Motor imagery is the visual and kinaesthetic mental representation of human movement, and it can be effective in improving motor performance and (re)learning in clinical and sporting contexts. However, individuals who experience aphantasia and self-report absent visual imagery abilities, would, presumably, be unable to engage with motor imagery and gain no benefits from imagery-based interventions. The aim of this study was to explore any self-reported motor imagery-related abilities in participants who experience aphantasia. One-hundred and ninety-four participants who self-reported experiencing a total absence of voluntary visual imagery completed motor simulation ability questionnaires to assess their visual motor imagery, kinaesthetic motor imagery, and combined action observation and motor imagery (AOMI) abilities. The findings indicate that aphantasic participants are unable to engage with visual motor imagery. However, participants reported significantly greater kinaesthetic imagery and AOMI abilities, with medium-to-large effect sizes, when compared to visual motor imagery ability. Although generating kinaesthetic imagery and AOMI was still difficult, the findings suggest that these motor simulation abilities may be somewhat less compromised compared to the complete absence of visual imagery for participants who experience aphantasia. The results also offer novel evidence that immediate prior action execution may have the potential to prime the generation of kinaesthetic imagery in those who experience aphantasia.

This study is the first to systematically investigate falls across the lifespan in Developmental Coordination Disorder (DCD). Using a mixed-methods approach, we conducted an online survey co-developed with a Participant Involvement and Engagement group, assessing fall frequency, causes, injuries, fall-related anxiety, and psychosocial consequences. The survey was completed by adults with DCD (n = 115), parents of children with DCD (n = 99), typically developing (TD) adults (n = 81), and parents of TD children (n = 86). Falls were significantly more frequent in DCD, with 26% of DCD adults falling one to two times per month (vs. 3% TD) and 55% of children with DCD falling one to two times per week (vs. 23% TD). Falls were caused by a wide range of activities (e.g., walking), environmental obstacles (e.g., uneven surfaces, stairs), and cognitive factors (e.g., multitasking). Fall-related injuries-including fractures-were more prevalent in the DCD groups, alongside higher fall-anxiety, reduced social participation, and lower activity engagement. Overall, falls in DCD are frequent, injurious, anxiety-provoking, and detrimental to well-being. Despite this, DCD is absent from fall prevention guidelines. Urgent action is needed to integrate fall risk screening and targeted interventions into clinical and public health frameworks.

PURPOSE:Prosthetic hand devices are frequently abandoned as they are difficult to use and impose high mental workload upon users. However, researchers are yet to establish whether personality factors might contribute to these negative prosthetic hand experiences. In this study, we examined whether key prosthetic hand outcome measures were associated with the trait inclination for conscious movement control-a phenomenon termed "reinvestment" that can impair motor performance and deplete cognitive resources. MATERIALS AND METHODS:A cross-sectional survey was distributed online to a sample of upper-limb prosthesis users. Thirty-six respondents answered demographic questions and completed three questionnaires related to device satisfaction, trait reinvestment, and mental workload. RESULTS:Correlational analysis revealed that a greater propensity for movement-specific reinvestment was associated with lower prosthesis satisfaction, higher mental workload, and lower levels of perceived device predictability. It was also found that mental workload mediated the relationship between reinvestment tendencies and both device satisfaction and hours of prosthesis use per day. CONCLUSIONS:This study provides first evidence that trait reinvestment is negatively implicated in the control and satisfaction of prosthetic hand use. We suggest that training interventions for prosthetic hand use should aim to limit the long-term reliance on conscious control of movements.

Combined action observation and motor imagery (AOMI) facilitates corticospinal excitability (CSE). This study used single-pulse transcranial magnetic stimulation (TMS) to explore changes in CSE for coordinative AOMI, where the observed and imagined actions are related but not identical, for a single-leg sit-to-stand (SL-STS) movement. Twenty-one healthy adults completed two testing sessions including baseline (BL), action observation (AO), and motor imagery (MI) control conditions, and three experimental conditions where they observed a slow-paced SL-STS while simultaneously imagining a slow- (AOMIHICO), medium- (AOMIMOCO), or fast-paced (AOMILOCO) SL-STS. A TMS pulse was delivered to the right leg representation of the left primary motor cortex at three stimulation timepoints aligned with peak electromyography (EMG) activity of the knee extensor muscle group for the fast- (T1), medium- (T2), and slow-paced (T3) SL-STS during each condition. Motor evoked potential (MEP) amplitudes were recorded from the knee extensor muscle group as a marker of CSE for all stimulation timepoints and conditions. A main effect for experimental condition was reported for all stimulation timepoints. MEP amplitudes were significantly greater for AOMIHICO at T1 and T3, and AOMIMOCO and AOMILOCO at all stimulation timepoints, when compared with control conditions. This study provides neurophysiological evidence supporting the use of coordinative AOMI.

