Covert speech is accompanied by a subjective multisensory experience with auditory and kinaesthetic components. An influential hypothesis states that these sensory percepts result from a simulation of the corresponding motor action that relies on the same internal models recruited for the control of overt speech. This simulationist view raises the question of how it is possible to imagine speech without executing it. In this perspective, we discuss the possible role played by motor inhibition during covert speech production. (...) We suggest that considering covert speech as an inhibited form of overt speech maps naturally to the purported progressive internalization of overt speech during childhood. We further argue that the role of motor inhibition may differ widely across different forms of covert speech and that considering this variety helps reconciling seemingly contradictory findings from the neuroimaging literature. (shrink)

Palatable, unhealthy food stimuli can be devalued via Go/No-Go (GNG) training that consistently pairs such stimuli with motor inhibition. However, it remains unclear whether this devaluation is caused via learned associations with motor inhibition or via inferential learning based on the valence of emitted motor responses. The present research disentangles the effects of motor assignment and response valence in GNG training through task instructions. In two studies, chocolate stimuli were consistently paired with motor (...) inhibition (“no-go”) or with motor excitation (“go”). Task instructions indicated that no-go responses were negatively valenced (“do not take”) and that go responses were positively valenced (“take”), or identified no-go responses as positively valenced (“keep”) and go as negatively valenced (“throw away”). The results show an effect of response valence on chocolate evaluations, but no effect of motor assignment: Chocolate stimuli were consistently devalued following pairings with a negatively valenced response, regardless of whether this response entailed motor inhibition or excitation. These findings align best with an inferential account of GNG training, suggesting that devaluation effects critically depend on inferential processes regarding motor response valence. GNG training procedures may, therefore, be optimised by disambiguating the valence of go and no-go motor responses prior to training. (shrink)

BackgroundMotor imagery training has a similar effect to that of physical training on motor performance. The objective of this study was to investigate the short-term effectiveness of motor imagery training on response inhibition using the stop signal task.MethodsParticipants were divided into a physical training group, a motor imagery training group, and a motor imagery combined with physical training group. All participants performed 10 SST training sessions over 5 days. Both stop signal reaction time and non-signal (...) reaction time were measured before and after SST training.ResultsThere were significant interaction and time effects, although the group effect was not statistically significant. Bonferroni post hoc analysis showed that MIPT group revealed a significantly greater change in SSRT than PT and MIT groups, while there was no significant difference between PT and MIT groups. SSRT significantly decreased after training in all groups. In NSRT, there was a significant effect of time, but there was no significant interaction effect or group effect.ConclusionResponse inhibition could be enhanced via training, and it was most effective when motor imagery and physical training were combined. We demonstrate that motor imagery training significantly improves response inhibition and should be accompanied by physical training when performing SST. (shrink)

IntroductionExcitability of the primary motor cortex measured with TMS has been associated with cognitive dysfunctions in patient populations. However, only a few studies have explored this relationship in healthy adults, and even fewer have considered the role of biological sex.MethodsNinety-seven healthy middle-aged adults completed a TMS protocol and a neuropsychological assessment. Resting Motor Threshold and Long-Interval Intracortical Inhibition were assessed in the left motor cortex and related to attention, episodic memory, working memory, reasoning, and global cognition (...) composite scores to evaluate the relationship between cortical excitability and cognitive functioning.ResultsIn the whole sample, there was a significant association between LICI and cognition; specifically, higher motor inhibition was related to better working memory performance. When the sample was broken down by biological sex, LICI was only associated with working memory, reasoning, and global cognition in men. No associations were found between RMT and cognitive functions.ConclusionGreater intracortical inhibition, measured by LICI, could be a possible marker of working memory in healthy middle-aged adults, and biological sex plays a critical role in this association. (shrink)

Deciding between different voluntary movements implies a continuous control of the competition between potential actions. Many theories postulate a leading role of prefrontal cortices in this executive function, but strong evidence exists that a motor region like the primary motor cortex is also involved, possibly via inhibitory mechanisms. This was already shown during the pre-movement decision period, but not after movement onset. For this pilot experiment we designed a new task compatible with the dynamics of post-onset control to (...) study the silent period duration, a pause in electromyographic activity after single-pulse transcranial magnetic stimulation that reflects inhibitory mechanisms. A careful analysis of the SP during the ongoing movement indicates a gradual increase in inhibitory mechanisms with the level of competition, consistent with an increase in mutual inhibition between alternative movement options. However, we also observed a decreased SP duration for high-competition trials associated with change-of-mind inflections in their trajectories. Our results suggest a new post-onset adaptive process that consists in a transient reduction of GABAergic inhibition within M1 for highly conflicting situations. We propose that this reduced inhibition softens the competition between concurrent motor options, thereby favoring response vacillation, an adaptive strategy that proved successful at improving behavioral performance. (shrink)

