The impact of focused attention on bilateral sensory threshold adaptation during unilateral short-term tactile stimulation
Abstract
Background/Aim. Neuroplasticity of the somatosensory system can be manifested after short-term or long-term peripheral tactile stimulation. Focused attention has been well established as a modulator of neural processing in the visual and auditory systems. However, its role in the primary somatosensory cortex is insufficiently elucidated. The aim of this study was to examine the effect of focused attention on short-term somatosensory neuroplasticity following repeated tactile stimulation of different intensity over identical locations on the hands and shoulders. The aim of the study was also to determine whether repeated tactile stimulation of different intensity in the shoulder area of the non-dominant hand leads to a reduction in the stimulus threshold and to assess whether similar changes occur in the contralateral, unstimulated shoulder somatotopically identical location. Methods. This study included 30 healthy volunteers of both sexes. The contingent negative variation (CNV) wave and the Go/NoGo paradigm for measuring reaction time were used to objectively register the stimulus threshold for light touch, before and after sensory stimulation. The CNV wave was registered within the paradigm with two known stimuli, the first of which was tactile and the second visual in the form of a green or red circle that appeared randomly on the screen. Peripheral sensory stimulation was conducted only over the non-dominant hand and shoulder using multiple series with 12 tactile stimuli of varying intensities. Results. The results showed statistically significant decrease in the stimulus threshold for light touch on both shoulders after tactile stimulation performed only on the non-dominant shoulder. In addition, whenever CNV waves were detected within the Go/NoGo paradigm, reaction times of the subjects were significantly shorter, which served as an objective validation of the initial detection of tactile thresholds before and after peripheral sensory stimulation. Conclusion. Short-term, unilateral tactile stimulation leads to bilateral, functional adaptation of the proximal regions of the upper extremities, which suggests interhemispheric homologous transfer within the somatosensory system, supporting the principle of somatotopic organization in somatosensory neuroplasticity.
References
Gao Z, Pang Z, Chen Y, Lei G, Zhu S, Li G, et al. Restoring Af-ter Central Nervous System Injuries: Neural Mechanisms and Translational Applications of Motor Recovery. Neurosci Bull 2022; 38(12): 1569–87.
Takase H, Regenhardt RW. Motor tract reorganization after acute central nervous system injury: a translational perspec-tive. Neural Regen Res 2020; 16(6): 1144–9.
Tommerdahl M, Favorov OV, Whitsel BL. Dynamic representa-tions of the somatosensory cortex. Neurosci Biobehav Rev 2010; 34(2): 160–70.
Lissek S, Wilimzig C, Stude P, Pleger B, Kalisch T, Maier C, et al. Immobilization impairs tactile perception and shrinks soma-tosensory cortical maps. Curr Biol 2009; 19(10): 837–42.
Chipchase LS, Schabrun SM, Hodges PW. Peripheral electrical stimulation to induce cortical plasticity: a systematic review of stimulus parameters. Clin Neurophysiol 2011; 122(3): 456–63.
Kowalewski R, Kattenstroth JC, Kalisch T, Dinse HR. Improved acuity and dexterity but unchanged touch and pain thresholds following repetitive sensory stimulation of the fingers. Neural Plast 2012; 2012: 974504.
Harrar V, Spence C, Makin TR. Topographic generalization of tactile perceptual learning. J Exp Psychol Hum Percept Per-form 2014; 40(1): 15–23.
Carrasco M. Visual attention: the past 25 years. Vision Res 2011; 51(13): 1484–525.
Friedrich J, Verrel J, Kleimaker M, Münchau A, Beste C, Bäumer T. Neurophysiological correlates of perception–action binding in the somatosensory system. Sci Rep 2020; 10(1): 14794.
Van Ede F, de Lange FP, Maris E. Anticipation increases tac-tile stimulus processing in the ipsilateral primary somatosenso-ry cortex. Cereb Cortex 2014; 24(10): 2562–71.