The reliance on vision to control a myoelectric prosthesis is cognitively burdensome and contributes to device abandonment. The feeling of uncertainty when gripping an object is thought to be the cause of this overreliance on vision in hand-related actions. We explored if experimentally reducing grip uncertainty alters the visuomotor control and mental workload experienced during initial prosthesis use. In a repeated measures design, twenty-one able-bodied participants took part in a pouring task across three conditions: (a) using their anatomical hand, (b) using a myoelectric prosthetic hand simulator, and (c) using a myoelectric prosthetic hand simulator with Velcro attached to reduce grip uncertainty. Performance, gaze behaviour (using mobile eye-tracking) and self-reported mental workload, was measured. Results showed that using a prosthesis (with or without Velcro) slowed task performance, impaired typical eye-hand coordination and increased mental workload compared to anatomic hand control. However, when using the prosthesis with Velcro, participants displayed better prosthesis control, more effective eye-hand coordination and reduced mental workload compared to when using the prosthesis without Velcro. These positive results indicate that reducing grip uncertainty could be a useful tool for encouraging more effective prosthesis control strategies in the early stages of prosthetic hand learning.

This scientific commentary refers to ‘Explicit and implicit motor simulations are impaired in individuals with aphantasia’, by Dupont et al. (https://doi.org/10.1093/braincomms/fcae072) in Brain Communications

Researchers from multiple disciplines have studied the simulation of actions through motor imagery, action observation, or their combination. Procedures used in these studies vary considerably between research groups, and no standardized approach to reporting experimental protocols has been proposed. This has led to under-reporting of critical details, impairing the assessment, replication, synthesis, and potential clinical translation of effects. We provide an overview of issues related to the reporting of information in action simulation studies, and discuss the benefits of standardized reporting. We propose a series of checklists that identify key details of research protocols to include when reporting action simulation studies. Each checklist comprises A) essential methodological details, B) essential details that are relevant to a specific mode of action simulation, and C) further points that may be useful on a case-by-case basis. We anticipate that the use of these guidelines will improve the understanding, reproduction, and synthesis of studies using action simulation, and enhance the translation of research using motor imagery and action observation to applied and clinical settings.

The aim of this research was to establish prevalence estimates for aphantasia, hypophantasia, typical imagery ability, and hyperphantasia in a large multi-national cohort. In Study 1, the Vividness of Visual Imagery Questionnaire was completed by 3,049 participants. Results indicated prevalence estimates of 1.2% for aphantasia, 3% for hypophantasia, 89.9% for typical imagery ability, and 5.9% for hyperphantasia. In Study 2, to replicate these findings in a larger sample, the Study 1 data were combined with openly available data from previous prevalence studies to create a total sample of 9,063 participants. Re-analysis of this data confirmed prevalence estimates of 0.9% for aphantasia, 3.3% for hypophantasia, 89.7% for typical imagery ability, and 6.1% for hyperphantasia. These robust and up-to-date estimates provide enhanced clarity to researchers regarding the prevalence of differing visual imagery abilities and provide a platform for future studies exploring the role of visual imagery in various cognitive and behavioral tasks.