Transcranial magnetic stimulation studies have demonstrated increased cortical facilitation and reduced inhibition following aerobic exercise, even when examining motor regions separate to the exercised muscle group. These changes in brain physiology following exercise may create favorable conditions for adaptive plasticity and motor learning. One candidate mechanism behind these benefits is the increase in brain-derived neurotropic factor observed following exercise, which can be quantified from a venous blood draw. The aim of this study was to investigate changes in (...) motor cortex excitability and inhibition of the upper limb, and circulating BDNF, following high-intensity interval training on a stationary bicycle. Nineteen sedentary adults participated in a randomized crossover design study involving a single bout of high-intensity interval cycling for 20 min or seated rest. Venous blood samples were collected, and transcranial magnetic stimulation was used to stimulate the extensor carpi radialis, where motor evoked potentials were recorded pre- and post-condition. Following exercise, there was a significant increase in corticospinal excitability measured at 120% of resting motor threshold and a reduction in short-interval cortical inhibition. There was a non-significant 23.6% increase in BDNF levels. Collectively, these results reflect a net reduction in gamma aminobutyric acid ergic synaptic transmission and increased glutamatergic facilitation, resulting in increased corticospinal excitability. This study supports the notion that acute high-intensity exercise provides a potent stimulus for inducing cortical neuroplasticity, which may support enhanced motor learning. (shrink)

In professional soccer, players, coaches, and researchers alike recognize the importance of cognitive skills. Research addressing the relevance of cognitive skills has been based on the cognitive component skills approach or the expert performance approach. Our project aimed to combine the strengths of both approaches to develop and validate cognitive tasks measuring inhibition and cognitive flexibility in a soccer-specific setting with a soccer-specific motor response. In the main study 77 elite youth soccer players completed a computerized version of (...) the standard flanker and number–letter tasks as well as flanker and number–letter tasks requiring a soccer-specific motor response in a soccer-specific setting. Results show good reliability for both tasks. For the SoccerBot360 number–letter task, switch effects for response times and accuracy and acceptable convergent validity were shown. A flanker effect for response time but not accuracy was apparent. Due to no acceptable convergent validity, the flanker task was revised and 63 adult soccer players participated in a follow-up validation study in the SoccerBot100. The revised flanker task showed the flanker effect for response time, but not for accuracy. However, acceptable convergent validity for response time was present. Thus, the soccer-specific number–letter and to some extent the soccer-specific flanker task show potential to be used as a valid cognitive diagnostic tool by soccer clubs. (shrink)

While slowness of movement is an obligatory characteristic of Parkinson’s disease (PD), there are conditions in which patients move uncharacteristically fast, attributed to deficient motor inhibition. Here we investigate deficient inhibition in an optimal sensory-motor integration framework, using a game in which subjects used a paddle to catch a virtual ball. Display of the ball was extinguished as soon as the catching movement started, segregating the task into a sensing and acting phase. We analyzed the behavior (...) of 9 PD patients (ON medication) and 10 age-matched controls (HC). The switching times (between sensing and acting phase) were compared to the predicted optimal switching time, based on the individual estimates of sensory and motor uncertainties. The comparison showed that deviation from predicted optimal switching times were similar between groups. However, PD patients showed a weaker correlation between variability in switching time and sensory-motor uncertainty, indicating a reduced propensity to generate exploratory behavior for optimizing goal-directed movements. Analysis of the movement kinematics revealed that PD patients, compared to controls, used a lower peak velocity of the paddle and intercepted the ball with greater velocity. Adjusting the trial duration to the time for the paddle to stop moving, we found that PD patients spent a smaller proportion of the trial duration for observing the ball. Altogether, the results do not show the premature movement initiation and truncated sensory processing that we predicted to ensue from deficient inhibition in PD. (shrink)

Using a new method, we examined whether incidental perception of need-rewarding (positive) objects unintentionally prepares motor action. Participants who varied in their level of need for water were presented with glasses of water (and control objects) that were accompanied by go and no-go cues that required a response (key-press) or withholding a response. Importantly, if need-rewarding objects unintentionally prepare action, presentation of no-go cues should lead to motor inhibition of these prepared motor impulses. Consistent with this (...) hypothesis, results showed that participants relatively high in need for water (and hence, who perceive water as a rewarding, positive object) were slower to react to a successive action probe after withholding a response during perception of water than during perception of the control object, suggesting motor inhibition of unintentionally prepared motor impulses. We propose that incidental perception of need-rewarding objects unintentionally potentiates preparation of motor action to these objects. (shrink)

