My research interests focus on studying the way our expectations influence how we attend to information in our environment, consequently impacting the things we might incidentally remember in the future. From examining the development of the low-prevalence effect (LPE) in visual search to studying the dynamics of rejection and recognition, much of my research centers around the basic processes of attention and memory, with an emphasis on how the two dynamically interact with each other.
The Low-Prevalence Effect (LPE)
The LPE is a robust effect in visual search in which rare targets are missed more frequently than common targets (Wolfe et al., 2005). Given its profound implications in high risk professions such as airport security and medical image screening, much of the research on the LPE has focused on explaining. and hopefully mitigating, the elevated miss rates associated with low target-prevalence. However, my research has examined how the LPE impacts cognition beyond increasing miss rates. For instance, we've examined the attentional demands of correctly identifying rare targets, and found that not only are people less likely to find a second target after identifying a rare, relative to a common, target in an attentional-blink (AB) paradigm, but also that is indexed by larger pupillary dilations!
More recently, I've been examining how the size of our attentional window (or functional viewing field) changes as a function of target prevalence. Using both eye-tracking and behavioral measures, I've found evidence indicating that the attentional window "narrows" when targets are frequently encountered in a search task!
Incidental Encoding in Visual Search
Although attending to distractor objects is antithetical to the goals of visual search, extensive research suggests that observers encode and remember distracting information from search tasks, particularly if visual search is difficult (e.g., Hout & Goldinger, 2010, 2012). Across several studies, we've examined how observers allocate attention based on the precision of target cues (e.g., template vs categorical, single vs multiple targets). Using Rapid Serial Visual Presentation (RSVP) tasks and traditional search "arrays," we've found that observers allocate attention to closely process each object when they are unsure of what the search target looks like. This strategy cause observers to adopt a narrow attentional window, incidentally encoding distractors in memory but missing other information presented in their periphery!
We've recently examined the fidelity of incidental distractors memory representations. By given participants a difficult surprise memory test (16-AFC) following a visual search task, we've found that although distractor memory is not always perfect, participants seem to retain some perceptual details of the encoded objects even when an incorrect recognition response is made. Our results showed that incidental memories from visual search are highly-detailed, as participants tended to falsely "recognize" foils that were perceptually similar to the encoded object. However this was only true if the object was encoded when searching for an imprecisely-cued target (e.g., four potential targets), suggesting that allocating attention to object-processing not only increases the number but also the quality of incidental object memories.
Incidental Encoding in Prospective Memory
Prospective memory (PM) is your ability to remember to carry-out intentions in the future, and is facilitated by attending to environmental cues indicating when and where we can implement said intentions. For instance, if you intend to talk to your professor about your latest exam grade, you are likely to monitor for cues (i.e., your professor) while you are on campus, but not when you are at the grocery store. We've examined whether expectations impact when we monitor for PM cues, consequentially influencing incidental encoding of task-irrelevant information. Participants completed a color-matching task (below), where they had to indicate whether the font color of a word matched any of four colors held in short-term memory. Importantly, participants were asked to make a different response if they saw any target words (e.g., words ending in -ion), and we gave them specific, vague, or no information about when to expect targets.
Our results show that when people explicitly expect PM cues in a specific context, they will allocate attention to monitor for such cues, slowing their ongoing (color-matching) task responses and making more errors. Furthermore, incidental item encoding is benefited from the allocated attention, resulting in better recognition during a subsequent surprise memory test for any words presented in-place of the expected PM cue!
Recognition & Rejection Dynamics
Knowing that you do not know something is equally important to knowing that you know it. To continuously assess how we recognize, or reject, items as being part of a studied list we measure participants hand-movements in real-time as they complete recognition tests. In these tests, participants begin by clicking on a "Start" button located at the bottom at the screen which prompts the presentation of the test item. They are then instructed to move the mouse-cursor as quickly as possible to indicate whether the item is old or new, allowing us measure, among many things, the x-, y-coordinates of the cursor, the speed of the movement, and the number of directional "flips" (left or right) a person makes as their recognition judgment unfolds over time.
Across multiple studies, we've used mouse-tracking to test the assumptions of different models of recognition memory. Our results have demonstrated a strong relationship between confidence and recognition hand-movements: When people are confident about their recognition decisions, they tend to make straight, linear movements towards the choice (even if they are incorrect!). Comparatively, when people are unsure about their judgments, they tend to make slow, curvilinear movements, as well as multiple "flips-in-motion," before settling on their selected response.