The Effects of Exam-Induced Stress on EEG Profiles and Memory Scores.

Common stressors amongst postsecondary students are exam-induced anxiety and stress. The purpose of this study was to measure stress alterations in the student population around examinations and determine how they affect electroencephalogram (EEG) profiles and memory scores. Twenty university students were measured multiple times in the study. During each measurement, participants were administered a cortisol saliva test and an EEG. We hypothesized that cortisol levels, memory scores, and EEG profiles would all demonstrate changes near examinations. The brain regions of interest (ROIs) were the parahippocampal gyrus, the medial frontal gyrus, and the middle frontal gyrus. Results demonstrated that memory performance and parahippocampal activity were correlated, specifically in the 5-9 Hz frequency band. Correlations were also computed between cortisol levels, memory performance, and parahippocampal activity. The medial frontal gyrus also displayed changes in the mean (19-20 Hz) current source density (CSD) throughout the experiment. The middle frontal gyrus activation was highly variable during the different measurement time points. Essentially, when an individual's memory scores were consistent between exam and nonexam trials, there was an increase in middle frontal gyrus activation during examination periods. Lastly, the right parahippocampal gyrus was found to be the most activated one day away from examination time. These results indicate that memory scores are related to cortisol levels and examination periods, but most importantly, there are overt and predictable alterations in student EEG profiles near examinations.

The impact of emotionally valenced music on emotional state and EEG profile: Convergence of self-report and quantitative data.

Musical stimuli can induce a variety of emotions in individuals. We sought to determine whether different valenced music would induce EEG profile changes and self-reported emotional states in individuals following the viewing of a complex video with a concrete narrative and emotional ambivalence. We used a five-minute video titled "El Empleo", coupled with either joyful, fearful, or no music. EEG recordings were taken throughout the duration of the experiment and a self-reported questionnaire on emotional state was administered after viewing of the video. We found self-reported measures of happiness increased following viewing of the video paired with joyful music, while EEG data demonstrated that the following brain regions displayed significant changes in activity following both fearful and joyful music: the right inferior parietal lobule, left uncus, and left insula. Additionally, we found that anxiety self-report scores correlated negatively with average gamma activity within the insula within each group. The convergence of self-reported data and quantitative EEG data was consistent across 27 participants. These data indicate that different valenced music can alter EEG activity in emotion specific regions, reflected in participants perceived emotional state.

Similar Spectral Power Densities Within the Schumann Resonance and a Large Population of Quantitative Electroencephalographic Profiles: Supportive Evidence for Koenig and Pobachenko.

In 1954 and 1960 Koenig and his colleagues described the remarkable similarities of spectral power density profiles and patterns between the earth-ionosphere resonance and human brain activity which also share magnitudes for both electric field (mV/m) and magnetic field (pT) components. In 2006 Pobachenko and colleagues reported real time coherence between variations in the Schumann and brain activity spectra within the 6-16 Hz band for a small sample. We examined the ratios of the average potential differences (~3 µV) obtained by whole brain quantitative electroencephalography (QEEG) between rostral-caudal and left-right (hemispheric) comparisons of 238 measurements from 184 individuals over a 3.5 year period. Spectral densities for the rostral-caudal axis revealed a powerful peak at 10.25 Hz while the left-right peak was 1.95 Hz with beat-differences of ~7.5 to 8 Hz. When global cerebral measures were employed, the first (7-8 Hz), second (13-14 Hz) and third (19-20 Hz) harmonics of the Schumann resonances were discernable in averaged QEEG profiles in some but not all participants. The intensity of the endogenous Schumann resonance was related to the 'best-of-fitness' of the traditional 4-class microstate model. Additional measurements demonstrated real-time coherence for durations approximating microstates in spectral power density variations between Schumann frequencies measured in Sudbury, Canada and Cumiana, Italy with the QEEGs of local subjects. Our results confirm the measurements reported by earlier researchers that demonstrated unexpected similarities in the spectral patterns and strengths of electromagnetic fields generated by the human brain and the earth-ionospheric cavity.

LORETA indicates frequency-specific suppressions of current sources within the cerebrums of blindfolded subjects from patterns of blue light flashes applied over the skull.

An array of eight cloistered (completely covered) 470-nm LEDs was attached to the right caudal scalp of subjects while each sat blindfolded within a darkened chamber. The LEDs were activated by a computer-generated complex (frequency-modulated) temporal pattern that, when applied as weak magnetic fields, has elicited sensed presences and changes in LORETA (low-resolution electromagnetic tomography) configurations. Serial 5-min on to 5-min off presentations of the blue light (10,000lx) resulted in suppression of gamma activity within the right cuneus (including the extrastriate area), beta activity within the left angular and right superior temporal regions, and alpha power within the right parahippocampal region. The effect required about 5min to emerge followed by a transient asymptote for about 15 to 20min when diminished current source density was evident even during no light conditions. Subjective experiences, as measured by our standard exit questionnaire, reflected sensations similar to those reported when the pattern was presented as a weak magnetic field. Given previous evidence that photon flux density of this magnitude can penetrate the skull, these results suggest that properly configured LEDs that generate physiologically patterned light sequences might be employed as noninvasive methods to explore the dynamic characteristics of cerebral activity in epileptic and nonepileptic brains.

