Distinct Haptic Cues Do Not Reduce Interference when Learning to Reach in Multiple Force Fields

Background: Previous studies of learning to adapt reaching movements in the presence of novel forces show that learning multiple force fields is prone to interference. Recently it has been suggested that force field learning may reflect learning to manipulate a novel object. Within this theoretical framework, interference in force field learning may be the result of static tactile or haptic cues associated with grasp, which fail to indicate changing dynamic conditions. The idea that different haptic cues (e.g. those associated with different grasped objects) signal motor requirements and promote the learning and retention of multiple motor skills has previously been unexplored in the context of force field learning. Methodology/Principle Findings: The present study tested the possibility that interference can be reduced when two different force fields are associated with differently shaped objects grasped in the hand. Human subjects were instructed to guide a cursor to targets while grasping a robotic manipulandum, which applied two opposing velocity-dependent curl fields to the hand. For one group of subjects the manipulandum was fitted with two different handles, one for each force field. No attenuation in interference was observed in these subjects relative to controls who used the same handle for both force fields. Conclusions/Significance: These results suggest that in the context of the present learning paradigm, haptic cues on their own are not sufficient to reduce interference and promote learning multiple force fields

The Effects of Tablets on Learning: Does Studying from a Tablet Computer Affect Student Learning Differently Across Educational Levels

In recent years, students and educators alike have utilized new technologies such as tablet computers as a means of enhancing the learning process. While prior research suggests that these implementations within the classroom provide a new and beneficial method of relaying and learning information, scientists have begun to explore the possible side effects that these technologies have on the learning process. Although much of the current literature suggests that learning from an electronic screen does not affect efficacy compared to learning from printed text (Bayliss et al., 2012; Dundar & Akcayir, 2012), researchers continue to explore the possible consequences that using said technologies may have in academia. The current study aims to address how tablet computers affect the process of learning differently across levels of education. It is proposed that older generations, such as college students, who did not grow up with tablets in the classroom may suffer from the effects of proactive interference when compared to younger students who have been exposed to technologies much more profoundly in their education (e.g. elementary students). If this is so, the current study also proposes a possible intervention that would help students at any educational level overcome this interference in order to integrate tablets into their studies effectively

Interference in Ballistic Motor Learning: Specificity and Role of Sensory Error Signals

Humans are capable of learning numerous motor skills, but newly acquired skills may be abolished by subsequent learning. Here we ask what factors determine whether interference occurs in motor learning. We speculated that interference requires competing processes of synaptic plasticity in overlapping circuits and predicted specificity. To test this, subjects learned a ballistic motor task. Interference was observed following subsequent learning of an accuracy-tracking task, but only if the competing task involved the same muscles and movement direction. Interference was not observed from a non-learning task suggesting that interference requires competing learning. Subsequent learning of the competing task 4 h after initial learning did not cause interference suggesting disruption of early motor memory consolidation as one possible mechanism underlying interference. Repeated transcranial magnetic stimulation (rTMS) of corticospinal motor output at intensities below movement threshold did not cause interference, whereas suprathreshold rTMS evoking motor responses and (re) afferent activation did. Finally, the experiments revealed that suprathreshold repetitive electrical stimulation of the agonist (but not antagonist) peripheral nerve caused interference. The present study is, to our knowledge, the first to demonstrate that peripheral nerve stimulation may cause interference. The finding underscores the importance of sensory feedback as error signals in motor learning. We conclude that interference requires competing plasticity in overlapping circuits. Interference is remarkably specific for circuits involved in a specific movement and it may relate to sensory error signals

To Examine the Effects of Exercise & Instructional Based Interventions on Executive Functioning, Motor Learning & Emotional Intelligence Abilities Among Older Adults

