Neurosurgical training: more hours needed or a new learning culture?

1. Core idea: integrating theoretical knowledge (“knowing-that”) and procedural knowledge (“knowing-how”) in neurosurgical training of operative techniques 

Microneurosurgical performance requires various types of knowledge. “Knowing-that” is a consciously accessible, declarative knowledge in prepositional or theoretical knowledge, which can be explained either verbally or illustrated symbolically (such as in a matrix). All of it exists today on the Internet [33], [38]. Included in today's learning is the use of the Internet to find necessary information. In contrast, procedural knowledge (“knowing-how”) is characterized by an expert who performs adequately without following an explicit method and perhaps even without being able to declare which rules or principles are being followed. It is also called embodied knowledge [44]. It is evident that much surgical function during an operation depends on a combination of these 2 types of knowledge. Our theoretical knowledge—a solid background knowledge of anatomy, physiology, and pathology—is fundamental. The basics of surgical techniques and procedures are likewise fundamental. This knowledge includes a memorized sequence of mental images with a detailed knowledge of surgical anatomy. Furthermore, an appreciation of the functional consequences and risks of each surgical step [9] is necessary. These types of knowledge are mainly stored in the hippocampus of our brains and provide the surgeon with the rules and principles (matrix) for their surgical functioning [9], [42], [44]. What is stored in the hippocampus is information that is needed to be reflected upon by our cortex during surgical procedures (multitasking). The way of storing this information varies from person to person, and thus is a personal qualitative function. The actual surgical performance, however, depends mainly on procedural knowledge, including microsurgical dexterity [39], [48]. This knowledge is mainly stored in the basal ganglia (striatum) and cerebellum of our brains. The memory encoded in the striatum is less flexible and governs habits. It must be developed through practice, much like learning to play the piano. Surgical performance includes precise control of motor (finger/hand) function and its regulation is on the basis of visual cues, hand-eye coordination, and particular tactile experience. [9], [48]. This dexterity is a standard that needs time (quantitative) and equals rehearsal that is stored. Our modern training program must clearly address both types of knowledge. The distinction of these 2 types of knowledge occurs in a learning model developed by Dreyfus and Dreyfus [15], suggesting the following 5 stages of expertise:

From our institution, Aalborg University (Aalborg, Denmark), a sixth level has been suggested relating to this discussion [18]:

Classical academic neurosurgical teaching is based on (a) reading about a certain operation, followed by (b) the see-one and (c) try-one principle [8], [14], [29], [31], [34], [45]. However, such classical information feeding will not take us very far in developing true surgical expertise according to Dreyfus [15]. In fact, a resident might never move past the first Dreyfus stage of learning as part of this type of neurosurgical training! From the second level on, the learning development depends on a combination of practical training, using a certain skill, and applying a certain set of rules in various situations. Only here do we slowly learn how to judge different operative methods and their consequences for the patients. Hence, it implies that we must introduce new learning methods radically different from classical neurosurgical teaching. Primarily, we have to implement motor routines in the striatum to become expert surgeons. What is missing in the current curricula is a focus on developing our procedural knowledge, which can only be acquired through one's own personal training. A substantial amount of practical training is needed to move our slow and clumsy cortical dexterity down into the striatum via the hierarchy brain system. Only when this has happened will the resident reach the next levels of performance according to Dreyfus [15]. This also includes someone of the fifth level (ie, the “true” surgical performance of the “expert”), who acts without explicitly reflecting on the principles or rules involved [9], [39], [45], [58]. Throughout our training, we learn to judge between different approaches and to validate complications and risks. We have to learn to do so, closely related to our own personal function [9], and this demands time spent.

This reasoning seems to support the views put forward by Sure [53] that to ensure a high level of neurosurgical competence, “all you need” is more time to train. However, for us, we want to add specific focus on what exactly are we going to do with the agreed time (quality) we shall spend?

