Key Points Question Is there preliminary evidence to support the effectiveness of mindfulness-based stress reduction for improving well-being and performance in postgraduate year 1 surgery residents? Findings In this pilot randomized clinical trial of 21 first-year surgery residents, taking a modified mindfulness-based stress reduction class was associated with higher mindfulness, lower stress, better executive function scores, faster motor skills, and unique activation of neural substrates associated with executive control and self-awareness during an emotional regulation task compared with control participants. Meaning Mindfulness-based stress reduction appeared to mitigate stress and enhance executive function in surgery residents, supporting the value of larger, more definitive trials of this promising intervention for surgeons.

BackgroundEntrainment of brain oscillations has been hypothesised as a potential mechanism of neuromodulation. While neuromodulation has been shown to be an effective therapy for a variety of pathologies, there is no algorithmic approach to programming neurostimulators for specific neurological disorders. This is due in part to the lack of understanding of the effects of stimulation on neuronal rhythms. Counterintuitively, cortical finely-tuned gamma oscillations around 75Hz have been reported to be entrained at 65Hz during 130Hz deep brain stimulation (DBS) in patients with Parkinson’s disease (PD).Objective/MethodsHere, we demonstrate that these observations are consistent with 1:2 entrainment, which is a special case of sub-harmonic entrainment predicted by synchronisation theory. We fit a coupled neuronal population model to selected features characterising a PD patient’s off-stimulation finely-tuned gamma rhythm recorded through electrocorticography.ResultsOur model predicts the patient-specific regions of entrainment (Arnold tongues) in the stimulation frequency/amplitude space. We show that the resulting patient-specific neural circuit model exhibits 1:2 entrainment when stimulation is provided at 130Hz. Furthermore, we verify keys features of the 1:2 Arnold tongue with follow-up recordings from the same patient, such as the loss of 1:2 entrainment beyond a certain stimulation amplitude.ConclusionOur results reveal that periodic DBS in patients can lead to counter-intuitive patterns of neuronal entrainment across stimulation parameters, and that these responses can be predicted by modelling. Should entrainment prove to be an important mechanism of therapeutic stimulation, our modelling framework may reduce the parameter space that clinicians must consider when programming devices for optimal benefit.HighlightsEntrainment of cortical gamma oscillation at half stimulation frequency in patients with Parkinson’s disease is predicted by synchronisation theory.A Wilson-Cowan model, fitted to off-stimulation patient data, predicts a 1:2 synchronisation region biased towards lower stimulation frequencies where 1:2 entrainment will be lost at increased stimulation amplitudes.The fitted model also predicts that power spectral density of the 1:2 entrained frequency will be largest at lower stimulation frequencies and amplitudes.Observations of 1:2 entrainment at variable stimulation parameters for the same patient as the model was fitted to, are in line with the predictions from the model.

Purpose fMRI is increasingly used for presurgical language mapping, but lack of standard methodology has made it difficult to combine/compare data across institutions or determine the relative efficacy of different approaches. Here, we describe a quantitative analytic framework for determining language laterality in clinical fMRI that addresses these concerns. Methods We retrospectively analyzed fMRI data from 59 patients who underwent presurgical language mapping at our institution with identical imaging and behavioral protocols. First, we compared the efficacy of different regional masks in capturing language activations. Then, we systematically explored how laterality indices (LIs) computed from these masks vary as a function of task and activation threshold. Finally, we determined the percentile threshold that maximized the correlation between the results of our LI approach and the laterality assessments from the original clinical radiology reports. Results First, we found that a regional mask derived from a meta-analysis of the fMRI literature better captured language task activations than masks based on anatomically defined language areas. Then, we showed that an LI approach based on this functional mask and percentile thresholding of subject activation can quantify the relative ability of different language tasks to lateralize language function at the population level. Finally, we determined that the 92nd percentile of subject-level activation provides the optimal LI threshold with which to reproduce the original clinical reports. Conclusion A quantitative framework for determining language laterality that uses a functionally-derived language mask and percentile thresholding of subject activation can combine/compare results across tasks and patients and reproduce clinical assessments of language laterality.