Effect of Music Listening on Neurocognition, Stress, and Performance in Neurosurgeons During Microsurgery

Abstract

Background

Stress in surgeons is well-known for its negative impact on neurocognition and surgical performance. Surgeons commonly use music for stress reduction, but its specific effects on neurosurgeons remain unclear. This study aims to investigate how listening to music during microsurgery affects neurocognitive (NC) functions, subjective anxiety, and stress levels in neurosurgeons.

Methods

Conducted in 2 phases, the pilot phase involved 23 neurosurgeons completing a survey and rating compositions based on ragas of North Indian/Hindustani classical music for suitability during surgery. Five excerpts were selected for the main phase, which involved 3 neurosurgeons performing 16 surgeries, 8 with and 8 without music. Data collection included presurgery assessments of sleep, caffeine intake, subjective stress levels, perceived complexity of the surgery that was to be performed, and NC tasks. Postsurgery subjective stress levels, actual complexity, and surgeon experiences with music were recorded.

Results

While there was a trend toward reduced stress and perceived complexity with music, statistical significance was not reached. NC tasks showed nonsignificant improvement with music, with a significant (at P < 0.001) speed-accuracy trade-off noted in response inhibition.

Conclusions

Music appears to reduce subjective stress and task complexity, influencing neurocognition, particularly through speed-accuracy trade-offs. Further research is needed to understand its mechanisms and appropriate contexts for use before widespread recommendation.

Introduction

Stress, the “nonspecific response of the body to any demand” has multiple consequences for mental and physical health.^1,2 Physicians are exposed to high levels of stress and are at greater risk of decline in work performance and developing mental health disorders including substance abuse and suicide.³

Surgery, recognized as highly stressful⁴ includes long work hours with seriously ill and/or dying patients, high workload, deadlines, and reduced work-life balance.^5,6 along with stressors specific to the operating room (OR). Continuing to operate effectively despite this has become a hallmark of expertise and thus forms an integral part of training. Despite this, stress is still underacknowledged within the surgical community.⁷

Surgeons require both efficiency and accuracy, and 1 is often obtained at the expense of the other,⁸ with performance deteriorating under stress.⁹ Microsurgery in general and microneurosurgery in particular, have been found to add to this burden of stress.¹⁰ It is well-established over decades of research that stress can cause structural changes in the brain with long-term effects on the nervous system, especially with learning and memory.^11,12

Stress management is not an official part of surgical training programs. However, many surgeons across areas of specialization and training levels use several techniques to reduce and manage their stress as effectively as they can, including both adaptive and relatively maladaptive techniques such as the use of music, caffeine consumption through tea and coffee, exercise and sport, and use of alcohol and nicotine (cigarettes).¹⁰

Music is often played in the OR to increase the surgeon’s concentration and to mask noise and may have a beneficial effect on performance.¹³ For example, playing preferred music made plastic surgery residents faster in completing wound closure, and these repairs were also judged to be of higher quality by blinded faculty.¹⁴ If used appropriately, classical music may positively affect surgical memory consolidation and it may be possible to predict surgeons’ performance and learning under stress through psychological tests. Further, relaxing auditory influences such as classical music can even positively impact the accuracy of experts. Previous musical experience could help to identify surgeons whose performance may be specifically affected by music or noise.¹⁵ A musical environment may benefit surgical training and make acquisition of surgical skills more efficient.¹³

All surgical performance parameters improved significantly with experience with a trend toward improvement when participants considered the music pleasant. However, to prevent music from becoming a distraction the in OR, when and which music is used, should be considered carefully.¹⁶

Stress in the OR is a significant concern for both trainees as well as experienced surgeons. Research shows the variety of productive and counterproductive methods used by surgeons to cope with this stress. Music has been found to be 1 such productive coping strategy. There is evidence towards reducing physiologic and perceived stress through music – pretask and during task performance. Several studies have highlighted the importance of institutional level changes to reduce and improve this OR stress. Thus, through this study, the aim was to compare stress and neurocognitive (NC) measures between the surgeries performed without and after listening to researcher-chosen music before surgery, with the eventual aim of bringing about changes that may lead to reduction in stress in neurosurgeons.

Methods

NC functions such as attention-concentration (AC), working memory (WM), response inhibition (RI), based on accuracy and reaction time (RT) through computer-based NC were measured.

Neurosurgeons holding faculty positions with an average of 10 years of experience at the Department of Neurosurgery, a tertiary center, and a national institute, who regularly performed microsurgery, in the age range of 35 to 50 years with normal hearing/vision or corrected hearing/vision, and no other medical conditions were invited to participate in the study.

