Trained Pigeons Read Mammograms As Well As Humans

Contrary to conventional belief, having a “bird brain” may not be a bad thing — at least for identifying cancer on radiology images. A recent study from the University of Iowa and the University of California (UC) Davis, showed that trained pigeons performed as well as humans in identifying benign and malignant breast tissue on digitized slides and mammograms. The results help elucidate how physicians process visual cues on diagnostic images and highlight pigeons’ ability to interpret complex visual images.

Previous research by Edward Wasserman, professor of psychological and brain sciences at the University of Iowa and co-author of the study, shows that pigeons can distinguish a variety of visual images, including emotional expressions on human faces, and have a visual memory recall of over 1800 images. Therefore, Wasserman, study co-author Richard Levenson at UC Davis, and their respective colleagues investigated whether pigeons could distinguish benign versus malignant tissue on pathology slides and mammogram images.

The researchers used traditional operant conditioning (with food rewards) to teach the pigeons to discriminate between cancerous and non-cancerous features on images of real human cases at UC Davis Medical Center. To eliminate the possibility that the birds were relying on rote memorization, the researchers presented brand new samples after the training period and dispensed food regardless of whether the bird was correct. The pigeons’ accuracy increased from 50% on the first day to 85% after 13-15 days of training. Similarly, the pigeons averaged 72% accuracy for novel mammography images — similar to the accuracy of human radiologists and radiology residents.

Although radiologists aren’t going to be replaced with pigeons any time soon, the authors suggested that the pigeons’ ability to detect features on the digitized slides and mammography images could aid researchers and engineers in the production, manipulation, and viewing of diagnostic images.

Source: Levenson RM, et al. (2015) Pigeons (Columba livia) as Trainable Observers of Pathology and Radiology Breast Cancer Images. PLOS ONE, 10 (11): e0141357