was clearly evident during the first, third, and fourth weeks but not during the second week of treatment. A telephone sensor coil (that can be readily obtained from local electronic shops) was then used instead of the solenoids along with an audio (.wav) file to generate the magnetic field; the analgesia was still apparent. However, when the magnetic pattern was generated from a compact disc source the analgesia was not evoked. The current results suggest that these fields can be generated through simple commercial devices controlled by available computer software.

Animals↗

PubMed2004

Weak-to-moderate correlations between global geomagnetic activity and reports of diminished pleasantness: a nonspecific source for multiple behavioral correlates?

In two previous experiments the ratings of the pleasantness of the experiences for a total of 45 subjects tested within a specific experimental setting were negatively correlated (rhos about -.35 to -.40) with the global geomagnetic activity on the days of the ratings. In the present analysis, subjective ratings from a comparable experiment completed 13 years ago were also negatively correlated (rho = -.50) with the global geomagnetic activity on the days of the experiences. The consistency of these results suggests a common neurophysiological process that generates hedonistic affect with which the multiple types of behaviors, such as aggression, homicide, traffic fatalities, epileptic seizures, and industrial accidents, are correlated. Consequently these apparently "divergent" behaviors are correlated with geomagnetic activity because they are correlated with a central neurophysiological process which may be sensitive to increases in geomagnetic activity.

Affect↗

PubMed2004

Geophysical variables and behavior: XCIX. Reductions in numbers of neurons within the parasolitary nucleus in rats exposed perinatally to a magnetic pattern designed to imitate geomagnetic continuous pulsations: implications for sudden infant death.

Correlational analyses have shown a moderate strength association between the occurrence of continuous pulsations, a type of geomagnetic activity within the 0.2-Hz to 5-Hz range, and the occurrence of Sudden Infant Deaths. In the present study, rats were exposed continuously from two days before birth to seven days after birth to 0.5-Hz pulsed-square wave magnetic fields whose intensities were within either the nanoTesla or microTesla range. The magnetic fields were generated in either an east-west (E-W) or north-south (N-S) direction. At 21 days of age, the area of the parasolitary nucleus (but not the solitary nucleus) was significantly smaller, and the numbers of neurons were significantly less in rats that had been exposed to the nanoT fields generated in the east-west direction or to the microTesla fields generated within either E-W or N-S direction relative to those exposed to the N-S nanoTesla fields. These results suggest nanoTesla magnetic fields, when applied in a specific direction, might interact with the local geomagnetic field to affect cell migration in structures within the brain stem that modulate vestibular-related arousal and respiratory or cardiovascular stability.

Animals↗

PubMed2004

Weekly treatments with a burst-firing magnetic field alters behavior in the elevated plus maze after two sessions.

In a split-litter design, rats were either injected with 15 mg/kg of clomipramine or saline from postnatal Days 8 through 21. Other rats from the same litters were not injected. When the rats were 90 days of age, the rats were tested once per week for five weeks in an elevated plus maze that contained two open arms (no alls) and two walled arms. Following each test, they were exposed (total of 4 exposures) for 30 min. to a burst-firing magnetic field (1 microTesla) that has been shown to reduce depression in human beings. After two treatments, the rats exposed to the burst-firing fields spent about half the amount of time in the open arms compared to the sham-field exposed rats. The interaction between adult treatment and whether the rats had received the antidepressant before weaning was not significant statistically. These results suggest that at least two weekly sessions may be required before significant changes in behavior occur after weekly 30-min. exposures to these potentially "therapeutic" magnetic fields.

Animals↗

PubMed2004

Geomagnetic activity during the previous day is correlated with increased consumption of sucrose during subsequent days: is increased geomagnetic activity aversive?

In five separate blocks over a period of several months for 33 female rats the amount of geomagnetic activity during the day before ad libitum access to 10% sucrose or water was positively correlated with the volume of sucrose consumed per 24-hr. period. The strength of the correlation (.62 to .77) declined over the subsequent 10 days from between .12 to -.18 and resembled an extinction curve. In a subsequent experiment four rats exposed to 5 nT to 8 nT, 0.5-Hz magnetic fields that ceased for 30 min. once every 4 hr. for 4 days consumed 11% more sucrose than the four rats exposed to no field. We suggest that the initial consumption of 10% sucrose may have been reinforced because it diminished the aversive physiological effects associated with the increased geomagnetic activity. However, over the subsequent days, as geomagnetic activity decreased or habituation occurred, negative reinforcement did not maintain this behavior.

