Geophysical variables and behavior: XCII. Experimental elicitation of the experience of a sentient being by right hemispheric, weak magnetic fields: interaction with temporal lobe sensitivity

We tested the hypothesis that proportionally more people with above average numbers of complex partial epileptic-like experiences before the experiment would report a proximal presence during applications of a weak (1 microTesla), frequency-modulated magnetic field over the right hemisphere. Each of 16 subjects sat in a darkened, quiet room and was exposed for 20 min. to complex fields, applied through a helmet, either along the right hemisphere or across both hemispheres. None of the 8 subjects with below average scores reported a presence during the applications of the magnetic fields while 75% and 60% of the 8 subjects with above average scores reported a presence during right hemispheric and bilateral stimulation, respectively.     

Facilitation of seizures in limbic epileptic rats by complex 1 microTesla magnetic fields

On three separate sessions 24 male rats with histories of limbic epilepsy were exposed to 10 temporal configurations for 5 min. each of one of two patterns of magnetic fields. Their intensities averaged about 1 microTesla (microT). The numbers of Level 5 (Racine) seizures, inferred by the rat's rearing, rapid forelimb clonus, and falling, were statistically more frequent for the frequency-modulated (Thomas) pattern when its pixel duration and interstimulus presentation were 3 msec. The effectiveness of this temporal configuration was replicated in a second within-subjects experiment (n = 9) that directly compared the numbers of seizures during exposures to each of the two patterns and to a sham-field. These results suggest that brains with sensitive limbic systems might respond to weak magnetic fields, generated from multiple overlapping fields from communication and computer systems whose temporal derivatives emerge as complex sequences with pixel durations within the millisecond range.     

Circumcerebral application of weak complex magnetic fields with derivatives and changes in electroencephalographic power spectra within the theta range: implications for states of consciousness

Relative power within the delta, theta, low-alpha, high-alpha, and gamma electroencephalographic spectra of 8 human volunteers was recorded over the left and right frontal, temporal, parietal, and occipital lobes during and after the circumcerebral application through an array of 8 solenoids of 6 different configurations of weak (5 to 10 microTesla) magnetic fields. The solenoids were equally spaced around the subject's head along a horizontal plane above the ears. An approximately 30% increase in power within the theta band occurred transcerebrally during the application of a specific configuration, previously shown to affect subjective time, involving 20-msec. rates of change in the duration of delivery of the magnetic fields to each successive solenoid. Compared to the left hemisphere, the right hemisphere displayed a 20% increase in power within the 5.0- to 5.9-Hz range for all 6 configurations. The results suggest that very complex magnetic fields with the appropriate temporal parameters rotated around and within brain space can interact with the cerebral processes, measured as specific hands of frequencies, generating consciousness. Implications for the roles of hippocampal theta activity, cortical resonance, and Goldstone bosons in these processes are discussed.     

The sensed presence within experimental settings: implications for the male and female concept of self

The sense of "a presence" or of a sentient being during partial sensory deprivation and exposure to very weak, complex magnetic fields across the cerebral hemispheres may be a normal neurocognitive experience that is associated with the brief intrusion of the right hemispheric homologue of the left hemispheric (and strongly linguistic) sense of self into awareness. Within an optimal experimental setting, women reported more frequent experiences of a sensed presence than did men, and men were more likely than women to consider these experiences as "intrusions" from extrapersonal or ego-alien sources. Both effects were predicted by the vectorial hemisphericity hypothesis and the known neurocognitive differences between right-handed men and right-handed women. Sociobiological implications for gender differences in the probability of intercalation between distinctive processes within the left and right temporoparietal lobes are discussed.     

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.     

Experimental simulation of a haunt experience and elicitation of paroxysmal electroencephalographic activity by transcerebral complex magnetic fields: induction of a synthetic "ghost"?

To test the hypothesis that experiences of apparitional phenomena with accompanying fear can be simulated within the laboratory, a 45-yr.-old journalist and professional musician who had experienced a classic haunt four years previously was exposed to 1 microTesla, complex, transcerebral magnetic fields. Within 10 min. after exposure to a frequency-modulated pattern applied over the right hemisphere, the man reported "rushes of fear" that culminated in the experience of an apparition. Concurrent electroencephalographic measurements showed conspicuous 1-sec.-to-2-sec. paroxysmal complex spikes (15 Hz) that accompanied the reports of fear. A second magnetic field pattern, applied bilaterally through the brain, was associated with pleasant experiences. The subject concluded that the synthetic experience of the apparition was very similar to the one experienced in the natural setting. The results of this experiment suggest that controlled simulation of these pervasive phenomena within the laboratory is possible and that this experimental protocol may help discern the physical stimuli that evoke their occurrence in nature.     

