Brain Electrical Activity

An integration of Heller's model of brain activity based on the affect circumplex and findings from personality research resulted in predictions for patterns of frontal and posterior EEG alpha related to basic dimensions of personality, extraversion and neuroticism (Heller, 1990, 1993). Extraversion was predicted to be associated with greater relative left frontal and increased right posterior region activity, and introversion with greater relative right frontal and decreased right posterior region activity. Neuroticism was predicted to be associated with greater relative right frontal and increased right posterior region activity, and emotional stability with greater relative left frontal and decreased right posterior activity. Measures of extraversion and neuroticism were collected, and resting EEG was recorded for males and females on one occasion for eight 60-s periods. As predicted, neuroticism was associated with greater relative right posterior activity. Predicted effects for neuroticism with frontal regions and for extraversion with brain activity were not significant. Results partially support the model of brain activity and affect proposed by Heller (1990, 1993), and suggest that it may be extended to include basic dimensions of personality such as neuroticism.

Research was carried out in collaboration with the Head and Neck Department and the
Clinical Neurophysiological Unit at the University of Trieste (Italy) to assess the effects of resonance
phenomena on the human body. We worked with volunteers who underwent examination by EEG while
listening to tones between 90Hz and 120Hz, similar to the resonant sounds found at some Neolithic
structures in Europe (England, Ireland, Italy, Malta). As in the study by Ian Cook at the University of
California (UCLA, 2008), all of our volunteers were subjected to a "comfortable" volume of sound whilst
in the absorbing sound room. This is used for audiometric tests at the Otorhinolaryngology Clinic and
has been modified with suitable software and hardware. This type of room is also protected by a Faraday
cage to shield from any possible external electromagnetic interference that could affect the results. After
two minutes of silence to evaluate the resting brain rhythm, the volunteers were subjected to the tones of
90, 95, 100, 105, 110, 115, 120Hz arranged in a random way for one minute each. At the end of every
cycle they listened to a mantra of the same frequency for a period of two minutes. Technicians examined
the EEGs to verify the data collected. They found there was a prevalence of frontal areas or occipital
(posterior) areas with no predominance of one cerebral hemisphere (left of right) over the other during
playing. Each volunteer had a different sensitivity to all the tones without one tone prevailing (i.e.
110Hz), with each exhibiting a strong response to a subjective and personal tone (90Hz, 105Hz, 120Hz
...).

The aim of the present work is to evaluate the effect of caffeine, the world’s most popular psychoactive drug, on the electric activity of the rat’s brain that exposed to extremely low-frequency magnetic field (ELF-MF), during 15 days. The obtained results showed that administration of caffeine in a group of rats by dose of 10 mg/kg (equivalent to human daily consumption) caused a reduction in the mean power amplitude of electroencephalogram (EEG) trace for almost all frequency bands especially α (8–12 Hz). It was observed that the influence of caffeine was more evident in motor cortex than in visual cortex. While the exposure of another group to ELF-MF of intensity 0.2 mT during the same period caused an enhancement in the mean power amplitude of most EEG frequency bands; this was more observed in the right hemisphere of the brain than that of the left hemisphere. The administration of caffeine while rats were exposed to ELF-MF, led, after 5 days of exposure, to a great increase in the mean power amplitude of α band at all places of recording electrodes. It may be concluded that caffeine administration was more effective in reducing the hazardous of ELF-MF in motor cortex than in visual cortex.

The EKG Glove is a wearable glove-based device on which all the necessary electrodes are pre-positioned hence the patient simply inserts his right hand into the glove and properly position the glove his chest to record a standard ECG. It is the first, lead wire free, simultaneous, and fully diagnostic ECG recording system in Pakistan with easy, natural and almost automatic placement of the electrodes, hence eliminating the difficulty of lead wire entanglement and electrode misplacement.

The processes giving rise to an event related potential engage several evoked and induced oscillatory components, which reflect phase or non-phase locked activity throughout the multiple trials. The separation and identification of such components could not only serve diagnostic purposes, but also facilitate the design of brain-computer interface systems. However, the effective analysis of components is hindered by many factors including the complexity of the EEG signal and its variation over the trials. In this paper we study several measures for the identification of the nature of independent components and address the means for efficient decomposition of the rich information content embedded in the multi-channel EEG recordings associated with the multiple trials of an event-related experiment. The efficiency of the proposed methodology is demonstrated through simulated and real experiments.

Abstract—This paper presents an implementation of an effective synchronization between a registration and a stimulation module that form part of a steady state visual evoked potential (SSVEP)-based Brain Computer Interface (BCI). Each of the synchronized modules were created and designed in two different platforms as well as in two different workstations, so a particular objective of this work consisted in finding the best platforms to stimulate and register the EEG in order to create a communication channel and protocol between the ...

