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Different roles of alpha and beta band oscillations in anticipatory sensorimotor gating.

Buchholz VN, Jensen O, Medendorp WP - Front Hum Neurosci (2014)

Bottom Line: Both frequency bands showed different lateralization profiles at central vs. posterior sensors, indicating anticipation of somatosensory and oculomotor processing.Furthermore, beta band power in somatosensory cortex correlated positively with saccade reaction time (SRT), with correlation values that were significantly higher with contralateral vs. ipsilateral activation.In contrast, alpha band power in parietal cortex correlated negatively with SRT, with correlation values that were significantly more negative with ipsilateral than contralateral activation.

View Article: PubMed Central - PubMed

Affiliation: Cognition and Behaviour, Donders Institute for Brain, Radboud University Nijmegen Nijmegen, Netherlands ; Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf Hamburg, Germany.

ABSTRACT
Alpha (8-12 Hz) and beta band (18-30 Hz) oscillations have been implicated in sensory anticipation and motor preparation. Here, using magneto-encephalography, we tested whether they have distinct functional roles in a saccade task that induces a remapping between sensory and motor reference frames. With a crossed hands posture, subjects had to saccade as fast and accurate as possible toward a tactile stimulus delivered to one of two non-visible index fingers, located to the left or right of gaze. Previous studies have shown that this task, in which the somatotopic stimulus must be remapped to activate oculomotor system in the opposing hemisphere, is occasionally preceded by intrahemispheric remapping, driving a premature saccade into the wrong direction. To test whether the brain could anticipate the remapping, we provided auditory predictive cues (80% validity), which indicated which finger is most likely to be stimulated. Both frequency bands showed different lateralization profiles at central vs. posterior sensors, indicating anticipation of somatosensory and oculomotor processing. Furthermore, beta band power in somatosensory cortex correlated positively with saccade reaction time (SRT), with correlation values that were significantly higher with contralateral vs. ipsilateral activation. In contrast, alpha band power in parietal cortex correlated negatively with SRT, with correlation values that were significantly more negative with ipsilateral than contralateral activation. These results suggest distinct functional roles of beta and alpha band activity: (1) somatosensory gating by beta oscillations, increasing excitability in contralateral somatosensory cortex (positive correlation); and (2) oculomotor gating by posterior alpha oscillations, inhibiting gaze-centered oculomotor regions involved in generating the saccade to the wrong direction (negative correlation). Our results show that low frequency rhythms gate upcoming sensorimotor transformations.

No MeSH data available.


Related in: MedlinePlus

Relationship between prestimulus power (beta and alpha band) and saccadic reaction time (SRT). Plotted are correlation values based on correct saccades in the valid trials. (A) Prestimulus beta. Left hand stimuli. (B) Prestimulus beta. Right hand stimuli. (C) Combined data. Correlation values differ significantly at central sensors between contralateral and ipsilateral hemispheres, mainly caused by positive correlation values contralateral, i.e., lower beta power for shorter SRTs. Correlation values do not differ at posterior sensors. (D) Depiction of expected stimulation corresponding to the format in C and G. (E–G) Prestimulus alpha; same format as in panel A–C. The more alpha ipsilateral to the saccade, the shorter its SRT. Correlation values do not differ at central sensors.
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Figure 4: Relationship between prestimulus power (beta and alpha band) and saccadic reaction time (SRT). Plotted are correlation values based on correct saccades in the valid trials. (A) Prestimulus beta. Left hand stimuli. (B) Prestimulus beta. Right hand stimuli. (C) Combined data. Correlation values differ significantly at central sensors between contralateral and ipsilateral hemispheres, mainly caused by positive correlation values contralateral, i.e., lower beta power for shorter SRTs. Correlation values do not differ at posterior sensors. (D) Depiction of expected stimulation corresponding to the format in C and G. (E–G) Prestimulus alpha; same format as in panel A–C. The more alpha ipsilateral to the saccade, the shorter its SRT. Correlation values do not differ at central sensors.

Mentions: Figure 4 demonstrates the correlation values between changes in beta band power and changes in SRT for valid trials with LH stimuli (A) and valid trials with right hand stimuli (B). In both there is a small but positive correlation between the beta power at the contralateral central area and the SRT. Consistent with the inverse relationship between beta band power and cortical excitability, the more beta band suppression at contralateral central sensors, the higher the excitability and the faster the saccade is initiated (or the higher the beta, the slower). We pooled the data of both conditions by averaging the right-hand pattern with the mirrored pattern corresponding to left-hand stimulation. Figure 4C shows pooled power-SRT correlation values, in a format that renders left hemisphere contralateral and the right hemisphere ipsilateral to the stimulated hand (depicted in D). The correlation values at contralateral central sensors were significantly higher than their ipsilateral counterparts (t = 2.90, P = 0.009). This suggests that the ipsilateral hemisphere (here right) does not cause the behavioral benefits, but that the suppressed beta band power in contralateral areas is associated with expediting behavior. Correlation values at posterior sensors did not differ between hemispheres (P > 0.1).


