The Effects of l-theanine on Alpha-Band Oscillatory Brain Activity During a Visuo-Spatial Attention Task

@article{GomezRamirez2008TheEO,
  title={The Effects of l-theanine on Alpha-Band Oscillatory Brain Activity During a Visuo-Spatial Attention Task},
  author={Manuel Gomez-Ramirez and Simon P. Kelly and Jennifer L. Montesi and John J. Foxe},
  journal={Brain Topography},
  year={2008},
  volume={22},
  pages={44-51}
}
Background/Objectives Ingestion of the non-proteinic amino acid l-theanine (γ-glutamylethylamide) has been shown to influence oscillatory brain activity in the alpha band (8–14 Hz) in humans during resting electroencephalographic (EEG) recordings and also during cognitive task performance. We have previously shown that ingestion of a 250-mg dose of l-theanine significantly reduced tonic (background) alpha power during a demanding intersensory (auditory-visual) attentional cueing task. Further… Expand
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References

SHOWING 1-10 OF 30 REFERENCES
The Deployment of Intersensory Selective Attention: A High-density Electrical Mapping Study of the Effects of Theanine
TLDR
It is concluded that theanine has clear psychoactive properties, and that it represents a potentially interesting, naturally occurring compound for further study, as it relates to the brain's attentional system. Expand
L-theanine and caffeine in combination affect human cognition as evidenced by oscillatory alpha-band activity and attention task performance.
TLDR
Electrophysiological results did not show increased differential biasing in phasic alpha across hemifields but showed lower overall tonic alpha power in the combined treatment, similar to previous findings at a larger dosage of L-theanine alone. Expand
Attentional shifts towards an expected visual target alter the level of alpha-band oscillatory activity in the human calcarine cortex.
TLDR
It is concluded that attentional shifts affect activity within the human calcarine cortex by altering the amplitude of spontaneous alpha rhythms and that subsequent modulation of visual input with attentional engagement follows as a consequence of these localized changes in oscillatory activity. Expand
A shift of visual spatial attention is selectively associated with human EEG alpha activity
TLDR
It was found that prefrontal cortex shows stronger phase coupling with posterior sites that are contralateral to the attended hemifield than ipsilateral sites, and that this posterior modulation of alpha activity is controlled by prefrontal regions. Expand
α-Band Electroencephalographic Activity over Occipital Cortex Indexes Visuospatial Attention Bias and Predicts Visual Target Detection
TLDR
Electroencephalography data indicate that collateral modulations of posterior α-activity, the momentary bias of visuospatial attention, and imminent visual processing are linked, and suggest that the Momentary direction of attention, predicting spatial biases in imminent visualprocessing, can be estimated from a lateralization index of posterior β-activity. Expand
Anticipatory Biasing of Visuospatial Attention Indexed by Retinotopically Specific α-Bank Electroencephalography Increases over Occipital Cortex
TLDR
Alpha-band (8-14 Hz) oscillatory EEG activity was examined with high-density scalp electrical recording during the cue-stimulus interval of an endogenous spatial cueing paradigm and results are consistent with active gating of uncued spatial locations. Expand
Increases in alpha oscillatory power reflect an active retinotopic mechanism for distracter suppression during sustained visuospatial attention.
TLDR
Bilateral flickering stimuli were presented simultaneously and continuously over entire trial blocks, such that externally evoked alpha desynchronization is equated in precue baseline and postcue intervals and suggests that alpha synchronization reflects an active attentional suppression mechanism, rather than a passive one reflecting "idling" circuits. Expand
Event-related desynchronization during anticipatory attention for an upcoming stimulus: a comparative EEG/MEG study
TLDR
The results are in line with the predictions of the neurophysiological model of anticipatory behaviour and indicate the presence of a 'tau' rhythm. Expand
Anticipatory attention: an event-related desynchronization approach.
  • M. Bastiaansen, C. Brunia
  • Psychology, Medicine
  • International journal of psychophysiology : official journal of the International Organization of Psychophysiology
  • 2001
TLDR
The results indicate to varying degrees that preceding the presentation of the KR stimuli, ERD is present over the sensory cortex, which corresponds to the modality of theKR stimulus, which supports the notion that a thalamocortical gating mechanism forms the neurophysiological basis of anticipatory attention. Expand
Attention-dependent suppression of distracter visual input can be cross-modally cued as indexed by anticipatory parieto-occipital alpha-band oscillations.
TLDR
The results of this series of studies suggest that these parietal regions are capable of integrating sensory cues from multiple sensory modalities in order to program the subsequent deployment of visual attention. Expand
...
1
2
3
...