Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Polarity- and Intensity-Independent Modulation of Timing During Delay Eyeblink Conditioning Using Cerebellar Transcranial Direct Current Stimulation


Delay eyeblink conditioning (dEBC) is widely used to assess cerebellar-dependent associative motor learning, including precise timing processes. Transcranial direct current stimulation (tDCS), noninvasive brain stimulation used to indirectly excite and inhibit select brain regions, may be a promising tool for understanding how functional integrity of the cerebellum influences dEBC behavior. The aim of this study was to assess whether tDCS-induced inhibition (cathodal) and excitation (anodal) of the cerebellum differentially impact timing of dEBC. A standard 10-block dEBC paradigm was administered to 102 healthy participants. Participants were randomized to stimulation conditions in a double-blind, between-subjects sham-controlled design. Participants received 20-min active (anodal or cathodal) stimulation at 1.5 mA (n = 20 anodal, n = 22 cathodal) or 2 mA (n = 19 anodal, n = 21 cathodal) or sham stimulation (n = 20) concurrently with dEBC training. Stimulation intensity and polarity effects on percent conditioned responses (CRs) and CR peak and onset latency were examined using repeated-measures analyses of variance. Acquisition of CRs increased over time at a similar rate across sham and all active stimulation groups. CR peak and onset latencies were later, i.e., closer to air puff onset, in all active stimulation groups compared to the sham group. Thus, tDCS facilitated cerebellar-dependent timing of dEBC, irrespective of stimulation intensity and polarity. These findings highlight the feasibility of using tDCS to modify cerebellar-dependent functions and provide further support for cerebellar contributions to human eyeblink conditioning and for exploring therapeutic tDCS interventions for cerebellar dysfunction.

This is a preview of subscription content, log in to check access.

Fig. 1


  1. 1.

    Llinas R, Walton K and Lang E. Chapter 7. Cerebellum. 2004.

  2. 2.

    Zagon IS, PJ ML, Smith S. Neural populations in the human cerebellum: estimations from isolated cell nuclei. Brain Res. 1977;127:279–82.

  3. 3.

    Bell CC, Han V, Sawtell NB. Cerebellum-like structures and their implications for cerebellar function. Annu Rev Neurosci. 2008;31:1–24.

  4. 4.

    Strick PL, Dum RP, Fiez JA. Cerebellum and nonmotor function. Annu Rev Neurosci. 2009;32:413–34.

  5. 5.

    Buckner RL. The cerebellum and cognitive function: 25 years of insight from anatomy and neuroimaging. Neuron. 2013;80:807–15.

  6. 6.

    Sokolov AA. The cerebellum in social cognition. Front Cell Neurosci. 2018;12. https://doi.org/10.3389/fncel.2018.00145.

  7. 7.

    van Es DM, van der Zwaag W, Knapen T. Topographic maps of visual space in the human cerebellum. Curr Biol. 2019. https://doi.org/10.1016/j.cub.2019.04.012.

  8. 8.

    Guell X, Gabrieli JDE, Schmahmann JD. Triple representation of language, working memory, social and emotion processing in the cerebellum: convergent evidence from task and seed-based resting-state fMRI analyses in a single large cohort. Neuroimage. 2018;172:437-449. https://doi.org/10.1016/j.neuroimage.2018.01.082.

  9. 9.

    Sokolov AA, Miall RC, Ivry RB. The cerebellum: adaptive prediction for movement and cognition. Trends Cogn Sci. 2017;21:313–32. https://doi.org/10.1016/j.tics.2017.02.005.

  10. 10.

    Bernard JA, Orr JM, Dean DJ, Mittal VA. The cerebellum and learning of non-motor associations in individuals at clinical-high risk for psychosis. Neuroimage Clin. 2018;19:137–46. https://doi.org/10.1016/j.nicl.2018.03.023.

  11. 11.

    Ito M. Control of mental activities by internal models in the cerebellum. Nat Rev Neurosci. 2008;9:304.

