Electroencephalography correlates of transcranial direct-current stimulation enhanced surgical skill learning: A replication and extension study

Using neuroimaging to assess brain activity and areas associated with surgical skills: a systematic review

BACKGROUND

Surgical skills acquisition is under continuous development due to the emergence of new technologies, and there is a need for assessment tools to develop along with these. A range of neuroimaging modalities has been used to map the functional activation of brain networks while surgeons acquire novel surgical skills. These have been proposed as a method to provide a deeper understanding of surgical expertise and offer new possibilities for the personalized training of future surgeons. With studies differing in modalities, outcomes, and surgical skills there is a need for a systematic review of the evidence. This systematic review aims to summarize the current knowledge on the topic and evaluate the potential use of neuroimaging in surgical education.

METHODS

We conducted a systematic review of neuroimaging studies that mapped functional brain activation while surgeons with different levels of expertise learned and performed technical and non-technical surgical tasks. We included all studies published before July 1st, 2023, in MEDLINE, EMBASE and WEB OF SCIENCE.

RESULTS

38 task-based brain mapping studies were identified, consisting of randomized controlled trials, case-control studies, and observational cohort or cross-sectional studies. The studies employed a wide range of brain mapping modalities, including electroencephalography, functional magnetic resonance imaging, positron emission tomography, and functional near-infrared spectroscopy, activating brain areas involved in the execution and sensorimotor or cognitive control of surgical skills, especially the prefrontal cortex, supplementary motor area, and primary motor area, showing significant changes between novices and experts.

CONCLUSION

Functional neuroimaging can reveal how task-related brain activity reflects technical and non-technical surgical skills. The existing body of work highlights the potential of neuroimaging to link task-related brain activity patterns with the individual level of competency or improvement in performance after training surgical skills. More research is needed to establish its validity and usefulness as an assessment tool.

Brain-behavior analysis of transcranial direct current stimulation effects on a complex surgical motor task

Transcranial Direct Current Stimulation (tDCS) has demonstrated its potential in enhancing surgical training and performance compared to sham tDCS. However, optimizing its efficacy requires the selection of appropriate brain targets informed by neuroimaging and mechanistic understanding. Previous studies have established the feasibility of using portable brain imaging, combining functional near-infrared spectroscopy (fNIRS) with tDCS during Fundamentals of Laparoscopic Surgery (FLS) tasks. This allows concurrent monitoring of cortical activations. Building on these foundations, our study aimed to explore the multi-modal imaging of the brain response using fNIRS and electroencephalogram (EEG) to tDCS targeting the right cerebellar (CER) and left ventrolateral prefrontal cortex (PFC) during a challenging FLS suturing with intracorporeal knot tying task. Involving twelve novices with a medical/premedical background (age: 22-28 years, two males, 10 females with one female with left-hand dominance), our investigation sought mechanistic insights into tDCS effects on brain areas related to error-based learning, a fundamental skill acquisition mechanism. The results revealed that right CER tDCS applied to the posterior lobe elicited a statistically significant (q < 0.05) brain response in bilateral prefrontal areas at the onset of the FLS task, surpassing the response seen with sham tDCS. Additionally, right CER tDCS led to a significant (p < 0.05) improvement in FLS scores compared to sham tDCS. Conversely, the left PFC tDCS did not yield a statistically significant brain response or improvement in FLS performance. In conclusion, right CER tDCS demonstrated the activation of bilateral prefrontal brain areas, providing valuable mechanistic insights into the effects of CER tDCS on FLS peformance. These insights motivate future investigations into the effects of CER tDCS on error-related perception-action coupling through directed functional connectivity studies.

Pathologists aren't pigeons: exploring the neural basis of visual recognition and perceptual expertise in pathology

