As clinicians progress from novices to experts, everything indicates that decision making relies less on basic biomedical knowledge and more on previous experience. According to a study published in Advances in Health Sciences Education, with increased task difficulty, the clinical decision process in novices and experts activates distinct neuronal areas in the left and right hemispheres, respectively. 

Madrid - April 24, 2018. Novices and experts differ in clinical reasoning in terms of activation of different neuronal areas. Although decision making involves the prefrontal cortex (PFC), hemispheric differences are appreciated between novice and expert clinicians when diagnosing complex cases, according to a Canadian study published in Advances in Health Sciences Education. Specifically, the team led by Pam Hruska, from the University of Calgary (Canada), concludes that "novices had greater activations in the neuronal regions of the left hemisphere, associated with factual knowledge, while experts prevailed in the right hemisphere, linked with experiential knowledge."

The researchers collected functional MRI data from ten second-year medical students and ten gastroenterologists while these subjects diagnosed sixteen clinical cases (eight simple and eight complex cases via multiple-choice questions) and collected data of accuracy and time to establish the diagnoses. Then, they compared the results of easy and complex cases within the respective groups and evaluated the neuronal differences between novices and experts. As expected, the experts correctly diagnosed more cases than the novices and established their diagnoses faster. “The interesting fact is that, with the complex cases, the novices presented greater activations in the left anterior temporal cortex and left ventral lateral prefrontal cortex, whereas the experts had greater activations in the right dorsal cortex, right ventral cortex, and right parietal cortex."

Research of hemispheric specialization suggests that the left hemisphere is dominant for analytical and semantic processing, depending on concrete facts, while the right is activated with episodes of memory recovery, by associating stimuli and responses, and with abstract or holistic processing. "Applied to the context of clinical decision making, we anticipate that although both groups will activate the PFC during clinical decision making, the underlying neural areas that support novices and experts will lateralize to different hemispheres." Furthermore, "we are the first to identify that differences in hemispheric activation occur at different clinical levels of experience with the increasing complexity of cognitive tasks.”

The neuronal activation of the left ventral lateral prefrontal cortex (VLPFC) observed in novices is in line with the literature that links this area with the recovery of semantic representations of memory, which is how novices would generate basic causal explanations and inferences. In contrast to this, experts had greater activation of the VLPFC and the dorsolateral prefrontal cortex (DLPFC) of the right hemisphere when facing complex clinical cases, a pattern that is not only associated with the use of stored knowledge, but also with the evaluation of options in light of clinical standards or patterns and their verification. Interestingly, Hruska also detected greater activation of the right parietal cortex in experts, a finding associated with increased attentional demand.

Some rely on concrete representations and others on more abstract representations. In other words, it is likely that novices will use more concrete representations of semantic knowledge (memory) during decision making. The left hemisphere, more active in novices during difficult tasks, is used when analyzing responses to environmental stimuli, for rule-based processes and by using explicit cues to guide decision making. On the other hand, activations of the right hemisphere, recruited by experts in difficult questions, require prior knowledge and were activated in decision making among several options, in comparison between patterns, in decisions based on personal experience, in categorization of information, and during resolution of situations of ambiguity, among other conditions.

Levels of analytical thinking

Hrsuska's conclusions about cognitive strategies at the stage of analytical or type 2 reasoning show that the PFC is a fundamental area (both in novices and experts) for clinical decision making in complex cases and, on the other hand, both demonstrate differences in neuroanatomical activation patterns in relation to the level of medical experience. "As we have highlighted, we find greater differences in hemispheric activation of PFC during difficult cases, which leads us to think that there are potentially different decision-making analytical processes within type 2 thinking: one based on factual knowledge (novices) and the other one in the experience (experts)," emphasizes the researcher.

These data imply that there are different analytical processes in clinical decision making that govern the novice-expert continuum. The challenge is to use this information to create a curriculum that reinforces the knowledge learned in combination with experimental learning through repeated exposure, so that professionals are able to provide the best care for the patient.

Reference

Hruska P, Hecker K G, Coderre S, McLaughlin K, Cortese F, Doig C. Beran T, Wright B. Krigolson O. Adv in Health Sci Educ. 2016 21: 921. https://doi.org/10.1007/s10459-015-9648-3