Quantitative EEG Changes in Patients with Parkinson’s Disease during Therapy with Rasagiline

It has been suggested that in patients with Parkinson’s disease (PD) metabolism of the MAO-B inhibitor selegiline to methamphetamine may contribute and/or exacerbate sleep problems, possibly leading to deficits of cognition. This open-label exploratory study included 30 PD patients currently being treated with selegiline (7.5 mg/day) and complaining of sleep disturbances. The aim of the study was to determine whether switching from selegiline to another MAO-B inhibitor without amphetamine-like metabolites, namely rasagiline, would improve sleep behaviour and cognitive function in PD patients. Pathologic aberrations as determined by comparison of the frequency pattern of patients to a database consisting of healthy subjects revealed an approximation of electric brain activity to normality. For verification of efficacy, a combination of questionnaires, quantitative source density EEG recording with CATEEMò and performance of two psychometric tasks (d2-test of attention and reading) during the EEG recording were done on the last day of selegiline treatment (7.5 mg/day) as well as 2 and 4 months later, during which the patients were treated with rasagiline (1 mg/day). In addition, performance of the mental tasks revealed a statistically significant (p < 0.05) increase of theta power (4.75 - 6.75 Hz) indicative of improved cognitive abilities at the end of the treatment period. At the same time evaluation of the psychometric test results indicated a statistical improvement with respect to the score of the d2-test (increase from 6.54 to 7.37;p < 0.05). Serum levels of methamphetamine were measured before and after intake of selegiline or rasagiline. They were correlated to alpha2 power, which is under dopaminergic control, within the temporal lobe. From these results it is concluded that the switch from selegiline to rasagiline not only improved sleep behaviour as reported separately but also had a positive effect on electric brain activity and on cognition in these patients.

Prejudgments for Reference Potential Determination to Quantitative EEG Interpretation:Amplitude Distribution and Ear-lobe Activation

This paper presents an automatic techruque of suitable reference potential selection for quantitative EEG interpretation.The 16-channels EEG recording under mono-polar derivation is analyzed.There are two prejudgments defined for checking the amplitude distribution and ear lobe activation.After prejudgments,the EEG is classified into several cases in cluding diffused case,non-diffused case,and artifact contami nation case.Due to the cases,an automatic reference selection method is applied in order to find out suitable reference potential.Finally,the referential derivation constructed according to the obtained reference potential,is evaluated for further EEG rhythm analysis.The presented technique can high light the EEG rhythm of interest,which is useful for quantitative EEG interpretation by both visual inspection and automatic evaluation.

EnkephaloVision: Anatomical Functionality Indicated by Ultrashort Transient Regional EEG Spectral Power Changes during Cognitive and Emotional Challenges

Anatomical functionality is a major topic in brain research. Numerous investigations have shown task dependent activation of focal brain areas, with most information based on time-averaged data due to methodological limitations. Ultra-fast quantitative EEG, especially in the newly developed combination with eye tracking (EnkephaloVision), is very suitable to follow activities of local electric circuits. This investigation in 57 subjects revealed transient focal frequency changes reaching up to more than 6000% of global median spectra power during cognitive and emotional challenges at frontal electrode positions. Recording epochs of 364 ms uncovered coherences with respect to focal brain areas and single frequencies, which are typically lost during averaged calculations. When averaging data over a whole scene, a least demanding challenge like viewing a boring animal video only activated the lateral frontal lobe, whereas solving brain-teasers and performance of mathematical calculations led to delta (modulated by acetylcholine) and theta (modulated by norepinephrine) increases in all brain regions in a statistically significant manner. In addition to delta and theta increases, performance of the Stroop test led to beta2 (related to GABA-ergic transmission) increases in the temporal lobe. The higher the mental demand the more brain regions were involved during 10 different challenges. There was no challenge which did not activate the lateral frontal brain in terms of increases of delta and theta spectral power. The results are in line with the view that the lateral frontal lobe is involved primarily during cognitive and emotional behavior related to activity changes of acetylcholine and norepinephrine.

Neuromarketing: Neurocode-Tracking in Combination with Eye-Tracking for Quantitative Objective Assessment of TV Commercials

The term “neuromarketing” suggests a combination of marketing research and brain research. Within marketing research, objective assessment of TV commercials is performed by use of Eye-Tracking devices. Brain research has been dominated by NMRI technologies during the last years. However, information content and time resolution are much better when monitoring electric activity by spectral analysis. The current experimental approach was initiated in order to test the combination of a newly developed EEG technology (Neurocode-Tracking) with commercially available Eye-Tracking. Ten male subjects were exposed to a reference recording condition (watching a fixed cross on the screen) followed by 5 TV commercials representing 5 different banks. Video films obtained from Eye-Tracking (so-called heat maps) were synchronized with the results of Neurocode-Tracking in form of a second video with a time resolution of 364 ms per image. Spectral power analysis of the EEG in different brain regions allowed for assessment of single scenes for cognitive and emotional responses. Averaging of data over the whole time course gave information on mental activation, attention, visual perception, memory, pleasure and tension. Comparison of the 5 commercials to reference recording revealed the clip of the Targo-Bank having the highest values with respect to mental activation and attention.These experiments have proven that the combination of Neurocode-Tracking with Eye-Tracking can be successfully used in advertisement research and gives valid information on individual as well as group dependent cognitive and emotional responses leading to objective assessment of TV commercials.

Lagged Coherence of Photon Emissions and Spectral Power Densities between the Cerebral Hemispheres of Human Subjects during Rest Conditions: Phase Shift and Quantum Possibilities

Photon counts about 15 cm from the left and right sides of the head while subjects sat quietly during baseline conditions within a hyper-dark chamber were measured by photomultiplier units. Lag/lead analyses for photon emissions between the two hemispheres indicated a weak but statistically significant correlation between the amplitude fluctuations that were separated by about 800 to 900 ms. Analyses of the spectral power densities of photon amplitude variations from the left and right hemispheres revealed peak values between 2 and 3 Hz which were equivalent to a difference of about 900 ms. The radiant flux densities were estimated to be in the order of 10?12 W?m?2 and to include the equivalence of about 107 neurons. Our calculations, which accounted for the small magnitude of the strength of the interhemispheric coefficients, suggest that the coherence could be strongly correlated with processes associated with the unmyelinated axons with diameters between 400 to 800 nm, the visible wavelengths, within the corpus callosum. When the ratio of the phase shift was applied to the Aharanov-Bohm equation, the time required for a photon-related electron to be within a cerebral magnetic field was the same duration as a single orbit of an electron and a photon’s traversal latency across a neuronal plasma membrane. We suggest that the peak photon decoherence between the two cerebral hemispheres may reveal a neuronal-quanta substrate to the conditions associated with consciousness.