Asymmetrical intermanual transfer of learning in a sensorimotor task

Implicit visuospatial sequence representations are accessible in both the practice and the transfer hand

A serial reaction time task was used to test whether the representations of a probabilistic second-order sequence structure are (i) stored in an effector-dependent, effector-independent intrinsic or effector-independent visuospatial code and (ii) are inter-manually accessible. Participants were trained either with the dominant or non-dominant hand. Tests were performed with both hands in the practice sequence, a random sequence, and a mirror sequence. Learning did not differ significantly between left and right-hand practice, suggesting symmetric intermanual transfer from the dominant to the non-dominant hand and vice versa. In the posttest, RTs were shorter for the practice sequence than for the random sequence, and longest for the mirror sequence. Participants were unable to freely generate or recognize the practice sequence, indicating implicit knowledge of the probabilistic sequence structure. Because sequence-specific learning did not differ significantly between hands, we conclude that representations of the probabilistic sequence structure are stored in an effector-independent visuospatial code.

Neural correlates of transfer of learning in motor coordination tasks: role of inhibitory and excitatory neurometabolites

We aimed to investigate transfer of learning, whereby previously acquired skills impact new task learning. While it has been debated whether such transfer may yield positive, negative, or no effects on performance, very little is known about the underlying neural mechanisms, especially concerning the role of inhibitory (GABA) and excitatory (Glu) (measured as Glu + glutamine (Glx)) neurometabolites, as measured by magnetic resonance spectroscopy (MRS). Participants practiced a bimanual coordination task across four days. The Experimental group trained a task variant with the right hand moving faster than the left (Task A) for three days and then switched to the opposite variant (Task B) on Day4. The control group trained Task B across four days. MRS data were collected before, during, and after task performance on Day4 in the somatosensory (S1) and visual (MT/V5) cortex. Results showed that both groups improved performance consistently across three days. On Day4, the Experimental group experienced performance decline due to negative task transfer while the control group continuously improved. GABA and Glx concentrations obtained during task performance showed no significant group-level changes. However, individual Glx levels during task performance correlated with better (less negative) transfer performance. These findings provide a first window into the neurochemical mechanisms underlying task transfer.

Impact of handedness on interlimb transfer depending on the task complexity combined with motor and cognitive skills

PURPOSE

Task complexity could affect acquisition efficiency of motor skills and interlimb transfer; however, how task complexity affects interlimb transfer remains unclear. We hypothesized that left- and right-handed participants may have different interlimb transfer efficiency depending on the task complexity.

METHODS

Left-hand (n = 28) and right-hand (n = 28) dominant participants (age = 24.70 ± 4.02 years, male:female = 28:28) performed a finger sequence test with two levels of complexity (simple: one-digit with four fingers vs. complex: two-digit with five fingers) before and after ten trials of 2-min practice each on the same apparatus. The speed and task errors were measured and analyzed.

RESULTS

Right-handed participants failed to improve performance on their right hand (non-trained hand) after contralateral left-hand practice in the simple finger sequence task. In contrast, the left-handed participants improved performance on non-trained hands both right and left after contralateral practices. In the complex task, however, both the left- and right-handed participants improved performance on non-trained hands by contralateral practices.

CONCLUSION

Our results showed that task complexity of skilled practice gave different effects on interlimb transfer between right- and left-handed subjects. It appears that a certain level of appropriate complexity is necessary to detect inter-limb transfers in motor learning in right-handed subjects.

1894 revisited: Cross-education of skilled muscular control in women and the importance of representation

In 1894 foundational work showed that training one limb for “muscular power” (i.e. strength) or “muscular control” (i.e. skill) improves performance in both limbs. Despite that the original data were exclusively from two female participants (“Miss Smith” and “Miss Brown”), in the decades that followed, such “cross-education” training interventions have focused predominantly on improving strength in men. Here, in a female cohort, we revisit that early research to underscore that training a task that requires precise movements in a timely fashion (i.e. “muscular control”) on one side of the body is transferred to the contralateral untrained limb. With unilateral practice, women reduced time to completion and the number of errors committed during the commercially available game of Operation^® Iron Man 2 with both limbs. Modest reductions in bilateral Hoffmann (H-) reflex excitability evoked in the wrist flexors suggest that alterations in the spinal cord circuitry may be related to improvements in performance of a fine motor task. These findings provide a long overdue follow-up to the efforts of Miss Theodate L. Smith from more than 125 years ago, highlight the need to focus on female participants, and advocate more study of cross-education of skilled tasks.

