A Comparison of Implicit and Explicit Motor Sequence Learning in Patients with Relapsing-Remitting Multiple Sclerosis

Abstract

This study tends to assess implicit and explicit types of motor learning in patients with Multiple Sclerosis (MS) and normal peers by means of a serial reaction time. Sample size was 15 for each group and Samples included 30 patients with MS and 30 normal peers and were assigned to implicit and explicit learning groups. A repeated measures ANOVA was used for measuring reaction time and response error, and a paired samples t-test was used to compare regular and irregular sequence data in each group. Comparison of these two types of learning in speed (response time) and accuracy (number of errors) showed the number of errors (P = 0.012) and response time (P = 0.012) in the implicit motor learning group of MS patients and the number of errors (P = 0.096) and response time (P = 0.954) in the explicit motor learning group of MS patients. Moreover, comparison showed the number of errors (P = 0.008) and response time (P = 0.05) in the implicit group of normal peers and the number of errors (P = 0.011) and response time (P = 0.442) in the explicit group of normal peers. The results showed that explaining and describing the task is less effective at training the motor sequence of MS patients and that these patients benefit more from implicit learning.

Motor sequence learning in a goal‐directed stepping task in persons with multiple sclerosis: a pilot study

“…This provides evidence for sequence-specific motor learning in a complex, whole-body movement stepping task in pwMS. In pwMS, this paradigm was thus far only performed with upper limb tasks, 12,17,18 but the findings are in accordance with a previous study in older adults that showed sequence-specific postural motor learning during a postural control weightshifting task. 63 Some studies that applied the SRT paradigm in reaching or weight-shifting tasks made a distinction between response initiation (i.e., a measure of anticipation or plan-based control) and movement time (i.e., a measure of movement optimization and online control), reflecting different motor and cognitive processes.…”

“…Furthermore, sample characteristics might moderate findings on sequence learning. Previous studies on sequence learning in pwMS included persons with low (quantified by EDSS ≤2) 18,20,21 or moderate to severe 12,17,19,22 disability, with the latter being most comparable to the sample in the present study in which on average moderately impaired pwMS (EDSS 3.4 ± 1.2) participated. Nevertheless, the literature reports contrasting findings regarding the learning rate of explicit compared with implicit learning in these studies, therefore, not providing explanations in light of disability.…”

“…Sequence learning has occurred when reaction times and/or errors are decreased in the repeated sequences as compared with random stimuli. 23,24 Studies comparing motor sequence learning in upper-limb tasks between pwMS and healthy adults indicated, in general, similar performance improvements during implicit conditions, but reduced improvements under explicit conditions, 12,13,[17][18][19] although contrastingly Tacchino et al reported no improvements for pwMS in the implicit condition, while healthy adults did improve. 21 Furthermore, only four studies examined both implicit and explicit learning conditions within pwMS, and contrasting results were reported on differences between those conditions in pwMS, with two studies reporting less learning in explicit conditions 17,18 and two in implicit conditions.…”

“…23,24 Studies comparing motor sequence learning in upper-limb tasks between pwMS and healthy adults indicated, in general, similar performance improvements during implicit conditions, but reduced improvements under explicit conditions, 12,13,[17][18][19] although contrastingly Tacchino et al reported no improvements for pwMS in the implicit condition, while healthy adults did improve. 21 Furthermore, only four studies examined both implicit and explicit learning conditions within pwMS, and contrasting results were reported on differences between those conditions in pwMS, with two studies reporting less learning in explicit conditions 17,18 and two in implicit conditions. 12,21 However, in pwMS, motor impairments in walking and balance are prevalent, and it is unknown whether the findings on motor sequence learning from the abovementioned upper-limb tasks generalize to motor tasks involving dynamic balance.…”

“…Sequential movements are an essential component in daily life functioning, 16 think of typing, tying a knot, or riding a bike. Experimentally, these seven studies all used a serial reaction time (SRT) paradigm involving the upper limb, such as key pressing tasks, 12,[17][18][19] touching the right finger with the thumb, 20,21 or an isometric visuomotor tracking task. 22 Within this paradigm, participants are required to react as fast as possible to certain stimuli, while repeated sequences of stimuli are hidden between random stimuli, either known (explicit) or unbeknownst (implicit) to the participant.…”