Cognitive mechanisms underlying anchoring bias in diagnosis: a randomized controlled experiment.

Anchoring bias happens when physicians fail to adjust diagnostic decisions despite conflicting information. This Brazilian eye-tracking study of 32 medical residents examined differences in attention when distracting features were placed in different locations in case vignettes. Accuracy of diagnosis did not differ based on attention to the distracting features, but accurate physicians remembered more critical diagnostic information and less distracting features. This implies that the accurate clinicians have different cognitive processing (retaining key data and discarding the distractors) than those who were inaccurate although they viewed the information similarly.