The neural correlates of intermanual transfer

Intermanual transfer of motor learning is a form of learning generalization that leads to behavioral advantages in various tasks of daily life. It might also be useful for rehabilitation of patients with unilateral motor deficits. Little is known about neural structures and cognitive processes that mediate intermanual transfer. Previous studies have suggested a role for primary motor cortex (M1) and the supplementary motor area (SMA). Here, we investigated the functional neuroanatomy of intermanual transfer with a special emphasis on functional connectivity within the motor network and between motor regions and attentional networks, including the fronto-parietal executive control network and visual attention networks. We designed a finger tapping task, in which young, heathy subjects trained the non-dominant left hand in the MRI scanner. Behaviorally, transfer of sequence learning was observed in most cases, independently of the trained hand's performance. Pre- and post-training functional connectivity patterns of cortical motor seeds were investigated using generalized psychophysiological interaction analyses. Transfer was correlated with the strength of connectivity between the left premotor cortex and structures within the dorsal attention network (superior parietal cortex, left middle temporal gyrus) and executive control network (right prefrontal regions) during pre-training, relative to post-training. Changes in connectivity within the motor network, and more particularly between trained and untrained M1, as well as between the SMA and untrained M1, correlated with transfer after training. Together, these results suggest that the interplay between attentional, executive and motor networks may support processes leading to transfer, whereas, following training, transfer translates into increased connectivity within the motor network.

Intermanual Transfer Effects on Performance Gain Following Dominant Hand Training in Community-Dwelling Healthy Adults: A Preliminary Study

PURPOSE

This study aimed to evaluate the intermanual transfer effects of dominant hand training on the functional task of the untrained hand.

METHODS

Fifty community-dwelling healthy adults (mean age, 23.4 ± 2.5 Y; females, 60%) were participated. Participants in the experimental group received 15 minutes of right-hand training on a pegboard apparatus twice a week for four weeks. The control group received no training. The Jebsen Taylor test (JTT) and a 16-hole pegboard test were used for the assessment of hand function and dexterity.

RESULTS

Most of the JTT subtests except the writing and simulated feeding subtests and the performance of pegboard task by untrained hand were significantly improved in the experimental group after 4 weeks of training. However, no changes in the untrained hand function after 4 weeks in the control group. There were no significant differences in the pegboard task and JTT subtests found at baseline between the two groups. There were significant differences in the pegboard task between the two groups after dominant hand training. The experimental group took 4.3- and 2.5-second lesser time to complete the pegboard task using the dominant and non-dominant hand, respectively. Similarly, most of the JTT subtests except the writing and simulated feeding subtests were significantly better in the training group than the control group.

CONCLUSION

This study indicates that the function of the untrained non-dominant hand may be improved after functional training of the dominant hand. Since this study included only healthy young adults, results of this study cannot be generalized to other groups of people such as the elderly. While this study suggests that intermanual transfer could have a therapeutic value in many clinical situations, more longitudinal studies are warranted to examine the intermanual transfer effects of functional gain in different clinical conditions, such as stroke, parkinsonism, rheumatoid arthritis, and so on.

Efficacy of Auditory versus Motor Learning for Skilled and Novice Performers

Humans must learn a variety of sensorimotor skills, yet the relative contributions of sensory and motor information to skill acquisition remain unclear. Here we compare the behavioral and neural contributions of perceptual learning to that of motor learning, and we test whether these contributions depend on the expertise of the learner. Pianists and nonmusicians learned to perform novel melodies on a piano during fMRI scanning in four learning conditions: listening (auditory learning), performing without auditory feedback (motor learning), performing with auditory feedback (auditory-motor learning), or observing visual cues without performing or listening (cue-only learning). Visual cues were present in every learning condition and consisted of musical notation for pianists and spatial cues for nonmusicians. Melodies were performed from memory with no visual cues and with auditory feedback (recall) five times during learning. Pianists showed greater improvements in pitch and rhythm accuracy at recall during auditory learning compared with motor learning. Nonmusicians demonstrated greater rhythm improvements at recall during auditory learning compared with all other learning conditions. Pianists showed greater primary motor response at recall during auditory learning compared with motor learning, and response in this region during auditory learning correlated with pitch accuracy at recall and with auditory-premotor network response during auditory learning. Nonmusicians showed greater inferior parietal response during auditory compared with auditory-motor learning, and response in this region correlated with pitch accuracy at recall. Results suggest an advantage for perceptual learning compared with motor learning that is both general and expertise-dependent. This advantage is hypothesized to depend on feedforward motor control systems that can be used during learning to transform sensory information into motor production.