  12. 12.

    Ghajar J, Ivry RB. The predictive brain state: asynchrony in disorders of attention? Neuroscientist. 2009;15:232–42.

  13. 13.

    Brown SM, Kieffaber PD, Carroll CA, Vohs JL, Tracy JA, Shekhar A, et al. Eyeblink conditioning deficits indicate timing and cerebellar abnormalities in schizophrenia. Brain Cogn. 2005;58:94–108. https://doi.org/10.1016/j.bandc.2004.09.011.

  14. 14.

    Daum I, Schugens MM, Ackermann H, Lutzenberger W, Dichgans J, Birbaumer N. Classical conditioning after cerebellar lesions in humans. Behav Neurosci. 1993;107:748.

  15. 15.

    Topka H, Valls-Solé J, Massaquoi SG, Hallett M. Deficit in classical conditioning in patients with cerebellar degeneration. Brain. 1993;116:961–9.

  16. 16.

    Woodruff-Pak DS, Papka M, Ivry RB. Cerebellar involvement in eyeblink classical conditioning in humans. Neuropsychology. 1996;10:443.

  17. 17.

    Christian KM, Thompson RF. Neural substrates of eyeblink conditioning: acquisition and retention. Learn Mem. 2003;10:427–55. https://doi.org/10.1101/lm.59603.

  18. 18.

    Christian KM, Thompson RF. Neural substrates of eyeblink conditioning: acquisition and retention. Learn Mem. 2003;10:427–55.

  19. 19.

    Kim JJ, Thompson RF. Cerebellar circuits and synaptic mechanisms involved in classical eyeblink conditioning. Trends Neurosci. 1997;20:177–81.

  20. 20.

    Steinmetz JE. Brain substrates of classical eyeblink conditioning: a highly localized but also distributed system. Behav Brain Res. 2000;110:13–24. https://doi.org/10.1016/s0166-4328(99)00181-3.

  21. 21.

    Logan CG, Grafton ST. Functional anatomy of human eyeblink conditioning determined with regional cerebral glucose metabolism and positron-emission tomography. Proc Natl Acad Sci U S A. 1995;92:7500–4.

  22. 22.

    Gerwig M, Kolb F, Timmann D. The involvement of the human cerebellum in eyeblink conditioning. Cerebellum. 2007;6:38.

  23. 23.

    McCormick DA, Thompson RF. Cerebellum: essential involvement in the classically conditioned eyelid response. Science. 1984;223:296–9.

  24. 24.

    Freeman JH. Cerebellar learning mechanisms. Brain Res. 1621;2015:260–9. https://doi.org/10.1016/j.brainres.2014.09.062.

  25. 25.

    Forsyth JK, Bolbecker AR, Mehta CS, Klaunig MJ, Steinmetz JE, O’Donnell BF, et al. Cerebellar-dependent eyeblink conditioning deficits in schizophrenia spectrum disorders. Schizophr Bull. 2012;38:751–9. https://doi.org/10.1093/schbul/sbq148.

  26. 26.

    Bolbecker AR, Mehta C, Johannesen JK, Edwards CR, O’Donnell BF, Shekhar A, et al. Eyeblink conditioning anomalies in bipolar disorder suggest cerebellar dysfunction. Bipolar Disord. 2009;11:19–32.

  27. 27.

    Sears LL, Finn PR, Steinmetz JE. Abnormal classical eye-blink conditioning in autism. J Autism Dev Disord. 1994;24:737–51.

  28. 28.

    Jacobson SW, Jacobson JL, Stanton ME, Meintjes EM, Molteno CD. Biobehavioral markers of adverse effect in fetal alcohol spectrum disorders. Neuropsychol Rev. 2011;21:148–66. https://doi.org/10.1007/s11065-011-9169-7.

  29. 29.

    Skosnik PD, Edwards CR, O’Donnell BF, Steffen A, Steinmetz JE, Hetrick WP. Cannabis use disrupts eyeblink conditioning: evidence for cannabinoid modulation of cerebellar-dependent learning. Neuropsychopharmacology. 2008;33.

