Human Movement-Related Potentials vs Desynchronization of EEG Alpha Rhythm: A High-Resolution EEG Study

Miniussi

Cognitive Brain Research

et al. 2004

Self Cite

118

In the present high-resolution electroencephalographic (EEG) study, event-related desynchronization/synchronization (ERD/ERS) of alpha rhythms was computed during an S1 -S2 paradigm, in which a visual cue (S1) predicted a SHORT (600 ms) or LONG (1400 ms) foreperiod, preceding a visual go stimulus (S2) triggering right or left finger movement. Could orienting attention to a selective point in time influence the alpha rhythms as a function of the SHORT vs. LONG foreperiod? Stronger selective attentional modulations were predicted for the SHORT than LONG condition. EEG data from 54 channels were ''depurated'' from phase-locked visual evoked potentials and spatially enhanced by surface Laplacian estimation (i.e., final data analysis was conducted on 16 subjects having a sufficient number of artifact-free EEG single trials). Low-band alpha rhythms (about 6 -10 Hz) were supposed to be related to anticipatory attentional processes, whereas high-band alpha rhythms (10 -12 Hz) would indicate task-specific visuo-motor processes.Compared to the LONG condition (foreperiod), the SHORT condition induced a quicker and stronger ERS at low-band alpha rhythm (about 6 -8 Hz) over midline and bilateral prefrontal, sensorimotor, and posterior parietal areas. In contrast, the concomitant high-band alpha (about 10 -12 Hz) ERD/ERS showed no significant difference between the two conditions. In conclusion, temporal attention for a sub-second delay (800 ms) did modulate low-band alpha rhythm over large regions of both cortical hemispheres. D 2004 Elsevier B.V. All rights reserved.Theme: Neural basis of behavior Topic: Cognition

Section: Methodological Remarksmentioning

confidence: 99%

Sub-second “temporal attention” modulates alpha rhythms. A high-resolution EEG study

Miniussi

Cognitive Brain Research

et al. 2004

Self Cite

118

“…As an advantage, the mapping procedure required no computational assumption such as the number of equivalent dipoles or the regularization parameters of the linear inverse estimation (Babiloni et al, 2001a). In previous studies, the mapping of the ERD/ERS has provided very interesting findings on brain rhythms accompanying somatosensory, motor and cognitive demands (Babiloni et al, 1999(Babiloni et al, , 2000(Babiloni et al, , 2001b(Babiloni et al, , 2002Gevins and Smith, 2000;Gevins et al, 1998;McEvoy et al, 2001;Okada and Salenius, 1998). As a limitation, the cortical sources of the ERD/ERS must be inferred with caution based on the topographical mapping.…”

Section: Methodological Remarksmentioning

confidence: 99%

Human cortical EEG rhythms during long-term episodic memory task. A high-resolution EEG study of the HERA model

Carducci

et al. 2004

NeuroImage

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Many recent neuroimaging studies of episodic memory have indicated an asymmetry in prefrontal involvement, with the left prefrontal cortex more involved than the right in encoding, the right more than the left in retrieval (hemispheric encoding and retrieval asymmetry, or HERA model). In this electroencephalographic (EEG) high-resolution study, we studied brain rhythmicity during a visual episodic memory (recognition) task. The theta (4-6 Hz), alpha (6-12 Hz) and gamma (28-48 Hz) oscillations were investigated during a visuospatial long-term episodic memory task including an encoding (ENC) and retrieval (RET) phases. During the ENC phase, 25 figures representing interiors of buildings ("indoor") were randomly intermingled with 25 figures representing landscapes ("landscapes"). Subject's response was given at left ("indoor") or right ("landscapes") mouse button. During the RET phase (1 h later), 25 figures representing previously presented "indoor" pictures ("tests") were randomly intermingled with 25 figures representing novel "indoor" ("distractors"). Again, a mouse response was required. Theta and alpha EEG results showed no change of frontal rhythmicity. In contrast, the HERA prediction of asymmetry was fitted only by EEG gamma responses, but only in the posterior parietal areas. The ENC phase was associated with gamma EEG oscillations over left parietal cortex. Afterward, the RET phase was associated with gamma EEG oscillations predominantly over right parietal cortex. The predicted HERA asymmetry was thus observed in an unexpected location. This discrepancy may be due to the differential sensitivity of neuroimaging methods to selected components of cognitive processing. The strict relation between gamma response and perception suggests that retrieval processes of long-term memory deeply impinged upon sensory representation of the stored material. © 2004 Elsevier Inc. All rights reserved

