Pauline M. Richards

Modification of Activation and Evaluation Properties of Narratives by Weak Complex Magnetic Field Patterns that Simulate Limbic Burst Firing

In two separate experiments a total of 71 volunteers were asked to generate spontaneous narratives that were scored automatically by the Whissell Dictionary of Affect. During the narratives, weak (1 microT; 10 mG) magnetic fields were applied briefly through the temporal planes. In Experiment I, subjects who were exposed to simple sine wave or pulsed fields generated more scorable words that indicated lower activation and evaluation than sham-field conditions. In Experiment II subjects exposed to a computer-generated wave form, designed to simulate neuronal burst firing, generated narratives dominated by more pleasantness and less activation than a reference group. The possibility that this approach could be utilized to study the affective dimension of language selection was indicated.

Differential ratings of pleasantness following right and left hemispheric application of low energy magnetic fields that stimulate long-term potentiation

A total of 40 normal men and women were exposed under double blind conditions for 20 min to either sham-conditions or to 1 microT (10 mG) electromagnetic fields (known to produce long-term potentiation within hippocampal slices) that were applied primarily over the right temporal lobe, over the left temporal lobe or over both temporal lobes homogeneously. The men and women who received the stimulation over the right hemisphere rated their experiences as significantly more pleasant than those who received the same stimulation over the left hemisphere [eta = 0.51]. Covariance for the variation in ambient geomagnetic activity, which was negatively correlated with pleasantness, increased the significance of the experimental treatment. The potential clinical utility of applying computer-generated local and penetrative but weak intensity complex magnetic fields over portions of the human brain is discussed.

DIFFERENTIAL ENTRAINMENT OF ELECTROENCEPHALOGRAPHIC ACTIVITY BY WEAK COMPLEX ELECTROMAGNETIC FIELDS

The hypothesis was tested that compensatory susceptibility to electro-encephalographic driving and entrainment by weak (1 microT) time-varying, externally applied complex magnetic fields would occur in normal subjects following successive stimulation by different patterns. 43% of the volunteers showed evidence of driving during the application of the complex magnetic fields and indications of resonance (entrainment) during the first 10 sec. following the cessation of the fields. The volunteers who exhibited driving and entrainment could be discriminated from those who did not by their more frequent reported experiences of fear and odd tastes during the stimulation. They were also more likely to have a preexposure history of a sense of presence and to experience intense meaningfulness when reading or writing prose or poetry.

DIFFERENTIAL EFFECTS OF WAVE FORM AND THE SUBJECT'S POSSIBLE TEMPORAL LOBE SIGNS UPON EXPERIENCES DURING CEREBRAL EXPOSURE TO WEAK INTENSITY MAGNETIC FIELDS

In three separate experiments a total of 85 male and female university students were exposed within a Ganzfeld setting to weak (1 mG, 100 nT), complex magnetic field patterns. They were applied across the temporal lobes and generated by computer software. When the patterns were rotated spatially over the temporal lobes the numbers of subjective experiences that simulate possible temporal lobe signs and symptoms were markedly increased and qualitatively more extreme than those evoked when the fields were not rotated. A 16 Hz pulsed square wave generated more experiences of thought intrusion than a 4 Hz wave. A positive-feedback ringing wave presented at 4 Hz evoked more visual memories and images than the mirror image of the same wave; the effect was only apparent when the subjects quantitative scores for possible temporal lobe signs was covaried. Only those subjects who displayed above average temporal lobe signs and were exposed to a burst-firing wave pattern for one second once every 4 seconds (a condi...

Modification of Semantic Memory in Normal Subjects by Application Across the Temporal Lobes of a Weak (1 Microt) Magnetic Field Structure that Promotes Long-Term Potentiation in Hippocampal Slices

Normal, right-handed human volunteers listened to a 5-min story and were then exposed to 15 min (3 successive segments of 5 min on/5 min off) of magnetic pulses (1 microT; 10 mG) whose temporal structure has been shown to enhance long-term potentiation (LTP) in hippocampal slices. There were four conditions: no stimulation, bilateral stimulation (across both temporoparietal regions), primary stimulation of the left temporoparietal lobes or primary stimulation of the right temporoparietal lobes. Reconstructions of the story were completed by the same subjects within 30 min (intermediate memory) and about 10 days (long-term memory) later. The strongest effect size (25% of the variance was accommodated) was due to the approximately two fold increase in the numbers of accurate details for the long-term memories for subjects who had received the left hemispheric stimulation. These results suggest that contemporary technology may have the capability to access fundamental algorithms of the neuronal activity asso...

