Activation of Bilateral Secondary Somatosensory Cortex With Right Hand Touch Stimulation: A Meta-Analysis of Functional Neuroimaging Studies

Abstract

Background: Brain regions involved in processing somatosensory information have been well documented through lesion, post-mortem, animal, and more recently, structural and functional neuroimaging studies. Functional neuroimaging studies characterize brain activation related to somatosensory processing; yet a meta-analysis synthesis of these findings is currently lacking and in-depth knowledge of the regions involved in somatosensory-related tasks may also be confounded by motor influences.Objectives: Our Activation Likelihood Estimate (ALE) meta-analysis sought to quantify brain regions that are involved in the tactile processing of the right (RH) and left hands (LH) separately, with the exclusion of motor related activity.Methods: The majority of studies (n = 41) measured activation associated with RH tactile stimulation. RH activation studies were grouped into those which conducted whole-brain analyses (n = 29) and those which examined specific regions of interest (ROI; n = 12). Few studies examined LH activation, though all were whole-brain studies (N = 7).Results: Meta-analysis of brain activation associated with RH tactile stimulation (whole-brain studies) revealed large clusters of activation in the left primary somatosensory cortex (S1) and bilaterally in the secondary somatosensory cortex (S2; including parietal operculum) and supramarginal gyrus (SMG), as well as the left anterior cingulate. Comparison between findings from RH whole-brain and ROI studies revealed activation as expected, but restricted primarily to S1 and S2 regions. Further, preliminary analyses of LH stimulation studies only, revealed two small clusters within the right S1 and S2 regions, likely limited due to the small number of studies. Contrast analyses revealed the one area of overlap for RH and LH, was right secondary somatosensory region.Conclusions: Findings from the whole-brain meta-analysis of right hand tactile stimulation emphasize the importance of taking into consideration bilateral activation, particularly in secondary somatosensory cortex. Further, the right parietal operculum/S2 region was commonly activated for right and left hand tactile stimulation, suggesting a lateralized pattern of somatosensory activation in right secondary somatosensory region. Implications for further research and for possible differences in right and left hemispheric stroke lesions are discussed.

Functional Connectivity between the Cerebellum and Somatosensory Areas Implements the Attenuation of Self-Generated Touch

“…3-2). Situated in the inferior parietal lobe, the supramarginal gyrus is part of the sensory association cortex and is involved in higher-order somatosensory processing (Bodegård et al, 2001;Lamp et al, 2019). At the uncorrected level of p Ͻ 0.001, the right primary somatosensory cortex (S1) was also activated (Table 2-2).…”

Age differences in predicting working memory performance from network-based functional connectivity

“…These control networks were linked to task-negative, social-affective and introspective processes, as well as motor and sensory processes. In particular, the three networks comprised (i) the extended social-affective default network (eSAD; Amft et al, 2015 ), (ii) a combined motor network associated with finger tapping and prosaccade eye movements (Motor + PS; Cieslik et al, 2016 ; Witt et al, 2008 ), and (iii) a combined motor-sensory network linked to finger tapping and hand stimulation/somatosensory processing (Motor + SS; Lamp et al, 2019 ; Witt et al, 2008 ). These motor-sensory systems are strongly interconnected compared to large-scale cognitive networks with transitions between network boundaries, and converge less with fronto-parietal cognitive areas ( Cieslik et al, 2016 ; Fox & Raichle, 2007 ; Yeo et al, 2011 ).…”

Tactile direction discrimination in humans after stroke

“…However, the OP1 area most likely processes tactile input in general, rather than tactile motion specifically. Evidence for this is that it is activated in response to a variety of tactile stimuli ( Burton et al , 2008 ), and that lesions affecting the parietal operculum are associated with impaired somatosensory processing in tasks that do not require processing of motion cues ( Preusser et al , 2015 ; Meyer et al , 2016 ; Lamp et al , 2019 ). Furthermore, S2 OP1 activation appears unaffected by the performance level on the TDD test ( Lundblad et al , 2011 ), and was still activated during TDD testing in a patient with a spinal cord lesion who, although he reported sensing the tactile stimulus, was unable report movement direction ( Lundblad et al , 2010 ).…”

“…Furthermore, ipsilateral impairment in somatosensory function is evident in 20–30% of patients with unilateral brain lesions ( Corkin et al , 1973 ; Connell et al , 2008 ). TDD bilaterally activates S2 and insula ( Lamp et al ., 2019 ; Lundblad et al , 2011 ), and restricted experimental lesions alter cortical processing in widespread areas ( Wahlbom et al , 2019 ). A recent meta-analysis of functional neuroimaging studies of tactile processing of stimulation applied to the hand found bilateral activation in both S2 and the insula ( Lamp et al , 2019 ).…”