Combined action observation and motor imagery (AOMI) facilitates corticospinal excitability (CSE) and may potentially induce plastic-like changes in the brain in a similar manner to physical practice. This study used transcranial magnetic stimulation (TMS) to explore changes in CSE for AOMI of coordinative lower-limb actions. Twenty-four healthy adults completed two baseline (BLH, BLNH) and three AOMI conditions, where they observed a knee extension while simultaneously imagining the same action (AOMICONG), plantarflexion (AOMICOOR-FUNC), or dorsiflexion (AOMICOOR-MOVE). Motor evoked potential (MEP) amplitudes were recorded as a marker of CSE for all conditions from two knee extensor, one dorsi flexor, and two plantar flexor muscles following TMS to the right leg representation of the left primary motor cortex. A main effect for experimental condition was reported for all three muscle groups. MEP amplitudes were significantly greater in the AOMICONG condition compared to the BLNH condition (p = .04) for the knee extensors, AOMICOOR-FUNC condition compared to the BLH condition (p = .03) for the plantar flexors, and AOMICOOR-MOVE condition compared to the two baseline conditions for the dorsi flexors (ps ≤ .01). The study findings support the notion that changes in CSE are driven by the imagined actions during coordinative AOMI.

Background Developmental coordination disorder (DCD) affects movement coordination, but little is known about how the condition impacts the behaviours of car drivers and pedestrians. Aims This study examined the self-reported driving and pedestrian behaviours of adults with Developmental Coordination Disorder (DCD). Methods and procedures One hundred and twenty-eight participants (62 adults with DCD vs. 66 TD adults) responded to an online survey asking them about their perceptions of confidence and self-reported driving and pedestrian behaviours in the real-world. Outcomes and results Results suggested that adults with DCD felt less confident and reported more lapses in attention (e.g., forgetting where their car was parked) and errors (e.g., failing to check their mirrors prior to a manoeuvre) when driving compared to typically developed (TD) adults. Adults with DCD also reported feeling less confident and reported less adherence to road traffic laws (e.g., not waiting for a green crossing signal before crossing the road) when walking as pedestrians. Conclusions and implications These results offer some much-needed insight into the behaviours of those with DCD outside of the laboratory environment and underline the need for research investigating the driving and pedestrian behaviours of individuals with DCD in ‘real-world’ contexts.

Combined use of action observation and motor imagery (AOMI) is an increasingly popular motor -simulation intervention, which involves observing movements on video while simultaneously imagining the feeling of movement execution. Measuring and reporting participant imagery-ability characteristics are essential in motor -simulation research, but no measure of AOMI ability currently exists. Accordingly, the AOMI Ability Questionnaire (AOMI-AQ) was developed to address this gap in the literature. In Study 1, two hundred eleven participants completed the AOMI-AQ and the kinesthetic imagery subscales of the Movement Imagery Questionnaire-3 and Vividness of Motor Imagery Questionnaire-2. Following exploratory factor analysis, an 8-item AOMI-AQ was found to correlate positively with existing motor-imagery measures. In Study 2, one hundred seventy-four participants completed the AOMI-AQ for a second time after a period of 7 - 10 days. Results indicate a good test - retest reliability for the AOMI-AQ. The new AOMI-AQ measure provides a valid and reliable tool for researchers and practitioners wishing to assess AOMI ability.

Combined action observation and motor imagery (AOMI) facilitates corticospinal excitability (CSE). This study used single-pulse transcranial magnetic stimulation (TMS) to explore changes in CSE for coordinative AOMI of a single-leg sit-to-stand (SL-STS) movement. Twenty-one healthy adults completed two testing sessions, where they engaged with baseline (BL), action observation (AO), and motor imagery (MI) control conditions, and three experimental conditions where they observed a slow-paced SL-STS while simultaneously imagining a slow- (AOMIHICO), medium- (AOMIMOCO), or fast-paced (AOMILOCO) SL-STS, with imagery guided through audio sonification. A TMS pulse was delivered to the right leg representation of the left primary motor cortex at three stimulation timepoints aligned with peak EMG activity of the knee extensor muscle group for the slow-, medium-, and fast-paced SL-STS during each condition. Motor evoked potential (MEP) amplitudes were recorded from the KE muscle group as a marker of CSE for all stimulation timepoints and conditions. A main effect for experimental condition was reported for all three stimulation timepoints. MEP amplitudes were significantly greater for AOMIHICO at T1 and T3, and AOMIMOCO and AOMILOCO at all stimulation timepoints, when compared with control conditions. The findings provide empirical support for the propositions of the Dual-Action Simulation Hypothesis and Visual Guidance Hypothesis accounts for coordinative AOMI. This study builds on existing neurophysiological support for the use of coordinative AOMI as an alternative method for movement (re)learning. Longitudinal research incorporating neurophysiological and behavioral measures is warranted to explore the efficacy of coordinative AOMI for this purpose. ### Competing Interest Statement The authors have declared no competing interest.