Cytoplasmic dynein is the major minus‐end‐directed motor protein in eukaryotes, and has functions ranging from organelle and vesicle transport to spindle positioning and orientation. The mode of regulation of dynein in the cell remains elusive, but a tantalising possibility is that dynein is maintained in an inhibited, non‐motile state until bound to cargo. In vivo, stable attachment of dynein to the cell membrane via anchor proteins enables dynein to produce force by pulling on microtubules and serves to organise the (...) nuclear material. Anchor proteins of dynein assume diverse structures and functions and differ in their interaction with the membrane. In yeast, the anchor protein has come to the fore as one of the key mediators of dynein activity. In other systems, much is yet to be discovered about the anchors, but future work in this area will prove invaluable in understanding dynein regulation in the cell. (shrink)

The vestibulo-ocular reflex (VOR) adaptation is an ideal model for investigating how the neurosteroid 17 beta-estradiol (E2) contributes to the modification of behavior by regulating synaptic activities. We hypothesized that E2 impacts VOR adaptation by affecting cerebellar synaptic plasticity at the parallel fiber–Purkinje cell (PF) synapse. To verify this hypothesis, we investigated the acute effect of blocking E2 synthesis on gain increases and decreases in adaptation of the VOR in male rats using an oral dose (2.5 mg/kg) of the aromatase (...) inhibitor letrozole. We also assessed the effect of letrozole on synaptic plasticity at the PF synapse in vitro, using cerebellar slices from male rats. We found that letrozole acutely impaired both gain increases and decreases adaptation of the VOR without altering basal ocular-motor performance. Moreover, letrozole prevented long-term potentiation at the PF synapse (PF-LTP) without affecting long-term depression (PF-LTD). Thus, in male rats neurosteroid E2 has a relevant impact on VOR adaptation and affects exclusively PF-LTP. These findings suggest that E2 might regulate changes in VOR adaptation by acting locally on cerebellar and extra-cerebellar synaptic plasticity sites. (shrink)

Motor Imagery reproduces cognitive operations associated with the actual motor preparation and execution. Postural recordings during MI reflect somatic motor commands targeting peripheral effectors involved in balance control. However, how these relate to the actual motor expertise and may vary along with the MI modality remains debated. In the present experiment, two groups of expert and non-expert gymnasts underwent stabilometric assessments while performing physically and mentally a balance skill. We implemented psychometric measures of MI ability, while (...) stabilometric variables were calculated from the center of pressure oscillations. Psychometric evaluations revealed greater MI ability in experts, specifically for the visual modality. Experts exhibited reduced surface COP oscillations in the antero-posterior axis compared to non-experts during the balance skill. Experts further exhibited reduced length of COP displacement in the antero-posterior axis and as a function of the displacement area during visual and kinesthetic MI compared to the control condition. Predictive relationships were found between the stabilometric correlates of visual MI and physical practice of the balance skill, as well as between the stabilometric correlates of kinesthetic MI and the training experience in experts. Present results provide original stabilometric insights into the relationships between MI and expertise level. While data support the incomplete inhibition of postural commands during MI, whether postural responses during MI of various modalities mirror the level of motor expertise remains unclear. (shrink)

Considering that motor and cognitive processes are intertwined and inhibit or help each other throughout life and that primary school age is one of the most critical stages of children's cognitive and motor development, this study aimed to investigate the relationship between executive functions and gross motor skills in Chinese children aged 9–10 years, as well as gender differences. The flanker task, the 1-back task, the more-odd shifting task, and the test of gross motor coordination were (...) used to collect data on executive functions and gross motor coordination. The results were as follows. First, there was a weak association between gross motor coordination and the inhibition reaction time in the congruent test and the reaction time of working memory, but no association was found between gross motor coordination and cognitive flexibility. Second, a weak-to-moderate correlation was presented between the move sideways test and the inhibition reaction time in the congruent test and the reaction time in the refreshing test of the working memory. Finally, gender influenced on the relationship between gross motor coordination and the reaction time of both inhibition and working memory. To conclude, our results suggest that children with better motor coordination skills require less reaction time, especially girls, and this association was more substantial than in boys. The finding supports the current assertion that there are commonalities between gross motor coordination and cognitive control by showing the relationship between gross motor coordination and complex cognitive processes in preadolescent children. (shrink)

ObjectiveThe main purpose of this study was to explore the association between early fundamental motor skills and executive function in preschool children.MethodsA total of 394 young children were evaluated. The FMS and EF were evaluated using the Test of Gross Motor Development-2 and the NIH Toolbox Cognition Battery, respectively.ResultsTotal FMS score was moderately and positively correlated with total EF score and was a significant predictor of total EF score. Specifically, locomotor skills were significant predictors of inhibition control, (...) working memory, and cognitive flexibility, while object control skills were only significant predictors of inhibition control.ConclusionFMS were significantly and positively correlated with EF and were significant predictors of EF. Early childhood policymakers, preschool teachers, and researchers should take these connections seriously and implement appropriate complex motor intervention programs in future teaching to stimulate the development of both motor and higher-order cognitive skills in preschool children. (shrink)