Motor skills are a vital part of our life, and there might be situations where we will be required to either learn a new skill or relearn a known one. We examined the effectiveness of two different interventions - eccentric exercise and motivation-based instructions on enhancing the ability of older adults to learn a novel motor skill. Exercise intervention studies have shown that as little as 12 weeks of exercise can lead to improvements in both physical fitness and cognitive function in older adults, particularly executive control. But it is still unclear whether those improvements translate to improvements in other domains that rely on executive control, like motor skill learning and emotional intelligence. Study 1 explored the effect of eccentric exercise on these domains, specifically the ability to handle proactive interference in motor learning. 22 healthy adults (65-85 years of age) were recruited and randomly assigned either to a non-exercise control group, or to an exercise intervention group that performed 12 weeks of low to moderate intensity eccentric leg exercise (Eccentron). Corresponding neurophysiological measures were also recorded using EEG. We found that the control group experienced more proactive interference from baseline learning to post-test compared to the exercise group. The latter also displayed a higher level of emotional processing abilities than controls. They provide preliminary evidence that the cognitive benefits of exercise for older adults can be extended to domains outside of but related to executive control and memory. In study 2, we examined the effectiveness of an intervention based on the OPTIMAL theory of motor learning and performance on skill acquisition in both younger and older adults. We recruited 39 younger adults and 30 older adults and randomly assigned them to either the experimental group or to the control group. The intervention affected the two groups differentially. It was somewhat successful at improving learning in the older adults, but not in the younger adults. In fact, the intervention may have interfered with learning in the latter

Interazione tra cTBS cerebellare e movimenti volontari semplici e complessi dell'arto superiore : nuove acquisizioni sui processi di plasticità omeostati e di formazione della memoria motoria

The aim of the present study was to investigate in healthy subjects whether continuous theta-burst stimulation (cTBS) applied over the lateral cerebellum alters motor learning (acquisition and retention phases) during ipsilateral simple and complex movements. Eighteen healthy subjects participated in the study. We delivered cTBS over the lateral cerebellum immediately before a motor learning task involving repeated simple (i.e. index finger-abductions) and complex (i.e. reaching) movements. As motor learning measures we evaluated kinematic variables for simple and complex movements during the task. To see whether cerebellar cTBS-induced changes in motor learning take place through changes in primary motor cortex (M1) activity we used single-pulse transcranial magnetic stimulation (TMS) and evaluated changes in motor evoked potential (MEP) amplitude throughout the experiment. Cerebellar cTBS left the practice-related increase in peak acceleration unchanged but decreased peak acceleration for index finger and reaching movements during motor retention. The smoothness and straightness for trajectories related to reaching movements remained unchanged. When subjects repeated simple and complex movements performed alone, M1 excitability, as measured by the TMS-induced MEP facilitation, increased and MEP amplitudes increased more during simple movements than during complex movements. Cerebellar cTBS given before simple and complex movement tasks decreased the MEP facilitation induced by simple movements, whereas it increased the MEP facilitation induced by complex movements. During simple and complex movement tasks testing motor learning, no matter how complicated the motor task, cerebellar cTBS interferes with motor memory formation. cTBS induces changes in cerebellar activity thus altering motor-learning-related synaptic activity in M1

Interazione tra cTBS cerebellare e movimenti volontari semplici e complessi dell'arto superiore : nuove acquisizioni sui processi di plasticità omeostati e di formazione della memoria motoria

The aim of the present study was to investigate in healthy subjects whether continuous theta-burst stimulation (cTBS) applied over the lateral cerebellum alters motor learning (acquisition and retention phases) during ipsilateral simple and complex movements. Eighteen healthy subjects participated in the study. We delivered cTBS over the lateral cerebellum immediately before a motor learning task involving repeated simple (i.e. index finger-abductions) and complex (i.e. reaching) movements. As motor learning measures we evaluated kinematic variables for simple and complex movements during the task. To see whether cerebellar cTBS-induced changes in motor learning take place through changes in primary motor cortex (M1) activity we used single-pulse transcranial magnetic stimulation (TMS) and evaluated changes in motor evoked potential (MEP) amplitude throughout the experiment. Cerebellar cTBS left the practice-related increase in peak acceleration unchanged but decreased peak acceleration for index finger and reaching movements during motor retention. The smoothness and straightness for trajectories related to reaching movements remained unchanged. When subjects repeated simple and complex movements performed alone, M1 excitability, as measured by the TMS-induced MEP facilitation, increased and MEP amplitudes increased more during simple movements than during complex movements. Cerebellar cTBS given before simple and complex movement tasks decreased the MEP facilitation induced by simple movements, whereas it increased the MEP facilitation induced by complex movements. During simple and complex movement tasks testing motor learning, no matter how complicated the motor task, cerebellar cTBS interferes with motor memory formation. cTBS induces changes in cerebellar activity thus altering motor-learning-related synaptic activity in M1