Siegert et al. Supplementary Online Material

Appendix 1 - References for 20 studies using SRT task1

Brown, R. G., Jahanshahi, M., Limousin-Dowsey, P., Thomas, D., Quinn, N. P., & Rothwell, J. C. (2003). Pallidotomy and incidental sequence learning in Parkinson's disease. NeuroReport, 14(1), 21-24.*

Dominey, P. F., Ventre-Dominey, J., Broussolle, E. & Jeannerod, M. (1996). Analogical transfer is effective in a serial reaction time task in Parkinson'e disease: Evidence for a dissociable form of sequence learning. Neuropsychologia, 35, (1), 1-9. **

Doyon, J., Gaudreau, D., Laforce Jr., R., Castonguay, M., Bédard, P. J., Bédard, F., & Bouchard, J.-P. (1997). Role of the striatum, cerebellum, and frontal lobes in the learning of a visuomotor sequence. Brain and Cognition, 34, 218-245.**

Doyon, J., Laforce Jr., R., Bouchard, G., Gaudreau, D., Roy, J., Poirier, M., Bédard, P. J., Bédard, F., & Bouchard, J.-P. (1998). Role of the striatum, cerebellum, and frontal lobes in the automatization of a repeated visuomotor sequence of movements. Neuropsychologia, 36, (7), 625-641.**

Ferraro, F. R., Balota, D. A., & Connor, L. T. (1993). Implicit memory and formation of new associations in nondemented Parkinson's disease individuals and individuals with senile dementia of the Alzheimer type: A serial reaction time (SRT) investigation. Brain and Cognition, 21, 163-180.*

Ghilardi, M.-F., Eidelberg, D., Silvestri, G., & Ghez, C. (2003). The differential effect of PD and normal aging on early explicit sequence learning. Neurology, 60, 1313-1319.**

Helmuth, L. L., Mayr, U., & Daum, I. (2000). Sequence learning in Parkinson's disease: a comparison of spatial-attention and number-response sequences. Neuropsychologia, 38, 1443-1451.**

Jackson, G. M., Jackson, S. R., Harrison, J., Henderson, L., & Kennard, C. (1995). Serial reaction time learning and Parkinson's disease: Evidence for a procedural learning deficit. Neuropsychologia, 33, 577-593.**

Kelly, S. W., Janhanshahi, M., & Dirnberger, G. (2004). Learning of ambiguous versus hybrid sequences by patients with Parkinson's disease. Neuropsychologia, 42, 1350-1357.*

Laforce Jr., R. & Doyon, J. (2001). Distinct contribution of the striatum and cerebellum to motor learning. Brain and Cognition, 45, 189-211.**

Pascual-Leone, A., Grafman, J., Clark, K., Stewart, M., Massaquoi, S., Lou, J.-S., & Hallett, M. (1993). Procedural learning in Parkinson's disease and cerebellar degeneration. Annals of Neurology, 34(4), 594-602.*

Pascual-Leone, A., Valls-Sole, J., Brasil-Neto, J. P., Cammarota, A., Grafman, J., & Hallett, M. (1994). Akinesia in Parkinson's disease. II. Effects of subthreshold repetitive transcranial motor cortex stimulation. Neurology, 44, 892-898.*

Shin, J. C., & Ivry, R. B. (2003). Spatial and temporal sequence learning in patients with Parkinson's disease or cerebellar lesions. Journal of Cognitive Neuroscience, 15(8), 1232-1243.*

Smith, J. G., & McDowall, J. (2004). impaired higher order implicit sequence learning on the verbal version of the Serial Reaction Time task in patients with Parkinson's disease. Neuropsychology, 18(4), 679-691.*

Smith, J., Siegert, R. J., & McDowall, J. (2001). Preserved implict learning on both the serial reaction time task and artificial grammar in patients with parkinson's disease. Brain and Cognition, 45, 378-391.*

Sommer, M., Grafman, J., Clark, K., & Hallett, M. (1999). Learning in Parkinson's disease: eyeblink conditioning, declarative learning, and procedural learning. Journal of Neurology, Neurosurgery and Psychiatry, 67, 27-34.*

Stefanova, E. D., Kostic, V. S., Ziropadja, L., Markovic, M., & Ocic, G. C. (2000). Visuomotor skill learning on Serial Reaction Time task in patients with early Parkinson's disease. Movement Disorders, 15(6), 1095-1103.*

Werheid, K., Ziessler, M., Nattkemper, D., & von Cramen, D. Y. (2003). Sequence learning in Parkinson's disease: The effect of spatial-stimulus response compatibility. Brain and Cognition, 52, 239-249.*

Werheid, K., Zysset, S., Muller, A., Reuter, M., & von Cramen, D. Y. (2003). Rule learning in a serial reaction time task: An fMRI study on patients with early Parkinson's disease. Cognitive Brain Research, 16, 273-284.*

Westwater, H., McDowall, J., Siegert, R. J., Mossman, S., & Abernethy, D. (1998). Implicit learning in Parkinson's disease: Evidence from a verbal version of the serial reaction time task. Journal of Clinical and Experimental Neuropsychology, 20(1), 1-6.*

1NOTE: A single asterisk denotes a study that used the SRT task and included both sequence blocks and a randomised block. Two asterisks denote a study that either used the SRT task but did not include a block of random sequence trials or used a variation of the SRT task that was so different from the standard Nissen and Bullemer SRT task that it precluded inclusion in the meta-anlysis.

Appendix 2 - Process of inclusion of studies in the meta-analysis.

Appendix 3 – Results of the Funnel plot for PD implicit learning