Animals↗

PubMed2004

Geophysical variables and behavior: C. Increased geomagnetic activity on days of commercial air crashes attributed to computer or pilot error but not mechanical failure.

Global geomagnetic activity (aa values) for the days of crashes of airplanes and for each of the three days before and after the crashes were compared for 373 events (years 1940 through 2002) attributed to unknown factors, mechanical errors, electronic/computer failures or pilot errors. Interactions between days and classifications of the crashes were due to the significantly greater geomagnetic activity on the days of crashes attributed to pilot or computer error but not to mechanical or unknown factors. Successive temporal analyses indicated that the elevated activity on the days of crashes attributed to pilot error have not changed over time, but there was an increase in those attributed to electronic errors after 1965. No more than 9% of the variance in geomagnetic activity on the days of the crashes was associated with the type of crash. These results are consistent with our hypothesis that some factor or factors associated with relative increases in geomagnetic activity may affect complex electronic systems composed of either silica (computer) or carbon (brain) aggregates.

Accidents, Aviation↗

PubMed2004

Students' perceptions of dangerousness to public safety of paraphrases from the Koran, New Testament, Book of Mormon, Tibetan Book of the Dead, and Egyptian Book of the Dead presented as patients' beliefs.

In one experiment 40 first-year psychology students were asked to judge dangerousness to society of 10 fictitious patients who professed beliefs about an "alien." The statements were actually paraphrases primarily concerning death and killing from the New Testament, the Koran, the Book of Mormon, the Egyptian Book of the Dead and the Tibetan Book of the Dead. In a second experiment 39 first-year psychology students were asked to rate the dangerousness of the verbatim statements with their sources identified. In the first experiment, statements from the Koran, which involved accessing a positive afterlife by killing nonbelievers in the name of a deity, were ranked as more dangerous. The differences between the sources accommodated 33% of the variance in the rankings for dangerousness. The group of students who were given the original statements and their actual sources ranked the statements from the New Testament and the Koran as significantly less dangerous than those who were told the statements were from patients. These results suggest that statements about killing and death may be rated as less dangerous if the person believes the source was a "sacred text."

Adult↗

PubMed2003

Combined effects of complex magnetic fields and agmatine for contextual fear learning deficits in rats.

Acute post-training exposures to weak intensity theta-burst stimulation (TBS) patterned complex magnetic fields attenuated the magnitude of conditioned fear learning for contextual stimuli. A similar learning impairment was evoked in a linear and dose-dependent manner by pre-conditioning injections of the polyamine agmatine. The present study examined the hypothesis that whole-body applications of the TBS complex magnetic field pattern when co-administered with systemic agmatine treatment may combine to evoke impairments in contextual fear learning. Within minutes of 4 mg/kg agmatine injections, male Wistar rats were fear conditioned to contextual stimuli and immediately exposed for 30 min to the TBS patterned complex magnetic field or to sham conditions. TBS patterned complex magnetic field treatment was found to linearly summate with the contextual fear learning impairment evoked by agmatine treatment alone. Furthermore, we report for sham-treated rats, but not rats exposed to the synthetic magnetic field pattern, that the magnitude of learned fear decreased and the amount of variability in learning increased, as the K-index (a measure of change in intensity of the time-varying ambient geomagnetic field) increased during the 3-hr intervals over which conditioning and testing sessions were conducted.

Agmatine↗

PubMed2003

Radial maze proficiency of adult Wistar rats given prenatal complex magnetic field treatments.

Exposure to sinusoidal (power-frequency) magnetic fields during prenatal development is implicated in adulthood behavioral impairments. However, the effects of prenatal exposure to weak-intensity, nonsinusoidal complex magnetic fields (CMFs), an increasingly common feature of the modern environment, have not been rigorously examined. In the present study, male and female Wistar-strain rats were exposed continually during prenatal development to one of three extremely low-frequency CMFs or a sham condition. As adults, rats were trained in an acquisition/reversal radial maze task. All rats exposed to the prenatal CMFs increased their commission of reference memory errors, but differences in working memory and motivation to complete the maze task were specific to the type of prenatal CMF. These results provide the first evidence that prenatal exposures to specific shapes of CMFs impair complex learning behaviors into adulthood.

Animals↗

PubMed2003

Behavioral effects of combined perinatal L-NAME and 0.5 Hz magnetic field treatments.

