Effect of focal cerebellar lesions on procedural learning in the serial reaction time task

Abstract

Prior studies have shown that procedural learning is severely impaired in patients with diffuse cerebellar damage (cortical degeneration) as measured by the serial reaction time task (SRTT). We hypothesize that focal cerebellar lesions can also have lateralized effects on procedural learning. Our objective was to assess the effects of focal cerebellar lesions in procedural learning as measured by the SRTT. We studied 14 patients with single, unilateral vascular lesions in the territory of the posterior-inferior or superior cerebellar artery, who were compared with ten age- and sex-matched controls in a one-handed version of the SRTT. Patients with lesions at any other level of the brain or posterior fossa were excluded by cranial magnetic resonance imaging. Our results show that patients do not acquire procedural knowledge when performing the task with the hand ipsilateral to the lesion, but show normal learning with the contralateral hand. No correlation was found with the side, size, or vascular territory of the lesion. We conclude that procedural learning is impaired in hemispheric cerebellar lesions and involves only the hand ipsilateral to the lesion, which suggests a critical role for the cerebellum and/or crossed cerebellar-prefrontal connections in this type of learning.

Learning of Sensory Sequences in Cerebellar Patients

“…These results are at variance with previous studies. An involvement of the human cerebellum in procedural learning of visuomotor sequences by performing a serial reaction-time task was shown by Gomez-Beldarrain et al (1998) and Molinari et al (1997). Differences in findings between these studies and the present study may be explained by differences in motor demands of the tasks, that is, deficits of cerebellar patients in sequence learning may increase with increasing motor requirements.…”

“…Although effects of oculomotor deficits cannot be excluded, motor requirements were less demanding compared to previous studies of learning of visuomotor sequences. Here, subjects had to press different response buttons for different visual items presented on a monitor (Molinari et al 1997;Gomez-Beldarrain et al 1998). Likewise, in previous studies of our group of stimulus-response and stimulusstimulus-response associations, subjects were required to release a rest button and push one of two response buttons (Drepper et al 1999;Maschke et al 2002;Timmann et al 2002).…”

“…An involvement of the cerebellum in procedural learning of visuomotor sequences has been shown in human subjects by several studies (Molinari et al 1997;Gomez-Beldarrain et al 1998). However, it is difficult to dissociate motor functions from learning functions in a motor-learning paradigm.…”

Cerebellar Stroke Impairs Temporal but not Spatial Accuracy during Implicit Motor Learning

“…Because damage to the cerebellum impairs skill acquisition, [6][7][8][9] it is considered to be a member of the neural network supporting implicit motor learning. Converging evidence for this view comes from neuroimaging data that commonly demonstrate cerebellar activity during skill practice.…”

“…Converging evidence for this view comes from neuroimaging data that commonly demonstrate cerebellar activity during skill practice. [10][11][12] Much of this work has used the serial reaction time (SRT) task, [6][7][8][9] in which participants practice a repeated sequence of keypresses but are unaware of repetition in their responses. 2 Deficient SRT task learning (as indexed by slowed response times and poor key-press accuracy) following damage to the cerebellum has solidified the conclusion that the cerebellum is important for implicit motor learning.…”