Tobacyk's Paranormal Belief Scale and Temporal Lobe Signs: Sex Differences in the Experiences of Ego-Alien Intrusions

Tobacyks Revised Paranormal Belief Scale and an inventory that infers temporal lobe signs were administered to 44 men and 54 women who were enrolled in first-year university courses. Women believed more in psi phenomena, witchcraft, and spiritualism than did men, who believed more in extraterrestrial life forms. Although complex partial epileptic-like signs were moderately (0.40) correlated with total beliefs for both sexes, these signs were dominated by experiences of ego-alien intrusions for women only. The results support the concept of greater interhemispheric coherence in women compared to men and emphasize the importance of limbic processes in the formation and maintenance of religious and paranormal beliefs.

Experimental Stimulation by Burst-Firing Weak Magnetic Fields over the Right Temporal Lobe May Facilitate Apprehension in Women

Intermittent bursts of weak magnetic fields whose patterns simulate normal amygdaloidal-hippocampal activity were generated by computer over the right or left temporal regions of men and women during partial sensory deprivation. As predicted, women but not men reported greater apprehension during right-hemispheric but not left-hemispheric stimulation. Intrusions of right-hemispheric processes have been hypothesized to affect self-esteem adversely. These results also support the role of the right parahippocampal region in the production of panic attacks.

Seizure onset times for rats receiving systemic lithium and pilocarpine: Sources of variability

Injection of 30 mg/kg of pilocarpine 24 h after systemic injection of lithium (3 mEq/kg) results in overt limbic motor seizures within about 30 min. Results of several experiments indicated that whereas food deprivation or repeated nociceptive stimulation during the previous 24 h decreased seizure onset times (SOTs) by about 11 to 12 min, food restriction, continuous lighting, or, handling during the previous 7 to 14 days increased SOTs by comparable durations. Early handling before weaning but not injections of clomimpramine also decreased SOTs. A difference of 18 min in the means of SOTs was produced by injecting either 1.0 (increased SOT) or 1.5 mg/kg (decreased SOT) of dexamethasome during the previous 24 h. A strong (multiple r=.87) association between SOTs and the amount of damage within five specific thalamic-limbic nuclei was observed. These results, in conjunction with blood corticosterone levels taken before and after induction of the seizures, suggest the neurochemical mechanisms affecting the range in SOTs could involve the adrenocorticotropic hormone (ACTH)-corticosterone system and influence the amount of post-seizure-induced damage.

Foot Agility and Toe Gnosis/Graphaesthesia as Potential Indicators of Integrity of the Medial Cerebral Surface: Normative Data and Comparison with Clinical Populations:

A protocol was designed to identify quantitative indicators of the function of the medial surfaces of the cerebral hemispheres. Normative data were collected from 40 volunteers for foot agility, toe gnosis, and toe graphaesthesia. A total of 100 patients (most of whom had been referred for possible closed-head injuries) completed thorough neuropsychological and cognitive assessments. Deficits for toe graphaesthesia were most consistently correlated with general brain impairment and with scores for tasks whose normal performance requires the integrity of structures within the dorsal half of the medial cerebral hemispheres.

Toe Graphaesthesia as a Discriminator of Brain Impairment: The Outstanding Feet for Neuropsychology:

Because of the vulnerability of the medial surfaces of the cerebral hemispheres to the consequences of shear forces, we hypothesized that quantitative sensorimotor deficits for the feet would be strong indicators of general brain dysfunction. On the basis of the Halstead-Reitan Impairment Index, 28 adults who had received closed head injuries were assigned to perfectly normal, normal, or (mildly to severely) impaired groups. Foot tap and finger tap as well as agnosia and graphaesthesia for the fingers and toes were measured. Deficits in toe graphaesthesia were the most powerful group discriminator. Potential usefulness of haptic/motor, finger/toe comparisons for recording the progress of degenerative diseases, such as AIDS, is also suggested.