To date, there is increasing evidence to suggest that age and adult attachment styles, such as secure, anxious and avoidant attachment are predictive or protective for psychological distress. The study aimed to investigate the extent to which age and adult attachment style, measured by the Attachment Style Questionnaire, predicted psychological distress, measured by the Kessler 10 Psychological Distress Scale, in the Singapore general population during COVID-19. Ninety-nine residents of Singapore (44 females, 52 males, 3 prefer not to state their gender) aged between 18 and 66 completed an online survey, which collected information on age, adult attachment styles and levels of psychological distress. Multiple regression analysis was performed to study the influence of predictive factors on psychological distress. The study identified 20.2%, 13.1% and 14.1% of participants reporting psychological distress at the mild, moderate and severe levels, respectively. The study also reported that age and psychological distress were negatively correlated, and that psychological distress was negatively correlated with both anxious and avoidant attachment styles. It was concluded that age and adult attachment style significantly predicted psychological distress in the Singapore general population during COVID-19. Further studies exploring other variables and risk factors are required to further consolidate these results. At the global level, these findings may help countries predict residents' reactions to future outbreaks and help them prepare strategies and approaches to address these situations.

When using a upper-limb prosthesis, mental, emotional, and physical effort is often experienced. These have been linked to high rates of device dissatisfaction and rejection. Therefore, understanding and quantifying the complex nature of workload experienced when using, or learning to use, a upper-limb prosthesis has practical and clinical importance for researchers and applied professionals. The aim of this paper was to design and validate a self-report measure of mental workload specific to prosthesis use (The Prosthesis Task Load Index; PROS-TLX) that encapsulates the array of mental, physical, and emotional demands often experienced by users of these devices. We first surveyed upper-limb prosthetic limb users who confirmed the importance of eight workload constructs taken from published literature and previous workload measures. These constructs were mental demands, physical demands, visual demands, conscious processing, frustration, situational stress, time pressure and device uncertainty. To validate the importance of these constructs during initial prosthesis learning, we then asked able-bodied participants to complete a coin-placement task using their anatomical hand and then using a myoelectric prosthesis simulator under low and high mental workload. As expected, using a prosthetic hand resulted in slower movements, more errors, and a greater tendency to visually fixate the hand (indexed using eye-tracking equipment). These changes in performance were accompanied by significant increases in PROS-TLX workload subscales. The scale was also found to have good convergent and divergent validity. Further work is required to validate whether the PROS-TLX can provide meaningful clinical insights to the workload experienced by clinical users of prosthetic devices.

Developmental coordination disorder (DCD) is characterised by poor motor coordination, which interferes with the ability to execute activities of daily living (ADLs). Combined action observation and motor imagery (AOMI) involves observing movement videos whilst imagining simultaneously the sensations of executing the same movement. Laboratory-based research indicates that AOMI can help improve movement coordination in children with DCD, but no previous research had investigated the efficacy of AOMI interventions for learning ADLs. This study investigated the efficacy of a home-based, parent-led, AOMI intervention for learning ADLs in children with DCD. Children with confirmed (n = 23) or suspected (n = 5) DCD (total sample n = 28), aged 7-12 years, were assigned to either an AOMI intervention or a control intervention (both n = 14). Participants attempted the following ADLs at pre-test (week 1), post-test (week 4), and retention test (week 6): shoelace tying, cutlery use, shirt buttoning, and cup stacking. Task completion times and movement techniques were recorded. The AOMI intervention produced significantly faster task completion times than the control intervention at post-test for shoelace tying, and significantly improved movement techniques for shoelace tying and cup stacking. Importantly, for children who could not tie shoelaces at pre-test (n = 9 per group), 89% of those following the AOMI intervention learnt the skill successfully by the end of the study, compared to only 44% of those following the control intervention. The findings indicate that home-based, parent-led, AOMI interventions can aid the learning of complex ADLs in children with DCD, and may be particularly effective for facilitating the learning of motor skills that do not currently exist within these children's motor repertoire.