NC were designed to take less than 20 minutes, assessed at baseline and after each intervention session i.e., before beginning the surgery. They were aimed at the measurement and comparison of accuracy and RT. To avoid fatigue effect, the 3 tests were counterbalanced in their administration. To prevent practice effect, Boolean randomization was included in the parameters of the NC tasks designed on Neurobehavioral Software’s Presentation software.

Any cranial microsurgery lasting not more than 90 minutes (about 1.5 hours) was included in the study with 2 conditions of observation.

1. Music condition – As part of the pilot study, a survey was conducted on nonparticipating neurosurgeons to understand their sociodemographic details, general and specific uses and preferences of music, musical training (vocal and instrumental) and the amount of time that was dedicated to music. Twelve music tracks had been shortlisted for inclusion in the main phase of the study, and excerpts from these music tracks, each 60 seconds long, were added to the survey. These excerpts were to be rated on a scale of 1 to 5, based on the question “While listening to the music, imagine that you are in the OR while performing a surgery. Rate each excerpt on a scale of 1 to 5, with 1 being - I never want this in my OR and 5 being - I always want this in my OR. A score of 3 indicates feeling neutral towards the music.” Excerpts with the highest positive rating were chosen. The final selected music tracks were 20 minutes to 1 hour long in duration and could be played on loop. During the presurgery NC assessment section of the study, the music was played through noise canceling headphones. During the surgery, the music was continuously played in the OR through 2.1 speakers connected to a computer at volume based on the comfort and preference of the neurosurgeon.

2. No music condition– The participants were asked to wait in a room for 20 minutes, equaling the time spent with music.

Data Collected During the Study Included

1. Socio demographic data sheet

2. Musical behavior data sheet (developed for the study – this included music listening and practicing habits, preference in genres, formal musical training, etc.)

3. Music Preference Questionnaire¹⁷

4. Scales for each session, collected presurgery and postsurgery to understand perceived and actual complexity as well as perceived stress regarding the procedure.

   1. Subjective anxiety – As the participants had been performing microsurgery for over ten years, anxiety related to specific procedures varied negligibly. Thus, the VAS measure was used to assess anticipated complexity of the surgery (quasi-blinded presurgery, preintervention), and actual complexity of the surgery (postsurgery).

   2. Subjective stress level, presurgery and postsurgery

5. Each participant’s subjective experience with the music was obtained through a postsurgery semistructured interview after surgery completion.

Three NC tasks were designed to measure each of the 3 variables being studied – AC, WM, and RI. The tasks were administered using Presentation Software (Neurobehavioural Systems, Inc. Berkeley, USA). The tasks were developed to record accuracy and RT under each of the tasks.

1. AC – The Mackworth Clock Test (MCT) was used to measure attention and concentration.^18–20

2. WM – WM was assessed through the visual letter-based n-back test, where n = 2.^21,22

3. RI – The Stop Signal Task (SST) was used to measure inhibitory control, i.e., RI.²³

The procedure for the entire study is presented below in Figure 1 from ethical approval to data collection.

Figure 1. Study procedure.

The collected data were analyzed through descriptive and inferential statistics, while the qualitative information was analyzed for repeated themes and phrases.

All stages of the research were conducted while adhering strictly to ethical considerations of nonmaleficence, benevolence, and scientific rigor as well as by obtaining informed consent, maintaining confidentiality and respect, and giving primary importance to the participant’s health and well-being. The study was approved by Departmental and Institutional Ethics Boards before commencement vide NIMH/DO/BEH. Sc. Div./2021–2022 dated 9 November 2021.

Results and Discussion

Selection of Music

Twenty-three neurosurgeons, across levels and years of practice, responded to the survey – 22 male and 1 female, with average age 36.87 (standard deviation [SD] = 7.69) years, all practicing at various levels.

The music selected was Indian classical instrumental music based on previous research and the results of the survey conducted to select the music are presented below in Figure 2.

Figure 2. Average ratings given to the musical excerpts in ascending order.

Based on these ratings, “9. Mangal Bhairav,” “1. Gorakh Kalyan,” “11. (Raga) Pahadi,” “4. Mishra Kaafi (Dhun),” and “2. Pahadi (Dhun)” were selected to be played in the main phase of the study (the numbers indicate order of presentation in the survey) [https://shorturl.at/iLpww].¹

Mangal Bhairav is part of the Bhairav family and is described as a “morning raga, and solemn peacefulness is its ideal mood.” It has a somber tone and conveys solemnity, introversion, and an attitude of dedication. Raga Gorakh Kalyan or Gorakh is intended for relaxation and contemplation. Pahadi is a raga for the evening that blends pensive and lighthearted elements. It is a basic raga that has its roots in Kashmiri folk music, is sometimes referred to as a dhun. ‘Dhun-s’ refer to light instrumental tunes, and those parts for Ragas Mishra Kaafi and Pahadi again were selected again.^24,25

The chosen excerpts were of instruments such as flute, santoor, and generally of slow to medium speed, all of which contributes to a relaxing effect as per the musical attributes and its impact. All these compositions were based on Hindustani classical/North Indian music ragas.

