Modelling dynamic fronto-parietal behaviour during minimally invasive surgery--a Markovian trip distribution approach

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.

Error-related brain state analysis using electroencephalography in conjunction with functional near-infrared spectroscopy during a complex surgical motor task

Error-based learning is one of the basic skill acquisition mechanisms that can be modeled as a perception-action system and investigated based on brain-behavior analysis during skill training. Here, the error-related chain of mental processes is postulated to depend on the skill level leading to a difference in the contextual switching of the brain states on error commission. Therefore, the objective of this paper was to compare error-related brain states, measured with multi-modal portable brain imaging, between experts and novices during the Fundamentals of Laparoscopic Surgery (FLS) "suturing and intracorporeal knot-tying" task (FLS complex task)-the most difficult among the five psychomotor FLS tasks. The multi-modal portable brain imaging combined functional near-infrared spectroscopy (fNIRS) and electroencephalography (EEG) for brain-behavior analysis in thirteen right-handed novice medical students and nine expert surgeons. The brain state changes were defined by quasi-stable EEG scalp topography (called microstates) changes using 32-channel EEG data acquired at 250 Hz. Six microstate prototypes were identified from the combined EEG data from experts and novices during the FLS complex task that explained 77.14% of the global variance. Analysis of variance (ANOVA) found that the proportion of the total time spent in different microstates during the 10-s error epoch was significantly affected by the skill level (p < 0.01), the microstate type (p < 0.01), and the interaction between the skill level and the microstate type (p < 0.01). Brain activation based on the slower oxyhemoglobin (HbO) changes corresponding to the EEG band power (1-40 Hz) changes were found using the regularized temporally embedded Canonical Correlation Analysis of the simultaneously acquired fNIRS-EEG signals. The HbO signal from the overlying the left inferior frontal gyrus-opercular part, left superior frontal gyrus-medial orbital, left postcentral gyrus, left superior temporal gyrus, right superior frontal gyrus-medial orbital cortical areas showed significant (p < 0.05) difference between experts and novices in the 10-s error epoch. We conclude that the difference in the error-related chain of mental processes was the activation of cognitive top-down attention-related brain areas, including left dorsolateral prefrontal/frontal eye field and left frontopolar brain regions, along with a 'focusing' effect of global suppression of hemodynamic activation in the experts, while the novices had a widespread stimulus(error)-driven hemodynamic activation without the 'focusing' effect.

Recent evidence on visual-spatial ability in surgical education: A scoping review

BACKGROUND

Understanding the relationships between structures is critical for surgical trainees. However, the heterogeneity of the literature on visual-spatial ability (VSA) in surgery makes it challenging for educators to make informed decisions on incorporating VSA into their programs. We conducted a scoping review of the literature on VSA in surgery to provide a map of the literature and identify where gaps still exist for future research.

METHODS

We searched databases until December 2019 using keywords related to VSA and surgery. The resulting articles were independently screened by two researchers for inclusion in our review.

RESULTS

We included 117 articles in the final review. Fifty-nine articles reported significant correlations between VSA tests and surgical performance, and this association is supported by neuroimaging studies. However, it remains unclear whether VSA should be incorporated into trainee selection and whether there is a benefit of three-dimensional (3D) over two-dimensional (2D) training.

CONCLUSIONS

It appears that VSA correlates with surgical performance in the simulated environment, particularly for novice learners. Based on our findings, we make suggestions for how surgical educators may use VSA to support novice learners. Further research should determine whether VSA remains correlated to surgical performance when trainees move into the operative environment.

Methodological Approaches and Recommendations for Functional Near-Infrared Spectroscopy Applications in HF/E Research

OBJECTIVE

The objective of this study was to systematically document current methods and protocols employed when using functional near-infrared spectroscopy (fNIRS) techniques in human factors and ergonomics (HF/E) research and generate recommendations for conducting and reporting fNIRS findings in HF/E applications.

METHOD

A total of 1,687 articles were identified through Ovid-MEDLINE, PubMed, Web of Science, and Scopus databases, of which 37 articles were included in the review based on review inclusion/exclusion criteria.

RESULTS

A majority of the HF/E fNIRS investigations were found in transportation, both ground and aviation, and in assessing cognitive (e.g., workload, working memory) over physical constructs. There were large variations pertaining to data cleaning, processing, and analysis approaches across the studies that warrant standardization of methodological approaches. The review identified major challenges in transparency and reporting of important fNIRS data collection and analyses specifications that diminishes study replicability, introduces potential biases, and increases likelihood of inaccurate results. As such, results reported in existing fNIRS studies need to be cautiously approached.