Feedforward modeling, the creation of one's own behaviour that is potentially achievable in the future, can support motor performance and learning. While this has been shown for sequences of motor actions, it remains to be tested whether feedforward modelling is beneficial for single complex motor actions. Using an immersive, state-of-the-art, low-latency Cave Automatic Virtual Environment (CAVE), we compared motor imagery during action observation (AOMI) of oneself performing at one's current skill level against AOMI of oneself performing at an achievable future skill level. We performed 3D scans and created a ready-to-animate virtual human of each participant. During acquisition, participants observed an avatar of themselves performing either one of their own previously executed squats (Me-Novice) or observed an avatar of themselves performing a skilled squat (Me-Skilled), whilst simultaneously imagining the feelings and sensations associated with movement execution. Findings revealed an advantage for the Me-Skilled group as compared to the Me-Novice group in motor performance and cognitive representation structure, while self-efficacy improved in both groups. In comparison to watching and imagining oneself performing at the current novice skill level, watching and imagining oneself performing at a more advanced skill level prevented from making errors in motor performance and led to perceptual-cognitive scaffolding as shown by functional changes in underlying representations. Simultaneous imagery whilst observing future states of action may therefore help to establish cognitive prerequisites that enable better motor performance. To this end, virtual reality is a promising tool to create learning environments that exceed an individual's current performance level.

Athletes spend a lot of time and effort practicing skills to get better at their sports. In addition to physical practice, athletes can use a technique called action observation to help themselves improve. Action observation is the process of watching movement. Humans naturally learn how to perform movements by watching the movements of other people. For example, from an early age, children learn important skills such as walking, throwing, and kicking by seeing other people perform those actions. Research has shown that watching movements activates similar parts of the brain to those that are involved in performing movement. This means watching sports performance might help athletes improve by strengthening the brain areas used when actions are performed. Coaches and sport psychologists use action observation methods, such as live demonstrations and video footage, to help athletes improve their techniques, develop their confidence, and get better at their sports.

Research has shown that motor imagery (MI) interventions, involving the systematic and repeated imagination of visual and kinaesthetic components of movements, can enhance performance in sport. Twenty years ago, Holmes and Collins (2001) published the PETTLEP model as a framework to improve the delivery and outcome of MI interventions. The model outlined seven principles to be considered when designing effective imagery interventions: Physical, Environment, Task, Timing, Learning, Emotion, Perspective (i.e., PETTLEP). The incorporation of these principles within MI interventions was assumed to facilitate performance through the optimisation of a functional equivalence between the neurophysiological substrates of motor preparation and execution, and that of MI. Since its conception, this model has become a standard for many in the delivery of imagery interventions in sport and has been corroborated through research and practice. This 20-year review first covers the reach and impact of this influential model and the more recent empirical investigations related to PETTLEP. We then outline how PETTLEP-based imagery may be integrated with action observation to support an increasingly popular approach to the delivery of imagery interventions in sport. Research indicates that combining these two simulation states can enhance sport performance whilst also providing the sport psychologist more control over the imagery experience than is possible through traditional imagery interventions. This article discusses the application of PETTLEP within a combined action observation and imagery framework and provides guidance for sport psychologists for the creation of new PETTLEP-informed interventions.

Although prosthetic hand rejection rates remain high, evidence suggests that effective training plays a major role in device acceptance. Receiving training early in the rehabilitation process also enhances functional prosthetic use, decreases the likelihood of developing an overreliance on the intact limb, and reduces amputation-related pain. Despite these obvious benefits, there is a current lack of evidence regarding the most effective training techniques to facilitate myoelectric prosthetic hand control, and it remains unknown whether training is effective in facilitating the acquisition and transfer of prosthetic skill. In this scoping review, we introduced and summarized key motor learning principles related to attentional focus, implicit motor learning, training eye–hand coordination, practice variability, motor imagery, and action observation, and virtual training and biofeedback. We then reviewed the existing literature that has applied these principles for training prosthetic hand control before outlining future avenues for further research. The importance of optimizing early and appropriate training cannot be overlooked. While the intuition and experience of clinicians holds enormous value, evidence-based guidelines based on well-established motor learning principles will also be crucial for training effective prosthetic hand control. While it is clear that more research is needed to form the basis of such guidelines, it is hoped that this review highlights the potential avenues for this work.