Different roles of alpha and beta band oscillations in anticipatory sensorimotor gating.

Buchholz VN, Jensen O, Medendorp WP - Front Hum Neurosci (2014)

Relationship between prestimulus power (beta and alpha band) and saccadic reaction time (SRT). Plotted are correlation values based on correct saccades in the valid trials. (A) Prestimulus beta. Left hand stimuli. (B) Prestimulus beta. Right hand stimuli. (C) Combined data. Correlation values differ significantly at central sensors between contralateral and ipsilateral hemispheres, mainly caused by positive correlation values contralateral, i.e., lower beta power for shorter SRTs. Correlation values do not differ at posterior sensors. (D) Depiction of expected stimulation corresponding to the format in C and G. (E–G) Prestimulus alpha; same format as in panel A–C. The more alpha ipsilateral to the saccade, the shorter its SRT. Correlation values do not differ at central sensors.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4060639&req=5

Figure 4: Relationship between prestimulus power (beta and alpha band) and saccadic reaction time (SRT). Plotted are correlation values based on correct saccades in the valid trials. (A) Prestimulus beta. Left hand stimuli. (B) Prestimulus beta. Right hand stimuli. (C) Combined data. Correlation values differ significantly at central sensors between contralateral and ipsilateral hemispheres, mainly caused by positive correlation values contralateral, i.e., lower beta power for shorter SRTs. Correlation values do not differ at posterior sensors. (D) Depiction of expected stimulation corresponding to the format in C and G. (E–G) Prestimulus alpha; same format as in panel A–C. The more alpha ipsilateral to the saccade, the shorter its SRT. Correlation values do not differ at central sensors.
Mentions: Figure 4 demonstrates the correlation values between changes in beta band power and changes in SRT for valid trials with LH stimuli (A) and valid trials with right hand stimuli (B). In both there is a small but positive correlation between the beta power at the contralateral central area and the SRT. Consistent with the inverse relationship between beta band power and cortical excitability, the more beta band suppression at contralateral central sensors, the higher the excitability and the faster the saccade is initiated (or the higher the beta, the slower). We pooled the data of both conditions by averaging the right-hand pattern with the mirrored pattern corresponding to left-hand stimulation. Figure 4C shows pooled power-SRT correlation values, in a format that renders left hemisphere contralateral and the right hemisphere ipsilateral to the stimulated hand (depicted in D). The correlation values at contralateral central sensors were significantly higher than their ipsilateral counterparts (t = 2.90, P = 0.009). This suggests that the ipsilateral hemisphere (here right) does not cause the behavioral benefits, but that the suppressed beta band power in contralateral areas is associated with expediting behavior. Correlation values at posterior sensors did not differ between hemispheres (P > 0.1).

Bottom Line: Both frequency bands showed different lateralization profiles at central vs. posterior sensors, indicating anticipation of somatosensory and oculomotor processing.Furthermore, beta band power in somatosensory cortex correlated positively with saccade reaction time (SRT), with correlation values that were significantly higher with contralateral vs. ipsilateral activation.In contrast, alpha band power in parietal cortex correlated negatively with SRT, with correlation values that were significantly more negative with ipsilateral than contralateral activation.

View Article: PubMed Central - PubMed

Affiliation: Cognition and Behaviour, Donders Institute for Brain, Radboud University Nijmegen Nijmegen, Netherlands ; Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf Hamburg, Germany.

ABSTRACT
Alpha (8-12 Hz) and beta band (18-30 Hz) oscillations have been implicated in sensory anticipation and motor preparation. Here, using magneto-encephalography, we tested whether they have distinct functional roles in a saccade task that induces a remapping between sensory and motor reference frames. With a crossed hands posture, subjects had to saccade as fast and accurate as possible toward a tactile stimulus delivered to one of two non-visible index fingers, located to the left or right of gaze. Previous studies have shown that this task, in which the somatotopic stimulus must be remapped to activate oculomotor system in the opposing hemisphere, is occasionally preceded by intrahemispheric remapping, driving a premature saccade into the wrong direction. To test whether the brain could anticipate the remapping, we provided auditory predictive cues (80% validity), which indicated which finger is most likely to be stimulated. Both frequency bands showed different lateralization profiles at central vs. posterior sensors, indicating anticipation of somatosensory and oculomotor processing. Furthermore, beta band power in somatosensory cortex correlated positively with saccade reaction time (SRT), with correlation values that were significantly higher with contralateral vs. ipsilateral activation. In contrast, alpha band power in parietal cortex correlated negatively with SRT, with correlation values that were significantly more negative with ipsilateral than contralateral activation. These results suggest distinct functional roles of beta and alpha band activity: (1) somatosensory gating by beta oscillations, increasing excitability in contralateral somatosensory cortex (positive correlation); and (2) oculomotor gating by posterior alpha oscillations, inhibiting gaze-centered oculomotor regions involved in generating the saccade to the wrong direction (negative correlation). Our results show that low frequency rhythms gate upcoming sensorimotor transformations.

No MeSH data available.


Related in: MedlinePlus