How doctors diagnose diseases and prescribe treatments: an fMRI study of diagnostic salience

Abstract

Understanding the brain mechanisms involved in diagnostic reasoning may contribute to the development of methods that reduce errors in medical practice. In this study we identified similar brain systems for diagnosing diseases, prescribing treatments, and naming animals and objects using written information as stimuli. Employing time resolved modeling of blood oxygen level dependent (BOLD) responses enabled time resolved (400 milliseconds epochs) analyses. With this approach it was possible to study neural processes during successive stages of decision making. Our results showed that highly diagnostic information, reducing uncertainty about the diagnosis, decreased monitoring activity in the frontoparietal attentional network and may contribute to premature diagnostic closure, an important cause of diagnostic errors. We observed an unexpected and remarkable switch of BOLD activity within a right lateralized set of brain regions related to awareness and auditory monitoring at the point of responding. We propose that this neurophysiological response is the neural substrate of awareness of one's own (verbal) response. Our results highlight the intimate relation between attentional mechanisms, uncertainty, and decision making and may assist the advance of approaches to prevent premature diagnostic closure.

Figure 1

Temporal structure of the experiments. (a) Experiment 1: The temporal structure of a trial, totaling 9.5 s, comprised: 1- task signaling - diagnosing or naming - with the presentation of the words ‘DISEASE’, ‘ANIMAL’, or ‘OBJECT’ followed by a central cross in a black screen, totaling 2 s of foreperiod; 2- presentation of three pieces of information; 3- an additional period with a central cross in a black screen. (b) Experiment 2: The temporal structure the trial, totaling 6.5 s, was the following: 1- task signaling - disease diagnosis or treatment prescription - with the presentation of the words ‘DIAGNOSIS’ or ‘TREATMENT’ followed by a white central cross in a black screen, totaling 2 s of foreperiod; 2- presentation of the cue for the task, a diagnostic information or the name of a disease; 3- an additional period with a central white cross in a black screen. In this example, the expected response to syphilis is ‘penicillin’; its treatment.

Figure 2

BOLD responses* to task effects in Experiments 1 and 2 versus control baseline and conjunction analyses of all tasks *p < 0.05 family-wise error (FWE) corrected; extent threshold k_E ≥ 10. Statistical parametric maps (SPMs) rendered on an International Consortium for Brain Mapping (ICBM) individual brain.

Figure 3

Experiment 1 contrast estimates in the frontoparietal attentional network in time periods* during tasks *400 ms epochs Abbreviations: FEF, frontal eye field; pIPS, posterior intraparietal sulcus; SEM, standard error of the mean. Foreperiod refers to task signaling in the beginning of the trial.

Figure 4

Experiment 1 BOLD effects* in contrasts of pre-RT epochs* p < 0.001 uncorrected for illustrative purposes; extent threshold k_E ≥ 10. SPMs rendered on an ICBM individual brain.

Figure 5

Experiment 1 contrast estimates in pre-RT epochs. Abbreviations: (a) AG, angular gyrus; AI, anterior insula; MFG, middle frontal gyrus; NRG, nucleus reticularis gigantocellularis; Prec, precuneus; TPJ, temporoparietal junction; TRN, thalamic reticular nucleus; (b) CN, cochlear nucleus; HG, Heschl’s gyrus; LC, laryngeal cortex; MOC, medial orbital cortex; NA, nucleus accumbens; poIFG, pars opercularis inferior frontal gyrus; pSTS, posterior superior temporal sulcus; vRC, ventral Rolandic cortex.