Visual (perceptual) reasoning is a critical skill in many medical specialties, including pathology, diagnostic imaging, and dermatology. However, in an ever-compressed medical curriculum, learning and practicing this skill can be challenging. Previous studies (including work with pigeons) have suggested that using reward-feedback-based activities, novices can gain expert levels of visual diagnostic accuracy in shortened training times. But is this level of diagnostic accuracy a result of image recognition (categorization) or is it the acquisition of diagnostic expertise? To answer this, the authors measured electroencephalographic data (EEG) and two components of the human event-related brain potential (reward positivity and N170) to explore the nature of visual expertise in a novice-expert study in pathology visual diagnosis. It was found that the amplitude of the reward positivity decreased with learning in novices (suggesting a decrease in reliance on feedback, as in other studies). However, this signal remained significantly different from the experts whose reward positivity signal did not change over the course of the experiment. There were no changes in the amplitude of the N170 (a reported neural marker of visual expertise) in novices over time. Novice N170 signals remained statistically and significantly lower in amplitude compared to experts throughout task performance. These data suggest that, while novices gained the ability to recognize (categorize) pathologies through reinforcement learning as quantified by the change in reward positivity, increased accuracy, and decreased time for responses, there was little change in the neural marker associated with visual expertise (N170). This is consistent with the multi-dimensional and complex nature of visual expertise and provides insight into future training programs for novices to bridge the expertise gap.

M1 transcranial direct current stimulation augments laparoscopic surgical skill acquisition

The acquisition of basic surgical skills is a key component of medical education and trainees in laparoscopic surgery typically begin developing their skills using simulation box trainers. However, despite the advantages of simulation surgical training, access can be difficult for many trainees. One technique that has shown promise to enhance the deliberate practice of motor skills is transcranial electric stimulation (tES). The purpose of this study was to assess the impact of transcranial direct current stimulation (tDCS) on training induced improvements and retention of traditional time and kinematic based laparoscopic surgical skill metrics. Forty-nine medical students were randomly allocated to a neurostimulation or sham group and completed 5 training sessions of a bead transfer and threading laparoscopic task. Participants in both the sham and stimulation groups significantly improved their time and kinematic performance on both tasks following training. Although we did find that participants who received M1 tDCS saw greater performance benefits in response to training on a bead transfer task compared to those receiving sham stimulation no effect of neurostimulation was found for the threading task. This finding raises new questions regarding the effect that motor task complexity has on the efficacy of neurostimulation to augment training induced improvement and contributes to a growing body of research investigating the effects of neurostimulation on the sensory-motor performance of laparoscopic surgical skill.

Optical neuroimaging and neurostimulation in surgical training and assessment: A state-of-the-art review

Introduction

Functional near-infrared spectroscopy (fNIRS) is a non-invasive optical neuroimaging technique used to assess surgeons' brain function. The aim of this narrative review is to outline the effect of expertise, stress, surgical technology, and neurostimulation on surgeons' neural activation patterns, and highlight key progress areas required in surgical neuroergonomics to modulate training and performance.

Methods

A literature search of PubMed and Embase was conducted to identify neuroimaging studies using fNIRS and neurostimulation in surgeons performing simulated tasks.

Results

Novice surgeons exhibit greater haemodynamic responses across the pre-frontal cortex than experts during simple surgical tasks, whilst expert surgical performance is characterized by relative prefrontal attenuation and upregulation of activation foci across other regions such as the supplementary motor area. The association between PFC activation and mental workload follows an inverted-U shaped curve, activation increasing then attenuating past a critical inflection point at which demands outstrip cognitive capacity Neuroimages are sensitive to the impact of laparoscopic and robotic tools on cognitive workload, helping inform the development of training programs which target neural learning curves. FNIRS differs in comparison to current tools to assess proficiency by depicting a cognitive state during surgery, enabling the development of cognitive benchmarks of expertise. Finally, neurostimulation using transcranial direct-current-stimulation may accelerate skill acquisition and enhance technical performance.

Conclusion

FNIRS can inform the development of surgical training programs which modulate stress responses, cognitive learning curves, and motor skill performance. Improved data processing with machine learning offers the possibility of live feedback regarding surgeons' cognitive states during operative procedures.

Use of neuroimaging to measure neurocognitive engagement in health professions education: a scoping review

PURPOSE

To map the current literature on functional neuroimaging use in medical education research as a novel measurement modality for neurocognitive engagement, learning, and expertise development.

METHOD

We searched PubMed, Embase, Cochrane, ERIC, and Web of Science, and hand-searched reference lists of relevant articles on April 4, 2019, and updated the search on July 7, 2020. Two authors screened the abstracts and then full-text articles for eligibility based on inclusion criteria. The data were then charted, synthesized, and analyzed descriptively.