The behavioral effects of the nitric oxide synthase inhibitor N-nitro-L-arginine methyl ester (L-NAME), when perinatally (2 d prenatal-14 d postnatal) co-administered with extremely low frequency magnetic fields, were examined in weanling and adult rats. Litters of rat pups and their dams were exposed continuously to biphasic pulsed fields presented once every 2 s. The magnetic fields were amplitude modulated in successively increasing and decreasing steps (each 30 min) between 0 and 1.8 microT or between 0 to 13 nanoT (reference field) during 4-h periods (6 periods per day). These two treatments were subdivided into dams that received tap water and dams that received 1.0 g/L L-NAME in tap water. The behavioral sequelae to these treatments for 242 progeny from 41 litters were followed from weaning (1 wk after termination of treatment) into adulthood. Compared to exposures to water and nanoT magnetic fields, perinatal exposures to the microT magnetic fields or to L-NAME in the maternal water supply were associated with increased activity levels when the rats were tested as weanling, but decreased activity levels when the rats were tested as adults. However, the activity of rats that received the combination of L-NAME and microT magnetic fields did not differ significantly from the activity of the rats that had received water and the nanoT fields. Long-term (adulthood) effects of these perinatal treatments on associative learning, as inferred by learned fear to contextual stimuli, were not evident. These results indicate that L-NAME and this particular pattern of magnetic field antagonized one another when co-administered during the perinatal period.

Animals↗

PubMed2003

A brief (one-hour) quantitative neuropsychological assessment with three performance-based tests: strong concordance with proficiency scores for a more extensive test battery.

Raw scores for each of several dozens of traditional and more recently developed neuropsychological tests were correlated with an impairment index composed of all of these scores from the records of 162 patients who had been assessed following impacts of substantial mechanical energies. A score of either less than 20 correct binaural responses for a dichotic word listening task, more than 99 sec. for Trails B, and more than 3.8 min. to complete the Tactual Performance Test with both hands correctly classified 85% of patients whose z scores were less than -1.0 (below average) or -1.0 or above (average) for a composite neurocognitive index. The results suggest that these three tests, administrable within about one hour, may be employed as a more objective criterion rather than "clinical impressions" for discerning if patients require more extensive neuropsychological testing.

Adolescent↗

PubMed2003

Rats' preferences for an analgesic compared to water: an alternative to "killing the rat so it does not suffer".

A common policy in research institutions is to kill rats when they display chronic disabilities or recurrent injuries. These guidelines appear to be derived from an oxymoron that "it's better for a rat to be killed so it does not suffer pain" and from untested assumptions that rats cannot control "pain." In a two-bottle paradigm, 10 rats with a history of brain damage following status epilepticus from a single systemic injection of lithium and pilocarpine were given options to consume freely either tap water or 1 mg/cc of acetaminophen in tap water. During periods of fresh lesions due to persistent gnawing or acute injuries associated with tonic-clonic convulsions, the rats consumed 3 to 10 times the fluid from the bottles containing acetaminophen (equivalent to 5 to 10 extra-strength Tylenol tablets per day for a 70-kg person) relative to periods when no lesions or old lesions were present. These results suggest that rats with chronic injuries sufficient to be terminated according to Animal Care guidelines may be capable of reducing the aversive physiological conditions associated with tissue damage by selecting analgesic treatments.

Analgesics↗

PubMed2003

Spatial heterogeneity not homogeneity of the magnetic field during exposures to complex frequency-modulated patterns facilitates analgesia.

24 young (4 mo.) and 24 old (8 mo.) male Wistar rats were exposed for 30 min. on two consecutive days to either a sham-field or to a frequency-modulated magnetic field applied through a pair of solenoids (spatially heterogeneous strength) or a Helmholtz coil (spatially homogeneous strength). The maximum field strength was about 2 microTesla. The rats exposed to the spatially heterogeneous magnetic field but not the homogeneous magnetic field exhibited strong analgesia to thermal stimuli applied to the footpads immediately after the treatment and 30 min. later. The effect accommodated 38% of the variance in the latency to respond to the thermal stimuli. These results suggest that the practice by many researchers in bioelectromagnetism to design coils to generate maximum spatial homogeneity of intensities within the exposure volume when applying complex weak magnetic fields may actually diminish any biological effects.

Analgesia↗

PubMed2003

Intermittent burst-firing weak (1 microTesla) magnetic fields reduce psychometric depression in patients who sustained closed head injuries: a replication and electroencephalographic validation.