“…typically recorded over somato--sensory regions during both action execution and observation 60 (Babiloni et al, 1999;Hari et al, 1998;Hari et al, 2000;Hari et al, 1997;Pfurtscheller, 1989; 61 Pineda et al, 2000). It has been reported that the µ rhythm waveform consists of a mixture of 62 alpha activity and the second harmonic beta rhythm, giving rise to an arch--shaped waveform 63 (Buzsaki, 2006).The relationship between these two bands within the µ rhythm is still under 64 debate.…”

Section: Accepted For Publication -Neuroimagementioning

confidence: 99%

Being an agent or an observer: Different spectral dynamics revealed by MEG

et al. 2014

14Several neuroimaging studies reported that a common set of regions are recruited during 15 action observation and execution and it has been proposed that the modulation of the µ rhythm, 16 in terms of oscillations in the alpha and beta bands might represent the electrophysiological 17 correlate of the underlying brain mechanisms. However, the specific functional role of these bands 18 within the µ rhythm is still unclear. Here, we used magnetoencephalography (MEG) to analyze the 19 spectral and temporal properties of the alpha and beta bands in healthy subjects during an action 20 observation and execution task. 21We associated the modulation of the alpha and beta power to a broad action observation 22 network comprising several parieto--frontal areas previously detected in fMRI studies. Of note, we 23 observed a dissociation between alpha and beta bands with a slow--down of beta oscillations 24 ACCEPTED FOR PUBLICATION -NEUROIMAGE2 compared to alpha during action observation. We hypothesize that this segregation is linked to a 25 different sequence of information processing and we interpret these modulations in terms of 26 internal models (forward and inverse). In fact, these processes showed opposite temporal 27 sequences of occurrence: anterior--posterior during action (both in alpha and beta bands) and 28 roughly posterior--anterior during observation (in the alpha band). The observed differentiation 29 between alpha and beta suggests that these two bands might pursue different functions in the 30 action observation and execution processes. 32Keywords: action observation and execution, alpha and beta rhythms, Event--Related 33Desynchronization (ERD), magnetoencephalography (MEG), internal models 34 35 36 INTRODUCTION 37Several studies report that our sensorimotor system is activated when we observe an 38 action performed by other people. This putative mirror--like activity in humans was found in the 39 precentral gyrus (vPM), the inferior frontal gyrus (IFG), the inferior parietal lobule (IPL), and 40 regions within the intraparietal sulcus (for a review see Rizzolatti and Sinigaglia, 2010). In addition 41 to this limited number of regions, neuroimaging studies observed a broader action observation 42 network (AON) which seems to be involved during action observation (OBS) and execution (EXE) 43 (Avenanti et al., 2012;Buccino et al., 2004;Gazzola and Keysers, 2009). A proposed theoretical 44 framework postulates that such AON implements forward and inverse internal models (Wolpert 45 and Ghahramani, 2000), which should be engaged during EXE and OBS. The internal models can 46 account both for how we link our actions to sensory consequences and how others' actions match 47 our own actions and sensations (Gazzola and Keysers, 2009;Iacoboni, 2005). It has been proposed 48 that the fronto--parietal AON has a predictive nature and according to this hypothesis, during 49 action observation the inverse and forward models are integrated to achieve a prediction of 50 ACCEPTED FOR PUBLICATION -NEUROIMA...