2004 — 2009 |
Jiang, Yuhong |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Contextual Cueing and Implicit Learning
DESCRIPTION (provided by applicant): This proposal investigates a powerful form of implicit visual learning - contextual cueing (Chun & Jiang, 1998). Contextual cueing reflects the influence of attention by implicitly-learned visual context. In this task, subjects search for a "T" among "L"s. When the spatial layout formed by all items repeats occasionally, search is faster among the repeated displays than among the new ones, suggesting that the repeated context "cues" attention to the target position. Contextual cueing is (1) fast, acquired after 4-5 repetitions, (2) long-lasting, persisting for at least a week, and (3) implicit, requiring no conscious effort to learn. This proposal has four specific Aims. 1. Is contextual cueing automatic or attention-dependent? To find out, subjects will be asked to attend to a subset of items and ignore the others and learning of the ignored repetition will be measured. 2. Do subjects learn the global spatial layout formed by all items or do they learn the individual item locations? To this end, we will measure whether contextual cueing transfers to displays whose global context or local context is selectively disrupted. 3. What is the extent of individual variabilities in contextual cueing and what is the source of such variation? We will measure the correlation between an individual's cueing effect and other cognitive abilities, such as digit-span, visual short-term memory capacity, and central executive function. 4. Do common brain regions underlie encoding display repetitions and learning of a consistent association? Here, we will use fMRI to measure brain regions important for repetition processing and those for associative learning. This proposal has direct health implications because unlike explicit learning and memory, implicit learning is largely preserved in many patient groups, in people with low IQ, and in small children and older adults. Contextual cueing is a powerful form of implicit learning. Understanding its cognitive and neural mechanisms is the first step toward understanding this ability in normal adults as well as in those whose explicit learning and memory mechanisms are impaired.
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1 |
2004 — 2008 |
Jiang, Yuhong |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Visual Short-Term Memory For Multiple Sequential Arrays
It is intuitive that ordinary activity requires on-going memory for what we see, hear, and do. When crossing a busy street we look left and then right and must remember both views. In a social gathering, we remember those around us even when they are not directly in sight. Yet laboratory tests of memory for visual details show surprising limitations: only three or four objects can be remembered at a time. Such severe limitations may contribute to human errors in driving and other activities for instance. With support from the National Science Foundation, Dr. Yuhong Jiang will study visual short-term memory, the form of memory that keeps a visual image in mind for a few seconds. Other researchers have focused on memory for single brief events. Dr. Jiang goes beyond the previous work to investigate memory for sequences of visual events. She also examines how and whether people remember better after prolonged training. Broader impact of this project lies in its educational value and potential practical application. The funded study provides research opportunities for students, who obtain first-hand experience in the conduct of scientific research. Also, by informing engineers what is humanly possible, the study can potentially improve the design of human-machine interface, such as computers, vehicles, and airport surveillance.
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1 |
2014 — 2015 |
Jiang, Yuhong |
R03Activity Code Description: To provide research support specifically limited in time and amount for studies in categorical program areas. Small grants provide flexibility for initiating studies which are generally for preliminary short-term projects and are non-renewable. |
Attentional Guidance by Implicit Learning and Explicit Goals @ University of Minnesota
DESCRIPTION (provided by applicant): This R03 project aims to dissociate two forms of spatial attention: a declarative form driven by an observer's goal and a procedural form driven by implicit learning. Contrary to existing theories that combine goals and implicit learning into a single source of top-down attention, we hypothesize that they differ qualitatively on several dimensions, including the spatial reference frame, reliance on visual working memory, and task specificity. We propose three lines of behavioral work to support this theoretical framework. First, we investigate the impact of explicit instructions on the magnitude and spatial reference frame of implicitly learned attention. A single-system view predicts that explicit instructions should increase the size of implicitly learned attention, and that explicit instructions should modulate the coordinate system used to code attended locations. A dual- system view predicts no effects of explicit knowledge on implicitly learned attention. Second, we examine the effect of increasing visual working memory load on goal-driven attention and implicitly learned attention. A single-system view predicts that increasing working memory load should impair both forms of attention, but a dual-system view predicts that only goal-driven attention is sensitive to working memory load. Finally, we test the transfer of implicitly learned attention between different tasks. If implicitly learned attention is procedural, then it should not transfer between visual search an change detection or between two types of visual search. But if implicit learning yields a generic change in how spatial locations are weighed, then it should transfer between tasks. Although many studies have shown that attention can be directed to spatial locations based on separate sources (e.g., goals and stimulus saliency), these separate sources of information guide attention in similar ways, often resulting in under-additive effects when multiple sources are available. In contrast, the current proposal suggests that spatial attention is fundamentally divided into multiple forms - declarative and procedural. This distinction, though clear in studies of memory, has not been proposed for attention. Future research should examine the brain basis of the dual-system view in normal adults, the development of the dual systems in children, and the selective impairment of each system in neurological and psychiatric patients.
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0.957 |