A semantic knowledge of the structure of raga is not required to experience emotions associated and elicited by the given raga.²⁶ This further indicates that when presented with choices, the sampled surgeons tended to choose simpler, more melodious, and somber classical tunes. This may suggest an awareness, instinctive or otherwise, regarding the effect of instrumental, Indian (Hindustani in this case) classical music. The effects of this kind of music have been well demonstrated across studies and contexts.^6,27,28

To prevent any effect of prior exposure and preference to the selected music, the neurosurgeons who were part of the main phase of this study were not included in the pilot phase of music selection.

Presurgery

Data for the main phase was collected from sixteen surgeries performed by 3 surgeons who consented to participate in this study. Of these sixteen surgeries, 8 surgeries were without music condition and 8 were with music condition. Despite the limited number of datasets in the study, the first step as part of the analysis was to check the normality of the data, done through the Shapiro-Wilk test of normality. All the data were found to be distributed normally (P < 0.05). Thus, further parametric data analysis was conducted on the collected data.

Information regarding the surgeons’ sleep duration, consumption of tea, perceived stress, and perceived complexity was recorded using a Likert scale (1–10, 1 being minimal and 10 being maximum) before the surgeons were informed of the day’s condition. The surgeons reported an average of seven hours of sleep across conditions and were consuming 1–1.5 cups (150 ml per cup) of tea. This indicated a general ease of stress management in the participant neurosurgeons. This is also reflected in their subjective reports of stress (ranging between 3 and 5, on a scale of Io), with no significant differences in the levels reported across the 2 conditions (P < 0.05).^10,29

Regarding complexity, though the surgeons reported an average perceived complexity of 6, there seemed to be more variation in perceived complexity of surgeries in the music condition (SD = 0.99 for nonmusic condition, and SD = 2 for music condition). As this information was collected before the condition for the day was revealed to the surgeon, expectancy effect is unlikely to have played a role and can likely be attributed to chance.

Neurocognition

The surgeons completed 3 tasks – MCT, NB, and SST – in control and music conditions. Data were collected from 8 surgeries each in both groups, which were again found to be normally distributed through the Shapiro-Wilk test of normality (P < 0.05). Their performance on MCT was compared through hits, misses, and false alarms, and on NB and SST through accuracy and RT. These comparisons are presented in Table 1.

Table 1. Comparisons of the Three Neurocognitive Tasks.

Comparison	Mean Difference	Std. Error Difference	t	P
MCT hits	–0.13	0.21	–0.61	0.55
MCT misses	0.13	0.21	0.61	0.55
MCT false alarms	–0.13	0.42	–0.30	0.77
nB target accuracy	–0.03	0.06	–0.39	0.71
nB target RT	–44.24	59.51	–0.74	0.47
nB distractor accuracy	–0.01	0.02	–0.55	0.59
nB distractor RT	24.07	63.98	0.38	0.71
SST Go accuracy	0.00	0.01	0.00	1.00
SST Go RT	–23.79	17.43	–1.37	0.19
SST stop accuracy	0.19	0.03	5.59	<0.001
SST stop RT	111.82	8.58	13.03	<0.001

n = 8 for both groups. Bold values indicate statistically significant.

MCT, mackworth clock test; RT, reaction time; SST, stop signal task.

While most differences between these measures were found to be nonsignificant, the general trend was towards better performance in the music group. However, there was a significant difference in the SST stop accuracy and RT between the control and music conditions.

This is suggestive of a significant speed-accuracy trade-off in the presence of music when it comes to stopping a response that has already been initiated. Though this trade-off is miniscule, it is statistically significant and may indicate a need for careful selection of what type of surgeries music is used in.

This is not without precedent, when Conrad et al. (2009) found that though classical music varied in its impact on experts’ time to task completion, all experts performed the tasks with greater accuracy.

Although it might lengthen the time needed to finish, mental load had no impact on memory or accuracy. The experts’ varying musical backgrounds affected how each of the circumstances affected their performance. Even soothing auditory effects, like classical music, might improve an expert’s accuracy. Identifying surgeons whose performance may be specifically impacted by music or noise may be made easier with the support of prior musical experience.^30–32

Postsurgery

Postsurgery values of stress and actual complexity were collected and found to have no significant difference at P < 0.05 when compared using t-test for dependent groups for both control and music groups. There were 8 data points in each group, and the data was determined to be distributed normally, through Shapiro-Wilk tests for normality (P < 0.05), after which the data were compared in groups using the appropriate t-tests, and there was no significant difference in the values between groups, nor across groups.