  30. 30.

    Rampersad SM, Janssen AM, Lucka F, Aydin Ü, Lanfer B, Lew S, et al. Simulating transcranial direct current stimulation with a detailed anisotropic human head model. IEEE Trans Neural Syst Rehabil Eng. 2014;22:441–52.

  31. 31.

    Brunoni AR, Nitsche MA, Bolognini N, Bikson M, Wagner T, Merabet L, et al. Clinical research with transcranial direct current stimulation (tDCS): challenges and future directions. Brain Stimul. 2012;5:175–95.

  32. 32.

    Beyer L, Batsikadze G, Timmann D, Gerwig M. Cerebellar tDCS effects on conditioned eyeblinks using different electrode placements and stimulation protocols. Front Hum Neurosci. 2017;11:23.

  33. 33.

    van der Vliet R, Jonker Z, Louwen S, Heuvelman M, de Vreede L, Ribbers G, et al. Cerebellar transcranial direct current stimulation interacts with BDNF Val66Met in motor learning. Brain Stimul. 2018;11:759–71.

  34. 34.

    Zuchowski ML, Timmann D, Gerwig M. Acquisition of conditioned eyeblink responses is modulated by cerebellar tDCS. Brain Stimul. 2014;7:525–31.

  35. 35.

    Liu A, Voroslakos M, Kronberg G, Henin S, Krause MR, Huang Y, et al. Immediate neurophysiological effects of transcranial electrical stimulation. Nat Commun. 2018;9:5092. https://doi.org/10.1038/s41467-018-07233-7.

  36. 36.

    Ferrucci R, Cortese F, Priori A. Cerebellar tDCS: how to do it. Cerebellum. 2015;14:27–30. https://doi.org/10.1007/s12311-014-0599-7.

  37. 37.

    Nosek BA, Spies JR, Motyl M. Scientific utopia: II. restructuring incentives and practices to promote truth over publishability. 2012;7:615–31.

  38. 38.

    Brunoni A, Amadera J, Berbel B, Volz M, Rizzerio B, Fregni F. A systematic review on reporting and assessment of adverse effects associated with transcranial direct current. Int J Neuropsychopharmacol. 2011;14:1133–45.

  39. 39.

    Kessler S, Turkeltaub P, Benson J, Hamilton R. Differences in the experience of active and sham transcranial direct current stimulation. Brain Stimul. 2012;5:155–62.

  40. 40.

    Brown S, Kieffaber P, Carroll C, Vohs J, Tracy J, Shekhar A, et al. Eyeblink conditioning deficits indicate timing and cerebellar abnormalities in schizophrenia. Brain Cogn. 2005;58:94–108.

  41. 41.

    Lang P, MK G. The international affective picture system standardization procedure and initial group results for affective judgements: technical report 1A: The Center for Research in Psychophysiology, University of Florida; 1988.

  42. 42.

    King D and Tracy J. DataMunch: a Matlab m-file collection available for the analysis of trial-based spike and behavioral data. 1999.

  43. 43.

    Oristaglio J, Hyman West S, Ghaffari M, Lech MS, Verma BR, Harvey JA, et al. Children with autism spectrum disorders show abnormal conditioned response timing on delay, but not trace, eyeblink conditioning. Neuroscience. 2013;248:708–18. https://doi.org/10.1016/j.neuroscience.2013.06.007.

  44. 44.

    Parker KL, Andreasen NC, Liu D, Freeman JH, O’Leary DS. Eyeblink conditioning in unmedicated schizophrenia patients: a positron emission tomography study. Psychiatry Res. 2013;214:402–9. https://doi.org/10.1016/j.pscychresns.2013.07.006.

  45. 45.

    Welsh JP, Oristaglio JT. Autism and classical eyeblink conditioning: performance changes of the conditioned response related to autism spectrum disorder diagnosis. Front Psych. 2016;7:137. https://doi.org/10.3389/fpsyt.2016.00137.