2. What kind of training to provide to become a good neurosurgeon and how, according to our core issue 

According to the British psychologist Guy Claxton [10], we all possess a fast-thinking mind, a “hare brain,” which is rational, analytic, focused, and linear—excellent for the declarative knowledge function. This mode of thinking is thought of as “clever thinking” in the traditional academic terms, while reflecting our Western or Cartesian understanding of human “intelligence” as deliberate conscious reason. Now, building on neuroscience, Claxton [10], [11] argues that an effort to maintain conscious comprehension can get in the way of a natural learning ability. Hence, the “hare brain” will never succeed to develop our residents into becoming true “experts.” This is fully in accordance with the ideas of the Dreyfus brothers [15]. Luckily, the human brain also harbors what is called a “tortoise mind", which is the slow-thinking mind that is intuitive, unfocused, and creative. Being explicit and strategic are not always the smartest ways to learn, and people who become addicted to conscious clarity undermine their creativity [11]. Or as expressed by Albert Einstein, “The intuitive mind is a sacred gift, and the rational mind is a faithful servant. We have created a society that honors the servant and has forgotten the gift.”

If we want to become experts in neurosurgery, we need to put more focus in our training program on the “tortoise mind,” which by tradition is downplayed in our current learning culture that focuses on declarative knowledge. We draw on a faculty of the human mind, which far exceeds the abilities of computers (ie, the Western understanding of human intelligence taken to its extreme) [10], [57], [58]. Again, to quote Albert Einstein, “Computers/robots are very fast, precise, and stupid in contrast to man that is unbelievably slow, imprecise, and still fantastically intelligent.”

Hence, interplay between these 2 modes of the mind (hare and tortoise) is essential for learning neurosurgery on the highest level. We often rely on learning skills. When discussing this, a fundamental distinction must be made between a neurosurgeon's abilities and skills [37]. For example, a person may learn the skill of walking, yet they may later develop traumatic paraplegia, leaving them without the ability to use the skill. Or, a person could be born paralyzed from birth, making it impossible to develop the skill of walking. Thus, in our understanding, abilities are the prerequisites for the training and performance of skills. These abilities are linked with the person in training and differ [36]. According to Fleishman and Quaintance [17], the abilities of surgeons can be divided into 4 areas as follows:

Therefore, the personality and psychological function of a resident is essential for being able to develop into an expert neurosurgeon. It has been documented that the performance of a surgeon is closely linked with their personality [4], [34], [37]. It has been shown that there is a parallel between the psychological dynamics of world-class athletes and expert surgeons, such as self-esteem and, particularly, positive imagery [37]. The mental preparations before performing a surgical procedure—being of major importance but most often neglected—must be understood and accepted as being an integrated part of every operative procedure [29], [34], [37]. Such psychological aspects may be considered skills, which may be acquired through repetitive training. Another aspect concerning personality that seems evident to us is a neurosurgeon who cannot handle their personal life and may also have difficulties showing compassion and empathy toward patients (and colleagues). Learning to judge in different stressful situations is a key issue in neurosurgery. Patients may not feel at ease with this type of surgeon, and this may weaken their communication. In such cases the training of better doctor-patient communications is needed and may help. We treat patients as whole human beings; we simply do not treat “just an aneurysm.” It is a well-known fact that airplane pilots are tested for abilities and psychological behavior before they are introduced into a training program [28]. In a similar way, such testing could—from our point-of-view—be a natural part of any surgical training program. Why is this not so? If a jet fighter plane crashes, it costs millions of US dollars/Euros, yet if a patient “crashes” (dies of a surgical accident), society costs are not of the same magnitude. The death is merely seen as a statistical problem.