RESULTS

Sixty-seven articles published between 2007 and 2020 were included in this scoping review. These studies used three main neuroimaging modalities: functional magnetic resonance imaging, functional near-infrared spectroscopy, and electroencephalography. Most of the publications (90%, n = 60) were from the last 10 years (2011-2020). Although these studies were conducted in 16 countries, 68.7% (n = 46) were from three countries: the USA (n = 21), UK (n = 15), and Canada (n = 10). These studies were mainly non-experimental (74.6%, n = 50). Most used neuroimaging techniques to examine psychomotor skill development (57%, n = 38), but several investigated neurocognitive correlates of clinical reasoning skills (22%, n = 15).

CONCLUSION

This scoping review maps the available literature on functional neuroimaging use in medical education. Despite the heterogeneity in research questions, study designs, and outcome measures, we identified a few common themes. Included studies are encouraging of the potential for neuroimaging to complement commonly used measures in education research and may help validate/challenge established theoretical assumptions and provide insight into training methods. This review highlighted several areas for further research. The use of these emerging technologies appears ripe for developing precision education, establishing viable study protocols for realistic operational settings, examining team dynamics, and exploring applications for real-time monitoring/intervention during critical clinical tasks.

Neuroenhancement of surgeons during robotic suturing

BACKGROUND

The initial phases of robotic surgical skills acquisition are associated with poor technical performance, such as low knot-tensile strength (KTS). Transcranial direct-current stimulation (tDCS) can improve force and accuracy in motor tasks but research in surgery is limited to open and laparoscopic tasks in students. More recently, robotic surgery has gained traction and is now the most common approach for certain procedures (e.g. prostatectomy). Early-phase robotic suturing performance is dependent on prefrontal cortex (PFC) activation, and this study aimed to determine whether performance can be improved with prefrontal tDCS.

METHODS

Fifteen surgical residents were randomized to either active then sham tDCS or sham then active tDCS, in two counterbalanced sessions in a double-blind crossover study. Within each session, participants performed a robotic suturing task repeated in three blocks: pre-, intra- and post-tDCS. During the intra-tDCS block, participants were randomized to either active tDCS (2 mA for 15 min) to the PFC or sham tDCS. Primary outcome measures of technical quality included KTS and error scores.

RESULTS

Significantly faster completion times were observed longitudinally, regardless of active (p < 0.001) or sham stimulation (p < 0.001). KTS was greater following active compared to sham stimulation (median: active = 44.35 N vs. sham = 27.12 N, p < 0.001). A significant reduction in error scores from "pre-" to "post-" (p = 0.029) were only observed in the active group.

CONCLUSION

tDCS could reduce error and enhance KTS during robotic suturing and warrants further exploration as an adjunct to robotic surgical training.

Neuroenhancement of a dexterous motor task with Anodal tDCS

Motor skill learning can cause structural and functional changes in the primary motor cortex (M1) leading to cortical plasticity that can be associated with the performance change during the motor skill that is practiced. Similarly, anodal transcranial direct current stimulation (a-tDCS) has been shown to facilitate and enhance plasticity in M1, causing even greater motor skill improvement. By using a fine motor task (O'Connor Tweezer Dexterity Task) in combination with a-tDCS we theorized that a-tDCS could increase the speed of skill acquisition. Forty subjects were recruited and randomized into either a-tDCS or SHAM groups. Subjects completed a single session performing the O'Connor Tweezer Dexterity Task with their non-dominant hand while receiving either a-tDCS stimulation or SHAM stimulation of the hand region of M1. The time it took to place 50- pins was assessed before and after 20 minutes of practice with a-tDCS or SHAM. We found that both groups had similar pre-test performance (P=0.94) and they both had a similar amount of practice pins placed (P=0.69). However, the a-tDCS group had a greater improvement than the SHAM group (p=0.028) for overall learning from pretest to posttest. These results suggest that a-tDCS improved the rate of motor learning and fine motor task performance. These results are in line with previous research and demonstrate that a-tDCS applied to M1 can increase manual precision and steadiness needed for delicate tasks and could have implications in the advancement of surgical training as well as in athletic, military, and other occupational settings.

The effects of unilateral transcranial direct current stimulation on unimanual laparoscopic peg-transfer task

INTRODUCTION

Efficient training methods are required for laparoscopic surgical skills training to reduce the time needed for proficiency. Transcranial direct current stimulation (tDCS) is widely used to enhance motor skill acquisition and can be used to supplement the training of laparoscopic surgical skill acquisition. The aim of this study was to investigate the effect of anodal tDCS over the primary motor cortex (M1) on the performance of a unimanual variant of the laparoscopic peg-transfer task.

