The association of age and aerobic activity history with 40-Hz EEG activity during cognitive challenge

1996 ◽  
Author(s):  
B. Hatfield ◽  
D. Santa Maria ◽  
T. Spalding ◽  
C. Blanchard ◽  
A. Haufler ◽  
...  
Keyword(s):  
Eeg Activity ◽  
Aerobic Activity ◽  
Cognitive Challenge ◽  
40 Hz

Cortical oscillations and temporal interactions in a computer simulation of piriform cortex

1992 ◽  
Vol 67 (4) ◽  
pp. 981-995 ◽  
Author(s):  
M. Wilson ◽  
J. M. Bower
Keyword(s):  
Large Scale ◽  
Activity Patterns ◽  
Piriform Cortex ◽  
Afferent Fiber ◽  
Field Potential ◽  
Afferent Input ◽  
Fiber System ◽  
Eeg Activity ◽  
Electrical Shocks ◽  
40 Hz

1. A large-scale computer model of the piriform cortex was constructed on the basis of the known anatomic and physiological organization of this region. 2. The oscillatory field potential and electroencephalographic (EEG) activity generated by the model was compared with actual physiological results. The model was able to produce patterns of activity similar to those recorded physiologically in response to both weak and strong electrical shocks to the afferent input. The model also generated activity patterns similar to EEGs recorded in behaving animals. 3. In addition to replicating known physiological responses, it has been possible to use the simulations to explore the interactions of network components that might underlie these responses. This analysis suggests that the physiological properties of the cortex are dependent on the complex interaction of both network and cellular properties. In particular, we have found that the relationship between conduction velocities in intrinsic cortical fiber systems and the time constants of excitatory and inhibitory effects are critical for replicating physiological results. 4. Analysis of the model also suggests a correspondence between the 40-Hz oscillatory patterns of activity induced by low levels of odor-like stimulation and oscillatory patterns seen in lightly anesthetized cortex in response to weak electrical shocks to the afferent fiber system. 5. The specific relationships we have found between the different components of the model also support several speculations on their functional significance. The simulations suggest that during each 40-Hz cycle of EEG activity there is a convergence in rostral cortex of afferent information from the olfactory bulb and recurrent association fiber information from caudal cortex. This convergence could underlie an iterative process central to the recognition of complex olfactory stimuli.

Sensorimotor EEG rhythms and their connection to local/global neocortical dynamic theory

2000 ◽  
Vol 23 (3) ◽  
pp. 399-400 ◽  
Author(s):  
Colin Andrew
Keyword(s):  
Cortical Area ◽  
Dynamic Theory ◽  
Rhythmic Activity ◽  
Eeg Rhythms ◽  
Eeg Activity ◽  
Sensorimotor Rhythms ◽  
40 Hz

The EEG activity recorded from the human sensorimotor cortical area exhibits rhythmic activity covering a broad range of frequencies, including alpha, mu, beta, and gamma (40-Hz) rhythms. This commentary elaborates on connections between these sensorimotor rhythms and Nunez's neocortical dynamic theory.

Decreases in 40-Hz EEG Activity in the Olfactory Bulb Following γ-Irradiation of the Cat

1971 ◽  
Vol 46 (2) ◽  
pp. 343 ◽  
Author(s):  
Barbara P. Uzzell ◽  
Daniel E. Sheer
Keyword(s):  
Olfactory Bulb ◽  
Γ Irradiation ◽  
Eeg Activity ◽  
40 Hz

scholarly journals Photobiological Neuromodulation of Resting-State EEG and Steady-State Visual-Evoked Potentials by 40 Hz Violet Light Optical Stimulation in Healthy Individuals

2021 ◽  
Vol 11 (6) ◽  
pp. 557
Author(s):  
Yoshihiro Noda ◽  
Mayuko Takano ◽  
Motoshi Hayano ◽  
Xuemei Li ◽  
Masataka Wada ◽  
...  
Keyword(s):  
Visual Processing ◽  
Gamma Oscillations ◽  
Electrode Site ◽  
Eeg Activity ◽  
Violet Light ◽  
Gamma Frequency ◽  
Specific Effects ◽  
Spectrum Density ◽  
Healthy Participants ◽  
40 Hz