Using Virtual Reality to Transfer Motor Skill Knowledge from One Hand to Another

As far as acquiring motor skills is concerned, training by voluntary physical movement is superior to all other forms of training (e.g. training by observation or passive movement of trainee's hands by a robotic device). This obviously presents a major challenge in the rehabilitation of a paretic limb since voluntary control of physical movement is limited. Here, we describe a novel training scheme we have developed that has the potential to circumvent this major challenge. We exploited the voluntary control of one hand and provided real-time movement-based manipulated sensory feedback as if the other hand is moving. Visual manipulation through virtual reality (VR) was combined with a device that yokes left-hand fingers to passively follow right-hand voluntary finger movements. In healthy subjects, we demonstrate enhanced within-session performance gains of a limb in the absence of voluntary physical training. Results in healthy subjects suggest that training with the unique VR setup might also be beneficial for patients with upper limb hemiparesis by exploiting the voluntary control of their healthy hand to improve rehabilitation of their affected hand.

Restricted transfer of learning between unimanual and bimanual finger sequences

When training bimanual skills, such as playing piano, people sometimes practice each hand separately and at a later stage combine the movements of the two hands. This poses the critical question of whether motor skills can be acquired by separately practicing each subcomponent or should be trained as a whole. In the present study, we addressed this question by training human subjects for 4 days in a unimanual or bimanual version of the discrete sequence production task. Both groups were then tested on trained and untrained sequences on both unimanual and bimanual versions of the task. Surprisingly, we found no evidence of transfer from trained unimanual to bimanual or from trained bimanual to unimanual sequences. In half the participants, we also investigated whether cuing the sequences on the left and right hand with unique letters would change transfer. With these cues, untrained sequences that shared some components with the trained sequences were performed more quickly than sequences that did not. However, the amount of this transfer was limited to ∼10% of the overall sequence-specific learning gains. These results suggest that unimanual and bimanual sequences are learned in separate representations. Making participants aware of the interrelationship between sequences can induce some transferrable component, although the main component of the skill remains unique to unimanual or bimanual execution.NEW & NOTEWORTHY Studies in reaching movement demonstrated that approximately half of motor learning can transfer across unimanual and bimanual contexts, suggesting that neural representations for unimanual and bimanual movements are fairly overlapping at the level of elementary movement. In this study, we show that little or no transfer occurred across unimanual and bimanual sequential finger movements. This result suggests that bimanual sequences are represented at a level of the motor hierarchy that integrates movements of both hands.

Lateral asymmetry as a function of motor practice type of complex upper- and lower-limb movement in young children

The influence of different motor practice types on lateral asymmetry of performance was investigated in 40 preschool children. Lateral preference was measured prior the experiment. For the purpose of present study dribbling a ball with a hand and foot was used to assess lateral asymmetry of performance before and after three different motor practice types. Motor practice with the non-dominant, dominant, and both (contralateral) limbs took place in the indoor facility 4 times/week for 6 weeks. Each session lasted 30-40 min. Our results showed that unilateral practice of dribbling is more beneficial for diminishing lateral asymmetry of performance in comparison to bilateral practice. Moreover, participants who practiced with their dominant limb diminished lateral asymmetry of performance the most and made the largest overall improvement. We did not find important differences between acquisitions of dribbling with upper- and lower-extremity. In this sense, the results support the notion of lateral asymmetry of performance to be task-specific.

Learning from the other limb's experience: sharing the 'trained' M1 representation of the motor sequence knowledge

Key points

Participants were scanned during the untrained‐hand performance of a motor sequence, intensively trained a day earlier, and also a similarly constructed but novel, untrained sequence.

The superior performance levels for the trained, compared to the untrained sequence, were associated with a greater magnitude of activity within the primary motor cortex (M1), bilaterally, for the trained sequence.

The differential responses in the ‘trained’ M1, ipsilateral to the untrained hand, were positively correlated with experience‐related differences in the functional connectivity between the ‘trained’ M1 and (1) its homologue and (2) the dorsal premotor cortex (PMd) within the contralateral hemisphere.