METHODS

Fifteen healthy subjects participated in this randomized, double-blinded crossover study involving an anodal tDCS and a sham tDCS intervention separated by 48 h. On each intervention day, subjects performed a unimanual variant of laparoscopic peg-transfer task in three sessions (baseline, tDCS, post-tDCS). The tDCS session consisted of 10 min of offline tDCS followed by 10 min of online tDCS. The scores based on the task completion time and the number of errors in each session were used as a primary outcome measure. A linear mixed-effects model was used for the analysis.

RESULTS

We found that the scores increased over sessions (p < 0.01). However, we found no effects of stimulation (anodal tDCS vs. sham tDCS) and no interaction of stimulation and sessions.

CONCLUSION

This study suggests that irrespective of the type of current stimulation (anodal and sham) over M1, there was an improvement in the performance of the unimanual peg-transfer task, implying that there was motor learning over time. The results would be useful in designing efficient training paradigms and further investigating the effects of tDCS on laparoscopic peg-transfer tasks.

Neuroimaging Guided Transcranial Electrical Stimulation in Enhancing Surgical Skill Acquisition. Comment on Hung et al. The Efficacy of Transcranial Direct Current Stimulation in Enhancing Surgical Skill Acquisition: A Preliminary Meta-Analysis of Randomized Controlled Trials. Brain Sci. 2021, 11, 707

Surgical skill acquisition may be facilitated with a safe application of transcranial direct current stimulation (tDCS). A preliminary meta-analysis of randomized control trials showed that tDCS was associated with significantly better improvement in surgical performance than the sham control; however, meta-analysis does not address the mechanistic understanding. It is known from skill learning studies that the hierarchy of cognitive control shows a rostrocaudal axis in the frontal lobe where a shift from posterior to anterior is postulated to mediate progressively abstract, higher-order control. Therefore, optimizing the transcranial electrical stimulation to target surgical task-related brain activation at different stages of motor learning may provide the causal link to the learning behavior. This comment paper presents the computational approach for neuroimaging guided tDCS based on open-source software pipelines and an open-data of functional near-infrared spectroscopy (fNIRS) for complex motor tasks. We performed an fNIRS-based cortical activation analysis using AtlasViewer software that was used as the target for tDCS of the motor complexity-related brain regions using ROAST software. For future studies on surgical skill training, it is postulated that the higher complexity laparoscopic suturing with intracorporeal knot tying task may result in more robust activation of the motor complexity-related brain areas when compared to the lower complexity laparoscopic tasks.

The Efficacy of Transcranial Direct Current Stimulation in Enhancing Surgical Skill Acquisition: A Preliminary Meta-Analysis of Randomized Controlled Trials

The application of transcranial direct current stimulation (tDCS) to targeted cortices has been found to improve in skill acquisition; however, these beneficial effects remained unclear in fine and complicated skill. The aim of the current meta-analysis was to investigate the association between tDCS application and the efficacy of surgical performance during surgical skill training. We included randomized controlled trials (RCTs) investigating the efficacy of tDCS in enhancing surgical skill acquisition. This meta-analysis was conducted under a random-effect model. Six RCTs with 198 participants were included. The main result revealed that tDCS was associated with significantly better improvement in surgical performance than the sham control (Hedges’ g = 0.659, 95% confidence intervals (95%CIs) = 0.383 to 0.935, p < 0.001). The subgroups of tDCS over the bilateral prefrontal cortex (Hedges’ g = 0.900, 95%CIs = 0.419 to 1.382, p < 0.001) and the primary motor cortex (Hedges’ g = 0.599, 95%CIs = 0.245 to 0.953, p = 0.001) were both associated with significantly better improvements in surgical performance. The tDCS application was not associated with significant differences in error scores or rates of local discomfort compared with a sham control. This meta-analysis supported the rationale for the tDCS application in surgical training programs to improve surgical skill acquisition.

Dataset of prefrontal transcranial direct-current stimulation to improve early surgical knot-tying skills

Transcranial direct-current stimulation (tDCS) has previously demonstrated promising effects in improving surgical performance with motor region stimulation [1], [2], [3], [4]. However, extensive prior research has revealed an important role of the prefrontal cortex in surgical skill development [5,6]. This article presents the data of a double-blind randomized sham-controlled trial investigating the effect of prefrontal tDCS on knot-tying performance [7]. Data was collected from an active (n = 20) and sham (n = 20) group across three blocks: pre-, online- (during) and post-tDCS. Group and block differences of knot-tying performance were analyzed using a Generalized linear mixed model and supported with a Friedman's test. Further sub-analyses were conducted to compare high vs. low skilled individuals and initial vs. last knots. Subjective workload was assessed after each block using a SURG-TLX questionnaire and side-effects of the tDCS block were recorded using an additional survey.