ABSTRACT Purpose: Habitually when pattern shift visual evoked potentials (PSVEP) are conducted on a patient for suspicion of a neurological disorder, the P100 latency is the factor that plays the dominant role in determining whether the test is normal. Traditionally the amplitude of the response is not given much consideration. Patients with normal PSVEPs would be diagnosed as normal if only latencies are considered. We asked the question “Can normal P100 latencies with abnormalities in the interocular amplitudes signify for an abnormality in the brain?” Method: 24/587 PSVEPs of patients were found with P100 latencies that were within normal limits, but the interocular N75-P100 amplitude difference was 50% or more. Brain MRIs concurrent with the time of testing were also looked at for lesions and compared. 5 of the 24 studies were omitted due to the absence of patient history or brain MRI. The age range of the patients was 14 to 68 with a mean average age of 34 years. There were 13 females and 6 males. Monocular PSVEPs were done using 1” checks at a distance of 1 meter and at an average of approximately 100 stimulations. Results: Of the 19 studies 15 had positive brain MRIs for demyelinating lesions, 1 was positive for atrophy, and 3 were negative for lesions. Patient Diagnosis VEP side with reduced amplitude MRI abnormalities AY MS Right Bil WMLs and CC KS MS Right Bil WMLs and CC HM MS Right Bil WMLs and CC LP MS Right Bil WMLs (R>L) MA MS Right Bil WMLs, rt occ. lobe and CS PC MS Right Bil WMLs and rt occ. lobe PC MS Left Left temporal PP MS Right Bil WMLs and CC DA ISP Right Occ. horns, CC and lt frontal lobe IC Unspec.Demyel. Right Brainstem KM Sturge-Weber Right Rt hemisphere PD E Left Rt hippocampal atrophy PN E Left WMLs TA NF-I Right Rt thalamus and frontal TE Diabetes/Vascular Left Lt temporal WMLs TN Lupus Right Prominence of optic nerve sheaths PY Unspec. Demyel. Right Negative PM Unspec. Demyel. Left Negative MK Idiop. Myelitis Right Negative Figure 1: Of the 15 positive MRI cases 4 were concordant with the side of the lower amplitude of the PSVEP. 10 cases had multiple and bilateral lesions. (CC= Corpus Callosum, CS=Centrum Semiovale, E=Epilepsy, ISP=Idiopathic Spastic Paraparesis, MS=Multiple Sclerosis, NF-I=Neurofibromatosis Type I, WML=White Matter Lesion) On average, the interocular N75-P100 amplitude difference was at 61%. Figure 2: Difference in interocular amplitudes with normal latencies Conclusion: Customarily the classical impression of a normal PSVEP would not lead to a definite diagnosis. This study indicates that the difference in PSVEP interocular N75-P100 amplitudes can signify for an abnormality in the brain even if the P100 latencies are within normal limits. Furthermore, brain imaging should be done when a N75-P100 interocular amplitude difference is observed. Due to the small number of patients we could not delineate the lesion involved in the difference in amplitudes and further studies are necessary to evaluate these findings. References: 1. Hood DC et al. An interocular comparison of the multifocal VEP: a possible technique for detecting local damage to the optic nerve. Invest Opthalmol Vis Sci. 2000 May; 41(6):1580-7. 2. Katsumi O et al. Pattern reversal VERas a tool for evaluating unbalanced visual inputs between the two eyes. Jpn J Opthalmol. 1988;32(1):86-97. 3. Shahrokhi F et al. Pattern shift visual evoked responses. Two hundred patients with optic neuritis and/or multiple sclerosis. Arch Neurol. 1978 Feb;35(2):65-71.

Research was carried out in collaboration with the Head and Neck Department and the Clinical Neurophysiological Unit at the University of Trieste (Italy) to assess the effects of resonance phenomena on the human body. We worked with volunteers who underwent examination by EEG while listening to tones between 90Hz and 120Hz, similar to the resonant sounds found at some Neolithic structures in Europe (England, Ireland, Italy, Malta). As in the study by Ian Cook at the University of California (UCLA, 2008), all of our volunteers were subjected to a "comfortable" volume of sound whilst in the absorbing sound room. This is used for audiometric tests at the Otorhinolaryngology Clinic and has has been modified with suitable software and hardware. This type of room is also protected by a Faraday cage to shield from any possible external electromagnetic interference that could affect the results. After two minutes of silence to evaluate the resting brain rhythm, the volunteers were...