No significant correlation was evident between experience‐related differences in M1 – M1 and M1 – PMd connectivity measures.

These results suggest that the transfer of sequence‐specific information between the two primary motor cortices is predominantly mediated by excitatory mechanisms driven by the ‘trained’ M1 via two independent neural pathways.

Abstract

Following unimanual training on a novel sequence of movements, sequence‐specific performance may improve overnight not only in the trained hand, but also in the hand afforded no actual physical experience. It is not clear, however, how transfer to the untrained hand is achieved. In the present study, we examined whether and how interaction between the two primary motor cortices contributes to the performance of a sequence of movements, extensively trained the day before, by the untrained hand. Acordingly, we studied participants during the untrained‐hand performance of a finger‐to‐thumb opposition sequence (FOS), intensively trained a day earlier (T‐FOS), and a similarly constructed, but novel, untrained FOS (U‐FOS). Changes in neural signals driven by task performance were assessed using functional magnetic resonance imaging. To minimize potential differences as a result of the rate of sequence execution per se, participants performed both sequences at an identical paced rate. The analyses showed that the superior fluency in executing the T‐FOS compared to the U‐FOS was associated with higher activity within the primary motor cortex (M1), bilaterally, for the T‐FOS. The differential responses in the ‘trained’ M1 were positively correlated with experience‐related differences in the functional connectivity between the ‘trained’ M1 and (1) its left homologue and (2) the left dorsal premotor cortex. However, no significant correlation was evident between the changes in connectivity in these two routes. These results suggest that the transfer of sequence‐specific information between the two primary motor cortices is predominantly mediated by excitatory mechanisms driven by the ‘trained’ M1 via at least two independent neural pathways.

Participants were scanned during the untrained‐hand performance of a motor sequence, intensively trained a day earlier, and also a similarly constructed but novel, untrained sequence.

The superior performance levels for the trained, compared to the untrained sequence, were associated with a greater magnitude of activity within the primary motor cortex (M1), bilaterally, for the trained sequence.

The differential responses in the ‘trained’ M1, ipsilateral to the untrained hand, were positively correlated with experience‐related differences in the functional connectivity between the ‘trained’ M1 and (1) its homologue and (2) the dorsal premotor cortex (PMd) within the contralateral hemisphere.

No significant correlation was evident between experience‐related differences in M1 – M1 and M1 – PMd connectivity measures.

These results suggest that the transfer of sequence‐specific information between the two primary motor cortices is predominantly mediated by excitatory mechanisms driven by the ‘trained’ M1 via two independent neural pathways.

Isolating Visual and Proprioceptive Components of Motor Sequence Learning in ASD

In addition to defining impairments in social communication skills, individuals with autism spectrum disorder (ASD) also show impairments in more basic sensory and motor skills. Development of new skills involves integrating information from multiple sensory modalities. This input is then used to form internal models of action that can be accessed when both performing skilled movements, as well as understanding those actions performed by others. Learning skilled gestures is particularly reliant on integration of visual and proprioceptive input. We used a modified serial reaction time task (SRTT) to decompose proprioceptive and visual components and examine whether patterns of implicit motor skill learning differ in ASD participants as compared with healthy controls. While both groups learned the implicit motor sequence during training, healthy controls showed robust generalization whereas ASD participants demonstrated little generalization when visual input was constant. In contrast, no group differences in generalization were observed when proprioceptive input was constant, with both groups showing limited degrees of generalization. The findings suggest, when learning a motor sequence, individuals with ASD tend to rely less on visual feedback than do healthy controls. Visuomotor representations are considered to underlie imitative learning and action understanding and are thereby crucial to social skill and cognitive development. Thus, anomalous patterns of implicit motor learning, with a tendency to discount visual feedback, may be an important contributor in core social communication deficits that characterize ASD. Autism Res 2016, 9: 563-569. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

Limb Dominance and Its Effects on the Benefits of Intralimb Transfer of Learning: A Visuomotor Aiming Task

Research has attempted to address what characteristics benefit from transfer of learning; however, it is still unclear which characteristics are effector dependent or independent. Furthermore, it is not clear if intralimb transfer shows, similarly to interlimb transfer, an asymmetry of benefits between the upper limbs. The purpose of the current study is to examine if effector independence effects emerge, as observed in interlimb transfer studies, when transfer to new effector group within the same limb occurs, and whether the pattern of intralimb transfer benefits differ between the limbs. Our results suggest that a visuomotor task transfers within both limbs, even though the transfer benefits within the limbs seem to differ. This was supported by more transfer occurring in the dominant limb than the nondominant limb. Potential control mechanisms used for intralimb transfer are discussed.

