scholarly journals Individual alpha frequency increases during a task but is unchanged by alpha‐band flicker

2019 ◽  
Vol 57 (2) ◽  
Author(s):  
Michael J. Gray ◽  
Tatiana A. Emmanouil
Keyword(s):  
Alpha Band ◽  
Alpha Frequency ◽  
Individual Alpha Frequency

scholarly journals Individual alpha frequency increases during a task but is unchanged by alpha-band flicker

2019 ◽  
Author(s):  
Michael J. Gray ◽  
Tatiana A. Emmanouil
Keyword(s):  
Visual Stimulation ◽  
Behavioral Measure ◽  
Neural Oscillations ◽  
Alpha Band ◽  
Frequency Bands ◽  
Alpha Frequency ◽  
Separate Source ◽  
Individual Alpha Frequency ◽  
Short Time ◽  
The Relationship

AbstractVisual perception fluctuates in-synch with ongoing neural oscillations in the delta, theta, and alpha frequency bands of the human EEG. Supporting the relationship between alpha and perceptual sampling, recent work has demonstrated that variations in individual alpha frequency (IAF) correlate with the ability to discriminate one from two stimuli presented briefly in the same location. Other studies have found that after being presented with a flickering stimulus at alpha frequencies, perception of near-threshold stimuli fluctuates for a short time at the same frequency. Motivated by previous work, we were interested in whether this alpha entrainment involves shifts in IAF. While recording EEG, we tested whether two-flash discrimination (a behavioral correlate of IAF) can be influenced by ∼1s of rhythmic visual stimulation at two different alpha frequencies (8.3hz and 12.5hz). Speaking against the bottom-up malleability of IAF, we found no change in IAF during stimulation and no change in two-flash discrimination immediately afterwards. We also found synchronous activity that persisted after 12.5hz stimulation, which suggests that a separate source of alpha was entrained. Importantly, we replicated the correlation between IAF and two-flash discrimination in a no-stimulation condition, demonstrating the sensitivity of our behavioral measure. We additionally found that IAF increased during the task compared to rest, which demonstrates that IAF is influenced by top-down factors but is not involved in entrainment. In the framework of existing findings, we suggest that visual entrainment may involve ongoing perceptually-relevant oscillations from the delta to alpha frequency bands, serving to maintain rhythmic temporal expectations.

scholarly journals Modulation of Individual Alpha Frequency with tACS shifts Time Perception

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Giovanna Mioni ◽  
Adam Shelp ◽  
Candice T Stanfield-Wiswell ◽  
Keri A Gladhill ◽  
Farah Bader ◽  
...  
Keyword(s):  
Time Perception ◽  
Human Subjects ◽  
Peak Frequency ◽  
Alpha Oscillations ◽  
Standard Interval ◽  
Alpha Frequency ◽  
Temporal Intervals ◽  
Transcranial Alternating Current Stimulation ◽  
Speed Effect ◽  
Individual Alpha Frequency

Abstract Previous studies have linked brain oscillation and timing, with evidence suggesting that alpha oscillations (10 Hz) may serve as a “sample rate” for the visual system. However, direct manipulation of alpha oscillations and time perception has not yet been demonstrated. To test this, we had 18 human subjects perform a time generalization task with visual stimuli. Additionally, we had previously recorded resting-state EEG from each subject and calculated their individual alpha frequency (IAF), estimated as the peak frequency from the mean spectrum over posterior electrodes between 8 and 13 Hz. Participants first learned a standard interval (600 ms) and were then required to judge if a new set of temporal intervals were equal or different compared with that standard. After learning the standard, participants performed this task while receiving occipital transcranial Alternating Current Stimulation (tACS). Crucially, for each subject, tACS was administered at their IAF or at off-peak alpha frequencies (IAF ± 2 Hz). Results demonstrated a linear shift in the psychometric function indicating a modification of perceived duration, such that progressively “faster” alpha stimulation led to longer perceived intervals. These results provide the first evidence that direct manipulations of alpha oscillations can shift perceived time in a manner consistent with a clock speed effect.

scholarly journals Peak individual alpha frequency qualifies as a stable neurophysiological trait marker in healthy younger and older adults

2013 ◽  
Vol 50 (6) ◽  
pp. 570-582 ◽  
Author(s):  
Thomas H. Grandy ◽  
Markus Werkle-Bergner ◽  
Christian Chicherio ◽  
Florian Schmiedek ◽  
Martin Lövdén ◽  
...  
Keyword(s):  
Older Adults ◽  
Alpha Frequency ◽  
Trait Marker ◽  
Individual Alpha Frequency

