BRIEF COMMUNICATION Motor and non-motor sequence learning in children and adolescents with cerebellar damage ANDREA BERGER, 1 MICHELLE SADEH, 2,3 GABRIEL TZUR, 1 AVINOAM SHUPER, 2,4 LIORA KORNREICH, 2,4 DOV INBAR, 2,4 IAN J. COHEN, 2,4 SHALOM MICHOWIZ, 2,4 ISAAC YANIV, 2,4 SHLOMI CONSTANTINI, 5 and ELI VAKIL 6 1 Ben-Gurion University of the Negev, Beer Sheva, Israel 2 Schneider Children’s Medical Center, Petach Tikva, Israel 3 Israel Cancer Association, Givataim, Israel 4 Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel 5 Dana Hospital, Sackler Faculty of Medicine, TelAviv University, TelAviv, Israel 6 Bar-Ilan University, Ramat Gan, Israel (Received August 25, 2004; Revised December 28, 2004; Accepted March 25, 2005) Abstract Cerebellar involvement in motor and non-motor sequence learning was examined with serial reaction time tasks (SRT). Our sample consisted of 8 children and adolescents who had undergone surgical removal of a benign posterior fossa tumor (PFT) during childhood. None of them had undergone chemotherapy or cranial radiation therapy (CRT). Ages ranged from 1–11 years at surgery and 9–17 years at testing. The children were tested not earlier than 2.5 years after surgery ( M 5 5.9 years), enabling brain plasticity and recovery of functions. Their performance was compared with a matched control sample. The PFT group was not impaired in the implicit learning of sequences, as reflected in their performance in blocks with a repeated sequence, both before and after a random block. However, in the perceptual task, their performance deteriorated more than that of the control group when a random block was introduced, suggesting that it was more difficult for the patients to respond flexibly or change their response set when encountering changing task demands. These results are in line with another study by our group on task switching with the same patients. ( JINS, 2005, 11, 482–487.) Keywords: Serial reaction time, Procedural learning, Motor learning, Perceptual learning, Cerebellum, Posterior fossa tumor INTRODUCTION Procedural learning refers to the acquisition of ability through practice. This acquisition can be purely implicit because it is reflected in improved performance, even without con- scious recognition or retrieval (Squire, 1992). In the SRT paradigm, procedural implicit learning is usually studied in terms of the learning of a repeated sequence of finger move- ments (Nissen & Bullemer, 1987). With practice, partici- pants usually learn the sequence implicitly, and responses become faster and more accurate even without conscious recognition of the sequence. At this point, changes in the stimuli order, such as switching to a random sequence, cause increases in reaction times and errors, which decrease again if the original sequence is reinstated. Implicit learning of the sequence occurs also in the perceptual 0non-motor ver- sion of the task, where the participants follow the sequence with their eyes instead of their fingers (Vakil et al., 2000). Although the exact brain network involved in procedural skill learning is still not fully understood, there is consistent evidence relating the basal ganglia to this kind of learning (Pascual-Leone et al., 1993; Vakil et al., 2000), and increas- ing evidence for the involvement of the cerebellum (Doyon, 1997; Laforce & Doyon, 2001; Friston et al., 1992; Grafton et al., 1995; Hallet & Grafman, 1997; Pascual-Leone et al., 1993; Seidler et al., 2002; Seitz et al., 1990). Imaging stud- Reprint requests to: Andrea Berger, Ph.D., Department of Behavioral Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105 Israel. E-mail: andrea@bgu.ac.il Journal of the International Neuropsychological Society (2005), 11, 482–487. Copyright © 2005 INS. Published by Cambridge University Press. Printed in the USA. DOI: 10.10170S1355617705050587 482