People frequently gesture when a word is on the tip of their tongue (TOT), yet research is mixed as to whether and why gesture aids lexical retrieval. We tested three accounts: the lexical retrieval hypothesis, which predicts that semantically related gestures facilitate successful lexical retrieval; the cognitive load account, which predicts that matching gestures facilitate lexical retrieval only when retrieval is hard, as in the case of a TOT; and the motor movement account, which predicts that any motor (...) movements should support lexical retrieval. In Experiment 1 (a between‐subjects study; N = 90), gesture inhibition, but not neck inhibition, affected TOT resolution but not overall lexical retrieval; participants in the gesture‐inhibited condition resolved fewer TOTs than participants who were allowed to gesture. When participants could gesture, they produced more representational gestures during resolved than unresolved TOTs, a pattern not observed for meaningless motor movements (e.g., beats). However, the effect of gesture inhibition on TOT resolution was not uniform; some participants resolved many TOTs, while others struggled. In Experiment 2 (a within‐subjects study; N = 34), the effect of gesture inhibition was traced to individual differences in verbal, not spatial short‐term memory (STM) span; those with weaker verbal STM resolved fewer TOTs when unable to gesture. This relationship between verbal STM and TOT resolution was not observed when participants were allowed to gesture. Taken together, these results fit the cognitive load account; when lexical retrieval is hard, gesture effectively reduces the cognitive load of TOT resolution for those who find the task especially taxing. (shrink)

Developmental coordination disorder is a heterogeneous condition. Besides motor impairments, children with DCD often exhibit poor visual perceptual skills and executive functions. This study aimed to characterize the motor, perceptual, and cognitive profiles of children with DCD at the group level and in terms of subtypes. A total of 50 children with DCD and 31 typically developing peers underwent a comprehensive neuropsychological and motor assessment. The percentage of children with DCD showing impairments in each measurement was first (...) described. Hierarchical agglomerative and K-means iterative partitioning clustering analyses were then performed to distinguish the subtypes present among the complete sample of children in a data-driven way. Moderate to large percentages of children with DCD showed impaired executive functions and praxis, as well as attentional, visual perceptual, and visuomotor skills. Clustering analyses identified five subtypes, four of them mainly consisting of children with DCD and one of TD children. These subtypes were characterized by: generalized impairments, impaired manual dexterity, poor balance, planning, and alertness, impaired manual dexterity, cognitive inhibition, and poor visual perception, impaired manual dexterity and cognitive inhibition, and no impairment. Besides subtle differences, the motor and praxis measures did not enable to discriminate between the four subtypes of children with DCD. The subtypes were, however, characterized by distinct perceptual or cognitive impairments. These results highlight the importance of assessing exhaustively the perceptual and cognitive skills of children with DCD. (shrink)

In this paper a tentative neurophysiologically framed approach of the Freudian unconscious that would function on the basis of linguistic (phonological) organizing principles, is proposed. A series of arguments, coming from different fields, are taken together. First, clinical reports indicate that in a state of high emotional arousal linguistic fragments are treated in a decontextualized way, and can lead to the isolation of phoneme sequences which, independently of their actual meaning, are able to resort emotional effects. Second, phonological and neurophysiological (...) arguments are given to make the case that language processing – be it producing, receiving or imagining language – is a motor event. A crucial distinction is proposed: while contextualized processing correlates on a neurophysiological level with action understanding, and is psychoanalytically akin to secondary processing, decontextualized language processing has a neurophysiological counterpart in object understanding and is psychoanalytically akin to primary processing. Third, isolated speech fragments are therefore considered as objects which, similarly to non-linguistic objects, undergo emotional conditioning and establish an idiosyncratic linguistically structured emotional memory. Phoneme sequences which in this way come to carry high emotional valences are thought to be more readily subject to threaten the bodily integrity, and therefore more readily inhibited. When this inhibition leads to the prevention of effective realization of the voluntary motor output, this is thought to result in the sustained high levels of neuronal activation which seek for release by attracting substitutes that are phonemically similar to the censored speech fragments though they are cognitively non threatening. As a result, the speech of the subject would be particularly concerned with the verbalizations of these substitutive phoneme sequences. In summary, the Freudian unconscious is conceived as the instantiation of a linguistic action space which would be idiosyncratically organized by particular phonemic “phantoms” operating as attractors for the subject’s (linguistic) actions. (shrink)