Concurrent sensorimotor temporal recalibration to different lags for the left and right hand

Perception of temporal synchrony between one’s own action and the sensory feedback of that action is quite flexible. We examined whether sensorimotor temporal recalibration (TR) involves central or motor-specific components by concurrently exposing the left and right hands to different lags. The experiment was composed of a pre-test, an adaptation phase, and a post-test. During the adaptation phase, participants tapped their left and right index fingers in alternating fashion while each tap induced an auditory feedback signal (a short click sound). One hand was exposed to a long delay between the tap and the sound (~150 ms), while the other hand was exposed to a subjective no-delay (~50 ms). Before and after the adaptation phase (the pre- and post-test), participants tried to tap in synchrony with pacer tones (ISI = 1000 ms). The results showed that the hand that was exposed to the delayed sound corrected for this delay by tapping earlier (a larger anticipation error) than the no-delay hand, indicating TR. Different amounts of TR were found when the left and right hand were concurrently exposed to the same versus different delays. With different exposure- delays for the two hands, there was a TR even for the hand that did not experience any delay in the feedback signal. However, it is not the case with the same exposure delay for the two hands. TR of the hand that experienced delayed feedback also occurred faster and was more complete (~40% greater than that of the hand with no subjective delay) if the two hands were exposed to the same rather than different delays (~20% greater than that of the hand with no subjective delay). These results suggest the existence of cross-talk between the hands, where both central and motor-specific components might be involved.

Effects of combining 2 weeks of passive sensory stimulation with active hand motor training in healthy adults

The gold standard to acquire motor skills is through intensive training and practicing. Recent studies have demonstrated that behavioral gains can also be acquired by mere exposure to repetitive sensory stimulation to drive the plasticity processes. Single application of repetitive electric stimulation (rES) of the fingers has been shown to improve tactile perception in young adults as well as sensorimotor performance in healthy elderly individuals. The combination of repetitive motor training with a preceding rES has not been reported yet. In addition, the impact of such a training on somatosensory tactile and spatial sensitivity as well as on somatosensory cortical activation remains elusive. Therefore, we tested 15 right-handed participants who underwent repetitive electric stimulation of all finger tips of the left hand for 20 minutes prior to one hour of motor training of the left hand over the period of two weeks. Overall, participants substantially improved the motor performance of the left trained hand by 34%, but also showed a relevant transfer to the untrained right hand by 24%. Baseline ipsilateral activation fMRI-magnitude in BA 1 to sensory index finger stimulation predicted training outcome for somatosensory guided movements: those who showed higher ipsilateral activation were those who did profit less from training. Improvement of spatial tactile discrimination was positively associated with gains in pinch grip velocity. Overall, a combination of priming rES and repetitive motor training is capable to induce motor and somatosensory performance increase and representation changes in BA1 in healthy young subjects.

Changes in brain activation patterns according to cross-training effect in serial reaction time task: An functional MRI study

Cross-training is a phenomenon related to motor learning, where motor performance of the untrained limb shows improvement in strength and skill execution following unilateral training of the homologous contralateral limb. We used functional MRI to investigate whether motor performance of the untrained limb could be improved using a serial reaction time task according to motor sequential learning of the trained limb, and whether these skill acquisitions led to changes in brain activation patterns. We recruited 20 right-handed healthy subjects, who were randomly allocated into training and control groups. The training group was trained in performance of a serial reaction time task using their non-dominant left hand, 40 minutes per day, for 10 days, over a period of 2 weeks. The control group did not receive training. Measurements of response time and percentile of response accuracy were performed twice during pre- and post-training, while brain functional MRI was scanned during performance of the serial reaction time task using the untrained right hand. In the training group, prominent changes in response time and percentile of response accuracy were observed in both the untrained right hand and the trained left hand between pre- and post-training. The control group showed no significant changes in the untrained hand between pre- and post-training. In the training group, the activated volume of the cortical areas related to motor function (i.e., primary motor cortex, premotor area, posterior parietal cortex) showed a gradual decrease, and enhanced cerebellar activation of the vermis and the newly activated ipsilateral dentate nucleus were observed during performance of the serial reaction time task using the untrained right hand, accompanied by the cross-motor learning effect. However, no significant changes were observed in the control group. Our findings indicate that motor skills learned over the 2-week training using the trained limb were transferred to the opposite homologous limb, and motor skill acquisition of the untrained limb led to changes in brain activation patterns in the cerebral cortex and cerebellum.

