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

Karbowski, Lukasz M.; Saroka, Kevin S.; Murugan, Nirosha J.; Persinger, Michael A.

doi:10.1016/j.yebeh.2015.06.039

Cited by 3 publications

(2 citation statements)

References 29 publications

(36 reference statements)

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“…FOP induction was achieved through LED stimulation (Karbowski, Saroka, Murugan, & Persinger, 2015), robotic mechanism (Blanke et al, 2014), and mainly with DPP protocols. FOP experience is not specifically relevant to typical dreams.…”

Section: Discussionmentioning

confidence: 99%

Analysis of the empirical research on the feeling of presence.

Roballo

Delgado

2019

Dreaming

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The feeling of presence consists of the feeling that another person or entity is detected near the extrapersonal space without any clear sensory evidence. Its symptoms include visual hallucinations and wrong coding of sensorial input. The phenomenon is sometimes present in pathologies such as sleep paralysis or neurodegenerative diseases, but it can also be found in healthy subjects. It has been associated with folk beliefs, but there is now enough evidence of its brain basis. A total of 72 studies from Web of Science and Scopus were analyzed considering 12 classificatory variables that were constructed bottom-up. Prevalence of neurodegenerative disease was higher for males, whereas sleep paralysis was prevalent for females. Twenty-one studies included participants with multiple pathologies. The episodes were generally associated to fear and anxiety. Some structural and functional alterations were found in neuroimaging case studies. Scale validation studies were scarce, usually showing scores with good psychometric properties. Diverse scales comprised different dimensions according to their objectives. Feeling of presence is a neuropsychological phenomenon, as failures in perception and self-concept are due to brain electric maladjustment. Evidence corroborates that mismatches are localized in cortical areas such as the temporal-parietal or insular cortex, as well as in subcortical areas, such as the hippocampus. The phenomenon main characteristics, associated factors, and measurement scales vary according to the studied pathological entity. Given that most scales have not been validated, a more empirical approach that takes into account the variety of associated pathologies is needed.

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Section: Discussionmentioning

confidence: 99%

Analysis of the empirical research on the feeling of presence.

Roballo

Delgado

2019

Dreaming

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“…Thus, some of them have reported the evaluation of sLORETA technique for source estimation in presence of noise and is compared with minimum norm estimation and LORETA (Wagner, ), One of the study have compared sLORETA and exact LORETA for the source estimation (Jatoi, ), the brain connectivity is analysis is done in an article by using LORETA and sLORETA methods (Hassan, ). However, some of the studies have used LORETA for brain disorders studies such as in (Bachiller, ; Karbowski, ; Lizio, ) and in drug assessment (Alsono, ).…”

Section: Introductionmentioning

confidence: 99%

EEG‐based brain source localization using visual stimuli

Jatoi

Kamel

Malik

et al. 2016

Int J Imaging Syst Tech

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Electroencephalography (EEG) is widely used in variety of research and clinical applications which includes the localization of active brain sources. Brain source localization provides useful information to understand the brain's behavior and cognitive analysis. Various source localization algorithms have been developed to determine the exact locations of the active brain sources due to which electromagnetic activity is generated in brain. These algorithms are based on digital filtering, 3D imaging, array signal processing and Bayesian approaches. According to the spatial resolution provided, the algorithms are categorized as either low resolution methods or high resolution methods. In this research study, EEG data is collected by providing visual stimulus to healthy subjects. FDM is used for head modelling to solve forward problem. The low-resolution brain electromagnetic tomography (LORETA) and standardized LORETA (sLORETA) have been used as inverse modelling methods to localize the active regions in the brain during the stimulus provided. The results are produced in the form of MRI images. The tables are also provided to describe the intensity levels for estimated current level for the inverse methods used. The higher current value or intensity level shows the higher electromagnetic activity for a particular source at certain time instant. Thus, the results obtained demonstrate that standardized method which is based on second order Laplacian (sLORETA) in conjunction with finite difference method (FDM) as head modelling technique outperforms other methods in terms of source estimation as it has higher current level and thus, current density (J) for an area as compared to others.

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Objective and Subjective Characteristics of Vigilance under Different Narrow-Bandwidth Light Conditions: Do Shorter Wavelengths Have an Alertness-Enhancing Effect?

et al. 2019

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The aim of this study was to explore the effects of 20 min of narrow-bandwidth light exposure of different wavelengths (455, 508, and 629 nm, with irradiance of 14 µW/cm<sup>2</sup>) on various neuropsychological and neurophysiological parameters of vigilance in healthy volunteers and to provide further evidence of the behavioral (subjective sleepiness, reaction time) and electrophysiological (P300 and spectral characteristics) responses to light. The results show that the short-wavelength light condition (455 nm) was found to be most effective in terms of its alerting effect for the following variables: subjective sleepiness, latency of P300 response, and absolute EEG power in higher beta (24–34 Hz) and gamma (35–50 Hz) range at each of the 19 recording electrodes. However, no differences in current power density were observed at the level of cortical EEG sources estimated by exact low-resolution electromagnetic tomography. Our results are in line with other research that shows significant alerting effects of blue (short-wavelength) light in comparison to lights of longer wavelengths. Our results confirm earlier findings that exposure to short-wavelength light during the day may enhance cognitive performance in task-specific scenarios.

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

Cited by 3 publications

References 29 publications

Analysis of the empirical research on the feeling of presence.

Analysis of the empirical research on the feeling of presence.

EEG‐based brain source localization using visual stimuli

Objective and Subjective Characteristics of Vigilance under Different Narrow-Bandwidth Light Conditions: Do Shorter Wavelengths Have an Alertness-Enhancing Effect?

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