Photobiological neuromodulation and its clinical application has been investigated in recent years. The response of the gamma-oscillation to human visual stimuli is known to be both burst and resonant in nature, and the coupling between alpha and gamma oscillations may play a functional role in visual processing. To date, there is no study that examined the effects of gamma-frequency violet light (VL) stimulation on human electroencephalography (EEG). In this study, we investigated the neurophysiological changes induced by light stimulation using EEG. The purpose of this study was to evaluate the specific effects of 40 Hz gamma-frequency VL stimulation on EEG activity by comparing the effects of white light (WL) with the same condition. Twenty healthy participants (10 females: 37.5 ± 14.3 years; 10 males: 38.0 ± 13.3 years) participated in this study and the following results were observed. First, when compared with the power spectrum density (PSD) of baseline EEG, 40 Hz-WL induced significant increase of PSD in theta band. Second, compared the PSDs between EEG with 40 Hz-VL and EEG with 40 Hz-WL, 40 Hz-VL induced significantly lower enhancement in delta and theta bands than 40 Hz-WL. Third, when focused on the occipital area, negative peak of VEP with 40 Hz-VL was smaller than that of 40 Hz-WL. Fourth, 40 Hz-VL induced an increase of alpha-gamma coupling during the VEP at the F5 electrode site as well as post-EEG at the C4 electrode site, compared with baseline EEG. Thus, the present study suggested that 40 Hz-VL stimulation may induce unique photobiological neuromodulations on human EEG activity.

Variations Across the Menstrual Cycle in EEG Activity During Thinking and Mental Relaxation

1999 ◽  
Vol 13 (3) ◽  
pp. 163-172 ◽  
Author(s):  
R. Krug ◽  
M. Mölle ◽  
H.L. Fehm ◽  
J. Born
Keyword(s):  
Menstrual Cycle ◽  
Divergent Thinking ◽  
Spectral Power ◽  
Plasma Concentrations ◽  
Task Demands ◽  
Menstrual Phase ◽  
Convergent Thinking ◽  
Eeg Activity ◽  
Dimensional Complexity ◽  
Mental Relaxation

Abstract Previous studies have indicated: (1) peak performance on tests of divergent creative thinking during the ovulatory phase of the menstrual cycle; (2) compared to convergent analytical thinking, divergent thinking was found to be associated with a distinctly increased dimensional complexity of ongoing EEG activity. Based on these findings, we hypothesized that cortical information processing during the ovulatory phase is characterized by an increased EEG dimensionality. Each of 16 women was tested on 3 occasions: during the ovulatory phase, the luteal phase, and menses. Presence of the phases was confirmed by determination of plasma concentrations of estradiol, progesterone, and luteinizing hormone. The EEG was recorded while the women performed: (1) tasks of divergent thinking; (2) tasks of convergent thinking; and (3) during mental relaxation. In addition to EEG dimensional complexity, conventional spectral power analysis was performed. Behavioral data confirmed enhanced creative performance during the ovulatory phase while convergent thinking did not vary across cycle phases. EEG complexity was higher during divergent than convergent thought, but this difference remained unaffected by the menstrual phase. Influences of the menstrual phase on EEG activity were most obvious during mental relaxation. In this condition, women during the ovulatory phase displayed highest EEG dimensionality as compared with the other cycle phases, with this effect being most prominent over the central and parietal cortex. Concurrently, power within the alpha frequency band as well as theta power at frontal and parietal leads were lower during the luteal than ovulatory phase. EEG results indicate that task demands of thinking overrode effects of menstrual cycle. However, with a less demanding situation, an ovulatory increase in EEG dimensionality became prominent suggesting a loosening of associative habits during this phase.

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