In a recently published study combining transcranial magnetic stimulation and electroencephalography (TMS-EEG), an early component of TMS-evoked potentials (TEPs), i.e., M1-P15, was proposed as a measure of transcallosal inhibition between motor cortices. Given that early TEPs are known to be highly variable, further evidence is needed before M1-P15 can be considered a reliable index of effective connectivity. Here, we conceived a new preregistered TMS-EEG study with two aims. The first aim was validating the M1-P15 as a cortical index (...) of transcallosal inhibition by replicating previous findings on its relationship with the ipsilateral silent period (iSP) and with performance in bimanual coordination. The second aim was inducing a task-dependent modulation of transcallosal inhibition. A new sample of 32 healthy right-handed participants underwent behavioral motor tasks and TMS-EEG recording, in which left and right M1 were stimulated both during bimanual tasks and during an iSP paradigm. Hypotheses and methods were preregistered before data collection. Results show a replication of our previous findings on the positive relationship between M1-P15 amplitude and the iSP normalized area. Differently, the relationship between M1-P15 latency and bimanual coordination was not confirmed. Finally, M1-P15 amplitude was modulated by the characteristics of the bimanual task the participants were performing, and not by the contralateral hand activity during the iSP paradigm. In sum, the present results corroborate our previous findings in validating the M1-P15 as a cortical marker of transcallosal inhibition and provide novel evidence of its task-dependent modulation. Importantly, we demonstrate the feasibility of preregistration in the TMS-EEG field to increase methodological rigor and transparency. (shrink)

In light of the interrelation between motor and cognitive development and the predictive value of the former for the latter, the secular decline observed in motor coordination ability as early as preschool urges identification of interventions that may jointly impact motor and cognitive efficiency. The aim of this study was twofold. It (1) explored the outcomes of enriched physical education, centered on deliberate play and cognitively challenging variability of practice, on motor coordination and cognitive processing; (2) (...) examined whether motor coordination outcomes mediate intervention effects on children’s cognition, while controlling for moderation by lifestyle factors as outdoor play habits and weight status. Four hundred and sixty children aged 5-10 years participated in a 6-month group randomized intervention in physical education, with or without playful coordinative and cognitive enrichment. The weight status and spontaneous outdoor play habits of children (parental report of outdoor play) were evaluated at baseline. Before and after the intervention, motor developmental level (Movement Assessment Battery for Children) was evaluated in all children, who were then assessed either with a test of working memory (Random Number Generation task), or with a test of attention (from the Cognitive Assessment System, CAS). Children assigned to the ‘enriched’ intervention showed more pronounced improvements in all motor coordination assessments (manual dexterity, ball skills, static/dynamic balance). The beneficial effect on ball skills was amplified by the level of spontaneous outdoor play and weight status. Among indices of executive function and attention, only that of inhibition showed a differential effect of intervention type. Moderated mediation showed that the better outcome of the enriched physical education on ball skills mediated the better inhibition outcome, but only when the enrichment intervention was paralleled by a medium-to-high level of outdoor play. Results suggest that specifically tailored physical activity games provide a unique form of enrichment that impacts children’s cognitive development through motor coordination improvement, particularly object control skills, which are linked to children’s physical activity habits later in life. Outdoor play appears to offer the natural ground for the stimulation by designed physical activity games to take root in children’s mind. (shrink)

Visual targets which follow a prime stimulus and a mask can be identified faster when they are incompatible rather than compatible with the prime . According to the self-inhibition hypothesis, the initial activation of the motor response is elicited by the prime based on its identity. This activation leads to benefits for compatible trials and costs for incompatible trials. This motor activation is followed by an inhibition phase, leading to an NCE if perceptual evidence of the (...) prime is immediately removed by the mask. The object-updating and mask-triggered inhibition hypotheses emphasize the role of the mask content . We show that the NCE may appear even if nonmasking neutral flankers are presented instead of a mask. Moreover, although with target-like flankers the NCE is larger, it occurred if flankers and targets are built from dissimilar elements. Therefore, masks/flankers can evoke an inhibition phase independently of whether or not they remove evidence for the prime and whether they are similar to the targets. (shrink)

Sustained peripheral somatosensory stimulations, such as high-frequency repetitive somatosensory stimulation (HF-RSS) and vibrated stimulation, are effective in altering the balance between excitation and inhibition in the somatosensory cortex (S1) and motor cortex (M1). A recent study reported that whole-hand water flow (WF) stimulation induced neural disinhibition in the M1. Based on previous results, we hypothesized that whole-hand WF stimulation would lead to neural disinhibition in the S1 because there is a strong neural connection between M1 and S1 and (...) aimed to examine whether whole-hand WF stimulation would change the neural balance between excitation and inhibition in the S1. Nineteen healthy volunteers were studied by measuring excitation and inhibition in the S1 before and after each of the four 15-min interventions. The excitation and inhibition in the S1 were assessed using somatosensory evoked potentials (SEPs) and paired-pulse inhibition (PPI) induced by single- and paired-pulse stimulations, respectively. The four interventions were as follows: control, whole-hand water immersion, whole-hand WF, and HF-RSS. The results showed no significant changes in SEPs and PPI following any intervention. However, changes in PPI with an interstimulus interval (ISI) of 30 ms were significantly correlated with the baseline value before whole-hand WF. Thus, the present findings indicated that the whole-hand WF stimulation had a greater decreased neural inhibition in participants with higher neural inhibition in the S1 at baseline. Considering previous results on M1, the present results possibly show that S1 has lower plasticity than M1 and that the duration (15 min) of each intervention may not have been enough to alter the balance of excitation and inhibition in the S1. (shrink)