Greater electroencephalographic coherence between left and right temporal lobe structures during increased geomagnetic activity.

Interhemispheric coherence for 19 channel EEG activity collected over a three year period from 184 men and women who relaxed in a quiet, darkened chamber showed significant increased coherence between caudal temporal regions for the 11 Hz frequency band during increased (>∼8 nT) global geomagnetic activity at the time of measurement. Detailed analyses from source-localization indicated that a likely origin was the parahippocampal regions whose net differences at 10, 11 and 12 Hz intervals were significantly correlated with geomagnetic activity. Analyses of residuals to obtain a "purer" measure of parahippocampal contributions indicated that interhemispheric temporal lobe coherence across unit increments between 1 and 40 Hz revealed the most statistically significant peaks at 7.5 Hz and 19.5 Hz. These weak but reliable correlations between global geomagnetic activity and the degree of inter-temporal lobe coherence for normal people relaxing in a dark, quiet area are consistent with the results of multiple studies indicating that intrusive experiences such as "presences" or "hallucinations" are more frequent when global geomagnetic activity increases above ∼15-20 nT.

Potential production of Hughlings Jackson's "parasitic consciousness" by physiologically-patterned weak transcerebral magnetic fields: QEEG and source localization.

Exotic experiences such as the sensing of another consciousness or the detachment of consciousness from the body are occasionally reported by individuals with partial seizures from a temporal lobe focus. The experiences display the characteristics of Hughlings Jackson's "parasitic consciousness". We have hypothesized that these experiences are encouraged by slight discrepancies in hemispheric activity that can be simulated by application of weak, physiologically-patterned magnetic fields across the cerebral hemispheres. Electroencephalographic and Low Resolution Electromagnetic Tomography (sLORETA) data revealed altered activity bands within specific regions within the cerebral cortices during these experiences. The clear changes in power of brain activity were discerned after consistent durations of exposure to specifically patterned weak magnetic fields. Millisecond range point durations were required. The technology may be useful to explore the subjective components associated with complex partial seizures.

Comparable proportions of classes of experiences and intracerebral consequences for surgical stimulation and external application of weak magnetic field patterns: implications for converging effects in complex partial seizures.

The similarity of the proportions of different types of experiences reported during surgical electrical stimulation of epileptic temporal lobes published in the scientific literature and those reported following exposures to weak, applied magnetic fields was supported by direct comparisons in a retrospective analysis. Of the 20 types of specific experiences, the surgical stimulation groups reported proportionally more fear experiences, while the groups exposed to temporally patterned magnetic fields applied across the temporoparietal regions reported more somesthetic and vestibular experiences. There were no group differences for the other 17 types of experiences. Calculations indicated that the spread of charge displacement from neuronal membranes by the currents employed in the surgical studies and the magnetic field energy associated with the applied fields could affect similar numbers of cortical neurons. The similar subjective experiences of the two techniques indicate that the less invasive procedures might be employed to systematically study complex partial seizures.

Protracted parahippocampal activity associated with Sean Harribance.

AIMS: Previous research published by Venkatasubramanian et al. (2008) in this journal showed markedly enhanced functional magnetic resonance imaging (fMRI) activity within the right parahippocampal region of a gifted person while he experienced accurate telepathic impression. The present research is designed to discern if Sean Harribance, a reliable psychic who reported independently verified accurate histories of others during his intuitive state, would also show similar enhancement as measured by standardized low resolution electromagnetic tomography (sLORETA). MATERIALS AND METHODS AND RESULTS: The raw data from the unique electroencephalographic pattern displayed by Sean Harribance (the Harribance configuration) during his intuitive state revealed a peak increase of power within the upper beta range (20-30 Hz) within the right parahippocampal region only. CONCLUSIONS: The congruence of the region of activation during "telepathy" by Sean Harribance and Gerard Senehi, especially when the specific electromagnetic and cellular characteristics are considered, suggests the parahippocampal region may be a focus for exploration of the mechanisms by which these phenomena might occur.

Case report: a prototypical experience of 'poltergeist' activity, conspicuous quantitative electroencephalographic patterns, and sLORETA profiles - suggestions for intervention.

People who report objects moving in their presence, unusual sounds, glows around other people, and multiple sensed presences but do not meet the criteria for psychiatric disorders have been shown to exhibit electrical anomalies over the right temporal lobes. This article reports the striking quantitative electroencephalography, sLORETA results, and experimental elicitation of similar subjective experiences in a middle-aged woman who has been distressed by these classic phenomena that began after a head injury. She exhibited a chronic electrical anomaly over the right temporoinsular region. The rotation of a small pinwheel near her while she 'concentrated' upon it was associated with increased coherence between the left and right temporal lobes and concurrent activation of the left prefrontal region. The occurrence of the unusual phenomena and marked 'sadness' was associated with increased geomagnetic activity; she reported a similar mood when these variations were simulated experimentally. Our quantitative measurements suggest people displaying these experiences and possible anomalous energies can be viewed clinically and potentially treated.