Limits...
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

Spectral boundaries of pre-stimulus modulations. Gaze-centered and body-centered lateralization at central (upper) and posterior (lower) sensors under the assumption of increased excitability by alpha and beta band suppression.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4060639&req=5

Figure 3: Spectral boundaries of pre-stimulus modulations. Gaze-centered and body-centered lateralization at central (upper) and posterior (lower) sensors under the assumption of increased excitability by alpha and beta band suppression.

Mentions: Figure 3 illustrates the spectral extent of the spatially specific alpha and beta band effects. Thus, at central sensors, beta band power is relatively lower for contralateral than ipsilateral hand stimuli, whereas the alpha band shows the opposite pattern at posterior sensors. Under the assumption that suppressed alpha and beta corresponds to increased excitability (see Section Materials and Methods), the beta band modulations are consistent with increased excitability of the somatotopic areas that will be engaged. In contrast, alpha band modulations observed at posterior sensors are consistent with regulating excitability of areas in a gaze-centered reference frame. Taken together, our data show that modulations do not only take place at the sensory level, but that the brain calculates the sensorimotor transformation in anticipation of a sensory event, modulating excitability at the level of the gaze-centered oculomotor structures.


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

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

Spectral boundaries of pre-stimulus modulations. Gaze-centered and body-centered lateralization at central (upper) and posterior (lower) sensors under the assumption of increased excitability by alpha and beta band suppression.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 3: Spectral boundaries of pre-stimulus modulations. Gaze-centered and body-centered lateralization at central (upper) and posterior (lower) sensors under the assumption of increased excitability by alpha and beta band suppression.
Mentions: Figure 3 illustrates the spectral extent of the spatially specific alpha and beta band effects. Thus, at central sensors, beta band power is relatively lower for contralateral than ipsilateral hand stimuli, whereas the alpha band shows the opposite pattern at posterior sensors. Under the assumption that suppressed alpha and beta corresponds to increased excitability (see Section Materials and Methods), the beta band modulations are consistent with increased excitability of the somatotopic areas that will be engaged. In contrast, alpha band modulations observed at posterior sensors are consistent with regulating excitability of areas in a gaze-centered reference frame. Taken together, our data show that modulations do not only take place at the sensory level, but that the brain calculates the sensorimotor transformation in anticipation of a sensory event, modulating excitability at the level of the gaze-centered oculomotor structures.

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