Providing Explicit Information Disrupts Implicit Motor Learning After Basal Ganglia Stroke

Abstract

Despite their purported neuroanatomic and functional isolation, empirical evidence suggests that sometimes conscious explicit processes can influence implicit motor skill learning. Our goal was to determine if the provision of explicit information affected implicit motor-sequence learning after damage to the basal ganglia. Individuals with stroke affecting the basal ganglia (BG) and healthy controls (HC) practiced a continuous implicit motor-sequencing task; half were provided with explicit information (EI) and half were not (No-EI). The focus of brain damage for both BG groups was in the putamen. All of the EI participants were at least explicitly aware of the repeating sequence. Across three days of practice, explicit information had a differential effect on the groups. Explicit information disrupted acquisition performance in participants with basal ganglia stroke but not healthy controls. By retention (day 4), a dissociation was apparent-explicit information hindered implicit learning in participants with basal ganglia lesions but aided healthy controls. It appears that after basal ganglia stroke explicit information is less helpful in the development of the motor plan than is discovering a motor solution using the implicit system alone. This may be due to the increased demand placed on working memory by explicit information. Thus, basal ganglia integrity may be a crucial factor in determining the efficacy of explicit information for implicit motor-sequence learning.Explicit learning and memory are neuroanatomically sub-served by discrete regions within the medial temporal lobe that support conscious recollection of events and facts. Because no single lesion completely eliminates the development of procedural memories (although many severely disrupt them) the identification of the particular neuroanatomic structures that mediate implicit memory is not entirely clear. Studies of individuals with local damage (Vakil et al. 2000) or degenerative disease (Doyon et al. 1997) demonstrate that the basal ganglia are one of the regions that support implicit motor-sequence learning.

Interference Effect of Prior Explicit Information on Motor Sequence Learning in Relapsing-Remitting Multiple Sclerosis Patients

“…The influence of EI on implicit learning has been disparately reported in the literature (12,(22)(23)(24)(25)(26)(27). The experimental data are rather controversial in that some investigators report the beneficial effects of EI on implicit motor learning (12,24,26), while other studies show detrimental effects (22)(23)27).…”

“…The experimental data are rather controversial in that some investigators report the beneficial effects of EI on implicit motor learning (12,24,26), while other studies show detrimental effects (22)(23)27). However, it seems that these contradictory findings may result from combined factors, such as task differences, type, timing and salience of EI, and personal characteristics (27).…”

“…Some studies suggest that explicit learning has a detrimental effect on implicit learning when cognitive capacity and working memory are reduced, such as in a cerebral vascular accident or healthy aged participants (27)(28)(29). These studies imply that simple practice without instruction and with general performance feedback, as opposed to explicit instruction, may lead to more efficient performance.…”

Refining the Continuous Tracking Paradigm to Investigate Implicit Motor Learning

“…Chambaron, Ginhac, Ferrel-Chapus, and Perruchet (2006) argued that the repeated segment originally used by Wulf and Schmidt (1997), and subsequently by others (e.g., Boyd & Winstein, 2004;Shea, Wulf, Whitacre, & Park, 2001), may have been easier to track than the random segments. Wulf and Schmidt (1997) tried to control for complexity by randomly selecting coefficients for their waveform pattern from a sine-cosine series function within a specified value range.…”

Structural and Functional Neuroimaging in the Investigation of the Brain Neuroplasticity in Post-Stroke Patients (Literature Review)

“…Многочисленные исследования показы-вают изменения нейронных сетей после инсульта, которые не зависят от спонтанных изменений, ас-социированных с восстановлением в острый пери-од [2,3]. Исследования других авторов [4][5][6][7][8] пока-зывают, что способность к нейропластическим из-менениям [9,10] сохраняются и в хронической ста-дии инсульта. Вероятно, существует зависимость между явлениями нейропластичности и обучением моторным навыкам [11].…”