Jeremy Wolfe, Ph.D

Professor of Ophthalmology and Radiology

Harvard Medical School

How did I miss that? How we ‘look but fail to see’ in the lab, the clinic, and the world

Why don’t we see everything that we want to see or that we think we should see? From typos to tumors to gorillas in Introductory Psychology demos, humans manage to routinely miss targets that are "right in front of our eyes". In the psychologically most interesting cases, these are instances where observers fail to respond to stimuli that are clearly visible. The observers may even directly fixate on those stimuli. Some of these “Looked But Failed to See” (LBFTS) errors are life-threatening (e.g. missing that tumor or a weapon in carry-on baggage). Nevertheless, such errors are common enough that we can describe them as “normal blindness". If you are a radiologist in the US, these errors can lead to malpractice legal cases. When should an LBFTS error be considered to be legal negligence. I will give a four-part account of LBFTS errors: Human visual attention is 1) limited, 2) misguided, 3) incomplete, and 4) misunderstood. I will place this in the context of the Guided Search 6.0 model and I will illustrate with some demonstrations and with an emphasis on examples from radiology. If all goes well, you will look, you will fail to see, and you will gain insight into why that happens.