CONCLUSION

To improve the quality of fNIRS investigations and/or to facilitate its adoption and integration in different HF/E applications, such as occupational ergonomics and rehabilitation, recommendations for fNIRS data collection, processing, analysis, and reporting are provided.

A decade of imaging surgeons' brain function (part I): Terminology, techniques, and clinical translation

BACKGROUND

Functional neuroimaging has the potential to deepen our understanding of technical and nontechnical skill acquisition in surgeons, particularly as established assessment tools leave unanswered questions about inter-operator differences in ability that seem independent of experience.

METHODS

In this first of a 2-part article, we aim to utilize our experience in neuroimaging surgeons to orientate the nonspecialist reader to the principles of brain imaging. Terminology commonly used in brain imaging research is explained, placing emphasis on the "activation response" to an surgical task and its effect on local cortical hemodynamic parameters (neurovascular coupling).

RESULTS

Skills learning and subsequent consolidation and refinement through practice lead to reorganization of the functional architecture of the brain (known as "neuroplasticity"), evidenced by changes in the strength of regional activation as well as alterations in connectivity between brain regions, culminating in more efficient use of neural resources during task performance.

CONCLUSION

Currently available neuroimaging techniques that either directly (ie, measure electrical activity) or indirectly (ie, measure tissue hemodynamics) assess brain function are discussed. Finally, we highlight the important practical considerations when conducting brain imaging research in surgeons.

The role of the posterior parietal cortex in stereopsis and hand-eye coordination during motor task behaviours

The field of 'Neuroergonomics' has the potential to improve safety in high-risk operative environments through a better appreciation of the way in which the brain responds during human-tool interactions. This is especially relevant to minimally invasive surgery (MIS). Amongst the many challenges imposed on the surgeon by traditional MIS (laparoscopy), arguably the greatest is the loss of depth perception. Robotic MIS platforms, on the other hand, provide the surgeon with a magnified three-dimensional view of the environment, and as a result may offload a degree of the cognitive burden. The posterior parietal cortex (PPC) plays an integral role in human depth perception. Therefore, it can be hypothesized that differences in PPC activation between monoscopic and stereoscopic vision may be observed. In order to investigate this hypothesis, the current study explores disparities in PPC responses between monoscopic and stereoscopic visual perception to better de-couple the burden imposed by laparoscopy and robotic surgery on the operator's brain. Fourteen participants conducted tasks of depth perception and hand-eye coordination under both monoscopic and stereoscopic visual feedback. Cortical haemodynamic responses were monitored throughout using optical functional neuroimaging. Overall, recruitment of the bilateral superior parietal lobule was observed during both depth perception and hand-eye coordination tasks. This occurred contrary to our hypothesis, regardless of the mode of visual feedback. Operator technical performance was significantly different in two- and three-dimensional visual displays. These differences in technical performance do not appear to be explained by significant differences in parietal lobe processing.

Neuroanatomical correlates of laparoscopic surgery training

BACKGROUND

Better understanding of the brain regions involved in performing laparoscopic surgery is likely to provide important insights for improving laparoscopic training and assessment in the future. To our knowledge, this is the first study using real Fundamentals of Laparoscopy Training (FLS)-based laparoscopic surgery training tasks in the functional magnetic resonance imaging (fMRI) environment to provide extensive characterization of the brain regions involved in this specific task execution.

METHODS

Nine right-handed subjects practiced five FLS-modified laparoscopic surgery-training tasks with a training box for ten sessions in a simulated fMRI environment. Following the last practice session, they underwent 3 T fMRI while performing each task.

RESULTS

An increase in the extent of brain activation was observed as the complexity of the tasks increased. Activation in the precentral gyrus, postcentral gyrus, and premotor regions was observed in the performance of all tasks, whereas the superior parietal lobe (SPL) was activated in the more complex tasks. The mean score and brain activation for performance with the dominant hand were larger than those observed during performance with the non-dominant hand.

CONCLUSIONS

Performing more complex tasks requires higher visual spatial ability and motor planning. Given the need for ambidextrous skills during laparoscopic tasks, the finding that lower scores and smaller brain recruitment occurred in executing tasks with the non-dominant hand than with the dominant hand suggests designing future training tasks to train the non-dominant hand more effectively. This may serve to improve overall performance in bi-manual tasks. Studies of this kind may facilitate the evidence-based development of strategies to improve the quality of laparoscopy training and assessment.