The cortical representation of centrally presented words: A magnetic stimulation study

The right and left visual fields each project to the contralateral cerebral hemispheres. The current study aimed to investigate the extent of the functional overlap of the two hemifields along the vertical meridian. We applied repetitive transcranial magnetic stimulation (rTMS) over the left and right occipital cortex to investigate whether the foveal representation of words is bilaterally represented or is split between the two hemispheres. Employing a lateralized lexical decision task, we first showed a double dissociation between the stimulated cortical site and performance; right visual field (RVF) but not left visual field (LVF) performance was impaired when the left visual cortex was stimulated, and LVF but not RVF performance was impairred when the right visual cortex was stimulated. Unilateral stimulation also significantly impaired lexical decision latencies to centrally presented words. These findings support the suggestion that foveal representation of words is split. We discuss future strategies for the use of TMS in further tests of the split representation account.     

Conditions of visual verbal extinction: does the ipsilesional stimulus have to be identified?

Six left-neglect patients were presented with four-letter words in the left and/or right hemifield, in different contextual conditions: unilateral, bilateral-x in which one word appears on one side and a string of "x" appears on the other side (the side of "x' was not predictable), and bilateral-word (presentation of one word in each hemifield). In Experiment 1, left extinction occurred even if the right stimulus was an easily discriminable string of "x." Experiment 2 showed that increasing the size of the left stimuli reduced extinction when a string of "x" was presented on the right hemifield. However, extinction was stronger with bilateral-word presentation. These results indicate the presence of an early component in the extinction phenomenon, i.e., a "magnetic" attraction toward the ipsilesional hemifield, but are also in favor of some additional deficit, at a later stage of information processing.     

Left ear (right temporal lobe) suppressions during dichotic listening, ego-alien intrusion experiences and spiritualistic beliefs in normal women.

Beliefs in spiritualism, a history of a sensed presence, and mental diplopia may share a common source of psychometric variance. We hypothesized that this variance should be specifically associated with right temporal-lobe function. Inferences of temporal lobe signs, hemisphericity (Vingiano's quotient) and self-esteem as well as dichotic listening measures were obtained for 26 university women. As predicted, the numbers of left-ear suppressions (right temporal-lobe function) but not of right-ear suppressions were specifically and moderately (rho = 0.64) correlated with the intensity of Tobacyk's spiritualistic beliefs and a history of sensed presences and ego-alien intrusions. However, the negative association (rhos about -0.45) between indices of left-right hemisphericity and self-esteem was related to a separate factor.     

Selective spatial attention and length representation in normal subjects and in patients with unilateral spatial neglect

The aim of this study was to assess whether perceptual representation along the horizontal axis is affected by hemispace position of the stimulus or by orienting attention to one side. Ten control subjects and 10 right brain damaged patients with left unilateral spatial neglect (USN) were asked to bisect lines of five lengths in three space positions (left, center, right) and under three cueing conditions (no cue, left cue, right cue). Normal controls showed significant displacement of bisection opposite to the side of hemispace presentation and toward the side of cueing. USN patients showed a bisection error toward the right end which increased with lines placed in the left hemispace and decreased with lines placed in the right hemispace and when attention was oriented toward the left side. We conclude that (1) In absence of cues normal subjects tend to overestimate the portions of space closer to their body midline; (2) both normal and USN patients tend to overestimate portions of space that they direct their attention to; (3) USN patients' performance without cueing is consistent with an attentional shift toward the right hemispace implying a gradient of overestimation of the right-most portions of space. A common neural substratum for directing attention and space representation can explain these findings.     

Increased analgesia to thermal stimuli in rats after brief exposures to complex pulsed 1 microTesla magnetic fields

Nociceptive thresholds to a 55 degrees C hot surface were measured for female Wistar rats before treatments and 30 min. and 60 min. after the treatments. After injection with either naloxone or saline following baseline measurements, the rats were exposed for 30 min. to either sham fields or to weak (about 1 microTesla) burst-firing magnetic fields composed of 230 points (4 msec. per point) presented once every 3 sec. The rats that had received the burst-firing magnetic fields exhibited elevated nociceptive thresholds that explained about 50% of the variance. A second pattern, designed after the behaviour of individual thalamic neurons during nociceptive input and called the "activity rhythm magnetic field" produced only a transient analgesic effect. These results replicated previous studies and suggest that weak, extremely low frequency, pulsed magnetic fields with biorelevant temporal structures may have utility as adjuncts for treatment of pain.     