However, qualitative reports of the surgeons’ experiences during the music condition provide valuable information on how the music influenced them in the OR. The surgeons reported that they seemed to tune out the music when they were focusing on a complex or intricate detail of the surgery. They also reported focusing on the music when they were between the surgery steps. One surgeon also reported that he found himself focusing on the music consciously during a particularly stressful surgery to relax and improve his focus on that day. The participant surgeons reported finding the surgeries with music less complex than perceived before scrubbing in. However, this difference is not significant. However, it does align with past findings, notably that by George et al. (2011), where they found that the presence of music in the OR reduced autonomic arousal of the surgery staff, allowing them to approach the surgery in a more “thoughtful” and “relaxed” manner.³³

This aspect of music helping in reducing stress and otherwise enhancing task performance has been repeated countless times anecdotally and seems to make intuitive sense to music creators and consumers, as well as researchers. However, research continues to yield mixed results.

Narayanan et al. (2022) screened over 4000 published articles for high-quality evidence on the effect of listening to music on surgeons’ performance and stress levels. Only 15 of these 4000 papers were eligible for inclusion in their analysis. They established that the overall inclination of research findings is towards the stress reductive and performance improving effects of music, but this trend has generally been nonsignificant or with small effect sizes when the findings are significant. This is also seen in the work done here.³⁴

Though this was not established with statistical significance, the surgeons’ experiences of having music in their OR seems to indicate that improvement in stress levels and functioning is the overall effect of playing music in their OR. It is well established that if all other factors are controlled for, perceived complexity of a task affects stress levels associated with it.^35,36 Juslin et al. (2013) concluded that physiological measures tend to confirm emotions as self-reported by experiment participants when indexing emotion valence and skin conductance responses to a range of music.³⁷

Further, in a meta-analysis by Boghdady and Ewalds-Kvist (2020), they established a significant positive impact of music in the OR while performing laparoscopic surgery, with caution on the type of music used, stating the positive impact of medium paced classical music vis a vis loud or discordant music.³⁸

The surgeons in this study consistently reported lower complexity of their surgeries with music in their ORs, even if this was also not found to be significant. However, as Bonassi et al. (2023) found, the presence of music has a positive correlation with improved skill-based motor learning in neutral environments.³⁹ Thus, further study in this context by combining this finding of lower perceived complexity with the findings of improved motor learning, both in the presence of music, may provide an avenue for changes in MNS clinical skills training.

Implications and Limitations

This study underscores several key points. Firstly, stress in the OR is a significant concern for surgeons’ health and performance, necessitating measures to reduce it. Secondly, the effects of music vary depending on individual preferences and context, highlighting the importance of selecting suitable music, especially during surgery. Thirdly, music can help alleviate stress and perceived complexity during surgery, warranting further investigation into its mechanisms. Fourthly, while the impact of music on surgeons’ neurocognition may be modest, understanding its extent is crucial. Lastly, the well-being of surgeons is an under-researched area with direct implications for patient outcomes, emphasizing the need for more studies and interventions.

However, this study has its limitations due to its small sample size, and the associated reduction in power leading to possible significant effects being missed. Further, with all included surgeons being male, the effect of gender also cannot be established. Further, with the addition of a physiological measure of stress e.g., heart rate variability, skin conductance, blood pressure, or other similar noninvasive methods, more robust answers may be found. This study aimed to take a cross-sectional view and understand the effect of music in the OR. Prior to implementing music in the OR long-term it is important to explore what, if any, long-term effects music may have on surgical performance and surgeon stress levels. While this study acknowledges its limitations, future research using larger sample sizes – across genders, experience levels, surgeries performed – and more sensitive NC tasks could offer deeper insights into the role and extent of music’s impact, building on the foundation of this work.

Conclusion

Music appears to alleviate subjective stress and perceived task complexity while influencing neurocognition, notably affecting speed-accuracy trade-offs in RI, although performance improvements are nonsignificant. Despite its potential as an intervention for physician stress and burnout, rigorous research is necessary before recommending widespread use in ORs.

Abbreviations and Acronyms

AC

Attention-concentration

MCT

Mackworth Clock Test

NC

Neurocognitive

OR

Operating room

RI

Response inhibition

RT

Reaction time

SD

Standard deviation

SST

Stop Signal Task

WM

Working Memory