Title: SBE-UKRI: "Looked but failed to see" errors in human vision
Funder: Economic and Social Research Council

Abstract: Overview: Human observers routinely fail to respond to important stimuli that are "right in front of their eyes" - stimuli that are clearly visible and identifiable when they are attended. This kind of error can be amusing when the missed item is something like the gorilla in Simons and Chabris' famous demonstration of inattentional blindness, but it is much more troubling when the missed item is a "retrospectively visible" cancer in a medical image or a cyclist on the roadway. The aim of our project is to understand the basic science of these "looked but failed to see" (LBFTS) errors and to investigate possible ways that these potentially dangerous errors might be reduced. Intellectual Merit: LBFTS errors are not like a disease caused by a single pathogen. There are a variety of different paths that lead someone to fail to report an item that is clearly visible when pointed out. We will study three such paths. Aim 1: Stochastic Errors: These are errors related to the inherently random nature of some type of visual search. In a visual search task, observers (Os) are looking for targets in a scene containing non-target (distractor) items. For example, looking for a can opener in a messy kitchen drawer. If you don't find that target, you have to quit at some point. Research suggests that Os develop an internal 'quitting threshold' that says, in effect, "I have looked long enough". Sometimes, at least under laboratory conditions, Os reach that quitting threshold before attending to the target item and, even though the target is clearly visible, an LBFTS error occurs. The same target might have been found by the same observer on a different occasion. Aim 1 experiments will test the hypothesis that, in simple "inefficient" search (e.g. for a letter, T, among Ls), most errors can be classified as this type of "stochastic error". Having validated a novel methodology for assessing stochastic error, we will test the hypothesis that errors in other search tasks (e.g. of scenes or medical images) are not purely stochastic. We will pilot interventions to reduce such errors. Aim 2: Attentional Bias Errors: When the eyes are fixated at one point, Os preferentially process stimuli in some surrounding region (a "Functional Visual Field" - FVF). Processing within the FVF is usually assumed to be roughly uniform. However, we have eye tracking pilot data that show that Os can have attentional biases that might make it, for example, more likely that you would find a target to the left of fixation than above fixation. In Aim 2, we will test the hypothesis that attentional bias can also cause LBFTS errors. Moreover, the two PIs on this collaborative grant have quite different ideas about the processing that goes on in the FVF during a fixation. We plan an "adversarial collaboration" in an attempt to resolve our amiable differences. Aim 3: Situational Awareness Errors: LBFTS errors are easy to produce in "gorilla-style" inattentional blindness (IB) experiments. We found that radiologists would miss a gorilla in a lung CT, for example. But no one misses the gorilla if warned, even generically, to look for something unusual. In daily life, it is in our interest to keep an eye out for the unusual. It may even be an explicit part of the job: E.g., look for lung cancer and any other clinically significant finding. In the usual IB experiment, you only get one critical trial. No one misses the gorilla twice. We have developed a new foraging search paradigm allows us track awareness of gorilla-style stimuli without having to ask explicitly and without the constraints of single trial paradigms. We refer to these LBFTS errors as "situational awareness" errors. We will test the hypothesis that we can reduce these situational awareness errors with very simple interventions.

Lay abstract: We have all had the experience of failing to notice something that is in plain view. Sometimes this can even be something that we are actively looking for, like typos in our writing or signs of cancer in a lung x-ray. The aim of our project is to understand the basic science of these "looked but failed to see" (LBFTS) errors and to investigate possible ways to reduce these potentially dangerous errors. LBFTS errors are not like a disease caused by a single virus. There are a variety of different paths that lead someone to fail to report something that is clearly visible when pointed out. We will study three such paths. Some LBFTS errors can be thought of as a version of bad luck. You can't process everything, so some visual stimuli get processed adequately and some don't. But it is nothing about the stimulus per se. The experiments in Aim 1 investigate whether LBFTS errors are mainly due to these random errors or whether there is something about certain stimuli that makes them less likely to be found. The idea of "looking" but failing to see, requires that we define "looking". When you look at one point, there is a region around that point within which you could find your target, even if you don't. This is known as the functional visual field (FVF) or useful field of view (UFOV). In Aim 2, we study biases within the FVF. For example, if you are reading, while you are looking at one word, you are biased to the next words to the right (or to the left, e.g., for Arabic or Hebrew), rather than the words directly above or below where you are fixating. We are asking similar questions but about vision more generally. The two principal investigators on this project have different ideas about where the biases in the FVF come from. Some Aim 2 experiments constitute an "adversarial collaboration" in which we will seek to resolve our differences. Finally, Aim 3 is devoted to LBFTS errors that occur when you are doing one task but when you might want to be keeping an eye out for other stimuli (e.g. when a doctor is examining a lung x-ray, it may show more than just the fractured rib about which the patient is complaining, such as a suspicious sign of cancer). Here we will try to develop ways to help observers to do their primary task whilst staying attuned to important but non-related events.

Research activity codes: 1.2 PSYCHOLOGICAL AND SOCIOECONOMIC PROCESSES
Health categories: MENTAL HEALTH