Fundamental motor skills of children can be affected by different variables, such as executive functions, gender and relative age. However, the effects of these variables on FMS have been scarce studied, especially in early childhood, and show inconsistent results. To clarify these relationships, this study was carried out. Its aim was to analyze whether EF, gender and relative age influenced FMS in 43 Spanish kindergarteners. A multimethod and mixed methods approach was used. Kindergarteners’ teachers completed the Childhood Executive Functioning (...) Inventory to know the children level of EF. Kindergarteners’ parents complimented ad hoc questionnaire reporting the children gender and birth data. A Nomothetic/Punctual/Multidimensional observational design was used to observe children FMS in their habitual motor sessions at school. Two-way ANOVAs were performed to know the independent and interactive effects of working memory level, inhibition control level, gender and relative age on FMS. Results showed these variables have independent and interactive effects on some FMS, but not on others. FMS influenced by these variables vary depending what independent variable is/are considered. Therefore, it can be concluded that the influences of teacher-rated EF, gender and relative age on observed FMS in kindergarteners are complex and specific. Results obtained must be taken into to design and implement instructional and intervention strategies, as well as educational and sport policy changes, especially in early childhood, when FMS are more malleable. (shrink)

How do cells direct the microtubule motor protein dynein to move cellular components to the right place at the right time? Recent studies in budding yeast shed light on a new mechanism for directing dynein, involving the protein She1. She1 restricts where and when dynein moves the nucleus and mitotic spindle. Experiments with purified proteins show that She1 binds to microtubules and inhibits dynein by stalling the motor on its track. Here I describe what we have learned so (...) far about She1, based on a combination of genetic, cell biology, and biophysical approaches. These findings set the stage for further interrogation of the She1 mechanism, and raise the question of whether similar mechanisms exist in other species. (shrink)

Recent evidence indicates that inhibition of protein translation may be a common pathogenic mechanism for peripheral neuropathy associated with mutant tRNA synthetases (aaRSs). aaRSs are enzymes that ligate amino acids to their cognate tRNA, thus catalyzing the first step of translation. Dominant mutations in five distinct aaRSs cause Charcot‐Marie‐Tooth (CMT) peripheral neuropathy, characterized by length‐dependent degeneration of peripheral motor and sensory axons. Surprisingly, loss of aminoacylation activity is not required for mutant aaRSs to cause CMT. Rather, at least (...) for some mutations, a toxic‐gain‐of‐function mechanism underlies CMT‐aaRS. Interestingly, several mutations in two distinct aaRSs were recently shown to inhibit global protein translation in Drosophila models of CMT‐aaRS, by a mechanism independent of aminoacylation, suggesting inhibition of translation as a common pathogenic mechanism. Future research aimed at elucidating the molecular mechanisms underlying the translation defect induced by CMT‐mutant aaRSs should provide novel insight into the molecular pathogenesis of these incurable diseases. (shrink)

Three experiments explore the role of working memory in motor skill acquisition and performance. Traditional theories postulate that skill acquisition proceeds through stages of knowing, which are initially declarative but later procedural. The reported experiments challenge that view and support an independent, parallel processing model, which predicts that procedural and declarative knowledge can be acquired separately and that the former does not depend on the availability of working memory, whereas, the latter does. The behaviour of these two processes was (...) manipulated by providing or withholding visual (and auditory) appraisal of outcome feedback. Withholding feedback was predicted to inhibit the use of working memory to appraise success and, thus, prevent the formation of declarative knowledge without affecting the accumulation of procedural knowledge. While the first experiment failed to support these predictions, the second and third experiments demonstrated that procedural and declarative knowledge can be acquired independently. It is suggested that the availability of working memory is crucial to motor performance only when the learner has come to rely on its use. (shrink)