Veale JF. Edinburgh Handedness Inventory - Short Form: a revised version based on confirmatory factor analysis. Laterali-ty 2014; 19(2): 164–77.
Ricupero S, Ritter FE. Caffeine and cognition: a cognitive ar-chitecture-based review. Theor Issues Ergon Sci 2024; 25(6): 655–79.
Fiani B, Zhu L, Musch BL, Briceno S, Andel R, Sadeq N, et al. The Neurophysiology of Caffeine as a Central Nervous System Stimulant and the Resultant Effects on Cognitive Function. Cureus 2021; 13(5): e15032.
Thube S, Shah MR, Kothari PH, Shah V. Assessment of Two Point Discrimination on Hand in Adult Population: An Ob-servational Study. Int J Health Res 2020; 10(5): 60–3.
Walter WG, Cooper R, Aldridge VJ, Mccallum WC, Winter AL. Contingent negative variation: an electric sign of sensorimotor association and expectancy in the human brain. Nature 1964; 203: 380–4.
Prevec TS, Berić A. Measurement of light touch perception threshold by contingent negative variation. Exp Brain Res 1991; 84(3): 643–8.
Kropp P, Kiewitt A, Göbel H, Vetter P, Gerber WD. Reliability and stability of contingent negative variation. Appl Psycho-physiol Biofeedback 2000; 25(1): 33–41.
Chong PS, Cros DP. Technology literature review: quantitative sensory testing. Muscle Nerve 2004; 29(5): 734–47.
Guidali G, Roncoroni C, Bolognini N. Paired associative stimula-tions: Novel tools for interacting with sensory and motor cor-tical plasticity. Behav Brain Res 2021; 414: 113484.
Schlieper S, Dinse HR. Perceptual improvement following re-petitive sensory stimulation depends monotonically on stimu-lation intensity. Brain Stimul 2012; 5(4): 647–51.
Tamè L, Farnè A, Pavani F. Spatial coding of touch at the fin-gers: Insights from double simultaneous stimulation within and between hands. Neurosci Lett 2011; 487(1): 78–82.
Dhillon GS, Krüger TB, Sandhu JS, Horch KW. Effects of short-term training on sensory and motor function in severed nerves of long-term human amputees. J Neurophysiol 2005; 93(5): 2625–33.
Ziemus B, Huonker R, Haueisen J, Liepert J, Spengler F, Weiller C. Effects of passive tactile co-activation on median ulnar nerve representation in human SI. Neuroreport 2000; 11(6): 1285–8.
Godde B, Ehrhardt J, Braun C. Behavioral significance of input-dependent plasticity of human somatosensory cortex. Neu-roreport 2003; 14(4): 543–6.
Parianen Lesemann FH, Reuter EM, Godde B. Tactile stimula-tion interventions: influence of stimulation parameters on sen-sorimotor behavior and neurophysiological correlates in healthy and clinical samples. Neurosci Biobehav Rev 2015; 51: 126–37.
Suzuki LY, Meehan SK. Attention focus modulates afferent in-put to motor cortex during skilled action. Hum Mov Sci 2020; 74: 102716.
Weinberger NM. Dynamic regulation of receptive fields and maps in the adult sensory cortex. Annu Rev Neurosci 1995; 18: 129–58.
Passmore SR, Mortaza N, Glazebrook CM, Murphy B, Lee TD. Somatosensory Integration and Masking of Complex Tactile Information: Peripheral and Cortical Contributions. Brain Sci 2020; 10(12): 954.
Hadoush H, Inoue K, Nakanishi K, Kurumadani H, Sunagawa T, Ochi M. Ipsilateral primary sensorimotor cortical response to mechanical tactile stimuli. Neuroreport 2010; 21(2): 108–13.
Tamè L, Braun C, Holmes NP, Farnè A, Pavani F. Bilateral rep-resentations of touch in the primary somatosensory cortex. Cogn Neuropsychol 2016; 33(1–2): 48–66.