3. Ability and skills testing 

We propose that a test to all neurosurgical residents for the aforementioned 4 types of abilities could be considered before we start them in a training program. Perhaps they will be better off within another specialty if they do not possess some of the abilities definitely needed to become neurosurgeons. Why wait until they have been working in the program for 2 to 5 years? As for the concept of skills, we follow several other authors (eg, Adams [2]) in defining skills strictly here in this context as relating to human motor skills or “dexterity.” However, a strict definition of dexterity is not easily obtainable [49]. Dexterity may, to some degree, be found in personal abilities, but it is still mainly a form of procedural knowledge and refers to skills and ease in physical manual activity. It includes visual cues as part of this [9], [48]. It is the frontal lobe supplementary and primary cortex that makes decisions for the concrete motor activities. Through rehearsal, the control of movements is functionally moved from the cortex to the deeper areas of the brain, the striatum. This hierarchic building of the brain explains why an operative technique once learned can be performed with little or no conscious control due to this fact [21], [23]. The striatum serves much like an autopilot. The striatum activates and sets the tempo in the sequential use of learned skills. Similarly, it is the cerebellum that controls these motor activities and fine adjustment running sequences of movements. We must learn to use our unstable hands/instruments by controlling their mechanical impedance. This can be learned through repetitive training/rehearsal [20]. However, merely to describe such dexterity skills as “automatic behavior” is a much too simplistic way of describing the expertise or skills of “true” neurosurgical performance, as it would be in the case of a virtuoso playing a musical instrument [20], [57]. Learning to play the piano from simple notes in a simple fashion can be achieved in 5 to 7 weeks by continuous training, and this basic procedural skill will stay with one for life. The musical score is the same, but unlike a dull routine, each performance is still different. With practice, the novice can proceed to become a performer (and function on another higher level) [25], [34], [57]. We know that all concert musicians rehearse daily for many hours to be able to play, for example, a Carl Nielsen Piano Concerto with a truly personal touch. This is something more than merely carrying out a series of automatic finger movements—the pianist is able to completely shift their attention from mechanical details of a performance to pure procedural knowledge that leads to an artistic interpretation as an act of performance, taking into account the circumstances here and now [6], [40], [49], [50], [57]. This artistic aspect is also essential within surgical performance. Otherwise, the surgeon merely operates as a machine and would not be able to adjust to changes within a situation in the operating room. As a result, they would not be able to perform within difficult situations, which may occur during any operation. Hence, through training, full-blown surgical skills or performance will no longer be based only on the cortex but mainly on striatum/cerebellar functions, which are necessary for a flowing, flexible, and adaptive performance [2], [5], [41], [47], [50]. Therefore, if our goal in training is to become excellent neurosurgeons—being fast and efficient, as well as flexible, our motor skills learning must achieve the storing of basic procedural dexterity knowledge in the striatum. A recent Japanese article postulated that you need to carry out some 10 000 microsurgical knots to obtain the necessary microsurgical skills—an automatic function from the striatum [27]. Accepting this, we must now ask: How can we speed up dexterity learning? Learning automatic dexterity (“knowing-how”) means we must be repetitive, but that we must also learn these skills in a continuous manner. Using such techniques touches on our principle of the interplay between “knowing-that” and “knowing-how” (by, eg, having an explicit measure of the development of a trainee's “knowing-how”). The use of simulations in virtual reality (VR) models has been advocated for surgeons [3], [23], [24], [30], [32], [47], [49], [51] and has proved beneficial for training endoscopic surgeons [54].

Why is that? When we move from a macrospace to a microspace, we change our working space and have to learn to function in this new space [23]. This change is even more pronounced within the transition from macrosurgery to endoscopic surgery [23]. It is very easy to make mistakes in this context, and all surgeons make mistakes. Unfortunately, our current Western culture favors the notion that we must never make mistakes! If you do, society (colleagues, lawyers, and others) will punish you [4]. This is a terrible failure of our present educational system. We become better by making mistakes, not by being punished. This factor was actually the main reason for developing VR training modules, where we can make as many mistakes as we like, without harming patients [23], [30], [37]. We have to—and can—learn from these mishaps that could be caused by wrong decisions/judgments, forgotten facts, lack of concentration, and tiredness [29]. In our neurosurgical field, a disappointing result of a training session should for us be considered a sign of failure of the training process more than a personal mistake or failure of the resident. Again, VR holds potential by supporting positive imagery, a part of hand-eye coordination. The session of positive imagery not only depends on the surgeon's declarative knowledge of a certain surgical procedure but also on their “knowing-how” (the tortoise brain). The mental practice of simply imagining surgical movements (visualization) recreates the effects of physical practice by modulation of the central motor systems. Visualization, could therefore be an important adjunct in training—not only for the learning of new motor skills, but also for the maintenance of motor skills [8], [30], [36], [47], [51]. Watching great neurosurgeons operate may be an important part of our training system.