Impact of hand orientation on bimanual finger coordination in an eight-finger tapping task

In the present experiment we examined whether a symmetry tendency in bimanual finger coordination is observable in an experimental setting resembling a serial learning task and whether this tendency is defined in hand-based coordinates. Participants performed an eight-finger bimanual coordination task, in which they responded to sequences of visual stimuli by sequences of tapping movements. Visual stimuli triggered flexion of fingers, which were parallel or mirror symmetrical in respect to the body midline. Additionally, the orientation of the right hand relative to the left hand was varied. When both hands had the same orientation, the mirror symmetrical mode was more stable than the parallel mode. When both hands had different orientations, in contrast, the parallel mode was more stable. This result suggests that the tendency towards mirror symmetry was defined in hand-based coordinates. This outcome is relevant for the research of skill learning regarding the issue of whether acquired sequence knowledge is tied to specific effectors.

Human motor plasticity induced by mirror visual feedback

The clinical use of mirror visual feedback (MVF) was initially introduced to alleviate phantom pain, and has since been applied to the improvement of hemiparesis following stroke. However, it is not known whether MVF can restore motor function by producing plastic changes in the human primary motor cortex (M1). Here, we used transcranial magnetic stimulation to test whether M1 plasticity is a physiological substrate of MVF-induced motor behavioral improvement. MVF intervention in normal volunteers using a mirror box improved motor behavior and enhanced excitatory functions of the M1. Moreover, behavioral and physiological measures of MVF-induced changes were positively correlated with each other. Improved motor performance occurred after observation of a simple action, but not after repetitive motor training of the nontarget hand without MVF, suggesting the crucial importance of visual feedback. The beneficial effects of MVF were disrupted by continuous theta burst stimulation (cTBS) over the M1, but not the control site in the occipital cortex. However, MVF following cTBS could further improve the motor functions. Our findings indicate that M1 plasticity, especially in its excitatory connections, is an essential component of MVF-based therapies.

Sequence specific motor performance gains after memory consolidation in children and adolescents

Memory consolidation for a trained sequence of finger opposition movements, in 9- and 12-year-old children, was recently found to be significantly less susceptible to interference by a subsequent training experience, compared to that of 17-year-olds. It was suggested that, in children, the experience of training on any sequence of finger movements may affect the performance of the sequence elements, component movements, rather than the sequence as a unit; the latter has been implicated in the learning of the task by adults. This hypothesis implied a possible childhood advantage in the ability to transfer the gains from a trained to the reversed, untrained, sequence of movements. Here we report the results of transfer tests undertaken to test this proposal in 9-, 12-, and 17-year-olds after training in the finger-to-thumb opposition sequence (FOS) learning task. Our results show that the performance gains in the trained sequence partially transferred from the left, trained hand, to the untrained hand at 48-hours after a single training session in the three age-groups tested. However, there was very little transfer of the gains from the trained to the untrained, reversed, sequence performed by either hand. The results indicate sequence specific post-training gains in FOS performance, as opposed to a general improvement in performance of the individual, component, movements that comprised both the trained and untrained sequences. These results do not support the proposal that the reduced susceptibility to interference, in children before adolescence, reflects a difference in movement syntax representation after training.

Impact of instruction on the acquisition of sequence knowledge in a sensorimotor task

We examined whether and to what extent a sequence of finger movements can be learned and transferred to the untrained hand according to the muscle homology depending on the relative salience of response locations and effectors. Participants performed a discrete sequence production task, in which they were asked to learn a sequence of either key locations or of finger movements. Each training block was followed by a transfer block in which responding with the opposite hand was required. Before the last transfer block participants received an unexpected instruction. They had to reproduce the sequence of key locations instead of the sequence of finger movements and conversely, the sequence of finger movements instead of the sequence of key locations. The results do not support the existence of a sequence representation for the order of finger movements irrespective of the hand used.