The Relationship between Eco-Innovation and Smart Working as Support for Sustainable Management

Nowadays, firms have to face challenging economical cirses, like the one caused by the COVID-19 pandemic, where volatility, uncertainty, complexity, and ambiguity are manifested. Strategic management is seen as one of the key approaches that firms can choose to implement sustainable smart working (on the support of Internet of Things and smart technologies) and to face global competition. In this article, as a response to the current crisis, we study the influence of Smart Working on Eco-innovation within EU 28 countries. Specifically, we evaluate the relationship between Eco-innovation index for EU 28 countries and Smart Working, by using a clustering analysis. The results show that the increased labor productivity and employees’ eco-innovation are associated, to a higher extent, with the companies agreeing to a flexible and comfortable environment. These companies agree with the introduction of special programs such as working from home. We also prove that Smart Working is implemented by innovative leaders gaining economic sustainability. This study also provides several theoretical and practical contributions. We provide (i) an overview of sustainable management, including the diverse theoretical and methodological perspectives; and (ii) the recommendation of an innovation model through the bilateral collaboration for the constructs of performant sustainable strategies.

Corticospinal and spinal adaptations to motor skill and resistance training: Potential mechanisms and implications for motor rehabilitation and athletic development

Optimal strategies for enhancing strength and improving motor skills are vital in athletic performance and clinical rehabilitation. Initial increases in strength and the acquisition of new motor skills have long been attributed to neurological adaptations. However, early increases in strength may be predominantly due to improvements in inter-muscular coordination rather than the force-generating capacity of the muscle. Despite the plethora of research investigating neurological adaptations from motor skill or resistance training in isolation, little effort has been made in consolidating this research to compare motor skill and resistance training adaptations. The findings of this review demonstrated that motor skill and resistance training adaptations show similar short-term mechanisms of adaptations, particularly at a cortical level. Increases in corticospinal excitability and a release in short-interval cortical inhibition occur as a result of the commencement of both resistance and motor skill training. Spinal changes show evidence of task-specific adaptations from the acquired motor skill, with an increase or decrease in spinal reflex excitability, dependant on the motor task. An increase in synaptic efficacy of the reticulospinal projections is likely to be a prominent mechanism for driving strength adaptations at the subcortical level, though more research is needed. Transcranial electric stimulation has been shown to increase corticospinal excitability and augment motor skill adaptations, but limited evidence exists for further enhancing strength adaptations from resistance training. Despite the logistical challenges, future work should compare the longitudinal adaptations between motor skill and resistance training to further optimise exercise programming.

The Effects of Transcranial Electrical Stimulation on Human Motor Functions: A Comprehensive Review of Functional Neuroimaging Studies

Transcranial electrical stimulation (tES) is a promising tool to enhance human motor skills. However, the underlying physiological mechanisms are not fully understood. On the other hand, neuroimaging modalities provide powerful tools to map some of the neurophysiological biomarkers associated with tES. Here, a comprehensive review was undertaken to summarize the neuroimaging evidence of how tES affects human motor skills. A literature search has been done on the PubMed database, and 46 relative articles were selected. After reviewing these articles, we conclude that neuroimaging techniques are feasible to be coupled with tES and offer valuable information of cortical excitability, connectivity, and oscillations regarding the effects of tES on human motor behavior. The biomarkers derived from neuroimaging could also indicate the motor performance under tES conditions. This approach could advance the understanding of tES effects on motor skill and shed light on a new generation of adaptive stimulation models.

Neuroenhancement in surgeons: benefits, risks and ethical dilemmas

Background

Surgeons traditionally aim to reduce mistakes in healthcare through repeated training and advancement of surgical technology. Recently, performance-enhancing interventions such as neurostimulation are emerging which may offset errors in surgical practice.