Multitasking during an operative procedure must also be learned. This is not possible if the trainee is concentrated/focused on “learning” [4], [40]. By meticulously tracking the development of the trainee's performance within our VR systems, it is possible to document any positive and negative changes throughout an ongoing basis. This tracking entails the potential for competing with oneself or other trainees—or even the master—something that may stimulate motivation [19]. Motivation is not, as Sure [53] states, solely linked to income but more to self-esteem [37]. By using a VR environment, it is possible to personalize the training of skills, ie by focusing on certain elements of a procedure in which the trainee is experiencing difficulties. Therefore, it has a potential of speeding up the learning process of all of our different trainees.

How do we secure that we did learn something during our training, and did it develop our skills? Today, society wants “proof” that a trainee has become professionally competent when completing a neurosurgical curriculum. When we test our trainees, we still use examinations whether they be oral or written—mostly in the form of multiple-choice (MCQ) [1], [7], [21], [43]. The American Board of Neurological Surgery MCQ and the present European Association of Neurosurgical Societies (EANS) MCQ only test what ad hoc “declarative knowledge” the trainee has at the time of the examination [7], [21]. It is, therefore, merely a test to determine whether you have been reading some books and have retained some of the declarative information at that moment you are tested [33]. It does not validate if the trainee can use this knowledge, let alone perform adequately as a neurosurgeon. Any examination can lead to a personal defeat, and no one feels great upon losing a battle. Therefore, the EANS added an oral session to the MCQ examination, hoping to test the trainee in function [21]. However, it never became a success for many reasons. In Europe, passing the examination is not necessary to function as a neurosurgeon—in contrast to the United States. The examination should therefore, in the future, center on being a tool for the trainee to develop the skills that are necessary for their professional life. In that way, we will make trainees responsible for their own education. This implies that a prerequisite for each trainee is to have a personal goal for the learning process, such as to develop continuously a personal subset of tasks to be rehearsed [8], [31], [41], [48], [49], [55], [58]. The solution to the problem of timing is thus to accept our personal differences and that the pace of learning—whatever the skill—is a truly personal one. This also means that all our future dexterity learning in neurosurgery should be self-administered and monitored from our point-of-view.

So for us, it is evident that we must consider testing residents for a number of cognitive functions before they enter a training program:

A core issue for future neurosurgical training is to accept that all trainees have different personalities. Nevertheless, they all have to set goals and to understand the basics of skill learning. A trainee must ask: What will I be able to do? What will I know in declarative knowledge (on procedures and anatomy and so forth)? And how will I train to acquire the necessary “knowing-how” given my current skills, abilities, and personality? After a training session, it is important to reflect on it with a debriefing: What did I learn? And how good was my performance using what I learned?

Keeping track of one's own learning in this way will be rewarding and most importantly, motivating [4], [31], [34]. Character and contribution are much more important in training than we once suspected, and we should be proud of them and use them [12], [37].

The trainee must, therefore, set personal procedural knowledge goals (eg, a degree of dexterity), develop personal methods/protocols on how to reach these goals, secure personal validation of how these goals are reached, and learn to use the trained dexterity in settings that simulate the operative environment with all its distracters. These steps create a necessary interplay between procedural knowledge (“knowing-how”) and declarative knowledge (“knowing-that”) and facilitate a better use of our training hours/curriculum (qualitative).

So, for neurosurgical trainees, forget about future positions and focus on your exercises in learning automatic procedural skills instead. By keeping this focus, you will acquire the necessary knowledge and be able to use your brain more efficiently for multitasking, which includes judgment. This is central to the process of developing your true neurosurgical proficiency. Think more “quality” instead of just “quantity” in your training, but remember that some of our training must be based on quantitative measures. Developing true neurosurgical expertise may be closer to craftsmanship than it is to academia. It may be as close to art as it is to science, and it is closer to sports than you might think! To become an expert neurosurgeon is a question of being talented. Furthermore, it is a question of “knowing-how,” of gut feelings, of being focused, and it is a question of being dedicated to dexterity training throughout your career [13], [45].

“Neurosurgeons have learned to be independent, and therefore tend to be very individualistic—which makes it difficult for most physicians to work together in a cooperative situation or in practice” [James I. Ausman, 1997].