We review the major phenomena of skilled typing and propose a model for the control of the hands and fingers during typing. The model is based upon an Activation‐Trigger‐Schema system in which a hierarchical structure of schemata directs the selection of the letters to be typed and, then, controls the hand and finger movements by a cooperative, relaxation algorithm. The interactions of the patterns of activation and inhibition among the schemata determine the temporal ordering for launching the keystrokes. To (...) account for the phenomena of doubling errors, the model has only “type” schemata—no “token” schemata—with only a weak binding between the special schema that signals a doubling, and its argument. The model exists as a working computer simulation and produces an output display of the hands and fingers moving over the keyboard. It reproduces some of the major phenomena of typing, including the interkeystroke interval times, the pattern of transposition errors found in skilled typists, and doubling errors. Although the model is clearly inadequate or wrong in some of its features and assumptions, it serves as a useful first approximation for the understanding of skilled typing. (shrink)

It is unclear whether the decline in executive function and perceptual-motor function found in older adults with mild cognitive impairment is the result of a normal aging process or due to MCI. This study aimed to determine age-related and MCI-related cognitive impairments of the EF and PMF. The EF and PMF were investigated across four groups of 240 participants, 60 in each group, including early adult, middle adult, older adult, and older adult with probable MCI. The EF, working memory, (...) inhibition, and cognitive flexibility were evaluated using digit span backward tasks, the Stroop color-word test, and the modified switching verbal fluency test, respectively. The PMF, visual perception, visuoconstructional reasoning, and perceptual-motor coordination were evaluated using the clock reading test, stick design test, and stick catching test, respectively. Group differences were found for all subdomains of EF and PMF, except for perceptual-motor coordination, indicating that this subdomain could be maintained in older adults and was not affected by MCI. For the age difference, working memory, cognitive flexibility, visual perception, and visuoconstructional reasoning remained stable across middle adults and started to decline in older adults, while cognitive inhibition began to decrease in middle adults and it further declined in older adults. To control the confounding effect of education level, the results showed that only cognitive flexibility was further decreased in older adults with probable MCI compared to those without MCI. In conclusion, cognitive inhibition decreased earlier in middle adults, whereas EF and PMF started to decline in older adults. Cognitive flexibility was the only MCI-sensitive cognitive function. (shrink)

Approaches to foster motor creativity differ according to whether creative movements are assumed to be enacted creative ideas, or solutions to emerging motor problems that arise from task and environmental constraints. The twofold aim of the current study was to investigate whether an enriched physical education intervention delivered with a joint constraints-led and cognitive stimulation approach fosters motor creativity, and the responsiveness to the intervention is moderated by baseline motor and cognitive skills and sex; the intervention (...) may benefit motor creativity through gains in motor coordination, executive function, and creative thinking. Ninety-five children, aged 6–9 years, participated in a 6-month group randomized trial with specialist-led enriched PE vs. generalist-led conventional PE. Before and after the intervention, Bertsch’s Test of Motor Creativity, Movement Assessment Battery for Children, Random Number Generation task and Torrance Test of Creative Thinking were administered. Linear mixed models were run accounting for the random effects of data clusters. Multiple mediation analysis was performed to assess whether motor coordination, executive function and creative thinking mediated any improvement of motor creativity. Results showed that specialist-led enriched PE, compared to generalist-led conventional practice, elicited a more pronounced improvement in all motor creativity dimensions independently of baseline levels of motor and cognitive skills and sex; and improved motor creativity was partially mediated by improved motor coordination and, as regards motor flexibility, also by improved inhibitory ability. In conclusion, enriching PE with tailored manipulations of constraints and variability may enhance the ability to create multiple and original task-pertinent movements both directly and through indirect paths. The results are discussed extending to motor creativity a theoretical framework that distinguishes different creativity modes. The intervention may have fostered the generation of creative movements directly through the exposure to variation in constraints, activating the sensorimotor ‘flow’ mode of creativity that bypasses higher-order cognition, but also indirectly through a systematic and conscious convergence on solutions, activating the ‘deliberate’ mode of creativity that relies on inhibition to reject common or task-inappropriate movement categories. (shrink)

Female sex steroids can affect the motor system, modulating motor cortex excitability as well as performance in dexterity and coordination tasks. However, it has not yet been explored whether FSS affects the cognitive components of motor behavior. Mu is a sensorimotor rhythm observed by electroencephalography in alpha and beta frequency bands in practices such as motor imagery and action observation. This rhythm represents a window for studying the activity of neural circuits involved in motor cognition. (...) Herein we investigated whether the alpha-mu and beta-mu power in the sensorimotor region and the alpha and beta power over frontal, parietal, and occipital regions are modulated differently in the menstrual, follicular, and luteal phases of menstrual cycles in right-handed dominant women. To do so, these women underwent MI and AO in the three menstrual cycle phases. The spectral activity of the cortical regions for the alpha and beta bands were compared between phases of the menstrual cycle and a correlation analysis was also performed in relation to estrogen and progesterone levels. For the hypothesis-based approach, beta-mu event-related desynchronization was significantly stronger in the C3 channel in the follicular phase than in the menstrual and luteal phases. For the data-driven approach, beta ERD during MI was higher in the follicular phase than in the menstrual and luteal phases in the frontal region. These findings suggest the effect of FSS on executive movement control. No effect of menstrual cycle phases was observed in cortical areas investigated during OA, but alpha and beta bands correlated positively with the follicular phase plasma estradiol level. Thus, the attenuation of alpha and beta bands referring to mirror neuron activities appears to be associated with inhibition of cortical activity when estradiol levels are lower, improving cognitive processing of motor action. (shrink)