Is Happy Facial Expression Identified by the Left or Right Hemisphere？

1IntroductionCorrectly identifying other people′s facial ex-pressions of emotions is important to human socialinteraction in all societies.Many studies suggestthat the identification of facial expressions in par-ticular and perceptual processing of emotional infor-mation is carried out mainly by the right hemi-sphere of the brain[1￣7].Damage to the righthemisphere generally produces more significant im-pairment in recognition of all facial expressions ofemotion than damage to the left hemisp…     

大脑两半球与整体和局部性质的选择性加工

研究大脑两半球在加工整体和局部性质中的优势以及两半球能否同时分别选择两个复合刺激的整体和局部性质。实验中把一个复合字母随机呈现在左视野或右视野,或者把两个复合字母同时分别呈现在左视野和右视野。实验一发现,在单侧呈现条件下,被试检测左右视野的整体或局部靶目标的反应时没有显著差别,但在双侧同时呈现条件下,检测右视野局部靶目标比检测左视野局部靶目标时的反应时短。实验二要求被试检测同时呈现在左右视野的整体或局部靶目标,发现当两个视野的靶目标处于同一水平时(整体或局部)反应时较短,两个视野的靶目标处于不同水平时(一侧处于整体水平而另一侧处于局部水平)反应时较长。这些结果提示,当两个复合刺激同时呈现在左右视野时,大脑左半球在选择性加工局部性质时具有优势;左右两半球更容易选择两个复合刺激同一个水平的性质,分别选择两个复合刺激不同水平的性质比较困难。     

Interhemispheric interaction when both hemispheres have access to the same stimulus information

Right-handed Ss identified consonant-vowel-consonant (CVC) nonsense syllables presented tachistoscopically. The CVC on each trial was presented to the left visual field-right hemisphere (LVF-RH), to the right visual field-left hemisphere (RVF-LH), or the same CVC was presented to both visual fields (bilateral presentation). When recognition was incorrect, the pattern of errors was qualitatively different on LVF-RH and RVF-LH trials, suggesting that each cerebral hemisphere has its own preferred mode of processing the CVC stimuli. The qualitative pattern of errors on bilateral trials was identical to that obtained on LVF-RH trials. The bilateral results are described well by a model that assumes the mode of processing characteristic of the RH dominates on bilateral trials but is applied to both the LVF-RH and RVF-LH stimuli.     

Tuning of human vestibulospinal reflexes by leg rotation

Changing the foot position modifies the mechanical action exerted by the ankle extensor and flexor muscles over the body. We verified, in two groups of healthy subjects standing with the heels touching or apart, whether a 90° external rotation of the right leg and foot also changes the pattern of vestibulospinal reflexes elicited by electrical stimulation of the labyrinth. With the head oriented forward, leg rotation did not modify the labyrinthine-driven displacements of the center of pressure (CoP). When the head was rotated in the horizontal plane, either to the right or to the left, the CoP displacement increased along the y axis in all subjects. Changes in the x component in most instances appropriate to preserve unmodified the direction of body sway elicited by the stimulus were observed. Right leg rotation increased the basal EMG activity of ankle extensors and flexors on the left side, while the right side activity was unaffected. The EMG responses to labyrinthine stimulation were modified only on the left side, in a way appropriate to correct the effects of the altered torque pattern exerted on the body by right leg muscles. It appears, therefore, that somatosensory signals related to leg rotation and/or copy of the corresponding voluntary motor commands modify the pattern of vestibulospinal reflexes and maintain the postural response appropriate to counteract a body sway in the direction inferred by labyrinthine signals.     

Right hemisphere sensitivity to word- and sentence-level context: evidence from event-related brain potentials

Researchers using lateralized stimuli have suggested that the left hemisphere is sensitive to sentence-level context, whereas the right hemisphere (RH) primarily processes word-level meaning. The authors investigated this message-blind RH model by measuring associative priming with event-related brain potentials (ERPs). For word pairs in isolation, associated words elicited more positive ERPs than unassociated words with similar magnitudes and onset latencies in both visual fields. Embedded in sentences, these same pairs showed large sentential context effects in both fields. Small effects of association were observed, confined to incongruous sentences after right visual hemifield presentation but present for both congruous and incongruous sentences after left visual hemifield presentation. Results do not support the message-blind RH model but do suggest hemispheric asymmetries in the use of word and sentence context during real-time processing.     

Visual exploration of reaching space during left and right arm movements in 6-month-old infants

Infant's manual laterality and eye-hand coordination emerge during the second part of the first year of life with the development of reaching. Nevertheless, little is known about the potential asymmetric characteristics of this coordination. The aim of this study was to describe visuo-spatial exploration in 6-month-old infants during reaching, according to the hand used. More specifically, we examined if the use of the left or the right hand was linked to a specific type of visual exploration. Gaze direction during goal-directed reaching towards an object placed on the table was measured with a remote ASL 504 eye tracker (Bedford MA). Twelve babies aged 6 months were observed during six reaching sessions, alterning three sessions with an object on the left side of the subject and three with an object on the right side. Gaze direction and some hand variables (hand activity, hand opening and hand position from the body) were coded with The Observer software. Results showed that babies visually explore their reaching space differently according to the hand used: they look more at the object when they use their right hand and more around the object when they use their left hand; they also look more often at their left hand than at their right one. These results suggest that an asymmetric visuo-manual coordination exists as early as 6 months: vision seems to support (1) left hand during reaching for evaluate distances from object to baby by means of visual feedbacks and (2) right hand for identify what sort of object is. Results are discussed in light of manual specialization and specific hemispheric skills at this age.