No Evidence for a Role of Spatially Modulated α-Band Activity in Tactile Remapping and Short-Latency, Overt Orienting Behavior

TY - JOUR

T1 - No Evidence for a Role of Spatially Modulated α-Band Activity in Tactile Remapping and Short-Latency, Overt Orienting Behavior

AU - Ossandón, José P.

AU - König, Peter

AU - Heed, Tobias

N1 - Copyright © 2020 the authors.

PY - 2020/11/18

Y1 - 2020/11/18

N2 - Oscillatory α-band activity is commonly associated with spatial attention and multisensory prioritization. It has also been suggested to reflect the automatic transformation of tactile stimuli from a skin-based, somatotopic reference frame into an external one. Previous research has not convincingly separated these two possible roles of α-band activity. Previous experimental paradigms have used artificially long delays between tactile stimuli and behavioral responses to aid relating oscillatory activity to these different events. However, this strategy potentially blurs the temporal relationship of α-band activity relative to behavioral indicators of tactile-spatial transformations. Here, we assessed α-band modulation with massive univariate deconvolution, an analysis approach that disentangles brain signals overlapping in time and space. Thirty-one male and female human participants performed a delay-free, visual search task in which saccade behavior was unrestricted. A tactile cue to uncrossed or crossed hands was either informative or uninformative about visual target location. α-Band suppression following tactile stimulation was lateralized relative to the stimulated hand over central-parietal electrodes but relative to its external location over parieto-occipital electrodes. α-Band suppression reflected external touch location only after informative cues, suggesting that posterior α-band lateralization does not index automatic tactile transformation. Moreover, α-band suppression occurred at the time of, or after, the production of the saccades guided by tactile stimulation. These findings challenge the idea that α-band activity is directly involved in tactile-spatial transformation and suggest instead that it reflects delayed, supramodal processes related to attentional reorienting.SIGNIFICANCE STATEMENT Localizing a touch in space requires integrating somatosensory information about skin location and proprioceptive or visual information about posture. The automatic remapping between skin-based tactile information to a location in external space has been proposed to rely on the modulation of oscillatory brain activity in the α-band range, across the multiple cortical areas that are involved in tactile, multisensory, and spatial processing. We report two findings that are inconsistent with this view. First, α-band activity reflected the remapped stimulus location only when touch was task relevant. Second, α-band modulation occurred too late to account for spatially directed behavioral responses and, thus, only after remapping must have taken place. These characteristics contradict the idea that α-band directly reflects automatic tactile remapping processes.

AB - Oscillatory α-band activity is commonly associated with spatial attention and multisensory prioritization. It has also been suggested to reflect the automatic transformation of tactile stimuli from a skin-based, somatotopic reference frame into an external one. Previous research has not convincingly separated these two possible roles of α-band activity. Previous experimental paradigms have used artificially long delays between tactile stimuli and behavioral responses to aid relating oscillatory activity to these different events. However, this strategy potentially blurs the temporal relationship of α-band activity relative to behavioral indicators of tactile-spatial transformations. Here, we assessed α-band modulation with massive univariate deconvolution, an analysis approach that disentangles brain signals overlapping in time and space. Thirty-one male and female human participants performed a delay-free, visual search task in which saccade behavior was unrestricted. A tactile cue to uncrossed or crossed hands was either informative or uninformative about visual target location. α-Band suppression following tactile stimulation was lateralized relative to the stimulated hand over central-parietal electrodes but relative to its external location over parieto-occipital electrodes. α-Band suppression reflected external touch location only after informative cues, suggesting that posterior α-band lateralization does not index automatic tactile transformation. Moreover, α-band suppression occurred at the time of, or after, the production of the saccades guided by tactile stimulation. These findings challenge the idea that α-band activity is directly involved in tactile-spatial transformation and suggest instead that it reflects delayed, supramodal processes related to attentional reorienting.SIGNIFICANCE STATEMENT Localizing a touch in space requires integrating somatosensory information about skin location and proprioceptive or visual information about posture. The automatic remapping between skin-based tactile information to a location in external space has been proposed to rely on the modulation of oscillatory brain activity in the α-band range, across the multiple cortical areas that are involved in tactile, multisensory, and spatial processing. We report two findings that are inconsistent with this view. First, α-band activity reflected the remapped stimulus location only when touch was task relevant. Second, α-band modulation occurred too late to account for spatially directed behavioral responses and, thus, only after remapping must have taken place. These characteristics contradict the idea that α-band directly reflects automatic tactile remapping processes.

KW - A-band activity

KW - EEG

KW - Free viewing

KW - Tactile remapping

KW - Visual search

KW - Visual Perception/physiology

KW - Humans

KW - Touch Perception/physiology

KW - Occipital Lobe/physiology

KW - Male

KW - Orientation, Spatial/physiology

KW - Electrodes

KW - Young Adult

KW - Saccades

KW - Adult

KW - Female

KW - Hand/innervation

KW - Cues

KW - Space Perception/physiology

KW - Parietal Lobe/physiology

KW - Somatosensory Cortex/physiology

KW - Eye Movements/physiology

KW - Adolescent

KW - Alpha Rhythm/physiology

KW - Photic Stimulation

UR - http://www.scopus.com/inward/record.url?scp=85096345096&partnerID=8YFLogxK

U2 - 10.1523/JNEUROSCI.0581-19.2020

DO - 10.1523/JNEUROSCI.0581-19.2020

M3 - SCORING: Journal article

C2 - 33087476

AN - SCOPUS:85096345096

VL - 40

SP - 9088

EP - 9102

JO - J NEUROSCI

JF - J NEUROSCI

SN - 0270-6474

IS - 47

ER -