14 patients who reported chronic depression more than one year after closed head injuries were exposed to weak (1 microTesla), burst-firing magnetic fields either across the temporal lobes or over the left frontal lobe. The treatment was for 30 min. once per week for 6 wk. The reduction in depression scores after 5 wk. of treatments and after 6 wk. of no treatment (follow-up) accommodated 54% of the variance for both groups. The changes in depression scores did not differ significantly between the two groups (temporal vs frontal). Following treatment, the frequency of complex partial epileptic-like experiences decreased significantly only for the 7 who received the bilateral stimulation over the temporal lobes. Quantitative bipolar electroencephalographic measurements over the occipital, prefrontal, and temporal regions showed increased power within the 16-Hz to 18-Hz range 6 wk. after termination of treatment for those 7 patients who received the burst-firing magnetic fields bilaterally over the temporal lobes but not over the left prefrontal region.

Adult↗

PubMed2003

Enhanced power within a specific band of theta activity in one person while another receives circumcerebral pulsed magnetic fields: a mechanism for cognitive influence at a distance?

Four pairs of adult siblings served once as either the stimulus or the response person in two sessions separated by one week. While the brain of the stimulus person, who was seated in a closed chamber, was exposed successively to six different complex magnetic fields for 5 min. each quantitative monopolar electroencephalographic measurements over the frontal, temporal, parietal, and occipital lobes were collected by computer for the response person who was seated in another room. The six configurations of fields served as different stimulus patterns and had been designed to affect consciousness. As predicted theoretically, a significant increase in electroencephalographic power within the 5.0-Hz to 6.0-Hz band over the frontal and occipital lobes was noted for the response persons when the stimulus persons received one of the six specific patterns of weak (1 microTesla range) magnetic fields. This magnetic stimulus was presented for 100 msec. with changes in rate of 20 msec. to each of the eight solenoids that were equally spaced in the horizontal plane around the head of the stimulus person. Derivatives within this narrow frequency band had been hypothesized to be a source of the "binding factor" for the cohesive cerebrogenic electromagnetic fields producing consciousness. The results suggest that an appropriate altered state of one brain can effect specific predictable frequencies of the electroncephalographic activity of another distant brain which is genetically related.

Adult↗

PubMed2003

Increased proportions of sensed presences and occipital spikes with 1- and 10-msec. point duration of continuous 7-Hz transcerebral magnetic fields.

To test the hypothesis that the numbers of "sensed presences" induced by the application of weak (1 microTesla) magnetic fields over the right hemisphere was subject to an optimal time of presentation, digital-to-analogue computer generated 7-Hz sine-waves were applied with point ("pixel") durations of 1, 3, 5, 7, 10, or 20 msec. for 5 min. each in a sequential counterbalanced order for six subjects. The proportion of numbers of sensed presences reported along the subjects' left sides and the proportions of electroencephalographic spikes over the occipital regions were greatest when 1- or 10-msec. point durations were employed. These results indicate that the specific duration of each successive field strength composing a complex sequence should be considered when designing optimal configurations for intercalating with neurocognition.

Brain↗

PubMed2003

Does phase-modulation of applied 40-Hz transcerebral magnetic fields affect subjective experiences and hypnotic induction?

12 men and 12 women were exposed to a sham-field, a 5-Hz sine-wave magnetic field, a 40-Hz sine-wave magnetic field, or the latter field-phase modulated five times per sec. (5-Hz) for 30 min. between two administrations of the Spiegel's Hypnotic Induction Profile. To replicate the geometry that has produced significant increases in these scores in previous studies, the weak (1 microT) magnetic fields were applied over the right parietotemporal region through a modified helmet. The hypothesis that the enhanced suggestibility previously observed was due to an intrinsic phase-modulation of the fields was not supported. However, the ratings of overall pleasantness of the experiences were negatively correlated (r = -.36) with global geomagnetic activity at the time of the experiment. The pleasantness was ranked significantly greater by subjects exposed to the 40-Hz field (explaining 41% of the variance) relative to subjects exposed to the 5-Hz field who also reported more visual experiences within their left peripheral visual fields. The percentages of time alpha rhythms were measured over the temporal lobes (but not frontal or occipital lobes) during the treatments were moderately and positively correlated with scores on questionnaires administered before the experiment, from which the capacity to imagine, temporal lobe signs, and religious (but not exotic) beliefs were inferred. The groups exposed to either the 5-Hz or 40-Hz/5-Hz phase-modulated field displayed greater durations of alpha rhythms over the temporal lobes than the other two groups.

Brain↗