Methods

Use of transcranial direct-current stimulation (tDCS), a novel neuroenhancement technique that has been applied to surgeons to improve surgical technical performance, was reviewed. Evidence supporting tDCS improvements in motor and cognitive performance outside of the field of surgery was assessed and correlated with emerging research investigating tDCS in the surgical setting and potential applications to wider aspects of healthcare. Ethical considerations and future implications of using tDCS in surgical training and perioperatively are also discussed.

Results

Outside of surgery, tDCS studies demonstrate improved motor performance with regards to reaction time, task completion, strength and fatigue, while also suggesting enhanced cognitive function through multitasking, vigilance and attention assessments. In surgery, current research has demonstrated improved performance in open knot-tying, laparoscopic and robotic skills while also offsetting subjective temporal demands. However, a number of ethical issues arise from the potential application of tDCS in surgery in the form of safety, coercion, distributive justice and fairness, all of which must be considered prior to implementation.

Conclusion

Neuroenhancement may improve motor and cognitive skills in healthcare professions with impact on patient safety. Implementation will require accurate protocols and regulations to balance benefits with the associated ethical dilemmas, and to direct safe use for clinicians and patients.

Systematic review of combined functional near-infrared spectroscopy and transcranial direct-current stimulation studies

Significance: Combining transcranial direct-current stimulation (tDCS) with functional near-infrared spectroscopy (fNIRS) is a recent approach to exploring brain activation evoked by neurostimulation. Aim: To critically evaluate studies combining tDCS and fNIRS and provide a consolidated overview of cortical hemodynamic responses to neurostimulation. Approach: Key terms were searched in three databases (MEDLINE, EMBASE, and PsycINFO) with cross-referencing and works from Google Scholar also evaluated. All studies reporting on fNIRS-derived hemoglobin changes evoked by tDCS were included. Results: Literature searches revealed 474 articles, of which 28 were included for final review (22 in healthy individuals: 9 involving rest and 13 with tasks; 6 in the clinical setting). At rest, an overall increase in cortical activation was observed in fNIRS responses at the site of stimulation, with evidence suggesting nonstimulated brain regions are also similarly affected. Conversely, during tasks, reduced cortical activation was observed during online stimulation. Offline and poststimulation effects were less consistent, as is the impact on clinical populations and their symptom correlation. Conclusion: This review explores the methodological frameworks for fNIRS-tDCS evaluations and summarizes hemodynamic responses associated with tDCS in all populations. Our findings provide further evidence of the impact of tDCS on neuronal activation within functionally connected networks.

Utilizing transcranial direct current stimulation to enhance laparoscopic technical skills training: A randomized controlled trial

BACKGROUND

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that delivers constant, low electrical current resulting in changes to cortical excitability. Prior work suggests it may enhance motor learning giving it the potential to augment surgical technical skill acquisition.

OBJECTIVES

The aim of this study was to test the efficacy of tDCS, coupled with motor skill training, to accelerate laparoscopic skill acquisition in a pre-registered (NCT03083483), double-blind and placebo-controlled study. We hypothesized that relative to sham tDCS, active tDCS would accelerate the development of laparoscopic technical skills, as measured by the Fundamentals of Laparoscopic Surgery (FLS) Peg Transfer task quantitative metrics.

METHODS

In this study, sixty subjects (mean age 22.7 years with 42 females) were randomized into sham or active tDCS in either bilateral primary motor cortex (bM1) or supplementary motor area (SMA) electrode configurations. All subjects practiced the FLS Peg Transfer Task during six 20-min training blocks, which were preceded and followed by a single trial pre-test and post-test. The primary outcome was changes in laparoscopic skill performance over time, quantified by group differences in completion time from pre-test to post-test and learning curves developed from a calculated score accounting for errors.

RESULTS

Learning curves calculated over the six 20-min training blocks showed significantly greater improvement in performance for the bM1 group than the sham group (t = 2.07, p = 0.039), with the bM1 group achieving approximately the same amount of improvement in 4 blocks compared to the 6 blocks required of the sham group. The SMA group also showed greater mean improvement than sham, but exhibited more variable learning performance and differences relative to sham were not significant (t = 0.85, p = 0.400). A significant main effect was present for pre-test versus post-test times (F = 133.2, p < 0.001), with lower completion times at post-test, however these did not significantly differ for the training groups.

CONCLUSION

Laparoscopic skill training with active bilateral tDCS exhibited significantly greater learning relative to sham. The potential for tDCS to enhance the training of surgical skills, therefore, merits further investigation to determine if these preliminary results may be replicated and extended.