Individual alpha-frequency correlates with amplitude of visual evoked potential and hemodynamic response

NeuroImage ◽  
2008 ◽  
Vol 41 (2) ◽  
pp. 233-242 ◽  
Author(s):  
Stefan P. Koch ◽  
Sophie Koendgen ◽  
Riad Bourayou ◽  
Jens Steinbrink ◽  
Hellmuth Obrig
Keyword(s):  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Hemodynamic Response ◽  
Alpha Frequency ◽  
Individual Alpha Frequency ◽  
Visual Evoked

scholarly journals Salient distractors open the door of perception: alpha desynchronization marks sensory gating in a working memory task

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zsuzsanna Fodor ◽  
Csilla Marosi ◽  
László Tombor ◽  
Gábor Csukly
Keyword(s):  
Working Memory ◽  
Memory Task ◽  
Relevant Information ◽  
Alpha Band ◽  
Theta Band ◽  
Retention Period ◽  
Alpha Frequency ◽  
Task Irrelevant ◽  
Spectral Perturbation ◽  
Distractor Rejection

Abstract Focusing attention on relevant information while ignoring distracting stimuli is essential to the efficacy of working memory. Alpha- and theta-band oscillations have been linked to the inhibition of anticipated and attentionally avoidable distractors. However, the neurophysiological background of the rejection of task-irrelevant stimuli appearing in the focus of attention is not fully understood. We aimed to examine whether theta and alpha-band oscillations serve as an indicator of successful distractor rejection. Twenty-four students were enrolled in the study. 64-channel EEG was recorded during a modified Sternberg working memory task where weak and strong (salient) distractors were presented during the retention period. Event-related spectral perturbation in the alpha frequency band was significantly modulated by the saliency of the distracting stimuli, while theta oscillation was modulated by the need for cognitive control. Moreover, stronger alpha desynchronization to strong relative to weak distracting stimuli significantly increased the probability of mistakenly identifying the presented distractor as a member of the memory sequence. Therefore, our results suggest that alpha activity reflects the vulnerability of attention to distracting salient stimuli.

Genetic variation of individual alpha frequency (IAF) and alpha power in a large adolescent twin sample

2006 ◽  
Vol 61 (2) ◽  
pp. 235-243 ◽  
Author(s):  
Christine M. Smit ◽  
Margaret J. Wright ◽  
Narelle K. Hansell ◽  
Gina M. Geffen ◽  
Nicholas G. Martin
Keyword(s):  
Genetic Variation ◽  
Alpha Power ◽  
Alpha Frequency ◽  
Individual Alpha Frequency

Individual Alpha Frequency Relates to the Sound-Induced Flash Illusion

2017 ◽  
Vol 30 (6) ◽  
pp. 565-578 ◽  
Author(s):  
Julian Keil ◽  
Daniel Senkowski
Keyword(s):  
Cortical Excitability ◽  
Multisensory Processing ◽  
Audiovisual Integration ◽  
Source Analysis ◽  
Neural Oscillations ◽  
Sensory Stimuli ◽  
Alpha Frequency ◽  
The Individual ◽  
Individual Alpha Frequency ◽  
The Relationship

Ongoing neural oscillations reflect fluctuations of cortical excitability. A growing body of research has underlined the role of neural oscillations for stimulus processing. Neural oscillations in the alpha band have gained special interest in electrophysiological research on perception. Recent studies proposed the idea that neural oscillations provide temporal windows in which sensory stimuli can be perceptually integrated. This also includes multisensory integration. In the current high-density EEG-study we examined the relationship between the individual alpha frequency (IAF) and cross-modal audiovisual integration in the sound-induced flash illusion (SIFI). In 26 human volunteers we found a negative correlation between the IAF and the SIFI illusion rate. Individuals with a lower IAF showed higher audiovisual illusions. Source analysis suggested an involvement of the visual cortex, especially the calcarine sulcus, for this relationship. Our findings corroborate the notion that the IAF affects the cross-modal integration of auditory on visual stimuli in the SIFI. We integrate our findings with recent observations on the relationship between audiovisual integration and neural oscillations and suggest a multifaceted influence of neural oscillations on multisensory processing.

Sign in / Sign up

Export Citation Format

Share Document