Behavioural Brain Research 228 (2012) 219–231 Contents lists available at SciVerse ScienceDirect Behavioural Brain Research j ourna l ho mepage: www.elsevier.com/locate/bbr Review Learning–performance distinction and memory processes for motor skills: A focused review and perspective Shailesh S. Kantak a,b,* , Carolee J. Winstein a,c a Motor Behavior and Neurorehabilitation Laboratory, Division of Biokinesiology and Physical Therapy at the Herman Ostrow School of Dentistry, University of Southern California, 1540 E. Alcazar Street, CHP 155, Los Angeles, CA 90089, USA b Neuroplasticity and Imaging Laboratory, Division of Biokinesiology and Physical Therapy at the Herman Ostrow School of Dentistry, University of Southern California, 1540 E. Alcazar Street, CHP 155, Los Angeles, CA 90089, USA c Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA a r t i c l e i n f o Article history: Received 22 September 2011 Received in revised form 17 November 2011 Accepted 21 November 2011 Available online 28 November 2011 Keywords: Motor learning Performance Motor memory a b s t r a c t Behavioral research in cognitive psychology provides evidence for an important distinction between immediate performance that accompanies practice and long-term performance that reflects the relative permanence in the capability for the practiced skill (i.e. learning). This learning–performance distinc- tion is strikingly evident when challenging practice conditions may impair practice performance, but enhance long-term retention of motor skills. A review of motor learning studies with a specific focus on comparing differences in performance between that at the end of practice and at delayed retention suggests that the delayed retention or transfer performance is a better indicator of motor learning than the performance at (or end of) practice. This provides objective evidence for the learning–performance distinction. This behavioral evidence coupled with an understanding of the motor memory processes of encoding, consolidation and retrieval may provide insight into the putative mechanism that imple- ments the learning–performance distinction. Here, we propose a simplistic empirically-based framework – motor behavior–memory framework – that integrates the temporal evolution of motor memory pro- cesses with the time course of practice and delayed retention frequently used in behavioral motor learning paradigms. In the context of the proposed framework, recent research has used noninvasive brain stim- ulation to decipher the role of each motor memory process, and specific cortical brain regions engaged in motor performance and learning. Such findings provide beginning insights into the relationship between the time course of practice-induced performance changes and motor memory processes. This in turn has promising implications for future research and practical applications. © 2011 Elsevier B.V. All rights reserved. Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 2. Learning–performance distinction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 2.1. Assessment of motor performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 2.2. Retention/transfer tests to assess motor learning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 2.3. The timing of the retention/transfer tests: immediate vs. delayed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 3. Motor memory processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222 3.1. Encoding of motor memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222 3.2. Selective interference to encoding phase attenuates the contextual interference effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 3.3. Motor memory consolidation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 3.4. Selective interference to motor memory consolidation provides insights in to the CI effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 3.5. Retrieval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 * Corresponding author. Present address: Department of Physical Therapy and Rehabilitation Science, School of Medicine, University of Maryland, Baltimore, MD 21201, USA. Tel.: +1 410 706 3242/213 210 4465; fax: +1 410 706 6387. E-mail address: skantak@som.umaryland.edu (S.S. Kantak). 0166-4328/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.bbr.2011.11.028