  46. 46.

    Steinmetz AB, Freeman JH. Retention and extinction of delay eyeblink conditioning are modulated by central cannabinoids. Learn Mem. 2011;18:634–8. https://doi.org/10.1101/lm.2254111.

  47. 47.

    Lipp J, Dragnova R, Batsikadze G, Ernst T, Uengoer D, Timmann D. Prefrontal but not cerebellar tDCS attenuates renewal of extinguished conditioned eyeblink responses. Neurobiol Learn Mem. 2019.

  48. 48.

    Kronberg G, Bridi M, Abel T, Bikson M, Parra LC. Direct current stimulation modulates LTP and LTD: activity dependence and dendritic effects. Brain Stimul. 2017;10:51–8. https://doi.org/10.1016/j.brs.2016.10.001.

  49. 49.

    Huang Y, Datta A, Bikson M, Parra LC. Realistic vOlumetric-Approach to Simulate Transcranial Electric Stimulation—ROAST—a fully automated open-source pipeline. J Neural Eng. 2019. https://doi.org/10.1088/1741-2552/ab208d.

  50. 50.

    Rezaee Z, Dutta A. Cerebellar Lobules Optimal Stimulation (CLOS): a computational pipeline to optimize cerebellar lobule-specific electric field distribution. Front Neurosci. 2019;13:266. https://doi.org/10.3389/fnins.2019.00266.

  51. 51.

    Grimaldi G, Argyropoulos GP, Bastian A, Cortes M, Davis NJ, Edwards DJ, et al. Cerebellar transcranial direct current stimulation (ctDCS) a novel approach to understanding cerebellar function in health and disease. Neuroscientist. 2016;22:83–97.

  52. 52.

    Stagg C, Best J, Stephenson M, O’Shea J, Wylezinska M, Kincses Z, et al. Polarity-sensitive modulation of cortical neurotransmitters by transcranial stimulation. J Neurosci. 2009;29:5202–6.

  53. 53.

    Ferrucci R, Bortolomasi M, Vergari M, Tadini L, Salvoro B, Giacopuzzi M, et al. Transcranial direct current stimulation in severe, drug-resistant major depression. J Affect Disord. 2009;118:215–9.

  54. 54.

    Brunelin J, Mondino M, Gassab L, Haesebaert F, Gaha L, Suaud-Chagny M-F, et al. Examining transcranial direct-current stimulation (tDCS) as a treatment for hallucinations in schizophrenia. Am J Psychiatry. 2012;169:719–24.

Download references


We wish to thank Karen Lorite-Gomez for her assistance with the data collection.


This work was supported by the National Institutes of Health (grant number T32 MH103213 to WPH, ABM, and NBL; R01 MH074983 to WPH; R21 MH091774 to BFO; Indiana Clinical and Translational Sciences Institute award TL1 TR001107 and UL1 TR001108 to ABM), the National Science Foundation (Graduate Research Fellowship Program Award 1342962 to NBL), and the Brain and Behavior Research Foundation (NARSAD Young Investigator Award to ARB).

Author information

Correspondence to William P. Hetrick.

Ethics declarations

Conflict of Interest

The authors declare that they have no conflict of interest.

Ethical Approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee (Indiana University Institutional Review Board protocol no. 1508694422) and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

Informed Consent

Informed consent was obtained from all individual participants included in the study.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Mitroi, J., Burroughs, L.P., Moussa-Tooks, A.B. et al. Polarity- and Intensity-Independent Modulation of Timing During Delay Eyeblink Conditioning Using Cerebellar Transcranial Direct Current Stimulation. Cerebellum (2020). https://doi.org/10.1007/s12311-020-01114-w

Download citation


  • Cerebellum
  • Transcranial direct current stimulation
  • Associative learning
  • Eyeblink conditioning
  • Polarity
  • Intensity