Valyear KF, Philip BA, Cirstea CM, Chen PW, Baune NA, Marchal N, et al. Interhemispheric transfer of post-amputation cortical plasticity within the human somatosensory cortex. NeuroImage 2020; 206: 116291.
Tamè L, Pavani F, Braun C, Salemme R, Farnè A, Reilly KT. Somatotopy and temporal dynamics of sensorimotor interac-tions: evidence from double afferent inhibition. Eur J Neuro-sci 2015; 41(11): 1459–65.
Tamura K. Ipsilateral somatosensory evoked responses in man. Folia Psychiatr Neurol Jpn 1972; 26(1): 83–94.
Frank SM, Otto A, Volberg G, Tse PU, Watanabe T, Greenlee MW. Transfer of Tactile Learning from Trained to Untrained Body Parts Supported by Cortical Coactivation in Primary Somatosensory Cortex. J Neurosci 2022; 42(31): 6131–44.
Frank SM. Transfer of Tactile Learning to Untrained Body Parts: Emerging Cortical Mechanisms. Neuroscientist 2025; 31(1): 98–114.
Williamson JN, Sikora WA, James SA, Parmar NJ, Lepak LV, Cheema CF, et al. Cortical Reorganization of Early Soma-tosensory Processing in Hemiparetic Stroke. J Clin Med 2022; 11(21): 6449.
Morrone M, Martinez G, Achene A, Scaglione M, Masala S, Manca A, et al. Size and site matter: the influence of corpus callosum subregional lesions on the magnitude of cross-education of strength. Front Physiol 2025; 16: 1554742.
Pauwels L, Gooijers J. The Role of the Corpus Callosum (Mi-cro)Structure in Bimanual Coordination: A Literature Review Update. J Mot Behav 2023; 55(5): 525–37.
Kicić D, Lioumis P, Ilmoniemi RJ, Nikulin VV. Bilateral changes in excitability of sensorimotor cortices during unilateral movement: Combined electroencephalographic and transcra-nial magnetic stimulation study. Neuroscience 2008; 152(4): 1119–29.
Carson RG. Neural pathways mediating bilateral interactions between the upper limbs. Brain Res Brain Res Rev 2005; 49(3): 641–62.
Nagai Y, Critchley HD, Featherstone E, Fenwick PBC, Trimble MR, Dolan RJ. Brain activity relating to the contingent nega-tive variation: an fMRI investigation. Neuroimage 2004; 21(4): 1232–41.
Kropp P, Linstedt U, Niederberger U, Gerber WD. Contingent negative variation and attentional performance in humans. Neurol Res 2001; 23(6): 647–50.
Raud L, Westerhausen R, Dooley N, Huster RJ. Differences in unity: The go/no-go and stop signal tasks rely on different mechanisms. Neuroimage 2020; 210: 116582.
Isfahani SA, McGurrin P, Vial F, Hallett M. Patterns of brain activity in choice or instructed go and no-go tasks. Exp Brain Res 2025; 243(3): 73.
Bundy DT, Leuthardt EC. The Cortical Physiology of Ipsilateral Limb Movements. Trends Neurosci 2019; 42(11): 825–39.
DeCosta-Fortune TM, Ramshur JT, Li CX, de Jongh Curry A, Pel-licer-Morata V, Wang L, et al. Repetitive microstimulation in rat primary somatosensory cortex (SI) strengthens the connec-tion between homotopic sites in the opposite SI and leads to expression of previously ineffective input from the ipsilateral forelimb. Brain Res 2020; 1732: 146694.
Jablonka JA, Binkowski R, Kazmierczak M, Sadowska M, Srednia-wa W, Szlachcic A, et al. The Role of Interhemispheric Interac-tions in Cortical Plasticity. Front Neurosci 2021; 15: 631328.
Aune TK, Aune MA, Ingvaldsen RP, Vereijken B. Transfer of Motor Learning Is More Pronounced in Proximal Compared to Distal Effectors in Upper Extremities. Front Psychol 2017; 8: 1530.