IntroductionPrevious transcranial magnetic stimulation studies have revealed that the activity of the primary motor cortex ipsilateral to an active hand plays an important role in motor control. The aim of this study was to investigate whether the ipsi-M1 excitability would be influenced by goal-directed movement and laterality during unilateral finger movements.MethodTen healthy right-handed subjects performed four finger tapping tasks with the index finger: simple tapping task, Real-word task, Pseudoword task, and Visually guided tapping task. In the Tap task, (...) the subject performed self-paced simple tapping on a touch screen. In the real-word task, the subject tapped letters displayed on the screen one by one to create a Real-word. Because the action had a specific purpose, this task was considered to be goal-directed as compared to the Tap task. In the Pseudoword task, the subject tapped the letters to create a pseudoword in the same manner as in the Real-word task; however, the word was less meaningful. In the VT task, the subject was required to touch a series of illuminated buttons. This task was considered to be less goal-directed than the Pseudoword task. The tasks were performed with the right and left hand, and a rest condition was added as control. Single- and paired-pulse TMS were applied to the ipsi-M1 to measure corticospinal excitability and short- and long-interval intracortical inhibition in the resting first dorsal interosseous muscle.ResultsWe found the smaller SICI in the ipsi-M1 during the VT task compared with the resting condition. Further, both SICI and LICI were smaller in the right than in the left M1, regardless of the task conditions.DiscussionWe found that SICI in the ipsi-M1 is smaller during visual illumination-guided finger movement than during the resting condition. Our finding provides basic data for designing a rehabilitation program that modulates the M1 ipsilateral to the moving limb, for example, for post-stroke patients with severe hemiparesis. (shrink)

Virtual reality (VR) is the computer simulation of a three‐dimensional environment that a person can interact with using special electronic equipment, such as a headset with an integrated display. Often coupled with VR, exergames are video games that involve physical exercise. Little is known regarding the chronic effects of exergaming through VR chon cognitive functions. Eleven young participants were enrolled in this crossover exploratory study. They had to follow two trainings of 5 consecutive days, 15 min per day, interspaced by (...) a 1‐month washout period. Trainings were performed in a random order: (1) a video training using shadow boxing fitness videos (SBV) and (2) a VR training using a three‐dimensional game where the aim is to cut moving cubes with a sword in each hand. Before and after each training period, a battery of cognitive tests was performed to assess executive functions, such as attention (change blindness), reaction time, response inhibition (go/no‐go, Stroop task), or flexibility (trail making test). Fine motor skills were also evaluated through a Fitt's task. No effect of the SBV training was observed on any of the cognitive functions tested. On the contrary, a significant increased performance in selective attention and observation tests was found after VR training, as well as in inhibitory processes (Stroop and go/no‐go). Other performances were unaffected by either VR or SBV training. The present study argues that VR exergaming is a promising tool to promote cognitive enhancement but targets specific functions according to the type of interface/game that is used. (shrink)

This paper is concerned with the nature of feminine bodily comportment described by Iris Marion Young in ‘Throwing Like a Girl.’ According to Young, the style of movement of women, who undergo patriarchal oppression, reveals their existential status as a socio-historically oppressed group. Her claim is that patriarchal oppression acts upon women’s bodily functions, thus causing feminine motility to exhibit an inhibited intentionality, an ambiguous transcendence and a discontinuous unity. In this paper I take issue with these three modalities of (...) feminine comportment. Firstly, I resort to Max Scheler’s phenomenological description of the different stages leading to motor action to show that the bodily functionality of oppressed women is intact when considered from the motor-intentional perspective. Secondly, I advocate, via Scheler’s phenomenology, a different mode through which to interpret the bodily expressivity of oppressed women. My claim is that feminine motility expresses the negative impact that sexism has upon the oppressed women’s emotional pre-theoretical and pre-non-motor level. My thesis is that patriarchal society negatively influences, and thereby compromises, the constitution of women’s axiological apparatus by inhibiting their preferences of values. Finally, I argue that the axiological apparatus of oppressive men is likewise compromised, and hence needs to be re-educated as much as that of the oppressed women. The main aim of this paper is to suggest a correct reading of the hampered motility of oppressed women, which keeps into consideration the phenomenon of ‘oppression’ in its entirety, and which can thus lead to adequate axiological therapies. (shrink)