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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

Experimental design. Subjects adopted a crossed hand posture, with the index fingers each at 10 cm distance from straight ahead. They had to fixate centrally, at a dim light between the two hands. Hands were resting on a tilted support, such that fixation was only slightly downward. Subjects had to saccade as fast and accurate as possible toward the tactile stimulus presented to the invisible fingertip. A tone cued with 80% validity the side of stimulation, such that subjects could anticipate the location of the sensory stimulus.
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Figure 1: Experimental design. Subjects adopted a crossed hand posture, with the index fingers each at 10 cm distance from straight ahead. They had to fixate centrally, at a dim light between the two hands. Hands were resting on a tilted support, such that fixation was only slightly downward. Subjects had to saccade as fast and accurate as possible toward the tactile stimulus presented to the invisible fingertip. A tone cued with 80% validity the side of stimulation, such that subjects could anticipate the location of the sensory stimulus.

Mentions: Thus the paradigm contains valid trials, in which the actual tactile stimulus location matches the expected location, and invalid trials, in which the actual tactile stimulus location is diametrically opposite from the expected location. Figure 1 illustrates the conditions of the paradigm, which are defined by the location of the target relative to the body (left vs. right hand) and cue validity (valid vs. invalid). That is, the location of the potential tactile target could be represented to the body, Left hand (LH) vs. right hand (RH), or alternatively, right or left relative to gaze. Due to the crossed hands posture, the hemisphere contralateral to the hand is ipsilateral to the target relative to gaze, and vice versa.


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

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

Experimental design. Subjects adopted a crossed hand posture, with the index fingers each at 10 cm distance from straight ahead. They had to fixate centrally, at a dim light between the two hands. Hands were resting on a tilted support, such that fixation was only slightly downward. Subjects had to saccade as fast and accurate as possible toward the tactile stimulus presented to the invisible fingertip. A tone cued with 80% validity the side of stimulation, such that subjects could anticipate the location of the sensory stimulus.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: Experimental design. Subjects adopted a crossed hand posture, with the index fingers each at 10 cm distance from straight ahead. They had to fixate centrally, at a dim light between the two hands. Hands were resting on a tilted support, such that fixation was only slightly downward. Subjects had to saccade as fast and accurate as possible toward the tactile stimulus presented to the invisible fingertip. A tone cued with 80% validity the side of stimulation, such that subjects could anticipate the location of the sensory stimulus.
Mentions: Thus the paradigm contains valid trials, in which the actual tactile stimulus location matches the expected location, and invalid trials, in which the actual tactile stimulus location is diametrically opposite from the expected location. Figure 1 illustrates the conditions of the paradigm, which are defined by the location of the target relative to the body (left vs. right hand) and cue validity (valid vs. invalid). That is, the location of the potential tactile target could be represented to the body, Left hand (LH) vs. right hand (RH), or alternatively, right or left relative to gaze. Due to the crossed hands posture, the hemisphere contralateral to the hand is ipsilateral to the target relative to gaze, and vice versa.

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